JP4258640B2 - Method for manufacturing waveguide optical device - Google Patents

Description

  The present invention relates to a waveguide type optical element, a method for manufacturing the same, an optical module, and an optical transmission device.

  A waveguide type optical element is a device having a core layer and a clad layer like an optical fiber. A waveguide-type optical element is a device that allows light to enter or exit from an end face of a core layer. Examples of the waveguide type optical element include a waveguide type photodiode, an edge emitting laser, and an optical waveguide.

  For example, in a waveguide type photodiode, if the light absorption layer is made thin for the purpose of increasing the frequency, the light incident surface becomes small and sufficient light receiving sensitivity may not be obtained.

  An object of the present invention is to provide a waveguide type optical device and a manufacturing method thereof.

  Another object of the present invention is to provide an optical module having the waveguide type optical element and an optical transmission device having the optical module.

A method for manufacturing a waveguide-type optical element according to the present invention includes:
Laminating a semiconductor layer for constituting a waveguide structure including at least a first cladding layer, a core layer, and a second cladding layer above the substrate;
Etching the semiconductor layer to form a columnar portion including at least the core layer;
Forming a lens portion facing the end face of the core layer above the substrate,
The lens unit is formed to have a function of changing the optical path of light incident on the end surface, and is formed by a droplet discharge method of discharging a droplet including the material of the lens unit,
The waveguide structure is formed to function as a waveguide photodiode,
The first cladding layer is formed to have a first conductivity type,
The core layer is formed to be a light absorption layer,
The second cladding layer is formed to have a second conductivity type,
The step of forming the lens portion includes a droplet discharge step,
The droplet discharge step includes
While making detection light incident on at least the end face of the core layer and detecting a photocurrent obtained by electrically converting the light, the droplets are sequentially discharged to the lens portion formation region,
When the predetermined value of the photocurrent is confirmed, the ejection of the droplet is terminated.
In the method for manufacturing a waveguide-type optical element according to the present invention,
The predetermined value of the photocurrent may be a maximum value of the photocurrent.
The waveguide type optical element according to the present invention is:
A substrate,
A waveguide structure formed above the substrate;
A lens part formed above the substrate,
The waveguide structure is
A first cladding layer formed above the substrate;
A core layer formed above the first cladding layer;
A second cladding layer formed above the core layer,
The lens portion is located away from the end face of the core layer, is formed facing the end face of the core layer, and has a function of changing the optical path of light incident on the end face,
It is formed by the above-described method for manufacturing a waveguide type optical element.
In the waveguide type optical device according to the present invention,
Having a base member formed above the substrate;
The lens part may be formed above the base member.
In the waveguide type optical device according to the present invention,
The base member may be integral with the substrate.
In the waveguide type optical device according to the present invention,
The base member may be made of resin.
In the waveguide type optical device according to the present invention,
A damming member formed above the substrate;
The lens unit may be formed to be blocked by the blocking member.
In the waveguide type optical device according to the present invention,
The cross-sectional shape of the damming member may be pointed.
In the waveguide type optical device according to the present invention,
The damming member may be integral with the substrate.
In the waveguide type optical device according to the present invention,
The damming member can be made of resin.
An optoelectronic integrated device according to the present invention includes the above-described waveguide optical device,
TIA (Trans-Impedance Amplifier).
The optical module according to the present invention can include the above-described optoelectronic integrated device.
The light transmission device according to the present invention can include the above-described optical module.
The waveguide type optical element according to the present invention is:
A substrate,
A waveguide structure formed above the substrate;
A lens part formed above the substrate,
The waveguide structure is
A first cladding layer formed above the substrate;
A core layer formed above the first cladding layer;
A second cladding layer formed above the core layer,
The lens portion is formed to face the end surface of the core layer, and has a function of changing an optical path of light incident on the end surface or light emitted from the end surface.

  In the waveguide type optical element according to the present invention, another specific device (hereinafter referred to as “B”) provided “above” a specific device (hereinafter referred to as “A”) is directly on A. B provided and B provided on A via the others on A are included. The definition of “above” is the same in the method for manufacturing a waveguide optical device according to the present invention.

In the waveguide type optical device according to the present invention,
The waveguide structure functions as a waveguide photodiode,
The first cladding layer is of a first conductivity type;
The core layer is a light absorbing layer;
The second cladding layer may be a second conductivity type.

  According to this waveguide type optical element, the lens portion is formed facing the end surface of the core layer of the waveguide structure portion, so that the optical axis shift in the direction perpendicular to the upper surface of the substrate is achieved. The allowable range of That is, according to this waveguide type optical element, the tolerance in the direction perpendicular to the upper surface of the substrate is improved.

  Further, according to the waveguide type optical element, since the lens portion is formed facing the end surface of the core layer of the waveguide structure portion, the tolerance in a horizontal direction with respect to the upper surface of the substrate is obtained. Will improve.

In the waveguide type optical device according to the present invention,
The waveguide structure functions as an edge-emitting laser,
The core layer may be a layer having at least an active layer.

  In the waveguide type optical device according to the present invention, when the waveguide structure functions as an edge emitting laser, the first cladding layer, the core layer, and the second cladding layer constitute a waveguide. be able to.

  According to this waveguide optical element, the lens portion is formed so as to be opposed to the end surface of the core layer of the waveguide structure portion, thereby emitting light emitted from the end surface of the core layer. The corner can be reduced.

In the waveguide type optical device according to the present invention,
The waveguide structure portion can function as an optical waveguide.

  According to this waveguide type optical element, the lens portion is formed facing the end surface of the core layer of the waveguide structure portion, so that the optical axis shift in the direction perpendicular to the upper surface of the substrate is achieved. The allowable range of That is, according to this waveguide type optical element, the tolerance in the direction perpendicular to the upper surface of the substrate is improved.

  Further, according to the waveguide type optical element, since the lens portion is formed facing the end surface of the core layer of the waveguide structure portion, the tolerance in a horizontal direction with respect to the upper surface of the substrate is obtained. Will improve.

In the waveguide type optical device according to the present invention,
The substrate includes a first substrate and a second substrate,
The waveguide structure is formed above the first substrate;
The lens portion is formed above the second substrate,
The first substrate may be placed above the second substrate.

