KR102590798B1 - Apparatus for lithography and method using the same - Google Patents

Abstract

The present invention provides a lithographic apparatus. In one embodiment, a lithographic apparatus includes a head positioned on top of a substrate; A lithographic apparatus including a moving means for moving a head, wherein the head includes: a measurement light source that irradiates light onto a substrate; A first beam splitter placed on the optical path of the measurement light source to separate the light emitted from the measurement light source; a second beam splitter that transmits the light transmitted from the first beam splitter to the substrate to form a first optical path; An objective lens placed on the optical path of the second beam splitter and converging light onto the substrate; a mirror that reflects light transmitted from the first beam splitter to form a second optical path; It may include an image collection device that acquires image information of the substrate by collecting interference patterns of light transmitted from the first optical path and light transmitted from the second optical path through an imaging lens.

Description

Lithography apparatus and method {APPARATUS FOR LITHOGRAPHY AND METHOD USING THE SAME}

The present invention relates to a lithography apparatus and a lithography method using the same to form a pattern on a substrate by selectively curing the resist applied on the substrate, and to produce a multi-layer pattern of two or more layers based on the initially formed pattern. It relates to a lithographic apparatus and method for performing positioning to fabricate patterns of different layers.

Generally, in a lithography process, a resist is applied on a substrate, the applied resist is selectively cured, and then developed to form a pattern on the substrate.

Figure 1 shows a general lithography process using a laser. Referring to FIG. 1, the lithographic apparatus includes a resist nozzle (not shown), a light source, a beam splitter, an objective lens, and a camera. A resist nozzle (not shown) applies resist on the substrate. The light source radiates an optical beam to the substrate, and the beam splitter separates the light and delivers it to the objective lens and camera. The objective lens focuses light and allows the resist to be cured at the desired location. The camera acquires an image of the substrate through the image of the substrate transmitted from the objective lens.

The lithographic apparatus 10 first forms a single layer pattern using a focused optical beam. For example, i) a resist nozzle (not shown) applies the resist R on the substrate W, and ii) the resist R is selectively cured using the light source 12. iii) When curing of the resist (R) is completed, iv) the resist (R) is developed to form the first pattern (P1).

After forming a single layer pattern using the method shown in Figure 1, it is possible to produce a three-dimensional pattern by repeating the process for multiple layers.

FIG. 2 shows a lithography process of forming a single layer pattern using FIG. 1 and then forming a second pattern layer on the pattern.

Referring to FIG. 2, i) resist (R) is applied on the substrate (W) to include the initially formed single-layer pattern (P1). ii) Afterwards, the position of the light source 12 is aligned and iii) the position of the light source 12 is moved and the uncured resist (R) is cured on the single-layer pattern (P1) to form a second pattern (P2). do. iv) Once the pattern formation is complete, v) the resist (R) is developed to obtain a three-dimensional pattern (P1+P2).

However, in the process of ii) described above, there is a problem in that it is very difficult to set a reference point for forming the second pattern. Resist R is generally provided as a transparent polymer, making it impossible to determine its shape with the naked eye or optical devices such as a microscope, regardless of whether it is cured or not. This is the same problem as having to determine the position of a transparent glass cup submerged in water.

To solve this problem, before forming a single-layer pattern as shown in FIG. 1, a separate process of forming an alignment key on a bare substrate is performed. Then, when forming the second pattern, the alignment key is recognized by searching for the corresponding alignment key through a camera, and a reference point for forming the second pattern is set.

However, this solution has the problem of increasing process time and cost because it requires a separate process of forming an alignment key on the bare board.

In order to solve the above-mentioned problems, the purpose of the present invention is to provide a lithography apparatus and method that can form a multi-layer pattern without a separate process of forming an alignment key on a bare substrate.

In addition, the present invention aims to smoothly align the process light source by obtaining an image of the difference in refractive index caused by the difference in curing degree of the resist.

