KR101105670B1 - Heterodyne interference lithography apparatus and micropattern forming method using the apparatus - Google Patents

Abstract

The present invention relates to a heterodyne interference lithography apparatus and a method for forming a micropattern using the apparatus. More particularly, an interference lithography apparatus comprising: a multi-laser light source unit for simultaneously oscillating a laser having two or more different wavelengths; A mirror for reflecting the direction of the laser oscillated by the light source unit in a predetermined direction; A beam expander for expanding the irradiation area of the laser reflected by the mirror; And a rotating stage including a base unit on which the specimen to be exposed by the laser expanded by the beam expander is installed, a reflector for injecting the extended laser into the base unit, and a rotating unit for rotating the base unit and the reflector in a predetermined direction. And a plurality of first order interference patterns generated by wavelengths incident in different directions to the test specimen and second order interference patterns generated when the plurality of first order interference patterns interfere with each other. A heterodyne interference lithographic apparatus, wherein a fine pattern is formed.

Description

Heterodyne Interference Lithography Apparatus and Method for drawing Fine Pattern using the Device

The present invention relates to a heterodyne interference lithography apparatus and a method for forming a micropattern using the apparatus. More specifically, lasers capable of oscillating two or more different wavelengths may cause indirect phenomena to periodically generate nanopatterns or to simultaneously form nanopatterns and micropatterns to form various patterns. Interference lithographic apparatus and pattern forming method.

Recently, there is an increasing demand for miniaturization and high performance of products in the mining, display, semiconductor and bio industries. In order to meet such demands, it is necessary to manufacture micropatterns (nanoscale or microstain pattern shapes) economically and easily.

Conventionally, a method of forming a fine pattern is E-beam lithography (E-beam lithogrephy). This method focuses the electron beam to form nanometer-level patterns. Such a method can produce a variety of fine patterns, but there is a problem in that the manufacturing of a large area is limited because it takes a lot of time.

In addition, in order to solve these problems, a single stamp is made through a photo process using the principle of laser interference lithography, and photolithography is replaced with nanoimprint lithography to mass produce micropatterns having a nanometer line width through an etching process. have.

Laser interference lithography is also called holographic lithography. Unlike photolithography, holographic lithography has continued to expand its field of application because of the advantage of being able to fabricate large structures of uniform shape without the use of photo masks. . The shape of the nanostructures fabricated on the photoresist using holographic lithography is influenced by the light intensity or exposure energy and development time to expose the photoresist. Macroscopic modeling techniques have been studied by FH Dill in 1975. have.

Holographic lithography is a technique for fabricating nanostructures on photoresist by using interference of two light incident on the photoresist in different directions. In this case, the intensity of light at an arbitrary point on the photoresist film is expressed by Equation 1 below.

Where I ₁ and I ₂ represent the intensity of light incident from each direction, k ₀ represents the propagation constant, θ represents the angle of incidence, and Φ ₁ and Φ ₂ represent the angle of light incident from each direction. As can be seen from the above equation, when the light intensity is the same (I ₁ = I ₂ = I ₀ ), the intensity of the interference on the plane is theoretically determined by the cosine term from the minimum I _min = 0 to the maximum I _max = 4I ₀ . Has In addition, the period P of light intensity due to interference of two lights is arranged as follows.

Where λ represents the wavelength of light used. Such an interference lithography method has an advantage in that a fine pattern can be quickly formed by exposure of several to several tens of seconds, but the same basic nano pattern, such as a line or a dot, is generated uniformly across the entire surface. There is. In addition, there is a disadvantage that the size and spacing of the pattern that can be realized by the incident angle and wavelength is determined.

Accordingly, the present invention has been made to solve the above problems, by generating two or more wavelengths at the same time by using a multi-argon ion laser scanning device is a secondary between the interference according to each wavelength and a plurality of generated interference Interference is formed to form nanopatterns periodically on specimens with spatial bit phenomena, or nanopatterns and micropatterns are manufactured simultaneously to form various micropatterns than those using conventional interference lithography.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION An object of the present invention is an interference lithography apparatus comprising: a multi-laser light source unit for simultaneously oscillating a laser having two or more different wavelengths; A mirror for reflecting the direction of the laser oscillated by the light source unit in a predetermined direction; A beam expander for expanding an irradiation area of the laser reflected by the mirror; And a base part on which a specimen to be exposed by the laser extended by the beam expander is installed, a reflecting part on which the extended laser is incident and reflected to the base part, and a rotating part rotating the base part and the reflecting part in a predetermined direction. And a rotation stage which includes a plurality of first order interference patterns and a plurality of first order interference patterns generated by wavelengths incident in different directions. It can be achieved as a heterodyne interference lithographic apparatus, characterized in that a fine pattern is formed in.