In the waveguide type optical device according to the present invention,
Having a base member formed above the substrate;
The lens part may be formed above the base member.

In the waveguide type optical device according to the present invention,
The base member may be integral with the substrate.

In the waveguide type optical device according to the present invention,
The base member may be made of resin.

In the waveguide type optical device according to the present invention,
A damming member formed above the substrate;
The lens unit may be formed to be blocked by the blocking member.

In the waveguide type optical device according to the present invention,
The cross-sectional shape of the damming member may be pointed.

In the waveguide type optical device according to the present invention,
The damming member may be integral with the substrate.

In the waveguide type optical device according to the present invention,
The damming member can be made of resin.

An optoelectronic integrated device according to the present invention includes the above-described waveguide optical device,
TIA (Trans-Impedance Amplifier).

An optical integrated device according to the present invention includes the above-described waveguide optical device,
A monitor photodiode.

An optical module according to the present invention includes the above-described optoelectronic integrated device,
And the above-described optical integrated device.

  The light transmission device according to the present invention can include the above-described optical module.

A method for manufacturing a waveguide-type optical element according to the present invention includes:
Laminating a semiconductor layer for constituting a waveguide structure including at least a first cladding layer, a core layer, and a second cladding layer above the substrate;
Etching the semiconductor layer to form a columnar portion including at least the core layer;
Forming a lens portion facing the end face of the core layer above the substrate,
The lens portion is formed to have a function of changing an optical path of light incident on the end surface or light emitted from the end surface, and ejects a droplet including a material of the lens portion. Formed by law.

In the method for manufacturing a waveguide-type optical element according to the present invention,
The waveguide structure is formed to function as a waveguide photodiode,
The first cladding layer is formed to have a first conductivity type,
The core layer is formed to be a light absorption layer,
The second cladding layer may be formed to have a second conductivity type.

In the method for manufacturing a waveguide-type optical element according to the present invention,
The step of forming the lens portion includes a droplet discharge step,
The droplet discharge step includes
While making detection light incident on at least the end face of the core layer and detecting a photocurrent obtained by electrically converting the light, the droplets are sequentially discharged to the lens portion formation region,
When the predetermined value of the photocurrent is confirmed, the ejection of the droplet can be terminated.

  According to this method for manufacturing a waveguide-type optical element, the liquid droplets are sequentially ejected while detecting a photocurrent, and when the predetermined value of the photocurrent is confirmed, the ejection of the liquid droplets is terminated. The lens portion can be formed such that the incidence efficiency on the end face of the core layer is higher.

In the method for manufacturing a waveguide-type optical element according to the present invention,
The predetermined value of the photocurrent may be a maximum value of the photocurrent.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1. 1. First embodiment 1-1. Device Structure FIG. 1 is a cross-sectional view schematically showing a waveguide type optical device 100 according to a first embodiment to which the present invention is applied. FIG. 2 is a plan view schematically showing the waveguide type optical element 100 shown in FIG. 1 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIGS. 1 and 2, the waveguide type optical element 100 according to the present embodiment includes a substrate 10, a waveguide structure part 110, a base member 60, and a lens part 50. In the present embodiment, the case where the waveguide structure 110 functions as a waveguide type photodiode is shown.

  The waveguide structure 110 includes a first contact layer 34, a first cladding layer 20, a core layer 22, a second cladding layer 24, a second contact layer 36, a first electrode 30, and a second electrode 32. And including. The first cladding layer 20 is of a first conductivity type (in this embodiment, n-type), the core layer 22 is a light absorption layer, and the second cladding layer 24 is of a second conductivity type (this embodiment). In the form of p-type).

  As the substrate 10, for example, an InP substrate or a GaAs substrate can be used. In this embodiment, an example using a semi-insulating InP substrate is described, but the substrate 10 is not particularly limited.

  As shown in FIGS. 1 and 2, the first contact layer 34 is formed on the substrate 10. The first cladding layer 20 is formed on the first contact layer 34. The core layer 22 is formed on the first cladding layer 20. The second cladding layer 24 is formed on the core layer 22. The second contact layer 36 is formed on the second cladding layer 24.

  A part of the first contact layer 34, the first cladding layer 20, the core layer 22, the second cladding layer 24, and the second contact layer 36 are columnar semiconductor deposits formed above the substrate 10. (Hereinafter referred to as “columnar portion”) 130. As shown in FIGS. 1 and 2, the planar shape of the columnar section 130 is a rectangle.

  The core layer 22 can be made of a material having a refractive index larger than that of the first cladding layer 20 and the second cladding layer 24. The first cladding layer 20 can be made of a material having a refractive index larger than that of the first contact layer 34. The second cladding layer 24 can be made of a material having a refractive index larger than that of the second contact layer 36.

  Specifically, the core layer 22 can be made of, for example, an InGaAs layer that is not doped with impurities. The first cladding layer 20 can be made of, for example, an n-type InGaAlAs layer or an n-type InGaAsP layer. The second cladding layer 24 can be made of, for example, a p-type InGaAlAs layer or a p-type InGaAsP layer. For example, when the first cladding layer 20 is made of an n-type InGaAlAs layer, the first contact layer 34 can be made of an n-type InAlAs layer, for example. The first contact layer 34 can be made of, for example, an n-type InP layer when the first cladding layer 20 is made of an n-type InGaAsP layer. For example, when the second cladding layer 24 is composed of a p-type InGaAlAs layer, the second contact layer 36 can be composed of, for example, a p-type InAlAs layer. The second contact layer 36 can be made of, for example, a p-type InP layer when the second cladding layer 24 is made of a p-type InGaAsP layer. The materials of the core layer 22, the first cladding layer 20, the second cladding layer 24, the first contact layer 34, and the second contact layer 36 are not limited to these.

  The first cladding layer 20 and the first contact layer 34 are made n-type by doping, for example, silicon (Si) or selenium (Se), and the second cladding layer 24 and the second contact layer 36 are made of, for example, carbon. It is made p-type by doping with (C) or zinc (Zn). Therefore, the p-type second cladding layer 24, the core layer 22 not doped with impurities, and the n-type first cladding layer 20 constitute a pin diode.

