KR100657040B1 - Pattern forming method and pattern forming apparatus - Google Patents

Abstract

In the prior art, a large cost and time were required to form a photomask. An object of the present invention is to provide a pattern forming method that can be obtained in a short time at a desired pattern inexpensively.

The problem is a method of forming a desired latent image pattern by irradiating light focused on a resist film formed on a substrate, wherein the intensity of the focused light or the size on the resist film is adjusted and irradiated according to the position of the pattern. It is solved by a pattern forming method having a.

Description

Pattern Forming Method and Pattern Forming Apparatus {PATTERN FORMING METHOD AND PATTERN FORMING APPARATUS}

1 is a schematic diagram showing an outline of a configuration of an apparatus for realizing a first embodiment of a pattern forming method of the present invention;

FIG. 2 is a longitudinal sectional view showing an example of a pattern formed by the first embodiment shown in FIG. 1; FIG.

3 is a schematic diagram showing an outline of a configuration of an apparatus for realizing a second embodiment of a pattern forming method of the present invention;

It is a longitudinal cross-sectional view which shows the example of the pattern formed by the 1st Embodiment shown in FIG.

※ Explanation of symbols for main parts of drawing

100, 300: stage

101, 201, 202, 301, 401: resist film

102, 203, 302, 403: substrate 103, 303: ultraviolet light source

104, 304: focused light 105, 305: light intensity modulator

106, 306: First lens 107, 307: Second lens

108: variable throttle 109, 310: optical control system

110, 311: control computer 111, 312: control, monitor signal

200, 400: Euro pattern 308: first variable throttle

309: second variable throttle 402: resist

The present invention relates to a method and apparatus for forming a pattern in a resist film formed on a substrate such as a semiconductor wafer. The present invention relates to a pattern forming method and a pattern forming apparatus for forming a pattern latent image by irradiating light to a resist film on the substrate. .

In the step for forming a semiconductor element from a substrate such as a semiconductor wafer, a pattern is formed on the substrate using a mask such as a resist film. In forming such a pattern, for example, in producing a pattern such as a micro flow path device, a photomask including a desired pattern having a width of several micrometers to several hundred micrometers needs to be produced in advance. Usually, these photomasks are manufactured through an electron beam direct drawing lithography process and the etching process of a chromium film. Next, the photomask is kept in close or close contact with the resist film applied and formed on the substrate using a contact exposure apparatus or a mask aligner, and ultraviolet light is irradiated to the resist film through the photomask. Form the desired latent image pattern. Subsequently, after the predetermined heat treatment (baking step) is performed on the resist film, the development process is performed to convert the latent image pattern into a resist pattern. In the case of using a positive resist, the latent image pattern formed by ultraviolet irradiation is removed to be dissolved by developing. In contrast, in the case of using a negative resist, only the latent image pattern region remains after development, thereby forming a resist shape.

In the research and development stage of the micro flow path device and the like, optimization by trial and error of not only the pattern configuration but also the fine adjustment of the dimension and the arrangement is essential according to each application, and the device pattern is frequently modified. These patterns need to be traced back to photomask remanufacturing, and they must rely on photomask manufacturing companies that own expensive electron beam direct lithography, so that the speed of R & D speeds up the acquisition period of the photomask. There is a problem that the cost of the photomask is limited, and is increased.

In a normal photomask, a latent image pattern is formed on the resist film with or without a light shielding material (chromium film) pattern. As a result, the resist pattern shape obtained after the development treatment, in particular, the profile in the resist film thickness direction is basically a sharp shape based on binary information with or without light irradiation. On the other hand, in the field of micro flow path devices and the like, in order to prevent the occurrence of turbulence in the fluid, a flow path pattern shape having a smooth profile including the change in the resist film thickness direction is desired. As a method of forming a resist pattern having such a profile, there is an exposure method using a grayscale mask in which the transmittance is gradually changed for each region by gradually changing the density of the dot pattern, but it is cumbersome to design and manufacture a grayscale mask. Since the cost and time required for the production of photomasks is greatly increased, it is not practical to apply them to research or start-up stages such as micro euro devices that require trial and error.