The object of the present invention is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

In order to solve the problems described above, the present invention provides a lithography apparatus. In one embodiment, a lithographic apparatus includes a head positioned on top of a substrate; A lithographic apparatus including a moving means for changing the relative positions of a substrate and a head, wherein the head includes: a measurement light source that irradiates light onto a substrate; A first beam splitter placed on the optical path of the measurement light source to separate the light emitted from the measurement light source; a second beam splitter that transmits the light transmitted from the first beam splitter to the substrate to form a first optical path; An objective lens placed on the optical path of the second beam splitter and converging light onto the substrate; a mirror that reflects light transmitted from the first beam splitter to form a second optical path; It may include an image collection device that acquires image information of the substrate by collecting interference patterns of light transmitted from the first optical path and light transmitted from the second optical path through an imaging lens.

In one embodiment, the first beam splitter, the second beam splitter, and the imaging lens are placed in parallel in the horizontal direction below the measurement light source, and the first optical path is such that light passes through the first beam splitter, the second beam splitter, and the objective. This is the path where light is incident from the substrate through the lens, reflected, and transmitted back to the imaging lens through the objective lens, second beam splitter, and first beam splitter. In the second optical path, light is reflected from the mirror through the first beam splitter. This may be a path that is transmitted back to the imaging lens through the first beam splitter.

In one embodiment, it may further include a first correction lens provided between the first beam splitter and the second beam splitter to parallel correct the light transmitted between the first beam splitter and the second beam splitter.

In one embodiment, a second correction lens is provided between the first beam splitter and the mirror to change the focal length of the light incident on the mirror to adjust the parallelism between the light of the first optical path and the light of the second optical path. It can be included.

In one embodiment, the material and coating of the second correction lens can be changed to adjust the amount of light transmitted from the second optical path to be similar to the amount of light transmitted from the first optical path.

In one embodiment, the transmittance of the second correction lens may be provided such that the amount of light transmitted from the second optical path is similar to the amount of light transmitted from the first optical path.

In one embodiment, the mirror may be provided to have a predetermined curvature. In one embodiment, the curvature may be provided so that the light transmitted from the second optical path and the light transmitted from the first optical path are parallel. there is.

In one embodiment, it further includes a third beam splitter and a fourth beam splitter, wherein the first beam splitter and the mirror are placed in parallel in the horizontal direction below the measurement light source, and the second beam splitter, the third beam splitter, and the mirror are placed in parallel in the horizontal direction below the measurement light source. The 4-beam splitter and the imaging lens are placed in parallel in the horizontal direction at the bottom of the first beam splitter, and the third beam splitter separates the light transmitted from the first beam splitter and transmits it to the second beam splitter and the fourth beam splitter. And, in the first optical path, light is incident from the substrate through the first beam splitter, the third beam splitter, the second beam splitter, and the objective lens, and then is reflected back to the objective lens, the second beam splitter, the third beam splitter, and the second objective lens. This is the path through which light is transmitted to the imaging lens through the 4-beam splitter, and the second optical path may be the path through which light is transmitted to the imaging lens through the first beam splitter, mirror, and fourth beam splitter.

In one embodiment, it may further include a third correction lens provided between the second beam splitter and the third beam splitter to adjust the degree of parallelism of light transmitted between the second beam splitter and the third beam splitter to be the same.

In one embodiment, the lithography apparatus further includes a fourth correction lens provided between the fourth beam splitter and the mirror to adjust the parallelism of light incident on the fourth beam splitter.

In one embodiment, the transmittance of the fourth correction lens may be provided such that the amount of light transmitted from the second optical path is similar to the amount of light transmitted from the first optical path.

In one embodiment, the reflectance of the mirror may be determined such that the amount of light provided between the first beam splitter and the mirror and transmitted from the second optical path is similar to the amount of light transmitted from the first optical path.

In one embodiment, the method may further include a process light source that irradiates light to the second beam splitter so that the light transmitted through the second beam splitter forms a pattern on the substrate.