  As shown in FIGS. 1 and 2, the first electrode 30 is formed on the first contact layer 34 and on the side of the columnar part 130. As shown in FIG. 2, the first electrode 30 has a rectangular planar shape. As shown in FIGS. 1 and 2, the second electrode 32 is formed on the second contact layer 36. As shown in FIG. 2, the second electrode 32 has a rectangular planar shape. The first electrode 30 and the second electrode 32 are not limited to having a rectangular planar shape. The first electrode 30 and the second electrode 32 are used to drive the waveguide structure 110 by applying a voltage to the waveguide structure 110.

  A material that is in ohmic contact with the first contact layer 34 can be used for the first electrode 30. The first electrode 30 can be made of, for example, a laminated film of chromium (Cr), an alloy of gold (Au) and germanium (Ge), nickel (Ni), and gold. The second electrode 32 can be made of a material that makes ohmic contact with the second contact layer 36. The second electrode 32 can be made of, for example, a laminated film of platinum (Pt), titanium (Ti), platinum, and gold. A voltage is applied to the core layer 22 which is a light absorption layer by the first electrode 30 and the second electrode 32. The materials for forming the first electrode 30 and the second electrode 32 are not limited to those described above. The second electrode 32 can be made of, for example, a laminated film of chromium, an alloy of gold and zinc (Zn), and gold, or a laminated film of chromium, manganese (Mn), and gold.

  The base member 60 can be a base of the lens unit 50. The three-dimensional shape of the base member 60 is not particularly limited, but may be a structure in which the lens unit 50 can be installed on the upper surface 60a.

  The shape of the upper surface 60 a of the base member 60 is determined by the function and application of the lens unit 50 formed on the upper surface 60 a of the base member 60. In other words, the shape of the lens unit 50 can be controlled by controlling the shape of the upper surface 60 a of the base member 60. For example, as shown in FIG. 2, the planar shape of the upper surface 60a of the base member 60 can be a circle. Thereby, the three-dimensional shape of the lens part 50 can be formed into a spherical shape or a shape obtained by cutting out a part of the spherical shape (see FIGS. 1 and 2). Further, for example, the planar shape of the upper surface 60a of the base member 60 can be rectangular.

  The height of the upper surface 60 a of the base member 60 can be made lower than the height of the lower surface 22 b of the core layer 22. The base member 60 can be formed using, for example, a polyimide resin, an acrylic resin, an epoxy resin, or a fluorine resin.

  The lens unit 50 is formed on the base member 60 so as to face the end surface 40 of the core layer 22. The end face 40 of the core layer 22 serves as a light receiving surface of the waveguide structure 110 that functions as a waveguide photodiode. In other words, the end surface 40 of the core layer 22 facing the lens unit 50 is a light receiving surface.

  The shape of the lens unit 50 can be a shape having a function of changing the optical path of light incident on the end face 40. For example, the shape of the lens unit 50 can be a convex shape. More specifically, the shape of the lens unit 50 may be a shape obtained by cutting a part of one sphere, as shown in FIGS. 1 and 2, for example. The lens unit 50 can have a function of collecting light on the end face 40, for example. Specifically, it is as follows.

  Arrows a, b, and c in FIG. 1 schematically show the path of light incident on the waveguide structure 110. First, as shown in FIG. 1, light (arrow a shown in FIG. 1) enters the lens unit 50 from the outside of the waveguide optical device 100 according to the present embodiment. When the light is incident on the lens unit 50, the light is refracted, and, for example, converges in the direction of the arrow b and proceeds. Next, the light emitted through the lens unit 50 is refracted and travels in the direction of the arrow c, for example. The light indicated by the arrow c enters the end face 40 of the core layer 22. That is, the light coming from the outside of the waveguide type optical element 100 can be converged by the lens unit 50 and incident on the end surface 40 of the core layer 22.

  As described above, the height of the upper surface 60 a of the base member 60 can be made lower than the height of the lower surface 22 b of the core layer 22. Thereby, the light (arrow a shown in FIG. 1) from the outside of the waveguide type optical element 100 can be efficiently incident on the lens unit 50 without being incident on the base member 60.

  The lens unit 50 is formed by curing a liquid material (for example, an ultraviolet curable resin or a thermosetting resin precursor) that can be cured by energy such as heat or light. Examples of the ultraviolet curable resin include an ultraviolet curable acrylic resin and an epoxy resin. Examples of the thermosetting resin include thermosetting polyimide resins.

1-2. Device Manufacturing Method Next, a method for manufacturing the waveguide optical device 100 shown in FIGS. 1 and 2 will be described with reference to FIGS. 3 to 9 are cross-sectional views schematically showing one manufacturing process of the waveguide type optical element 100 shown in FIGS. 1 and 2, and correspond to the cross sections shown in FIG. 1, respectively.

  (1) First, as shown in FIG. 3, the semiconductor multilayer film 15 is formed by epitaxial growth on the surface of the substrate 10 made of semi-insulating InP. Here, the semiconductor multilayer film 15 includes, for example, a first contact layer 34 made of an n-type InAlAs layer, a first cladding layer 20 made of an n-type InGaAlAs layer, and a core layer 22 made of an InGaAs layer not doped with impurities. And a second cladding layer 24 made of a p-type InGaAlAs layer and a second contact layer 36 made of a p-type InAlAs layer. Alternatively, the semiconductor multilayer film 15 includes, for example, a first contact layer 34 made of an n-type InP layer, a first cladding layer 20 made of an n-type InGaAsP layer, and a core layer 22 made of an InGaAs layer not doped with impurities. The second clad layer 24 made of a p-type InGaAsP layer and the second contact layer 36 made of a p-type InP layer.

  By laminating these layers on the substrate 10 in order, the semiconductor multilayer film 15 is formed. The materials of the core layer 22, the first cladding layer 20, the second cladding layer 24, the first contact layer 34, and the second contact layer 36 are not limited to these.

  The temperature at which the epitaxial growth is performed is appropriately determined depending on the growth method, the raw material, the type of the substrate 10, or the type and thickness of the semiconductor multilayer film 15 to be formed. In general, the temperature is preferably 450 ° C to 800 ° C. . Further, the time required for performing the epitaxial growth is also appropriately determined in the same manner as the temperature. In addition, as a method of epitaxial growth, a metal-organic vapor phase epitaxy (MOVPE) method, an MBE (Molecular Beam Epitaxy) method, an LPE (Liquid Phase Epitaxy) method, or the like can be used.

