JP2005044861A - Semiconductor device, method of using semiconductor device, method of manufacturing semiconductor device, and electronic device - Google Patents

Abstract

In a three-dimensionally mounted semiconductor device, power can be supplied to each substrate, and accurate signal transmission between the substrates can be performed.
A semiconductor device 1 in which a plurality of substrates 100, 200, and 300 including an integrated circuit 105 are stacked, each substrate having a light-transmitting substrate body 101 and an electrical signal as an optical signal. Light-emitting elements that can be converted and transmitted, light-receiving elements 122 and 123 that can receive optical signals and convert them into electrical signals, and through-electrodes 160 that supply power to each substrate, and through-electrodes on adjacent substrates 160 is configured to be electrically connected.
[Selection] Figure 1

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device, a method for manufacturing the semiconductor device, a method for using the semiconductor device, and an electronic apparatus.
[0002]
[Prior art]
A semiconductor device including an integrated circuit is mounted on an electronic device such as a mobile phone, a notebook personal computer, or a PDA (Personal Data Assistance). Recently, downsizing and weight reduction of the above-described portable electronic devices are strongly demanded, and the mounting space for semiconductor devices is extremely limited. Therefore, a three-dimensional mounting technique has been proposed in order to achieve high-density mounting of semiconductor chips. The three-dimensional mounting technique is a technique for achieving high-density mounting of semiconductor chips by stacking substrates on which integrated circuits are formed and interconnecting the substrates.
[0003]
In such a three-dimensionally mounted semiconductor device, transmission / reception of signals between the substrates is performed via conductive lines disposed between the substrates. However, the occurrence of signal delay is inevitable due to the presence of wiring resistance and wiring capacitance. Thus, a technique (optical interconnection) for transmitting and receiving optical signals between substrates has been proposed (see, for example, Patent Document 1). In this technique, an optical signal is transmitted and received between a light emitting element formed on one substrate and a light receiving element formed on another substrate.
[0004]
[Patent Document 1]
JP 2000-277794 A
[0005]
[Problems to be solved by the invention]
In order to drive the integrated circuit and the light emitting element and the light receiving element of each substrate, it is necessary to supply power to each substrate. However, there is a problem that it is difficult or impossible to supply power using an optical signal with low energy.
[0006]
On the other hand, even when a pair of light emitting elements and a light receiving element transmits and receives an optical signal, the light emitting element may emit an optical signal in a predetermined angle range, and the light receiving element emits light incident in a predetermined angle range. A signal may be received. As described above, when the directivity of the light emitting element or the light receiving element is weak, the light signal from the light emitting element is received by a light receiving element other than the light receiving element, or the light receiving element is received from a light emitting element other than the light emitting element. In some cases, an optical signal may be received. As a result, there is a problem that accurate signal transmission becomes difficult or impossible.
[0007]
The present invention has been made to solve the above-described problems, and can provide power to each substrate, and can accurately perform signal transmission between the substrates, and a manufacturing method thereof. And to provide a method of using the same.
Another object is to provide a highly reliable electronic device.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a semiconductor device of the present invention is a semiconductor device in which a plurality of substrates each having an integrated circuit are stacked, and each substrate is a material that can transmit an optical signal of at least one wavelength. A substrate body comprising: at least one of a light-emitting element capable of converting an electrical signal into the optical signal and transmitting the light signal; and a light-receiving element capable of receiving the optical signal and converted into an electrical signal; And a conductive portion for supplying electric power to each of the substrates, wherein the conductive portions of the adjacent substrates are electrically connected.
According to this configuration, the conductive portions that supply power to each substrate are formed through each substrate, and the conductive portions of adjacent substrates are electrically connected, so that all the substrates are connected via the conductive portions. Can be powered.
[0009]
Each substrate body is preferably made of an electrically insulating material. According to this configuration, there is no need to form an insulating film between the conductive portion and the substrate body. Therefore, the cost of the semiconductor device can be reduced.
[0010]
In addition, a first light shielding film made of a material capable of blocking the optical signal is formed between the pair of light emitting elements and the light receiving element that transmit and receive the optical signal, and the first light shielding film is formed of the pair of light emitting elements. It is good also as a structure which has an opening part on the optical axis which connects a light emitting element and a light receiving element.
According to this configuration, only the optical signal emitted from the light emitting element to the opening formation region and the optical signal incident from the opening formation region to the light receiving element pass through the first light shielding film. Therefore, even when the directivity of the light emitting element or the light receiving element is weak, it is possible to transmit and receive optical signals only between the pair of light emitting elements and the light receiving element, and signal transmission between the substrates can be performed accurately. .