In one embodiment, the device further includes a controller that controls the moving means, and the controller can determine the location of the process light source based on image information.

In one embodiment, the substrate includes a pattern layer where the cured resist forms a first pattern; It includes an uncured resist layer applied to cover the first pattern on the substrate, and the controller recognizes the position of the first pattern based on image information and places the uncured resist layer at a predetermined position on the first pattern. The process light source can be controlled to partially cure the material to form a second pattern.

In one embodiment, an alignment key may be formed on the first pattern.

Additionally, the present invention provides a method of performing a lithography process. In one embodiment, the method includes forming a first pattern by applying and selectively curing and developing a resist on a substrate to form a first pattern; A resist application step of applying resist on the substrate to cover the first pattern; A position recognition step of recognizing the position of the first pattern based on image information; It may include a second pattern forming step of forming a second pattern by curing a portion of the uncured resist layer at a predetermined location on the first pattern using a process light source.

In one embodiment, the first pattern forming step may further include forming an alignment key on the first pattern.

In one embodiment, the process light source may be provided as light with an ultraviolet to blue wavelength, and the measurement light source may be provided as light with a red to infrared wavelength that is longer than the wavelength of the process light source.

According to the present invention, there is an advantage in that a multi-layer pattern can be formed without a separate process of forming an alignment key on a bare substrate.

In addition, according to the present invention, there is an advantage in that the position of the process light source can be smoothly aligned by obtaining an image of the difference in refractive index caused by the difference in curing degree of the resist.

The effects of the present invention are not limited to the effects described above, and effects not mentioned can be clearly understood by those skilled in the art from this specification and the attached drawings.

1 to 2 each show a lithography method using a conventional lithography apparatus.
Figure 3 shows a lithography apparatus using the principle of Michelson interferometry according to an embodiment of the present invention.
4 to 5 respectively show an interference image and a phase difference image according to an embodiment of the present invention.
6 to 8 respectively show a lithography apparatus using the principle of Michelson interferometry according to another embodiment of the present invention.
Figure 9 shows a lithography apparatus using the principle of Mach-Zehnder interferometry according to an embodiment of the present invention.
10 and 11 each show a lithography apparatus using the principle of Mach-Zehnder interferometry according to another embodiment of the present invention.
Figure 12 shows a flowchart of a lithography method according to one embodiment of the present invention.

The embodiments described in this specification may be modified into various other forms, and the technology according to one embodiment is not limited to the embodiments described below. Additionally, the embodiment of one embodiment is provided to more completely explain the present disclosure to those skilled in the art.

Additionally, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to also include the plural forms, unless the context clearly dictates otherwise.

In addition, the numerical range used in this specification includes the lower limit and upper limit and all values within the range, increments logically derived from the shape and width of the defined range, all double-defined values, and the upper limit of the numerical range defined in different forms. and all possible combinations of the lower bounds. Unless otherwise specified in the specification of the present invention, values outside the numerical range that may occur due to experimental error or rounding of values are also included in the defined numerical range.

Furthermore, “including” a certain element throughout the specification means that other elements may be further included, rather than excluding other elements, unless specifically stated to the contrary.

The present invention provides a lithographic apparatus (100). In one example, the lithographic apparatus 100 of the present invention is used to form a multilayer pattern on a substrate W. The present invention discloses an apparatus 100 and a method for forming a second pattern (P2) based on an initially formed first pattern (P1).

In one example, lithographic apparatus 100 includes a head 101, a moving means (not shown), and a controller (not shown). The head 101 is placed on top of the substrate W, and a moving means (not shown) moves the head 101 up, down, left, and right on the substrate W.

A controller (not shown) determines the position of the process light source 104 by controlling the moving means (not shown) based on an interference image obtained through the measurement light source 102, which will be described later. The process light source 104 irradiates light onto the substrate W to form a pattern on the substrate W. In one example, the measurement light source 102 may be provided in infrared light and the process light source 104 may be provided in ultraviolet light.