  (2) Next, after applying a resist on the semiconductor multilayer film 15, the resist is patterned by a lithography method to form a resist layer R1 having a predetermined pattern as shown in FIG. The resist layer R1 is formed above a region where the columnar portion 130 (see FIGS. 1 and 2) is to be formed. Next, using the resist layer R1 as a mask, the second contact layer 36, the second cladding layer 24, the core layer 22, the first cladding layer 20, One contact layer 34 is partially etched. Thereby, as shown in FIG. 4, the columnar part 130 is formed. Thereafter, the resist layer R1 is removed.

  (3) Next, a process of forming the first electrode 30 and the second electrode 32 for applying a voltage to the waveguide structure 110 will be described.

  First, before forming the first electrode 30 and the second electrode 32, if necessary, at least the upper surface 34a of the first contact layer 34 and the upper surface 36a of the second contact layer 36 are cleaned using a plasma processing method or the like. To do. Thereby, an element having more stable characteristics can be formed.

  Next, as shown in FIG. 5, the first electrode 30 is formed on the upper surface 34 a of the first contact layer 34. Specifically, for example, a laminated film (not shown) of chromium, an alloy of gold and germanium, nickel, and gold is formed by, for example, a vacuum deposition method, a sputtering method, or a plating method. Next, the first electrode 30 is formed by removing the laminated film other than the predetermined position by, for example, a lift-off method or a dry etching method.

  In the above description, an example of forming a laminated film of chromium, an alloy of gold and germanium, nickel, and gold has been described. However, the material for forming the first electrode 30 is not limited to the above. is not. Next, an annealing process is performed. The annealing temperature depends on the electrode material. In the case of the electrode material used in the present embodiment, it is usually performed at around 400 ° C.

  Next, the second electrode 32 is formed on the upper surface 36a of the second contact layer 36 by patterning, for example, a laminated film of platinum, titanium, platinum, and gold by the same method as shown in FIG. Form. Next, an annealing process is performed. The annealing temperature depends on the electrode material. In the case of the electrode material used in the present embodiment, it is usually performed at about 300 to 330 ° C. Through the above steps, the second electrode 32 is formed.

  In the above description, an example of forming a laminated film of platinum, titanium, platinum, and gold has been described. For example, a laminated film of chromium, an alloy of gold and zinc, and gold, or chromium and manganese. A laminated film of gold and the like can also be formed.

  (4) Next, as shown in FIG. 6, the base member 60 is formed on the substrate 10 in the lens portion 50 (see FIGS. 1 and 2) formation region. For the formation of the base member 60, an appropriate method (for example, a selective growth method, a dry etching method, a wet etching method, a lift-off method, a transfer method, or the like) can be selected according to the material, shape, and size of the base member 60. . In the present embodiment, a case where the base member 60 is formed by patterning using a wet etching method will be described.

  First, a resin layer (not shown) is formed over the first contact layer 34 and the columnar part 130 by, for example, spin coating. Next, a resist layer having a predetermined pattern is formed on the resin layer. This resist layer is used to form the base member 60 by patterning the resin layer. Specifically, the resin layer is patterned by a lithography process using the resist layer as a mask, for example, by a wet etching method using an alkaline solution as an etchant. Thereby, as shown in FIG. 6, the base member 60 is formed in the lens part 50 (refer FIG. 1 and FIG. 2) formation area. Thereafter, the resist layer is removed.

  (5) Next, the lens part precursor 50a is formed. Specifically, it is as follows.

  First, as shown in FIG. 7, light (arrow a shown in FIG. 7) is incident on at least the end face 40 of the core layer 22 from the outside of the waveguide optical device 100. The arrow a schematically shows the path of incident light. The light is absorbed by the core layer 22 by being incident on the end face 40 of the core layer 22 which is a light absorption layer. As a result, photoexcitation occurs in the core layer 22, and electrons are generated in the conduction band of the core layer 22 and holes are generated in the valence band of the core layer 22. Electrons move to the first electrode 30 and holes move to the second electrode 32 by the electric field applied from the power supply 64 outside the element. As a result, in the waveguide structure 110, a current (photocurrent) is generated in the direction from the first electrode 30 to the second electrode 32. This photocurrent can be detected by the ammeter 62.

  Next, as shown in FIG. 7, the discharge of the liquid material droplet 52 for forming the lens unit 50 is started on the upper surface 60 a of the base member 60. As shown in FIG. 8, the droplets 52 are sequentially ejected onto the upper surface 60 a of the base member 60 while detecting a photocurrent with an ammeter 62. The liquid droplets 52 land on the upper surface 60a of the base member 60 to form the lens portion precursor 50a. Here, the light incident on the lens unit precursor 50a is refracted by the lens unit precursor 50a and travels in the direction of the arrow b, for example. And the light which passed the lens part precursor 50a advances to the direction of the arrow c, for example. As a result, the amount of light incident on the end face 22 of the core layer 22 changes as compared with the case where the lens portion precursor 50a is not formed. The ammeter 62 detects the change in photocurrent.

  As shown in FIG. 9, the ejection of the droplet 52 can be terminated when the predetermined value of the photocurrent is confirmed. For example, the predetermined value of the photocurrent can be set to a value at which the photocurrent after the lens portion precursor 50a is cured (described later) and the lens portion 50 is formed becomes the maximum value. Accordingly, it is possible to form the lens unit 50 that increases the efficiency of incidence on the end surface 40 of the core layer 22.

  The liquid material has a property of being curable by applying energy (for example, ultraviolet rays or heat). Examples of the liquid material include an ultraviolet curable resin and a thermosetting resin precursor. Examples of the ultraviolet curable resin include an ultraviolet curable acrylic resin and an epoxy resin. Examples of the thermosetting resin include thermosetting polyimide resins.

  The precursor of the ultraviolet curable resin is cured by short-time ultraviolet irradiation. For this reason, it can harden | cure without passing through the process which is easy to give a damage with respect to elements, such as a heat process. For this reason, the influence with respect to an element can be decreased by forming the lens part 50 using the precursor of an ultraviolet curable resin.