[0011]
In addition, it is desirable to include a second light shielding film that prevents light from entering the integrated circuit. According to this configuration, it is possible to reduce the rate of occurrence of malfunction or malfunction of the integrated circuit due to the incidence of light.
[0012]
The first light-shielding film and / or the second light-shielding film is preferably formed on a surface of an insulating film that covers the integrated circuit. According to this configuration, even when the first light-shielding film and / or the second light-shielding film is made of a conductive material, a short circuit between these and the integrated circuit can be prevented. In addition, by stacking the substrates on which the first light shielding film is formed in this manner, the first light shielding film can be disposed between a pair of light emitting elements and light receiving elements that transmit and receive optical signals. Furthermore, the first light shielding film can be easily formed after the formation of each substrate.
[0013]
Further, it is desirable that the first light shielding film and / or the second light shielding film function as electrical wiring. According to this configuration, it is possible to reduce the space for electrical wiring, and the semiconductor device can be reduced in size.
[0014]
The first light-shielding film and / or the second light-shielding film preferably have a function of radiating heat generated from the integrated circuit. According to this configuration, it is possible to reduce the rate of occurrence of malfunction or malfunction of the integrated circuit due to heat generation.
[0015]
Further, the one light emitting element or the one light receiving element may be configured to be capable of transmitting and receiving the optical signal between the plurality of light receiving elements or the plurality of light emitting elements. According to this configuration, the number of light emitting elements or light receiving elements can be reduced, and the cost of the semiconductor device can be reduced.
[0016]
On the other hand, the method of using the semiconductor device of the present invention includes a plurality of the light receiving elements or a plurality of the light emitting elements that are capable of transmitting and receiving the optical signal between the one light emitting element or the one light receiving element. The light receiving element or the light emitting element that should transmit and receive the optical signal is driven in synchronization with the one light emitting element or the one light receiving element.
According to this configuration, one light emitting element or one light receiving element can perform transmission / reception of an optical signal only with a light receiving element or light emitting element that should perform transmission / reception of an optical signal. Alternatively, crosstalk with other light-emitting elements can be prevented. Accordingly, signal transmission between the substrates can be performed accurately.
[0017]
On the other hand, in the method for manufacturing a semiconductor device of the present invention, a non-through hole is formed in the substrate from one surface of the substrate, and a conductive material is applied to the non-through hole by a droplet discharge means. Filling and forming the conductive part, and grinding the surface of the other side of the substrate to expose the conductive part.
According to this configuration, since the conductive portion is formed by filling the conductive material with the droplet discharge means, the conductive portion having a predetermined shape can be accurately formed at a predetermined position. Further, since the substrate is thinned in the final process, the semiconductor device can be reduced in size while ensuring the rigidity of the substrate in the semiconductor process.
[0018]
On the other hand, an electronic apparatus according to the present invention includes the semiconductor device described above.
According to this configuration, since the semiconductor device that can supply power to each substrate and can accurately transmit signals between the substrates is provided, a highly reliable semiconductor device can be provided. it can.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.
[0020]
[Semiconductor device]
FIG. 1 is a side sectional view of the semiconductor device of this embodiment. The semiconductor device 1 of this embodiment is configured by stacking a plurality of substrates 100, 200, and 300 including an integrated circuit 105. 1 illustrates the case where three substrates are stacked, the number of stacked substrates may be other than three. Each substrate 100, 200, 300 is formed with through electrodes 160, 260, 360, and adjacent substrates are stacked with the through electrodes electrically connected. Note that adhesives 190 and 290 having optical signal transparency are filled between the substrates 100, 200, and 300.
[0021]
(Substrate body, integrated circuit)
As shown in FIG. 1, the substrates 100, 200, and 300 are configured in the same manner. Therefore, the case of the substrate 100 will be described below as an example. The substrate 100 includes a substrate body 101 made of a light transmissive material capable of transmitting an optical signal having at least one wavelength. Thereby, optical signal communication between substrates becomes possible. The substrate 100 is made of an electrically insulating material. Thereby, as will be described later, it is not necessary to form an insulating film between each substrate 100 and the through electrode 160, and the cost of the semiconductor device 1 can be reduced. In addition, specifically, materials such as sapphire, glass, and quartz can be employed as the material having the above-described optical transparency and electrical insulation. When a sapphire substrate is employed, the light emitting element and the light receiving element can be directly formed on the substrate as described later, and the substrate can be formed as thin as about 150 μm. Therefore, the semiconductor device 1 can be reduced in size.