An object of the present invention is to provide a pattern forming method and a pattern forming apparatus which can obtain a desired pattern at low cost in a short time.

Another object of the present invention is to provide a pattern forming method and a pattern forming apparatus in which a desired pattern can be obtained easily and with high accuracy.

Another object of the present invention is to provide a pattern forming method and a pattern forming apparatus which can easily realize a target pattern correction in a short time.

The object is a method and apparatus for irradiating light focused on a resist film formed on a substrate to form a desired latent image pattern, wherein the intensity of the focused light or the size on the resist film are adjusted according to the position of the pattern. A pattern forming method and a pattern forming apparatus are provided.

Moreover, it is achieved by providing the process of changing the diameter of the said focused light on the said resist film in the range of 5 micrometers-500 micrometers. In addition, it is achieved by adjusting the diameter of the focused light by adjusting the throttle provided in the light transmission means including a lens and a throttle provided between the light source of the focused light and the resist film.

Moreover, it is achieved by adjusting the energy irradiation amount per unit area in the said resist film, adjusting the diameter of the said focused light. The amount of energy irradiation per unit area in the resist film is achieved by controlling the transmittance to the focused light using a light intensity modulator provided in the light transmission means provided between the light source of the focused light and the resist film. Furthermore, it is achieved by controlling the relative moving speed of the focused light on the resist surface and adjusting the amount of energy irradiation per unit area in the resist film.

In addition, the above object is a method and apparatus for forming a desired latent image pattern by irradiating light focused on a resist film formed on a substrate, wherein the irradiation direction of the focused light or the position of the substrate is variably adjusted according to the position of the pattern It is achieved by a pattern forming method and a pattern forming apparatus having a step of irradiating the focused light.

It is also achieved by providing a step of adjusting the sharpness of the focused light according to the pattern. It is also achieved by adjusting the numerical aperture (NA) of the objective lens by adjusting the numerical aperture (NA) of the objective lens to adjust the sharpness or depth of focus of the focused light by using the throttle of the optical transmission means having a lens and a throttle provided between the light source of the focused light and the resist film. Moreover, it is achieved by using the semiconductor light emitting element which has the emission light intensity distribution which mainly uses the wavelength of 365 nm vicinity as said light source of focused light.

EMBODIMENT OF THE INVENTION Embodiment of this invention is described in detail using drawing below.

1 shows a first embodiment of a pattern forming apparatus for realizing the pattern forming method of the present invention. FIG. 1: is a schematic diagram which shows the outline of the structure of the apparatus which concerns on this embodiment. FIG. 2 is a longitudinal cross-sectional view showing an example of a pattern formed using the embodiment shown in FIG. 1. FIG.

In the embodiment shown in FIG. 1, the substrate 102 on which the resist film 101 is applied and formed on the stage 10 is mounted, and the position thereof is fixed. Next, the focused light 104 from the ultraviolet light source 103 having a peak in intensity at wavelengths around 365 nm is directly exposed to the resist film 101 to form a latent image of a desired pattern on the substrate 102. The focused light 104 passes through the optical control system 109, which is an optical transmission means including at least a light intensity modulation element 105, a first lens 106, a second lens 107 and a variable throttle 108. The film 101 is irradiated.

On the basis of the control between the control computer 110 and the ultraviolet light source 103 and the communication of the monitor signal 111, it is possible to operate the ultraviolet light source 103 and the optical control system 109 from the control computer 110. The command signal is transmitted, and the intensity of the light of the focused light 104 in the resist film 101 and the size of the spot diameter of the light at the irradiated portion are precisely controlled and controlled.