  Examples of the method for discharging the droplet 52 include a dispenser method and a droplet discharge method. The dispenser method is a general method for discharging droplets, and is effective when the droplets 52 are discharged over a relatively wide area. The droplet discharge method is a method of discharging droplets using a droplet discharge head, and the position at which droplets are discharged can be controlled in units of μm. Further, since the amount of liquid droplets to be discharged can be controlled in units of picoliters, the lens unit 50 having a fine structure can be manufactured. In this embodiment, an example in which a droplet discharge method is used will be described.

  As the droplet discharge method, for example, (I) a method in which pressure is generated by changing the size of bubbles in the liquid (here, the droplet 52) by heat, and the liquid is discharged from the nozzle 112 of the inkjet head 114. And (II) a method of discharging a liquid from the nozzle 112 of the inkjet head 114 by a pressure generated by the piezoelectric element. From the viewpoint of controllability of pressure, the method (II) is desirable.

  The alignment between the position of the nozzle 112 of the inkjet head 114 and the discharge position of the droplet 52 is performed using a known image recognition technique used in an exposure process or an inspection process in a general semiconductor integrated circuit manufacturing process. For example, alignment between the position of the nozzle 112 of the inkjet head 114 and the position of the base member 60 is performed by image recognition. After the alignment, the voltage 52 applied to the inkjet head 114 is controlled to discharge the droplets 52.

  (6) Next, the lens part precursor 50a is cured to form the lens part 50 as shown in FIGS. Specifically, energy such as heat or light is applied to the lens portion precursor 50a. When the lens part precursor 50a is cured, an appropriate method is used depending on the type of the liquid material. Specifically, for example, addition of heat energy or light irradiation such as ultraviolet light or laser light can be mentioned.

  Through the above process, the waveguide optical device 100 shown in FIGS. 1 and 2 is obtained.

1-3. Action / Effect According to the waveguide-type optical device 100 according to the present embodiment, the lens unit 50 is formed so as to face the end surface 40 of the core layer 22 of the waveguide structure 110, whereby the upper surface of the substrate 10. However, the allowable range of optical axis deviation in the vertical direction (Z direction in the examples of FIGS. 1 and 2) is widened. That is, according to the waveguide type optical device 100 according to the present embodiment, the tolerance in the direction perpendicular to the upper surface of the substrate 10 is improved.

  In addition, according to the waveguide type optical device 100 according to the present embodiment, the lens unit 50 is formed opposite to the end surface 40 of the core layer 22 of the waveguide structure unit 110, so that the lens unit 50 is formed on the upper surface of the substrate 10. On the other hand, the tolerance in the horizontal direction (in the example of FIGS. 1 and 2, the XY plane direction) is improved.

  In addition, according to the waveguide type optical element 100 according to the present embodiment, the lens unit 50 is formed so as to face the end surface 40 of the core layer 22 of the waveguide structure 110, so that it is a light absorption layer. Even if the core layer 22 is thinned, the incident light can be narrowed down by the lens unit 50, so that good incident efficiency can be obtained. That is, according to the waveguide type optical element 100 according to the present embodiment, both high frequency and improvement in light receiving sensitivity can be achieved.

  Moreover, according to the waveguide type optical element 100 and the manufacturing method thereof according to the present embodiment, the base member 60 is provided, so that the lens unit 50 can be easily formed in a desired shape.

  Further, according to the method for manufacturing the waveguide type optical element 100 according to the present embodiment, the droplets 52 are sequentially ejected while detecting the photocurrent, and when the predetermined value of the photocurrent is confirmed, By ending the ejection, it is possible to form the lens unit 50 such that the efficiency of incidence on the end surface 40 of the core layer 22 becomes higher.

1-4. In the waveguide type optical device 100 shown in FIGS. 1 and 2, the first electrode 30 is formed on the upper surface 34a of the first contact layer 34. For example, as shown in FIG. The first electrode 30 can also be formed on the back surface 10 b of the substrate 10. In this case, as the substrate 10, a conductive substrate such as an InP substrate or a GaAs substrate can be used. FIG. 10 is a sectional view schematically showing the waveguide type optical element 100 in this case, and corresponds to the sectional view of FIG.

  In the waveguide type optical device 100 shown in FIGS. 1 and 2, the base member 60 is made of a material different from that of the first contact layer 34. For example, as shown in FIG. 60 may be integral with the first contact layer 34. That is, the base member 60 can be made of the same material as the first contact layer 34. Such a base member 60 can be formed by patterning the first contact layer 34, for example. FIG. 11 is a cross-sectional view schematically showing the waveguide type optical element 100 in this case, and corresponds to the cross-sectional view of FIG.

  For example, as shown in FIG. 12, the base member 60 may be integrated with the substrate 10, and the first electrode 30 may be formed on the back surface 10 b of the substrate 10. That is, the base member 60 can be made of the same material as the substrate 10. Such a base member 60 can be formed, for example, by patterning the substrate 10. FIG. 12 is a cross-sectional view schematically showing the waveguide type optical element 100 in this case, and corresponds to the cross-sectional view of FIG.

  In the waveguide type optical device 100 shown in FIGS. 1 and 2, the case where the waveguide structure portion 110 and the lens portion 50 are formed on the same substrate 10 has been shown. For example, as shown in FIG. The waveguide structure part 110 is formed on the first substrate 12, the lens part 50 is formed on the second substrate 14, and the first substrate 12 is placed on the second substrate 14. Can also be. Thereby, compared with the case where the waveguide structure part 110 and the lens part 50 are integrated monolithically, a semiconductor manufacturing process can be simplified. Moreover, since the waveguide structure part 110 and the lens part 50 can be manufactured in separate processes, the manufacturing process of the waveguide structure part 110 and the manufacturing process of the lens part 50 are simplified. be able to.

  In this case, the same material as the substrate 10 used for the waveguide type optical element 100 shown in FIGS. 1 and 2 can be used as the first substrate 12. Moreover, as the 2nd board | substrate 14, a glass substrate, a ceramic substrate, or a silicon substrate can be used, for example. The first substrate 12 can be placed on the second substrate 14 using, for example, an adhesive such as solder or silver paste. FIG. 13 is a cross-sectional view schematically showing the waveguide type optical element 100 in this case, and corresponds to the cross-sectional view of FIG.