[0022]
An integrated circuit 105 is disposed in the circuit formation region of the substrate 100. Note that an integrated circuit may be directly formed on the surface of the substrate 100, or an integrated circuit element may be mounted on the surface of the substrate 100. Any circuit such as a processor circuit or a memory circuit of an electronic computer can be applied to the integrated circuit 105. Note that a light emitting element and a light receiving element driving circuit described below may be added in order to transmit and receive optical signals between the substrates.
[0023]
(Light emitting element, light receiving element)
The optical signal communication area of the substrate 100 includes light emitting elements 112 and 113 (see FIG. 2) or light receiving elements 122 and 123 (see FIG. 1). The light emitting elements 112 and 113 convert an electrical signal used in the integrated circuit into an optical signal having a specific wavelength. Specifically, a light emitting diode (LED), a semiconductor laser (laser diode), an organic EL element, or the like can be employed as the light emitting elements 112 and 113. The light receiving elements 122 and 123 convert an optical signal having a specific wavelength into an electric signal used in an integrated circuit. Specifically, a photodiode, a phototransistor, a photo IC, or the like can be employed as the light receiving elements 122 and 123.
[0024]
An LED that can be used as a light emitting element is a diode that emits light when a current flows through a pn junction. In a LED having a simple homojunction structure, crystals of a p-type semiconductor and an n-type semiconductor are made of the same material. When a forward bias voltage is applied to the LED having a homojunction structure, electrons of the n-type semiconductor move to the p-type semiconductor, fall from a high energy conduction band to a low energy valence band, and recombine with holes. The energy lost at that time is released as light, and the LED emits light. In addition, since the emitted light intensity of LED is proportional to the electric current which flows through a pn junction part, the optical signal according to an electrical signal can be obtained. The wavelength of the optical signal depends on the energy difference (band gap) between the conduction band and the valence band, and the band gap is determined by the semiconductor material used.
[0025]
Note that an LED having a double heterojunction structure may be employed instead of an LED having a homojunction structure with low luminous efficiency. An LED having a double heterojunction structure is obtained by sandwiching an active layer having a small band gap between a p-type semiconductor (p-type cladding layer) and an n-type semiconductor (n-type cladding layer). When a forward bias voltage is applied to an LED having a double heterojunction structure, electrons and holes are confined in the active layer and become a high density (inversion distribution) state. Thereby, recombination (stimulated radiation) is performed efficiently and high luminous efficiency can be obtained. By adopting such an LED as a light emitting element, it is possible to ensure high output with low power consumption, and efficient optical signal communication can be performed. Moreover, LED is excellent in durability performance.
[0026]
In addition, a semiconductor laser that can be employed as a light emitting element is one that amplifies and emits light from the semiconductor element by laser oscillation. The structure of the semiconductor laser is the same as that of the LED having a double heterojunction structure. In the semiconductor laser, the cladding layer and the active layer are made of semiconductor materials having different refractive indexes. Thereby, the boundary portion between the cladding layer and the active layer functions as a reflecting mirror. Then, the induced radiation is repeated as the light generated by the recombination reciprocates between the reflecting mirrors (laser oscillation). Thereby, light is amplified and irradiated to the outside of the semiconductor element. Therefore, the semiconductor laser has a higher output than the LED. By employing such a semiconductor laser as a light emitting element, it is possible to perform optical signal communication between distant substrates.
[0027]
The above-described LED and semiconductor laser can be composed of a compound semiconductor such as gallium arsenide (GaAs). And when the board | substrate 100 is comprised by a sapphire, LED and a semiconductor laser can be directly formed in the surface of the board | substrate 100. FIG. As a result, the degree of integration of the semiconductor device 1 can be improved, and the semiconductor device 1 can be reduced in size. When a sapphire substrate is employed, a single crystal Si layer is formed on the substrate, and the integrated circuit 105 is formed on the Si layer.
[0028]
Moreover, it is also possible to employ an organic EL element as the light emitting element. In the organic EL element, a hole injection / transport layer and a light emitting layer made of an organic compound are sandwiched between an anode made of ITO or the like and a cathode made of LiF / Al or the like. Specifically, a mixture of a polythiophene derivative and polystyrene sulfonic acid or the like can be used as a constituent material of the hole injection / transport layer. As a constituent material of the light emitting layer, a polymer material such as a polyfluorene derivative can be used. In the light emitting layer, holes injected from the hole injecting / transporting layer and electrons injected from the cathode are recombined to emit light. By employing such an organic EL element as a light emitting element, the light emitting element can be easily formed.