In addition, in this embodiment, the control computer 110 controls the position and the moving speed of the stage 10, and the latent image of the flow path pattern 200 in the micro flow path device as shown in the example of FIG. The focused light 104 is irradiated while adjusting the light intensity or spot diameter according to the portion of the pattern on the substrate surface to which the focused light 104 is irradiated. The latent image is formed by the vector method of changing the direction, position, and intensity of the focused light irradiated in this way.

In the portions having different widths of the flow path pattern 200 in FIG. 2 (a), the variable throttle 108 or the like is controlled to control the spot diameter of the focused light 104 in a range of typically 5 µm to 500 µm. The desired latent image pattern is formed. In addition, the optical energy density on the resist surface can be controlled by controlling the moving speed of the stage 10 in consideration of the diameter of the focused light 104.

After the latent image is formed in this manner, a predetermined PEB (Post Exposure Bake) baking process and a developing process are performed on the resist film 101 to form a desired resist film pattern. In this embodiment, the case where the positive resist film 201 is used is described, and the latent image portion formed by the irradiation of the focused light 104 is dissolved and removed by the development treatment.

In the above embodiment, as a method of forming a desired latent image pattern such as a microchannel device in a resist film formed on a substrate, a desired pattern is directly exposed to the resist film by using focused light in an ultraviolet region. By setting it as such a structure, the photomask in the said prior art is unnecessary. According to this embodiment, the flow path pattern 200 shown in FIG. 2 can be formed without using a photomask.

In addition, as in the flow path pattern 200 between A and B in FIG. 2A, the pattern width can be changed more smoothly than before. That is, by controlling the diameter of the focused light according to the flow path width of the main straight or curved pattern in the micro flow path device or the like, it is possible to easily use a vector method similar to the writing without multi-scanning the linear or curved pattern. It is also possible to form a latent image of a desired pattern.

In addition, when exposing a straight or curved pattern on the resist film in a manner similar to writing, by gradually changing the diameter of the focused light on the resist surface, a smoothly varying channel width can be easily formed. That is, by gradually changing the light irradiation amount per unit area in the resist film along a straight line or a curve, a pattern having a smooth profile (change in euro depth) in the thickness direction of the resist film can be formed. For example, by gradually changing the numerical aperture NA of the objective lens in the optical system of the focused light along a straight line or curve, the profile (sidewall shape of the flow path) of the resist film cross section in the straight line or curved pattern is smoothed. It is also possible to form the changed pattern.

In addition, it is possible to gradually change the optical energy density per unit area irradiated to the resist surface between the ABs, and as shown in Figs. Similarly, the resist film 202 is completely dissolved to leave the resist film 202 on the substrate 203 from the state where the surface of the substrate 203 is exposed (Fig. 2 (b)) (Fig. 2 (c)). ], It is possible to change the depth of the flow path. In the present embodiment, the flow path is deep in the cross section A and shallow in the cross section B. On the contrary, the depth can be controlled independently of the flow path width such as deepening the side of the flow path of the cross section B.

In the present embodiment, a light emitting device LED (Light Emitting Diode) of a compound semiconductor (GaN-based) having a peak wavelength around 365 nm is used as the ultraviolet light source, and is cheaper than a light source such as an ultraviolet lamp or a gas laser. In addition, maintenance is also easy. Instead of the LED, it is possible to apply a GaN semiconductor laser having a peak wavelength around 365 nm, but at present it is difficult to obtain a laser having a long life.

In this embodiment, only the light intensity modulation device 105, the first lens 106, the second lens 107, and the variable throttle 108 are representatively illustrated as the optical control system 109. The relationship is not limited to these, and in order to monitor and control the focus state or relative distance to the resist film 101 or the substrate 102 of the second lens 107 as the objective lens, the resist film 101 is exposed to light. It goes without saying that the optical system for injecting a laser light having a wavelength not to be incident on the resist film 101 or the substrate 102 via at least a part of the optical control system 109 is effective for forming a stable latent image.