  For example, as shown in FIG. 14, the 1st board | substrate 12 and the 2nd board | substrate 14 can also be fixed facing. That is, the waveguide structure part 110 and the lens part 50 are formed between the first substrate 12 and the second substrate 14. The first substrate 12 and the second substrate 14 can be fixed using, for example, a known fixing mechanism (not shown). FIG. 14 is a cross-sectional view schematically showing the waveguide type optical element 100 in this case, and corresponds to the cross-sectional view of FIG.

  Further, for example, as shown in FIG. 15, the damming member 70 can be formed on the first contact layer 34 and in the lens part 50 formation region. The cross-sectional shape and the planar shape of the damming member 70 are such that the lens portion precursor 50a is formed in the above-described step of forming the lens portion precursor 50a (see FIGS. 7 to 9) until the lens portion precursor 50a has a desired shape. It is possible to have a shape that can block outflow of water. In the example shown in FIG. 15, the cross-sectional shape of the damming member 70 is pointed. Although the planar shape of the damming member 70 is not shown, it is, for example, a circular ring shape.

  As the damming member 70, for example, a resist layer can be used. When a resist layer is used as the damming member 70, patterning of the damming member 70 can be performed using a lithography technique. The damming member 70 is not limited to a resist layer, and can be formed using, for example, a polyimide resin, an acrylic resin, an epoxy resin, or a fluorine resin. FIG. 15 is a cross-sectional view schematically showing the waveguide type optical element 100 in this case, and corresponds to the cross-sectional view of FIG.

  Further, for example, although not shown, the damming member 60 may be formed integrally with the first contact layer 34 or the substrate 10 in the same manner as the base member 60 shown in FIG. . That is, in this case, the damming member 60 is formed from the same material as the first contact layer 34 or the substrate 10.

2. Second embodiment 2-1. Device Structure FIG. 16 is a cross-sectional view schematically showing a waveguide type optical element 200 according to a second embodiment to which the present invention is applied. In addition, the same code | symbol is attached | subjected to the substantially same component as the waveguide type optical element 100 which concerns on 1st Embodiment, and the detailed description is abbreviate | omitted.

  In the waveguide type optical device 200 according to the present embodiment, the waveguide structure unit 100 functions as an edge-emitting laser, the core layer 22 is a layer having at least an active layer, and the end surface of the core layer 22. It differs from the waveguide type optical device 100 of the first embodiment in that light is emitted from 40.

  Arrows a, b, and c in FIG. 16 schematically show the path of light emitted from the waveguide structure 110. First, light (arrow a shown in FIG. 16) is emitted from the end face 40 of the core layer 22 having at least the active layer. Next, the emitted light enters the lens unit 50. When the light is incident on the lens unit 50, the light is refracted, and converges, for example, in the direction of the arrow b. Next, the light emitted through the lens unit 50 is refracted and travels in the direction of the arrow c, for example. That is, the light emitted from the waveguide structure unit 110 is converged by the lens unit 50. Thereby, the radiation angle of the light radiate | emitted from the waveguide structure part 110 can be made small.

  Note that a modification of the waveguide optical device 100 according to the first embodiment can also be applied to the waveguide optical device 200 according to the second embodiment.

2-2. Device Manufacturing Method Next, an example of a manufacturing method of the waveguide optical device 200 according to the second embodiment to which the present invention is applied will be described.

  The waveguide optical device 200 according to the second embodiment can be formed by substantially the same process as the manufacturing process of the waveguide optical device 100 according to the first embodiment described above. Specifically, in the step of discharging the droplets 52 (see FIGS. 7 to 9), the droplets 52 are sequentially discharged without detecting the photocurrent to form the lens portion precursor 50a having a desired shape. Except for this point, it is formed by substantially the same process as the manufacturing process of the waveguide type optical device 100 of the first embodiment. Therefore, detailed description is omitted here.

  As the core layer 22 in the waveguide type optical element 200 according to the present embodiment, for example, GaAs, InGaAs, GaInNAs, GaAsSb, GaN, InGaAsP, or the like can be used, and depending on these materials, The materials of the first cladding layer 20, the second cladding layer 24, the first contact layer 34, and the second contact layer 36 can be appropriately selected.

2-3. Action / Effect According to the waveguide-type optical element 200 according to the present embodiment, the lens unit 50 is formed so as to face the end surface 40 of the core layer 22 of the waveguide structure unit 110. The radiation angle of the light emitted from the end face 40 can be reduced. Therefore, the coupling efficiency with a light guide member such as an optical fiber or an optical waveguide can be improved.

  Moreover, according to the waveguide type optical element 200 and the manufacturing method thereof according to the present embodiment, the base member 60 makes it easy to form the lens unit 50 in a desired shape.

3. Third embodiment 3-1. Device Structure FIG. 17 is a cross-sectional view schematically showing a waveguide type optical element 300 according to a third embodiment to which the present invention is applied. In addition, the same code | symbol is attached | subjected to the substantially same component as the waveguide type optical element 100 which concerns on 1st Embodiment, and the detailed description is abbreviate | omitted.

  The waveguide type optical element 300 according to the present embodiment includes a point where the waveguide structure unit 100 functions as an optical waveguide, a point where light enters or exits from the end face 40 of the core layer 22, and the first electrode 30 and The second embodiment differs from the waveguide optical device 100 of the first embodiment in that the second electrode 32 is not provided.

  Note that a modification of the waveguide optical device 100 according to the first embodiment can also be applied to the waveguide optical device 300 according to the third embodiment.

3-2. Device Manufacturing Method Next, an example of a method for manufacturing the waveguide optical device 300 according to the third embodiment to which the present invention is applied will be described.

  The waveguide type optical element 300 according to the third embodiment can be formed by almost the same process as the manufacturing process of the waveguide type optical element 100 according to the first embodiment described above. Specifically, in the step of forming the first electrode 30 and the second electrode 32 (see FIG. 5), the photocurrent is detected in the step of discharging the droplet 52 (see FIGS. 7 to 9). Steps substantially similar to the manufacturing process of the waveguide-type optical device 100 of the first embodiment except that the droplets 52 are sequentially ejected without forming the lens portion precursor 50a having a desired shape. Formed by. Therefore, detailed description is omitted here.