[0029]
A photodiode can be adopted as one light receiving element. In contrast to an LED, a photodiode is a device in which light is incident on a pn junction to generate holes and electrons to obtain a current. Since the current obtained here is proportional to the intensity of the light incident on the pn junction, an electric signal corresponding to the optical signal can be obtained. Note that a reverse bias voltage is applied during the operation of the photodiode. As the photodiode, a pin photodiode may be adopted in addition to the pn photodiode described above. In the pin structure, an intrinsic semiconductor (intrinsic) layer with few carriers is provided between pn junctions. When an electric field is applied to the intrinsic semiconductor layer, holes and electrons generated as described above can be moved at high speed. Thereby, the high-speed responsiveness of a light receiving element is securable. As the light receiving element, a phototransistor in which a photodiode is combined with an amplifier circuit, a photo IC in which a photodiode is combined with an integrated circuit, or the like can be used.
[0030]
FIG. 2 is a layout diagram of light emitting elements and light receiving elements on a plurality of substrates. In this embodiment, a light emitting element and a light receiving element (hereinafter referred to as a pair of light emitting element and light receiving element) that are in charge of transmitting and receiving optical signals between a pair of substrates are formed on each substrate. For example, in order to transmit an optical signal from the substrate 100 to the substrate 200, a light emitting element 112 is formed on the substrate 100, and a light receiving element 221 is formed on the substrate 200. Conversely, in order to transmit an optical signal from the substrate 200 to the substrate 100, a light emitting element 211 is formed on the substrate 200, and a light receiving element 122 is formed on the substrate 100. Similarly, in order to transmit and receive optical signals between the substrate 200 and the substrate 300, a light emitting element 213 and a light receiving element 223 are formed on the substrate 200, and a light receiving element 322 and a light emitting element 312 are formed on the substrate 300. Yes. Further, in order to transmit and receive optical signals between the substrate 300 and the substrate 100, a light emitting element 311 and a light receiving element 321 are formed on the substrate 300, and a light receiving element 123 and a light emitting element 113 are formed on the substrate 100.
[0031]
In FIG. 2, one light emitting element or one light receiving element can transmit and receive an optical signal to and from one light receiving element or one light emitting element. That is, each of the pair of light emitting elements and light receiving elements is configured to perform only transmission / reception of optical signals with the substrate on which the counterpart element is formed, and not to perform transmission / reception of optical signals with other substrates. Note that it is not necessary to provide a light emitting element and a light receiving element on a substrate that does not transmit signals. Further, it is sufficient to provide only one of the light-emitting element and the light-receiving element on the substrate that performs only one-way signal transmission in accordance with the signal transmission direction.
[0032]
In addition, the optical signal communication area on each substrate is partitioned in a matrix, and a light emitting element or a light receiving element is arranged in each element. Here, the pair of light-emitting elements and light-receiving elements are arranged on the same element of the matrix on each substrate. Thereby, the optical axes of the pair of light emitting elements and light receiving elements are arranged perpendicular to the substrate. In this case, the transmission distance of the optical signal is the shortest, and the signal delay can be minimized. However, the pair of light-emitting elements and light-receiving elements can be arranged on different elements of the matrix on each substrate. In this case, the optical axes of the pair of light emitting elements and light receiving elements are arranged obliquely with respect to the substrate.
[0033]
On the other hand, as shown in FIG. 1, an interlayer insulating film 108 is formed so as to cover the integrated circuit 105, the light emitting elements 112 and 113, and the light receiving elements 122 and 123 formed on the active surface of the substrate 100. This interlayer insulating film 108 is made of silicon oxide (SiO 2 ₂ ) And other electrically insulating materials. Thereby, a short circuit of the integrated circuit 105 and the like formed on the active surface of the substrate 100 can be prevented. The interlayer insulating film 108 is made of a light transmissive material that can transmit an optical signal. Since the substrate body 101 is also made of a light transmissive material, the entire substrate 100 can transmit an optical signal. Therefore, even when an intermediate substrate exists between a pair of substrates that transmit and receive an optical signal, the optical signal can be transmitted without forming a through hole in the intermediate substrate. This makes it possible to transmit and receive optical signals between a pair of substrates sandwiching the intermediate substrate.