The lithographic apparatus 100 of the present invention forms a first optical path and a second optical path in order to obtain an optical phase difference generated due to a slight difference in the refractive index of light generated depending on whether the resist R is cured. In one example, the lithographic apparatus 100 includes a first optical path, which is a path of light incident and reflected from the measurement light source 102 to the substrate W, and a first optical path, which is a path of light incident and reflected from the measurement light source 102 to the mirror 150. The second optical path, which is the path of the light, causes interference to occur at a specific point. The image collection device 190 acquires an interference image due to light interference at a specific point and images it. Depending on whether the resist (R) is cured, a difference occurs in the refractive index of light, and the boundary between the cured resist (R) and the uncured resist (R) is revealed in the interference image. In order to acquire such images, the image collection device 190 is provided as a device that can use the principles of interferometry.

Hereinafter, the lithographic apparatus 100 of the present invention will be described with reference to FIGS. 3 to 3.

The first to fourth embodiments use the principle of Michelson interferometry.

<First Example>

Figure 3 shows a lithographic apparatus 100 according to an embodiment of the present invention. Specifically, FIG. 3 shows a lithographic apparatus 100 using the principle of Michelson interferometry. Referring to FIG. 3, the head 101 includes a measurement light source 102, a first beam splitter 110, a second beam splitter 120, a mirror 150, an objective lens 140, and an image collection device 190. ) includes. In one example, head 101 further includes a process light source 104.

The measurement light source 102 irradiates light onto the substrate W. The first beam splitter 110 is placed on the optical path of the measurement light source 102, separates the light emitted from the measurement light source 102, and transmits it to the second beam splitter 120 and the mirror 150. In one example, the first beam splitter 110 is provided below the measurement light source 102. The second beam splitter 120 transmits the light transmitted from the first beam splitter 110 to the substrate (W). The objective lens 140 is placed on the optical path of the second beam splitter 120 and focuses light onto the substrate (W). In one example, the objective lens 140 is placed below the second beam splitter 120. The objective lens 140 may be positioned sufficiently close to the substrate W when performing a lithography method. The mirror 150 reflects the light transmitted from the first beam splitter 110 to form a second optical path. In one example, image collection device 190 includes an image lens 160 and an image sensor 170. The image lens 160 is a lens that condenses light to the image sensor 170, and the image sensor 170 is a device 100 for acquiring an image, like a camera.

The image lens 160 is placed at a specific point where the first optical path and the second optical path meet. The imaging lens 160 acquires an interference image of light transmitted through the first optical path and the second optical path. In one example, the first beam splitter 110, the second beam splitter 120, and the imaging lens 160 are placed horizontally and parallel to the lower part of the measurement light source 102.

The optical beam emitted from the measurement light source 102 is transmitted to the first beam splitter 110. The first beam splitter 110 reflects part of the light and transmits part of it. The light reflected from the first beam splitter 110 is transmitted to the second beam splitter 120 (first optical path), and the light transmitted through the first beam splitter 110 is transmitted to the mirror 150 (first optical path). 2 optical path). To form such an optical path, the angles of the first beam splitter 110, the second beam splitter 120, and the mirror 150 may be set.

At this time, in the first optical path, light is incident from the substrate (W) through the first beam splitter 110, the second beam splitter 120, and the objective lens 140, and is then reflected back to the objective lens 140, This is the path transmitted to the imaging lens 160 through the second beam splitter 120 and the first beam splitter 110.

Specifically, the second beam splitter 120, which receives light from the first beam splitter 110, reflects part of the light and transmits part of the light. The light passing through the second beam splitter 120 is incident on the substrate W through the objective lens 140, is reflected again from the substrate W, and is then incident on the second beam splitter 120 again. The second beam splitter 120 reflects some of this and transmits it to the first beam splitter 110. Some of the light transmitted to the first beam splitter 110 passes through the first beam splitter 110 and reaches the image sensor through the image lens 160.