As the core layer 22 in the waveguide type optical element 300 according to the present embodiment, for example, GaAs / AlGaAs, InGaAsP mixed crystal as a semiconductor material, or polycarbonate, polymethyl methacrylate, epoxy as an organic thin film, Polyurethane, LiNbO ₃ crystal, quartz glass, or the like can be used, and materials of the first cladding layer 20 and the second cladding layer 24 can be appropriately selected according to these materials.

3-3. Action / Effect According to the waveguide-type optical element 300 according to the present embodiment, the lens unit 50 is formed so as to face the end surface 40 of the core layer 22 of the waveguide structure 110, whereby the upper surface of the substrate 10 is obtained. However, the allowable range of optical axis deviation in the vertical direction (Z direction in the examples of FIGS. 1 and 2) is widened. That is, according to the waveguide type optical device 100 according to the present embodiment, the tolerance in the direction perpendicular to the upper surface of the substrate 10 is improved.

  Further, according to the waveguide type optical element 300 according to the present embodiment, the lens unit 50 is formed so as to face the end surface 40 of the core layer 22 of the waveguide structure unit 110, so that the lens unit 50 is formed on the upper surface of the substrate 10. On the other hand, the tolerance in the horizontal direction (in the example of FIGS. 1 and 2, the XY plane direction) is improved.

  Moreover, according to the waveguide type optical element 300 according to the present embodiment, the lens part 50 is formed so as to face the end face 40 of the core layer 22 of the waveguide structure part 110, thereby being a light absorption layer. Even if the core layer 40 is thinned, the incident light can be narrowed down by the lens unit 50, so that good incident efficiency can be obtained. That is, according to the waveguide type optical element 300 according to the present embodiment, it is possible to achieve both reduction in the size of the device and improvement in incident efficiency into the waveguide.

  Further, according to the waveguide type optical element 300 according to the present embodiment, the lens unit 50 is formed so as to face the end surface 40 of the core layer 22 of the waveguide structure unit 110, so that the end surface of the core layer 22 is formed. When light is emitted from 40, the radiation angle of the emitted light can be reduced.

  Moreover, according to the waveguide type optical element 300 and the manufacturing method thereof according to the present embodiment, the base member 60 is provided, so that the lens unit 50 can be easily formed in a desired shape.

4). Fourth Embodiment Next, with reference to FIG. 18, an optoelectronic integrated device 300 to which the waveguide optical device 100 according to the first embodiment is applied, and a waveguide optical device according to the second embodiment. The optical integrated device 350 and the optical module 700 to which 200 is applied will be described. FIG. 18 is a cross-sectional view schematically showing an optoelectronic integrated device 300, an optical integrated device 350, and an optical module 700 according to the present embodiment.

  The optoelectronic integrated device 300 includes the waveguide optical device 100 according to the first embodiment, and a TIA 150 (Trans-Impedance Amplifier). TIA 150 is formed of, for example, a heterojunction bipolar transistor. Specifically, the optoelectronic integrated device 300 includes a substrate 10, a waveguide optical device 100, and a TIA 150, as shown in FIG. The waveguide type optical device 100 and the TIA 150 are formed on the submount substrate 406.

  The optical integrated device 350 includes the waveguide type optical device 200 according to the second embodiment and a monitor photodiode 512. The waveguide optical device 200 and the monitor photodiode 512 are formed on the submount substrate 508.

  The optical module 700 includes a receiving unit 400, a transmitting unit 500, and an electronic circuit unit 600. The electronic circuit unit 600 includes an amplifier circuit unit 610 and a drive circuit unit 620.

  The receiving unit 400 includes a submount substrate 406, an optoelectronic integrated device 300, a housing unit 402, and a glass unit 404.

  The transmission unit 500 includes a submount substrate 508, an optical integrated element 350, an oblique glass unit 504, and a housing unit 502.

  The casing unit 402 is formed of a resin material, and is formed integrally with a sleeve 420 and a condensing unit 405 described later. Similarly, the housing portion 502 is formed of a resin material and is formed integrally with a sleeve 520 described later. As the resin material, a material that can transmit light is selected. For example, polymethyl methacrylate (PMMA), epoxy resin, phenol resin, diallyl phthalate, phenyl methacrylate, fluorine resin used for plastic optical fiber (POF) A polymer or the like can be employed.

  The sleeves 420 and 520 are formed in a shape in which a light guide member (not shown) such as an optical fiber can be fitted from the outside, and constitute a part of the peripheral wall of the accommodation spaces 422 and 522. As the light guide member, for example, the waveguide type optical element 300 according to the third embodiment, an optical fiber, or the like can be used.

  The condensing part 405 is provided in the accommodation space 422 side of the sleeve 420, and condenses and sends out the optical signal from the light guide member. Thereby, the loss of light from the light guide member can be reduced, and the light coupling efficiency between the waveguide optical element 100 and the light guide member can be improved.

  The oblique glass portion 504 is provided on the accommodation space 522 side of the sleeve 520 and reflects and transmits light from the waveguide type optical element 200. The monitor photodiode 512 receives the light reflected by the oblique glass portion 504. The drive circuit unit 620 adjusts the amount of light emitted by the waveguide optical element 200 according to the amount of light received by the monitor photodiode 512. The light transmitted through the oblique glass portion 504 is sent out to a light guide member fitted in the sleeve 520 of the transmission unit 500.

  The waveguide type optical element 200 converts an electrical signal input from the outside into an optical signal and outputs it to the outside via, for example, an optical fiber (not shown). For example, the waveguide optical device 100 receives an optical signal via an optical fiber, converts the optical signal into a current, and sends the converted current to the TIA 150. The TIA 150 converts the received current into a voltage output, amplifies it, and sends it to the electronic circuit unit 600. The amplifier circuit unit 610 performs control so that the voltage output does not exceed a certain level, and outputs the voltage output to the outside. In addition, description of external terminals, such as an electrical signal output terminal and an input terminal, is abbreviate | omitted.

  As described above, the waveguide optical device 100 according to the first embodiment is used in the optoelectronic integrated device 300 and the optical module 700, and the waveguide optical device 200 according to the second embodiment is an optical device. The integrated device 350 and the optical module 700 can be used.