In the present embodiment, the flow path pattern 200 by the positive resist film 201 has been described. However, there are variations in the manufacturing process of the micro flow path device, and the method of transferring the flow path pattern to the base substrate using the resist film pattern as a mask. For example, there is a method in which a resist film pattern is used as a template to perform replication, and accordingly, resist and positive type are used separately.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. It is a schematic diagram which shows the outline of the structure of the apparatus which implements the pattern formation method of 2nd Embodiment of this invention. 4 is a longitudinal cross-sectional view showing an example of a pattern formed by using the pattern forming apparatus shown in FIG. 3.

In this FIG. 3, the board | substrate 302 by which the resist film 301 was apply | coated and formed into a film was mounted on the stage 300, and the position is fixed. Next, the focused light 304 from the ultraviolet light source 303 having a peak at a wavelength around 365 nm is irradiated onto the resist film 301, so that the surface of the substrate 302 is directly exposed to form a latent image of a desired pattern. . The focused light 304 includes at least a light intensity modulator 305, a first lens 306, a second lens 307, a first variable throttle 308, and a second variable throttle 309. The resist film 301 is irradiated through the optical control system 310.

Commands for operating the ultraviolet light source 303 and the optical control system 310 from the control computer 311 based on the control between the control computer 311 and the ultraviolet light source 303 and the communication of the monitor signal 312. The signal is transmitted, and the intensity of the light and the size of the spot diameter of the focused light 304 in the resist film 301 are precisely adjusted and controlled.

In the present embodiment, the control computer 311 controls the position and the moving speed of the stage 300 so that the latent image pattern of the microchannel device as shown in the example of FIG. Forming. At portions where the pattern width in Fig. 4A differs, the first variable throttle 308 or the like is controlled to control the spot diameter of the focused light 304 in a range of 5 m to 500 m typically, thereby providing a desired latent image. The pattern is formed.

In addition, the optical energy density on the resist surface is controlled by controlling the moving speed of the stage 300 in consideration of the diameter of the focused light 304. In addition, by controlling the second variable throttle 309 independently of this, the light intensity profile and the sharpness of the focused light 304 can be controlled by controlling the numerical aperture NA of the second lens 307 serving as the objective lens. have. After forming the latent image in this manner, a desired PEB (Post Exposure Bake) baking process and developing process are performed on the resist film 301 to form a desired resist film pattern.

According to the present embodiment described above, the flow path pattern shown in FIG. 4 can be formed without using a photomask. In addition, the pattern width can be smoothly changed like the flow path pattern between A-B in Fig. 4A. Further, the optical energy density per unit area irradiated to the resist surface can also be gradually changed between ABs, and as shown in Fig. 4 (b) and 4 (c), as shown in the cross section A of the flow path pattern 400 portion. Between the state where the resist film 402 is completely dissolved and the surface of the substrate 403 is exposed (FIG. 4B), leaving the resist film 402 on the substrate 403 (FIG. 4C). It is possible to change the depth of the flow path at. In the present embodiment, as described above, the second variable throttle 309 is controlled to make the numerical aperture NA of the second lens 307, which is the objective lens, larger in cross section A and smaller in cross section B. As shown in Fig. 4 (c), the resist side wall shape perpendicular to the A cross section and the tapered side wall cross section can be formed from the B cross section. Here, between A-B, the sidewall shape can be gradually changed by gradually changing the numerical aperture NA of the second lens 307.

As described above, according to the above embodiment, a method of forming a desired latent image pattern such as a micro euro device in a resist film formed on a substrate is carried out by directly exposing a desired pattern to the resist film using focused light in an ultraviolet region. The photomask as described in the technique becomes unnecessary. Further, by controlling the diameter of the focused light according to the flow path width of the main straight or curved pattern of the micro-channel device, it is possible to easily form the latent image of the desired pattern by using a vector method similar to writing.