At this time, the second optical path is a path in which light is reflected from the mirror 150 through the first beam splitter 110 and transmitted to the imaging lens 160 through the first beam splitter 110. Specifically, the light that passes through the first beam splitter 110 is reflected by the mirror 150 and is transmitted back to the first beam splitter 110. Some of the light transmitted to the first beam splitter 110 is reflected and reaches the image sensor through the image lens 160.

The light transmitted through the first optical path is reflected from the substrate W and includes information about the substrate W. Meanwhile, the light transmitted through the second optical path is constant regardless of the state of the substrate W, and causes interference with the first optical path.

In this way, the two lights that are separated through different paths and overlap to reach the image sensor 170 may experience interference at each location, such as constructive interference or destructive interference due to the phase difference caused by the difference in each optical path. This generates an image signal corresponding to the difference in light and dark.

Figures 4 and 5 show images obtained through the image collection device 190 according to an embodiment of the present invention.

In one example, it is assumed that the first pattern (P1) is formed by the cured resist (R) on the substrate (W), and the uncured resist (R) is applied to cover the first pattern (P1). do. There is a difference between the interference pattern formed by the cured resist (R) and the interference pattern formed by the uncured resist (R) due to the difference in the refractive index of light between the cured resist (R) and the uncured resist (R). . Accordingly, the position of the first pattern (P1) where the resist (R) has been hardened can be determined. In one example, an align key is inserted into the first pattern (P1). In this case, the position of the align key on the first pattern (P1) can be determined using the same principle.

Due to the slight difference in incident angle between the first and second optical paths, an interference image in the form of stripes with light and dark repeating at regular intervals is obtained, as shown in (a) of FIG. 4. Through the interference image of FIG. 4(a), an image of the phase difference according to each position on the substrate W can be reconstructed as shown in FIG. 4(b), and the image of this phase difference can be obtained from a process light source (described later) 104) is used for sorting.

When the angle between the first and second optical paths that are separated from the measurement light source 102 and then returned is adjusted more precisely to reduce the difference in the angle of incidence between the two lights, stripes are formed in the image of the interference image. The gap can be gradually widened. For example, Figure 5 shows that the difference in incident angle between the first optical path and the second optical path is adjusted to decrease as it moves to the right. If the incident angles of the two lights are adjusted to be the same, the interference image itself becomes the same as the phase difference image, so there is no need to reconstruct the phase difference image, so a separate image processing process may be unnecessary.

The process light source 104 irradiates light onto the substrate W to form a pattern. In one example, the process light source 104 is provided above the second beam splitter 120. The process light source 104 forms a single-layer pattern on the substrate W, or forms a three-dimensional multi-layer pattern on the single layer based on the interference image obtained from the measurement light source 102.

<Second Embodiment>

Figure 6 shows a lithographic apparatus 100a according to a second embodiment of the present invention. The second embodiment is, in the first embodiment, provided between the first beam splitter 110 and the second beam splitter 120 and transmitted between the first beam splitter 110 and the second beam splitter 120. It may further include a first correction lens 131 that corrects light to be parallel.

Using the principle that the light starting from the measurement light source 102 is divided into two, one is reflected from the substrate W and the other is reflected from the mirror 150, the interference phenomenon between the first optical path and the second optical path is prevented. In order to use it, it is desirable that the parallelism of the first optical path and the second optical path incident on the imaging lens 160 match. This is to ensure sufficient quality of the interference image obtained from the image sensor 170 by making the field of view obtained through the first optical path and the second optical path the same.

Accordingly, it is preferable that both the first optical path and the second optical path enter the imaging lens 160 as parallel beams, or enter the imaging lens 160 so that they converge or diverge to the same degree and interfere with each other.