5. Fifth Embodiment FIG. 19 is a diagram schematically showing a light transmission device according to a fifth embodiment to which the present invention is applied. The light transmission device 90 connects electronic devices 92 such as a computer, a display, a storage device, and a printer to each other. The electronic device 92 may be an information communication device. The light transmission device 90 may be one in which plugs 96 are provided at both ends of the cable 94. The cable 94 can include a light guide member (eg, an optical fiber). The plug 96 incorporates the optical module 700 according to the fourth embodiment. Since the light guide member is built in the cable 94 and the optical module 700 is built in the plug 96, it is not shown in FIG. The relationship between the light guide member and the optical module 700 is as described in the fourth embodiment.

  Optical modules 700 according to the fourth embodiment are provided at both ends of the light guide member. As shown in FIGS. 18 and 19, the waveguide-type optical device 100 according to the first embodiment installed at one end of the light guide member converts the optical signal into an electrical signal, and then The signal is input to the electronic device 92 via the TIA 150 and the electronic circuit unit 600. A waveguide type optical element 200 according to the second embodiment is installed at the other end of the light guide member. That is, in the waveguide type optical element 200, the electrical signal output from the electronic device 92 is converted into an optical signal. This optical signal travels through the light guide member and is input to the waveguide type optical element 100.

  As described above, according to the light transmission device 90 of the present embodiment, information transmission between the electronic devices 92 can be performed by an optical signal.

6). Sixth Embodiment FIG. 20 is a diagram schematically showing a usage pattern of a light transmission device according to a sixth embodiment to which the present invention is applied. The light transmission device 90 is connected between the electronic devices 80. As the electronic device 80, a liquid crystal display monitor or a digital CRT (may be used in the fields of finance, mail order, medical care, education), a liquid crystal projector, a plasma display panel (PDP), a digital TV, a retail store A cash register (for POS (Point of Sale Scanning)), a video, a tuner, a game device, a printer, and the like can be given.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments and can take various forms. For example, in the above-described embodiment of the present invention, the case where the core layer 22 is made of InGaAs has been described. However, other materials such as AlGaP, GaInP, ZnSe, InGaN, AlGaN, GaInNAs, GaAs, A semiconductor material such as GaAsSb can also be used, and materials of the first cladding layer 20, the second cladding layer 24, the first contact layer 34, and the second contact layer 36 are appropriately selected according to these materials. Can be done.

1 is a cross-sectional view schematically showing a waveguide type optical device according to a first embodiment. The top view which shows typically the waveguide type optical element which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing method of the waveguide type optical element which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing method of the waveguide type optical element which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing method of the waveguide type optical element which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing method of the waveguide type optical element which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing method of the waveguide type optical element which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing method of the waveguide type optical element which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing method of the waveguide type optical element which concerns on 1st Embodiment. 1 is a cross-sectional view schematically showing a waveguide type optical device according to a first embodiment. 1 is a cross-sectional view schematically showing a waveguide type optical device according to a first embodiment. 1 is a cross-sectional view schematically showing a waveguide type optical device according to a first embodiment. 1 is a cross-sectional view schematically showing a waveguide type optical device according to a first embodiment. 1 is a cross-sectional view schematically showing a waveguide type optical device according to a first embodiment. 1 is a cross-sectional view schematically showing a waveguide type optical device according to a first embodiment. Sectional drawing which shows typically the waveguide type optical element which concerns on 2nd Embodiment. Sectional drawing which shows typically the waveguide type optical element which concerns on 3rd Embodiment. Sectional drawing which shows typically the optoelectronic integrated device which concerns on 4th Embodiment, an optical integrated device, and an optical module. The figure which shows typically the light transmission apparatus which concerns on 5th Embodiment. The figure which shows typically the usage condition of the optical transmission apparatus which concerns on 6th Embodiment.

Explanation of symbols

10 substrate, 12 first substrate, 14 second substrate, 15 semiconductor multilayer film, 20 first cladding layer, 22 core layer, 24 second cladding layer, 30 first electrode, 32 second electrode, 34 first contact layer, 36 Second contact layer, 40 end face, 50 lens part, 51 upper part, 52 droplet, 53 lower part, 60 base member, 62 ammeter, 64 power source, 70 damming member, 80 electronic device, 90 light transmission device, 92 electron Equipment, 94 cable, 96 plug, 100 waveguide type optical element, 110 waveguide structure part, 112 nozzle, 114 inkjet head, 130 columnar part, 150 TIA, 200 waveguide type optical element, 300 waveguide type optical element, 350 Integrated optical device, 400 receiving unit, 402 housing unit, 404 glass unit, 405 condensing unit 406 submount substrate, 420 sleeve, 422 accommodation space, 500 transmitter, 502 housing, 504 oblique glass, 508 submount substrate, 512 monitor photodiode, 520 sleeve, 522 accommodation space, 600 electronic circuit, 610 amplification circuit, 620 drive Circuit part, 700 Optical module

Claims (2)

Laminating a semiconductor layer for constituting a waveguide structure including at least a first cladding layer, a core layer, and a second cladding layer above the substrate;
Etching the semiconductor layer to form a columnar portion including at least the core layer;
Forming a lens portion at a position away from the end surface of the core layer, facing the end surface of the core layer above the substrate,
The lens unit is formed to have a function of changing the optical path of light incident on the end surface, and is formed by a droplet discharge method of discharging a droplet including the material of the lens unit,
The waveguide structure is formed to function as a waveguide photodiode,
The first cladding layer is formed to have a first conductivity type,
The core layer is formed to be a light absorption layer,
The second cladding layer is formed to have a second conductivity type,
The step of forming the lens portion includes a droplet discharge step,
The droplet discharge step includes
While making detection light incident on at least the end face of the core layer and detecting a photocurrent obtained by electrically converting the light, the droplets are sequentially discharged to the lens portion formation region,
A method for manufacturing a waveguide-type optical element, wherein discharge of the droplet is terminated when a predetermined value of the photocurrent is confirmed. In claim 1,
The method of manufacturing a waveguide type optical element, wherein the predetermined value of the photocurrent is a maximum value of the photocurrent.

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