[0034]
(Light shielding film)
By the way, the light emitting element described above may emit an optical signal in a predetermined angle range, and the light receiving element described above may receive an optical signal incident in a predetermined angle range. Thus, when the directivity of a light emitting element or a light receiving element is weak, there is a possibility that an optical signal transmitted from one light emitting element is received by a light receiving element other than the light receiving element corresponding to the light emitting element. One light receiving element may receive an optical signal transmitted from a light emitting element other than the light emitting element corresponding to the light receiving element. As a countermeasure, it may be possible to dispose each light emitting element and each light receiving element to be formed on each substrate by a predetermined distance from each other, but there is a problem that each substrate becomes large. Therefore, it is desirable to form the light shielding films 140 and 150 as shown in FIG.
[0035]
The light shielding films 140 and 150 are made of metal chromium and / or chromium oxide or the like. The light shielding films 140 and 150 are formed on the surface of the interlayer insulating film 108. Note that a light shielding film may be formed on the active surface of the substrate 100, an interlayer insulating film may be formed on the surface of the light shielding film, and an integrated circuit or the like may be formed on the surface of the interlayer insulating film. Further, a light shielding film may be formed on the back surface of the substrate 200. In any case, the light shielding films 140 and 150 are disposed between the two substrates by laminating the substrate 200 on the active surface side of the substrate 100 on which the light shielding film is formed. On the other hand, the light shielding films 140 and 150 are constituted by a first light shielding film 140 formed in the optical signal communication region and a second light shielding film 150 formed in the circuit formation region.
[0036]
The first light shielding film 140 formed in the optical signal communication region ensures the directivity of the light emitting element and the light receiving element. Therefore, an opening of the first light shielding film 140 is formed on the optical axis of the pair of light emitting elements and light receiving elements. For example, the opening 142 of the first light shielding film 140 is formed on the optical axes of the light emitting element 211 and the light receiving element 122. In addition, an opening 141 of the first light shielding film 140 and an opening 241 of the first light shielding film 240 are formed on the optical axes of the light emitting element 311 and the light receiving element 123. Each opening is formed in such a size that an optical signal transmitted from the light emitting element is not received by a light receiving element other than the light receiving element corresponding to the light emitting element. Each opening is formed in a size that does not receive an optical signal transmitted from a light emitting element other than the light emitting element corresponding to the light receiving element.
[0037]
According to this configuration, among the optical signals emitted from one light emitting element, the optical signal emitted to the region other than the opening formation region is blocked by the first light shielding film and emitted to the opening formation region. Only the optical signal passes through the first light shielding film. Therefore, the optical signal is received only by the light receiving element corresponding to the light emitting element. In addition, among the optical signals incident on one light receiving element, the optical signal incident from a region other than the opening formation region is blocked by the first light shielding film, and only the optical signal incident from the opening formation region is received. Passes through the first light shielding film. Therefore, only the optical signal from the light emitting element corresponding to the light receiving element can be received. As described above, even when the directivity of the light-emitting element or the light-receiving element is weak, it is possible to transmit and receive optical signals only between the pair of light-emitting elements and the light-receiving element, and signal transmission between the substrates can be performed accurately. it can.
[0038]
On the other hand, the second light shielding film 150 formed in the circuit formation region prevents light from entering the integrated circuit 105. Therefore, the second light-shielding film 150 is formed at a position where the light signal from each light emitting element can be prevented from entering the integrated circuit 105. The second light shielding film 150 is desirably formed at least over the entire circuit formation region. This makes it possible to prevent light other than the optical signal from entering the integrated circuit 105 perpendicularly. Accordingly, it is possible to reduce the rate of occurrence of malfunctions and malfunctions of the integrated circuit due to the incidence of light.
[0039]
The first light-shielding film 140 and the second light-shielding film 150 may be formed in a separated state, but are preferably formed in a continuous state. Specifically, a light shielding film may be formed on the entire active surface side of the substrate 100 except for the openings 141 and 142 described above. In this case, the incidence of light on the integrated circuit 105 can be kept to a minimum, and the rate of occurrence of malfunctions and malfunctions of the integrated circuit due to the incidence of light can be further reduced.