To this end, the first correction lens 131 ensures that the light of the first optical path collected by the objective lens 140 has the same degree of parallelism as the second optical path when it is collected by the image lens 160. That is, the first correction lens 131 causes the light of the first light path collected by the objective lens 140 to be parallel, converge, or diverge to the same extent as the second light path.

<Third Embodiment>

Figure 7 shows a lithographic apparatus 100b according to a third embodiment of the present invention. In the third embodiment, in the first embodiment, the mirror 150a may be provided to have a predetermined curvature so that the first optical path and the second optical path have the same degree of parallelism. In one example, the curvature may be provided so that the light transmitted from the second optical path and the light transmitted from the first optical path are both parallel, or converge or diverge to the same extent.

<Fourth Embodiment>

Figure 8 shows a lithographic apparatus 100c according to a fifth embodiment of the present invention. In the fourth embodiment, in the first embodiment, a second correction lens 132 is provided between the first beam splitter 110 and the mirror 150 to adjust the focal length of light incident on the mirror 150. It may further include.

In one example, the focal distance may be adjusted so that the amount of light transmitted from the second optical path is similar to the amount of light transmitted from the first optical path.

In one example, the transmittance of the second correction lens 132 may be provided such that the amount of light transmitted from the second optical path is similar to the amount of light transmitted from the first optical path.

A plurality of beam splitters are provided in the first optical path, so the amount of light incident on the imaging lens 160 is significantly lower than that in the second optical path. In order to use light interference, it is advantageous to provide two lights with similar amounts of light. Accordingly, the distance or transmittance of the second correction lens 132 from the mirror 150 may be adjusted so that the amount and parallelism of the light transmitted from the first optical path and the second optical path are similar.

For example, the second correction lens 132 is provided to be movable up and down so that the distance from the mirror 150 can be adjusted. Alternatively, the second correction lens 132 is provided with a plurality of lenses having different transmittances, and a lens having a transmittance according to need can be selected and used.

The fifth to seventh embodiments use the principle of Mach-Zehnder interferometry.

<Embodiment 5>

Figure 9 shows a lithographic apparatus 100d according to a fifth embodiment of the present invention.

Referring to FIG. 3, the head 101 includes a measurement light source 102, a first beam splitter 110, a second beam splitter 120, a third beam splitter 130, a fourth beam splitter 140, It includes a mirror 150, an objective lens 140, and an image collection device 190.

The measurement light source 102 irradiates light onto the substrate W. The first beam splitter 110 is placed on the optical path of the measurement light source 102, separates the light emitted from the measurement light source 102, and transmits it to the third beam splitter 130 and the mirror 150. In one example, the first beam splitter 110 and the mirror 150 are provided horizontally and parallel to the lower part of the measurement light source 102. In addition, the second beam splitter 120, the third beam splitter 130, the fourth beam splitter 140, and the image lens 160 are provided horizontally and parallel to the lower part of the first beam splitter 110. The third beam splitter 130 transmits the light transmitted from the first beam splitter 110 to the second beam splitter 120. The objective lens 140 is placed on the optical path of the second beam splitter 120 and focuses light onto the substrate (W). In one example, the objective lens 140 is placed below the second beam splitter 120. The objective lens 140 may be positioned sufficiently close to the substrate W when performing a lithography method.

The mirror 150 reflects the light transmitted from the first beam splitter 110 to form a second optical path. The light reflected by the mirror 150 is transmitted to the fourth beam splitter 140 and collected by the image sensor 170 through the image lens 160. As described above, the image collection device 190 includes an image lens 160 and an image sensor 170. The image lens 160 is a lens that condenses light to the image sensor 170, and the image sensor 170 is a device 100 for acquiring an image, like a camera.

The optical beam emitted from the measurement light source 102 is transmitted to the first beam splitter 110. The first beam splitter 110 reflects part of the light and transmits part of it. The light reflected from the first beam splitter 110 is transmitted to the second beam splitter 120 (first optical path), and the light transmitted through the first beam splitter 110 is transmitted to the mirror 150 (first optical path). 2 optical path). The imaging lens 160 is placed at a specific point where the first optical path and the second optical path meet. The imaging lens 160 acquires an interference image of light transmitted through the first optical path and the second optical path.