In addition, when exposing the straight or curved pattern in a manner similar to writing, the pattern with smooth fluctuations in the channel width can be easily formed by gradually changing the diameter of the focused light on the resist surface. Further, by gradually changing the light irradiation amount per unit area in the resist film along a straight line or a curve, a pattern with a smooth profile (change in euro depth) in the thickness direction of the resist film can be formed. In addition, the numerical aperture NA of the objective lens in the optical system of the focused light is gradually changed in accordance with a straight line or a curve to smoothly change the profile (sidewall shape of the flow path) of the resist film cross section in the straight or curved pattern. It is also possible to form a pattern.

By using the pattern formation method disclosed in the above-described embodiment of the present invention, the flow path pattern of the micro flow path device can be produced in a short time without using a photomask that requires a large amount of money and a time required for acquisition, so that the desired flow path pattern can be formed. By simply editing the relevant data and the control data on a computer, it becomes possible to correct and improve the flow path pattern in a short time. In addition, it is possible to form a resist film pattern in which the depth of the flow path and the side wall shape of the flow path are smoothly controlled in the exposure method using a normal photomask.

As a result, the research and development and start-up period of the micro-channel device can be greatly shortened, and it is possible to manufacture a high-performance, high-quality micro-channel device having a three-dimensional design parameter.

Claims (13)

In a method of forming a desired latent image pattern by irradiating light focused on a resist film formed on a substrate, The intensity of the focused light or the size on the resist film is controlled by the position control of the stage on which the substrate is mounted by using a throttle provided in an optical transmission means including a lens and a throttle provided between the light source of the focused light and the resist film. And adjusting and irradiating according to the position of the resist film on the substrate to be controlled. The method of claim 1, And controlling the amount of energy irradiation per unit area in the resist film while adjusting the diameter of the focused light. The method of claim 2, A relative speed of movement of the focused light on the surface of the resist is controlled, and an amount of energy irradiation per unit area in the resist film is adjusted. The method according to any one of claims 1 to 3, And irradiating the focused light while adjusting the irradiation direction of the focused light or the position of the substrate in accordance with the position of the pattern. An apparatus for forming a desired latent image pattern by irradiating light focused on a resist film formed on a substrate, Position control means for controlling the position of the stage on which the substrate is mounted; And And a light transmitting means including a lens and a throttle provided between the light source of the focused light and the light source of the focused light and the resist film, Pattern formation, characterized in that the irradiation is performed by adjusting the intensity of the focused light or the size on the resist film according to the position of the resist film on the substrate mounted on the stage controlled by the position control means by using the throttle of the light transmitting means. Device. The method of claim 5, A pattern forming apparatus, characterized in that the diameter of the focused light on the resist film is changed within a range of 5 µm to 500 µm. The method of claim 5, And means for adjusting an amount of energy irradiation per unit area in the resist film while adjusting the diameter of the focused light on the resist film. The method of claim 7, wherein Means for controlling the amount of energy applied per unit area in the resist film, wherein the transmittance to the focused light is controlled by using a light intensity modulator provided in the light transmission means provided between the light source of the focused light and the resist film; Pattern forming apparatus characterized in that. The method of claim 7, wherein And means for controlling the relative moving speed of the focused light on the resist surface to adjust the amount of energy irradiation per unit area in the resist film. The method of claim 5, And means for irradiating the focused light while adjusting the irradiation direction of the focused light or the position of the substrate in accordance with the position of the latent image pattern. The method of claim 10, And means for adjusting the sharpness of the focused light according to the pattern. The method of claim 10, And means for adjusting the sharpness or the depth of focus by adjusting the numerical aperture (NA) of the objective lens by using the throttle of the optical transmission means having a lens and a throttle provided between the light source of the focused light and the resist film. Pattern forming apparatus. The method according to any one of claims 5 to 7, and 9 to 12, And a semiconductor light emitting element having an emission light intensity distribution mainly having a wavelength in the vicinity of 365 nm as the light source of the focused light.

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