The micropattern may be characterized in that the nanoscale pattern and the microscale pattern are formed at the same time.

The shape of the fine pattern may be determined by the length of the wavelength, the difference between each of the different wavelengths, the number of overlapping wavelengths, the difference in the intensity of each wavelength, and the degree of rotation of the specimen by the rotating part.

The multi-laser light source unit may be a multi-argon ion laser scanning device.

The multi-argon ion laser scanning device may be characterized in that the laser having a plurality of wavelengths are respectively oscillated between 300 ~ 500nm.

It may be characterized in that it further comprises a path separating means installed between the mirror and the beam expander to separate the path of each of the different wavelengths and the intensity control unit for adjusting the intensity of each wavelength separated by the path separating means. Such path separation means may use a dichroic mirror, a prism, and the like, and the specific construction name does not affect the scope of the present invention as long as it can separate light.

It may be characterized in that it is provided between the beam expander and the rotating stage further comprises a light amount adjuster for adjusting the light amount of the laser.

It may be characterized in that it further comprises an alignment lens installed between the light adjuster and the rotating stage.

It may be characterized in that it further comprises an electric shutter for adjusting the exposure time of the laser oscillated from the multi-laser light source.

In another category, an object of the present invention is to provide a micropattern forming method using a heterodyne interference lithography apparatus, comprising: oscillating a laser having different wavelengths in a multi-laser light source unit; Reflecting the laser reflected by the mirror in a predetermined direction; Expanding the irradiation area of the laser by a beam expander; And forming a fine pattern on a specimen installed on the rotating stage by interference by the extended laser beam being irradiated to the rotating stage. The method may be achieved by forming a fine pattern using a heterodyne interference lithography apparatus.

In the fine pattern shape step, a fine pattern is formed on the specimen according to the interference fringe generated between the laser directly irradiated onto the specimen and the laser reflected from the reflecting portion of the rotating stage and irradiated onto the specimen, and the interference fringe is formed by each wavelength. The first and second interference fringes may be generated by interfering with each other.

In the micropattern forming step, the micropattern may be characterized in that the nanoscale pattern and the micrometer size pattern are simultaneously formed.

The micropattern forming step may further include varying angles of the base portion and the reflecting portion on which the specimen is mounted by the rotating portion of the rotating stage, wherein the shape of the micropattern has a length of wavelength, a difference in length of different wavelengths, and overlapping of wavelengths. The strength difference between the number and the wavelength may be determined by the degree of rotation of the specimen by the rotating part.

After the oscillation step, it may be characterized in that it further comprises the step of separating the path of the laser for each wavelength by the dichroic mirror and adjusting the intensity of each of the separated wavelength by the intensity control unit.

After the step of expanding, the method of forming a fine pattern using a heterodyne interference lithography apparatus, characterized in that further comprising the step of adjusting the light amount of the laser by the light amount controller.

Therefore, as described above, according to an embodiment of the present invention, by generating two or more wavelengths simultaneously using a multi-argon ion laser scanning device, secondary interference between the interference according to each wavelength and the generated plurality of interferences is generated. By forming the nano-pattern on the specimen periodically by the spatial bit phenomenon, or nano-pattern and micro-pattern are produced at the same time, there is an effect that can form a variety of fine patterns than using the conventional interference lithography method.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it will be readily apparent to those skilled in the art that various other modifications and variations are possible without departing from the spirit and scope of the present invention. Are all within the scope of the appended claims.

1 is a block diagram of a heterodyne interference lithography apparatus according to a first embodiment of the present invention;
2 is a flowchart of a method for forming a micropattern using a heterodyne interference lithography apparatus according to a first embodiment of the present invention;
3A is a graph of simulation results of interference intensity caused by one-time exposure according to the first embodiment of the present invention;
3B is a graph of a result of simulating interference intensity when the specimen is rotated 90 ° by the rotating unit after one exposure according to FIG. 3A;
Figure 4a is a fine pattern formed on the specimen in accordance with the grating pattern of Figure 3a,
Figure 4b is a fine pattern formed on the specimen in accordance with the grating pattern of Figure 3b,
5 is a block diagram of a heterodyne interference lithographic apparatus according to a second embodiment of the present invention;
6 shows a flowchart of a method for forming a micropattern using a heterodyne interference lithography apparatus according to a second embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing in detail the operating principle of the preferred embodiment of the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, the same reference numerals are used for parts having similar functions and functions throughout the drawings. Throughout the specification, when a part is 'connected' to another part, this includes not only 'directly connected' but also 'indirectly connected' with another element in between. do. In addition, "including" a certain component does not exclude other components unless specifically stated otherwise, it means that may further include other components.