In order to form the optical path as shown below, the angles of the first beam splitter 110, the second beam splitter 120, the third beam splitter 130, the fourth beam splitter 140 and the mirror 150 are set. You can.

In the first optical path, light is incident from the substrate W through the first beam splitter 110, the third beam splitter 130, the second beam splitter 120, and the objective lens 140, and then is reflected again. The objective lens 140 is a path transmitted to the imaging lens 160 through the second beam splitter 120, third beam splitter 130, and fourth beam splitter 140.

Specifically, the third beam splitter 130, which receives light from the first beam splitter 110, reflects part of the light and transmits part of it. The third beam splitter 130 reflects part of the light and transmits it to the second beam splitter 120. The light reflected from the second beam splitter 120 is incident on the substrate W through the objective lens 140, is reflected again from the substrate W, and then is incident on the second beam splitter 120 again. The second beam splitter 120 reflects some of this and transmits it to the third beam splitter 130. Some of the light transmitted to the third beam splitter 130 passes through the third beam splitter 130 and is transmitted to the fourth beam splitter 140. The light passing through the fourth beam splitter 140 reaches the image sensor through the image lens 160.

The second optical path is a path through which light is transmitted to the imaging lens 160 through the first beam splitter 110, mirror 150, and fourth beam splitter 140. This is the path where light is reflected from the mirror 150 through the first beam splitter 110 and transmitted back to the imaging lens 160 through the fourth beam splitter 140.

In one example, the reflectance of the mirror 150 is determined by the amount of light provided between the first beam splitter 110 and the mirror 150 and transmitted from the second optical path and the amount of light transmitted from the first optical path. may be determined to be similar. This is to facilitate interference between light transmitted from the first optical path and light transmitted from the second optical path.

The process light source 104 irradiates light onto the substrate W to form a pattern. In one example, the process light source 104 is provided above the second beam splitter 120. The process light source 104 forms a single-layer pattern on the substrate W, or forms a three-dimensional multi-layer pattern on the single layer based on the interference image obtained from the measurement light source 102.

<Example 6>

In addition to the fifth embodiment, as shown in FIG. 10, the lithography apparatus 100e is provided between the second beam splitter 120 and the third beam splitter 130 to separate the second beam splitter 120 and the third beam splitter 120. It may further include a third correction lens 133 that parallelizes the light transmitted between the beam splitters 130.

In order to utilize the interference phenomenon between the first optical path and the second optical path, it is desirable that the degree of parallelism of the first optical path and the second optical path incident on the imaging lens 160 match. This is to ensure sufficient quality of the interference image obtained from the image sensor 170 by making the field of view obtained through the first optical path and the second optical path the same.

<Embodiment 7>

In addition to the fifth embodiment, as shown in FIG. 11, the lithography apparatus 100f is provided between the fourth beam splitter 140 and the mirror 150 to split the light incident on the fourth beam splitter 140. It may further include a fourth correction lens 134 that adjusts the focal distance.

In one example, the focal distance may be adjusted so that the degree of parallelism between the light transmitted from the second optical path and the light transmitted from the first optical path is the same. In one example, the transmittance of the fourth correction lens 134 may be provided such that the amount of light transmitted from the second optical path is similar to the amount of light transmitted from the first optical path.

A plurality of beam splitters are provided in the first optical path, so the amount of light incident on the imaging lens 160 is significantly lower than that in the second optical path. In order to utilize light interference, it is advantageous to provide two lights with similar amounts of light. Accordingly, the amount of light transmitted from the first optical path and the second optical path can be adjusted to be similar by setting the material, shape, and mounting position of the fourth correction lens 134.