[0040]
In addition, the second light-shielding film 150 can be given a function of radiating heat generated from the integrated circuit 105. In this case, the second light shielding film 150 is made of a metal material having a high thermal conductivity. The second light shielding film 150 is extended to the peripheral edge of the substrate 100. Thereby, heat generated in the integrated circuit 105 is released to the outside of the substrate 100 through the interlayer insulating film 108 and the second light shielding film 150. Therefore, the heat dissipation efficiency of the integrated circuit 105 can be improved. Further, by forming the first light shielding film 140 continuously with the second light shielding film 150, it is possible to impart a heat dissipation function to the first light shielding film 140. In this case, the first light shielding film 140 is also made of a metal material having a high thermal conductivity, and is extended to the peripheral edge of the substrate 100. Thereby, the heat dissipation efficiency of the integrated circuit 105 can be further improved.
[0041]
FIG. 3 is another layout view of the light emitting elements and the light receiving elements on the plurality of substrates. In FIG. 3, one light emitting element or one light receiving element can transmit and receive an optical signal between a plurality of light receiving elements or a plurality of light emitting elements. That is, each of the pair of light emitting elements and light receiving elements is configured not only to transmit / receive optical signals to / from the substrate on which the counterpart element is formed, but also to transmit / receive to / from other substrates. For example, the light emitting element 310 of the substrate 300 not only transmits an optical signal to the light receiving element 223 of the substrate 200, but also transmits an optical signal to the light receiving element 120 of the substrate 100. In addition, the light receiving element 120 of the substrate 100 not only receives an optical signal from the light emitting element 310 of the substrate 300 but also receives an optical signal from the light emitting element 211 of the substrate 200. Even in this case, optical signals can be transmitted and received between all the substrates 100, 200, and 300 constituting the semiconductor device 2. Thereby, the number of light emitting elements or light receiving elements can be reduced, and the cost of the semiconductor device can be reduced.
[0042]
However, when optical signals are transmitted and received between a pair of light emitting elements and light receiving elements, it is necessary to prevent crosstalk with other light emitting elements or light receiving elements. Therefore, in the semiconductor device 2 shown in FIG. 3, a pair of light emitting elements and light receiving elements that transmit and receive optical signals are driven in synchronization. For example, when optical signals are transmitted and received between the light emitting element 310 of the substrate 300 and the light receiving element 223 of the substrate 200, a driving voltage is applied to the light emitting element 310 and the light receiving element 223, while A driving voltage is not applied to the light receiving element 120. Thereby, the optical signal transmitted from the light emitting element 310 is received only by the light receiving element 223 and is not received by the light receiving element 120. In addition, when optical signals are transmitted and received between the light emitting element 211 of the substrate 200 and the light receiving element 120 of the substrate 100, a driving voltage is applied to the light emitting element 211 and the light receiving element 120, while A driving voltage is not applied to the light emitting element 310. As a result, the light receiving element 120 receives only the optical signal transmitted from the light emitting element 211 and does not receive the optical signal transmitted from the light emitting element 310. Therefore, crosstalk with other light emitting elements or light receiving elements can be prevented, and signal transmission between substrates can be performed accurately.
[0043]
(Penetration electrode)
On the other hand, as shown in FIG. 1, a through electrode 160 is formed on the substrate 100. The through electrode 160 is made of a conductive material such as Al or Cu. The through electrode 160 includes a plug portion 161 that is formed so as to penetrate in the thickness direction of the substrate 100 and a post portion 162 that is formed so as to protrude from the active surface of the substrate 100. The cross section of the plug part 161 and the post part 162 in the direction perpendicular to the axis is circular or polygonal, and the post part 162 has a larger cross-sectional shape than that of the plug part 161.
[0044]
Since the substrate body 101 is made of an electrically insulating material, it is not necessary to form an insulating film between the through electrode 160 and the substrate 100. In addition, since the constituent material of the through electrode does not diffuse into the substrate body 101, it is not necessary to provide a barrier layer between the through electrode 160 and the substrate 100. Therefore, the cost of the semiconductor device 1 can be reduced. On the other hand, a conductive film 155 is formed between the through electrode 160 and the substrate 100. The conductive film 155 can be used as an electrode when the through electrode 160 is formed by a plating method. In addition, the conductive film 155 is formed on the surface of the substrate 100 so as to function as an electrical wiring, whereby power can be supplied to the integrated circuit 105 and the like of the substrate 100. In this case, a power receiving pad (not shown) is formed on the surface of the substrate body 101, a through hole is formed from the surface of the interlayer insulating film 108 toward the pad, and the conductive film 155 is extended inside the through hole. Form. As a result, the through electrode 160 and the power receiving pad are brought into conduction through the conductive film 155, so that power can be supplied from the through electrode 160 to the integrated circuit 105 and the like.