<First Example >

Hereinafter, a method of forming a micropattern using the heterodyne interference lithography apparatus 1 according to the first embodiment of the present invention will be described. First, FIG. 1 shows a schematic diagram of a heterodyne interference lithographic apparatus 1 according to a first embodiment of the present invention. 2 shows a flowchart of a method for forming a micropattern using the heterodyne interference lithography apparatus 1 according to the first embodiment of the present invention. As shown in FIG. 1, the heterodyne interference lithography apparatus 1 according to an exemplary embodiment of the present invention includes a multi-laser light source unit 10, a mirror 20, a beam expander 50, and a light amount controller 60. ), A collimination lens 70, a rotation stage 100.

The heterodyne interference lithographic apparatus 1 according to the first embodiment of the present invention includes a multi laser light source unit 10. The multi-laser light source unit 10 simultaneously oscillates the laser 2 having two or more different wavelengths (S10). The multi-laser light source unit 10 preferably uses a multi-argon ion laser scanning device. The laser 2 oscillated in the multi-argon ion laser scanning device has various wavelength bands. In general, it has several to several dozen oscillating wavelength band between 300-500nm. In a specific embodiment, the oscillating laser 2 includes a first wavelength λ1 and a second wavelength λ2 having different wavelengths, the first wavelength λ1 is 351.1 nm, and the second wavelength λ2 is 363.8. nm was used. In addition, the heterodyne interference lithographic apparatus 1 according to the embodiment of the present invention may further include an electric shutter (not shown) for adjusting the exposure time of the laser 2 oscillated by the multi-laser light source unit 10. .

Generally, the laser oscillates at a single wavelength, but the multi-laser light source unit 10 according to an embodiment of the present invention is characterized by using a laser 2 having two or more different wavelengths. Therefore, as will be described later, the laser 2 generates interference between different wavelengths as well as the interference between different wavelengths, and by generating such various interference fringes, a fine pattern is applied to the specimen 3. It is formed.

As shown in FIG. 1, the multi-laser light source unit 10 according to an exemplary embodiment of the present invention has a laser 2 having two different wavelengths (a first wavelength λ ₁ and a second wavelength λ ₂ ). The heterodyne interference lithographic apparatus 1 according to an embodiment of the present invention may further include one or more mirrors 20 in the oscillation path of the laser 2. The mirrors 20 may include lasers 2. ) Is changed in a predetermined direction to change the moving direction (S20) In one embodiment of the present invention, two mirrors 20 are used, as shown in Fig. 1. Position and angle of the mirror 20 The number is determined by the number and position of the components included in the heterodyne interference lithographic apparatus 1, and these are all within the scope of the present invention as long as those skilled in the art can clearly design and change them.

Then, the laser 2 whose direction is changed by the mirror 20 is incident on the beam expander 50, as shown in FIG. In a specific embodiment, the beam expander 50 is composed of a focusing lens 51 and a pinhole 52. The laser 2 incident on the beam expander 50 is extended and emitted in order to generate a grating pattern on the specimen 3 (S30). And, in one embodiment of the present invention, as shown in Figure 1, it may further include a light amount controller 60 to adjust the amount of light of the laser (2) is extended by the beam expander (50). Light amount controller 60 is preferably composed of an iris (iris), an optical aperture, and the like. The amount of light of the laser 2 incident on the rotating stage 100 is adjusted to the light amount controller 60 (S40).

In addition, an alignment lens 70 may be further included between the rotation stage 100 and the beam expander 50 to allow the laser 2 to enter the rotation stage 100 in parallel. The alignment lens 70 is composed of a collimation lens or the like. When the laser 2 is incident on the alignment lens 70, the laser 2 is emitted by the parallel laser 2 (S50).

Then, the laser 2 incident on the alignment lens 70 and exiting in parallel is incident on the rotation stage 100 (S60) to form a grating pattern (S70) to thereby fine the specimen 3 by the interference lithography phenomenon. A pattern is formed (S80). As shown in FIG. 1, the rotation stage 100 includes a base 110, a reflector 120, and a rotor 130. A part of the laser 2 incident to the rotating stage 100 is incident to the base part on which the specimen 3 is installed, and the other part is incident to the reflector 120. Thus, the laser 2 incident on the reflector 120 is reflected back to the base portion. As the lasers 2 in two directions interfere with each other, a first order interference pattern is generated.