[0045]
Incidentally, the second light-shielding film 150 described above can be configured by extending the conductive film 155. Further, the first light shielding film 140 can be formed by extending the conductive film 155. In this case, the conductive film 155 is made of a conductive material such as metallic chromium having excellent light shielding properties. Thereby, the first light-shielding film 140 and the second light-shielding film 150 can also function as the electrical wiring described above. Note that since the first light shielding film 140 and the second light shielding film 150 are formed on the surface of the interlayer insulating film 108, a short circuit with the integrated circuit 105 can be prevented. Then, the conductive film 155 and the first light shielding film 140 and / or the second light shielding film 150 can be formed at the same time, and the manufacturing cost can be reduced. In addition, the space for electrical wiring can be reduced, and the semiconductor device can be reduced in size.
[0046]
[Method for Manufacturing Semiconductor Device]
4 and 5 are explanatory diagrams of a method for manufacturing the through electrode. The through electrode 160 is formed as follows. First, as shown in FIG. 4A, a non-through hole 165 is formed from the surface of the interlayer insulating film 108 to the inside of the substrate body 101. A thin substrate is likely to break when the non-through hole 165 is formed, and it is difficult to form the non-through hole 165 with a thick substrate. In this respect, if a sapphire substrate is employed, even a thin substrate of about 150 μm can be subjected to a normal semiconductor process, and is not broken when the non-through hole 165 is formed. Next, a conductive film 155 is formed on the surface of the interlayer insulating film 108 and the inner surface of the non-through hole 165. For the formation of the conductive film 155, a sputtering method, a CVD method, or the like can be used. Next, as shown in FIG. 4B, a resist 168 is applied to the surface of the conductive film 155. Furthermore, the resist applied to the inside of the non-through hole 165 and the opening edge is removed by performing photolithography. Note that the resist 168 is removed to a size corresponding to the post portion of the through electrode at the opening edge of the non-through hole 165.
[0047]
Next, as shown in FIG. 5A, the inside of the non-through hole 165 and the opening edge are filled with a conductive material using the resist 168 as a mask. An ink jet method, a sputtering method, a plating method, or the like can be used for filling the conductive material. If an ink jet method using a droplet discharge device is employed, a predetermined amount of conductive material can be accurately discharged to a predetermined position, so that a through electrode having a predetermined shape can be accurately formed at a predetermined position. it can. In the case where a conductive material is filled by a plating method, the conductive film 155 can be used as an electrode. As described above, the plug portion 161 is formed inside the non-through hole 165, and the post portion 162 is formed at the opening edge of the non-through hole 165. Next, as shown in FIG. 5B, the resist 168 is removed. Note that the conductive material attached to the surface of the resist 168 is also removed at the same time. Next, the back surface of the substrate body 101 is etched to expose the tip of the plug portion 161. Further, the conductive film 155 formed at the tip of the plug portion 161 may be removed by polishing. Note that since the substrate is thinned in the final process, the semiconductor device can be reduced in size while ensuring the rigidity of the substrate in the semiconductor process. Thus, the through electrode 160 is formed.
[0048]
And as shown in FIG. 1, the penetration electrode of an adjacent board | substrate is electrically connected and each board | substrate is laminated | stacked. In order to electrically connect the through electrodes, first, solder, a metal brazing material, or the like is applied to the surface of the post portion of the lower layer substrate. A bump made of solder or the like may be formed on the tip of the plug portion of the upper layer substrate or the surface of the post portion of the lower layer substrate. Next, the tip of the plug portion of the upper substrate is brought into contact with the surface of the post portion of the lower substrate. And if both are thermocompression-bonded, each penetration electrode will be connected electrically and mechanically. In addition, if an adhesive is applied to the inner surfaces of adjacent substrates before connecting the through electrodes, the inner surfaces of the substrates can be bonded together with the connection of the through electrodes. In addition, after connecting the through electrodes, a gap between adjacent substrates may be filled with resin or the like. In addition, what has optical transparency and electrical insulation is employ | adopted for the adhesive agent or resin with which it fills between board | substrates. As described above, the semiconductor device 1 of this embodiment is completed.
[0049]
As described in detail above, the semiconductor device according to the present embodiment is configured by stacking the substrates provided with the light emitting elements or the light receiving elements. According to this configuration, in a semiconductor device mounted three-dimensionally, signal transmission between substrates can be performed using an optical signal. As a result, signal delay does not become a problem as in the case of conductive lines, and a semiconductor device with excellent high-speed response can be provided. Further, the semiconductor device of the present embodiment has a configuration in which a conductive portion that supplies power to each substrate is formed through each substrate and the conductive portions of adjacent substrates are electrically connected. Thereby, it becomes possible to supply electric power through the conductive portion without using an optical signal with low energy. Therefore, sufficient power can be supplied to all the substrates.