In addition, one embodiment of the present invention uses the laser (2) having two or more different wavelengths, as well as the interference to each wavelength itself, as well as the first interference caused by each wavelength itself is interfered with each other Secondary secondary interference patterns are generated to form a grating pattern. Accordingly, various grating patterns are formed than interference lithography using the single wavelength laser 2, thereby forming various fine patterns on the specimen 3.

FIG. 3A illustrates a graph of simulation results of interference intensity caused by a single exposure according to the first embodiment of the present invention. As shown in FIG. 3A, the interference intensity appears in the form of a line. 3B shows a graph of simulation results of the interference intensity when the rotating stage is rotated 90 degrees after one exposure according to FIG. 3A. A grating pattern is formed by the intensity distribution, and the photolast PR of the specimen 3 is selectively developed by the grating pattern to form a fine pattern. FIG. 4A illustrates the micropattern formed on the specimen 3 according to the grating pattern of FIG. 3A, and FIG. 4B illustrates the micropattern formed on the specimen 3 according to the grating pattern of FIG. 3B. As expected, it can be seen that the shape of the micropattern formed on the specimen 3 is formed in the same pattern as the grating pattern, which is the interference intensity distribution. In addition, as shown in Figures 4a and 4b, it can be seen that the micro-pattern formed on the specimen (3) is formed at the same time nano-size and micro-size.

Therefore, the shape of such a fine pattern is determined according to the shape of the grating pattern which is the interference intensity distribution. If more wavelengths overlap (using the multi-laser light source unit 10 for oscillating more wavelengths), more complicated shapes and more various shapes can be obtained. In addition, the shape of the micropattern includes the length of each wavelength, the length difference of each wavelength, the number of overlapping wavelengths, the difference in relative intensity of each wavelength, the degree of rotation (number of times, angle) of the specimen 3, and the photo of the specimen 3. Depending on the sensitivity of the resist (PR) for each wavelength, it is possible to form a variety of fine patterns according to the change of these parameters.

In addition, the influence of the fine pattern shape according to each variable is as follows. The length of each wavelength affects the size of the nanopattern, and the difference in length of each wavelength affects the size of the micropattern. In addition, the number of overlapping wavelengths affects the density, size, and shape of the micropattern, and the relative intensity difference of each wavelength affects the size of the micropattern and the size of the nanopattern. In addition, the degree of rotation (number, degree) of the specimen 3 affects the shape of the micropattern, and the sensitivity of each photoresist to the wavelength affects the size of the micropattern.

<Second Example >

Hereinafter, a method of forming a micropattern using the heterodyne interference lithography apparatus 1 according to the second embodiment of the present invention will be described. 5 shows a schematic diagram of a heterodyne interference lithographic apparatus 1 according to a second embodiment of the present invention. 6 shows a flowchart of a method for forming a micropattern using the heterodyne interference lithography apparatus 1 according to the second embodiment of the present invention.

The second embodiment is the same as the first embodiment except for the configuration and method described below. Accordingly, the laser 2 having two or more different wavelengths is oscillated by the multi-laser light source unit 10 (S100), and the laser 2 is reflected by the mirror 20 in a predetermined direction (S200). As shown in FIG. 5, the second embodiment, unlike the first embodiment, further includes a path separating means 30 and an intensity adjusting part 40. The path separating means 30 includes all components capable of separating paths of light such as dichroic mirrors and prisms. As shown in FIG. 2, in one embodiment of the present invention, a path separating means used a dichroic mirror. The dichroic mirror is configured to separate paths so that when two or more wavelengths are oscillated in the multi laser light source unit 10, the output can be adjusted according to each wavelength. As shown in FIG. 5, in the second embodiment, two wavelengths are oscillated and incident on a dichroic mirror to separate the paths of the first wavelength λ ₁ and the second wavelength λ ₂ (S300). ). In addition, an intensity control unit 40 is provided in each of the separated first wavelength λ ₁ and second wavelength λ ₂ paths. Therefore, the intensity adjusting unit 40 adjusts the intensity of each of the first wavelength λ ₁ and the second wavelength λ ₂ (S40). The first wavelength λ ₁ and the second wavelength λ ₂ adjusted by the intensity controller 40 are incident on another dichroic mirror again to be incident on the beam expander 50 (S500).

In the second embodiment, as in the first embodiment described above, the irradiation area of the laser 2 is extended by the beam expander 50 (S600), and the light amount is adjusted by the light amount controller 60 (S700). Incidence and exit of the alignment lens 70 (S800), the laser 2 is irradiated to the rotating stage 100 (S900). As in the first embodiment, the grating pattern is formed by forming the first and second interference patterns (S1000), and a fine pattern is formed on the specimen 3 (S1100).

< Variant >

The first and second embodiments mentioned above are merely specific and preferred examples, and the scope of the present invention should not be limited to these embodiments. It is also possible to use lasers 2 having three or more different wavelengths instead of two, and the specific wavelengths and the like can be modified. In addition, the scope of the present invention corresponds to the technical idea itself that by using a laser (2) having two or more wavelengths can form a variety of fine patterns, unlike the prior art according to the change of these various variables. Therefore, the specific wavelength length, the number of mirrors, the number of wavelengths, etc. mentioned in the above specific embodiment do not affect the scope of rights.

1: heterodyne lithography apparatus
2: laser
3: Psalms
10: multi-laser light source
20: mirror
30: path separation means
40: strength adjustment
50: beam expander
51: focusing lens
52: pinhole
60: Light regulator
70: alignment lens
100: rotating stage
110: base part
120: Reflector
130: rotating part
λ ₁ : first wavelength
λ ₂ : second wavelength

Claims (15)

An interference lithographic apparatus,
A multi-laser light source unit for simultaneously oscillating a laser having two or more different wavelengths;
A beam expander for expanding an irradiation area of the oscillated laser; And
A base part on which a specimen to be exposed by the laser extended by the beam expander is installed, a reflecting part to which the extended laser is incident and reflected to the base part, and a rotating part to rotate the base part and the reflecting part in a predetermined direction Including a rotating stage;
A fine pattern is formed on the specimen by a plurality of first order interference patterns generated by wavelengths incident to the specimen in different directions and a second order interference pattern generated by interference of the plurality of first order interference patterns. The micropattern includes nanoscale nanopatterns and microscale micropatterns,
The length of the wavelength determines the size of the nanopattern, the wavelength difference between each of the different wavelengths determines the size of the micropattern, and the number of overlapping wavelengths determines the density and size of the micropattern, The intensity difference between the wavelengths determines the size of the nanopattern and the size of the micropattern, and the degree of rotation of the specimen by the rotating part determines the shape of the micropattern. delete delete The method of claim 1,
And said multi-laser light source portion is a multi-argon ion laser scanning device. The method of claim 4, wherein
The multi-argon ion laser scanning apparatus is a heterodyne interference lithography apparatus, characterized in that each of the laser having a plurality of different wavelengths oscillate between 300 ~ 700nm. The method of claim 1,
And a path adjusting means installed between the multi-laser light source unit and the beam expander to separate paths of different wavelengths, and an intensity control unit controlling the intensity of each of the wavelengths separated by the path separating means. Heterodyne interference lithographic apparatus. The method of claim 1,
And a light amount controller disposed between the beam expander and the rotating stage to adjust the light amount of the laser. The method of claim 7, wherein
And an alignment lens disposed between the light intensity controller and the rotation stage. The method of claim 1,
And an electric shutter for adjusting an exposure time of the laser oscillated by the multi-laser light source unit. In the method of forming a fine pattern using the heterodyne interference lithography apparatus of claim 1,
Oscillating lasers having different wavelengths in the multi-laser light source;
Expanding the irradiation area of the laser by a beam expander; And
Irradiating the expanded laser to the rotating stage to form a fine pattern on a specimen installed in the rotating stage by interference;
In the fine pattern forming step,
A fine pattern is formed on the specimen according to an interference fringe generated between the laser directly irradiated onto the specimen and the laser reflected from the reflecting portion of the rotating stage and irradiated onto the specimen, and the interference fringe is generated by each wavelength. There is a second interference pattern generated when the first interference pattern and the first interference pattern interfere with each other, the fine pattern is a nano-pattern nano-pattern and micrometer-sized micropattern is formed at the same time,
The fine pattern forming step
Changing an angle of the base portion on which the specimen is mounted and the reflecting portion by the rotating portion of the rotating stage;
The length of the wavelength determines the size of the nanopattern, the difference between each of the different wavelengths determines the size of the micropattern, and the number of overlapping wavelengths determines the density and size of the micropattern, The intensity difference of the wavelength determines the size of the nanopattern and the size of the micropattern, and the degree of rotation of the specimen by the rotating part determines the shape of the micropattern. Pattern formation method. delete delete delete The method of claim 10,
After the oscillation step,
Separating the path by wavelength by the path separating means for the fine pattern formed using a heterodyne interference lithography apparatus further comprising the step of adjusting the intensity of each of the separated wavelength by an intensity control unit Way. The method of claim 10,
After the expansion step,
The method of forming a fine pattern using a heterodyne interference lithography apparatus, further comprising the step of adjusting the light quantity of the laser by a light quantity controller.

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