[0050]
[Electronics]
Next, an example of an electronic device including the above-described semiconductor device will be described with reference to FIGS. FIG. 6 is a perspective view of the mobile phone. The above-described semiconductor device is arranged inside the housing of the mobile phone 3000. The semiconductor device described above can supply power to each substrate and can accurately transmit signals between the substrates, so that a highly reliable mobile phone 3000 can be provided.
[0051]
Note that the semiconductor device described above can be applied to various electronic devices other than cellular phones. For example, LCD projectors, multimedia-compatible personal computers (PCs) and engineering workstations (EWS), pagers, word processors, TVs, viewfinder type or monitor direct view type video tape recorders, electronic notebooks, electronic desk calculators, car navigation systems The semiconductor device of this embodiment can be applied to electronic devices such as a device, a POS terminal, and a device including a touch panel.
[0052]
It should be noted that the technical scope of the present invention is not limited to the above-described embodiments, and includes those in which various modifications are made to the above-described embodiments without departing from the spirit of the present invention. In other words, the specific materials and layer configurations described in the embodiments are merely examples, and can be changed as appropriate.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a semiconductor device according to an embodiment.
FIG. 2 is a layout view of light emitting elements and light receiving elements on a plurality of substrates.
FIG. 3 is another layout view of a light emitting element and a light receiving element on a plurality of substrates.
FIG. 4 is a first explanatory view of a through electrode manufacturing method.
FIG. 5 is a second explanatory view of the method for manufacturing the through electrode.
FIG. 6 is a perspective view of a mobile phone.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Semiconductor device 100,200,300 board | substrate 101 board | substrate body 105 integrated circuit 122,123 light receiving element 140 1st light shielding film 141,142 opening part 150 2nd light shielding film 160 penetration electrode

Claims (11)

A semiconductor device in which a plurality of substrates including integrated circuits are stacked,
Each substrate includes a substrate body made of a material capable of transmitting an optical signal having at least one wavelength, a light emitting element capable of transmitting an electrical signal by converting the electrical signal, or receiving and converting the optical signal into an electrical signal. At least one of the possible light receiving elements, and a conductive portion that is formed through each of the substrates and supplies power to each of the substrates,
A semiconductor device, wherein the conductive portions of adjacent substrates are electrically connected. The semiconductor device according to claim 1, wherein each of the substrate bodies is made of an electrically insulating material. A first light-shielding film made of a material capable of blocking the optical signal is formed between the pair of the light-emitting element and the light-receiving element that transmit and receive the optical signal,
The semiconductor device according to claim 1, wherein the first light shielding film has an opening on an optical axis connecting the pair of light emitting elements and light receiving elements. 4. The semiconductor device according to claim 1, further comprising a second light-shielding film that prevents light from entering the integrated circuit. 5. 5. The semiconductor device according to claim 3, wherein the first light shielding film and / or the second light shielding film is formed on a surface of an insulating film covering the integrated circuit. 6. The semiconductor device according to claim 3, wherein the first light shielding film and / or the second light shielding film functions as an electrical wiring. 7. The semiconductor device according to claim 3, wherein the first light shielding film and / or the second light shielding film has a function of radiating heat generated from the integrated circuit. The one light emitting element or the one light receiving element can transmit and receive the optical signal to / from the plurality of light receiving elements or the plurality of light emitting elements. The semiconductor device according to any one of the above. A method of using the semiconductor device according to claim 8,
Among the plurality of light receiving elements or the plurality of light emitting elements that are capable of transmitting / receiving the optical signal to / from one light emitting element or the one light receiving element, the light receiving element to transmit / receive the optical signal or A method of using a semiconductor device, wherein a light emitting element is driven in synchronization with the one light emitting element or the one light receiving element. A method for manufacturing a semiconductor device according to claim 1, wherein:
Forming a non-through hole for the substrate from the surface on one side of the substrate;
Filling the non-through hole with a conductive material by a droplet discharge means to form the conductive portion;
Polishing the surface of the other side of the substrate to expose the conductive portion;
A method for manufacturing a semiconductor device, comprising: An electronic apparatus comprising the semiconductor device according to claim 1.

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