For example, the fourth correction lens 134 is provided to be movable up and down so that the distance from the mirror 150 can be adjusted. Alternatively, the fourth correction lens 134 is provided with a plurality of lenses having different transmittances, and a lens having a transmittance according to need can be selected and used.

Referring to FIG. 12, the lithography method of the present invention includes a first pattern forming step (S100), a resist applying step (S200), a position recognition step (S300), and a second pattern forming step (S400).

In one example, in the first pattern forming step, resist (R) is applied on the substrate (W) using a resist nozzle (not shown), and the resist (R) is selectively cured using the process light source 104. Developed to form a first pattern (P1). The first pattern forming step (S100) includes forming an alignment key on the first pattern (P1).

Thereafter, in the resist application step (S200), the resist (R) is applied on the substrate (W) using a resist nozzle (not shown) to cover the first pattern (P1).

Thereafter, in the position recognition step (S300), the position of the first pattern (P1) and the position of the align key are recognized based on the image information, and in the second pattern forming step (S400), the position of the alignment key is recognized through the process light source 104. A portion of the uncured resist (R) layer is cured at a designated location on the first pattern (P1) to form a second pattern (P2). In the position recognition step (S300) and the second pattern forming step (S400), the head 101 is moved to a position corresponding to a local area or the entire surface of the substrate W and the steps are performed. In one example, the process light source 104 may use light having a wavelength of purple or blue, and the measurement light source 102 may use light with a longer wavelength than the process light source 104, such as red or infrared. For example, the measurement light source 102 used in the position recognition step (S300) is provided in infrared light, and the process light source 104 used in the first pattern forming step (S100) and the second pattern forming step (P2) is provided in ultraviolet light. can be provided.

According to the present invention, in the first pattern forming step (S100), the first pattern is formed on the substrate W and the alignment key is formed at the same time, so there is no need to separately form the alignment key on the bare substrate W. . Accordingly, there is an advantage that process time and cost are reduced.

In addition, according to the present invention, even if the resist R is provided as a transparent material, a new pattern can be formed by stacking on the initially formed pattern based on the initially formed pattern in the process of performing multilayer lithography. There is an advantage.

In the above-described example, it has been described that the first pattern P1 and the second pattern P2 are formed, but a three-dimensional shape can be formed by stacking n or more patterns using the lithography method disclosed in the present invention.

As described above, the present disclosure has been described in the present specification using specific details and limited examples, but these are provided only to facilitate a more general understanding of the present disclosure, and the present disclosure is not limited to the above embodiments. Anyone skilled in the art can make various modifications and variations from this description.

Therefore, the idea described in this specification should not be limited to the described embodiments, and all claims that are equivalent or equivalent to this claim as well as the later-described claims fall within the scope of the idea described in this specification. They will say they do it.

Claims (20)

A head placed on top of the substrate;
A lithographic apparatus including a moving means for changing the relative positions of the substrate and the head,
The head is,
A measurement light source that radiates light onto the substrate;
A first beam splitter placed on the optical path of the measurement light source to separate the light emitted from the measurement light source;
a second beam splitter that transmits the light transmitted from the first beam splitter to the substrate to form a first optical path;
an objective lens placed on the optical path of the second beam splitter and converging light onto the substrate;
a mirror that reflects light transmitted from the first beam splitter to form a second optical path;
A lithographic apparatus comprising an image collection device that acquires image information of the substrate by collecting interference patterns of light transmitted from the first optical path and the light transmitted from the second optical path through an imaging lens. According to paragraph 1,
The first beam splitter, the second beam splitter, and the imaging lens are placed parallel to the horizontal direction below the measurement light source,
The first optical path is,
Light is incident from the substrate through the first beam splitter, the second beam splitter, and the objective lens, is reflected, and is transmitted to the imaging lens again through the objective lens, the second beam splitter, and the first beam splitter. It is a path,
The second optical path is,
A lithography device in which light is reflected from the mirror through the first beam splitter and transmitted to the imaging lens through the first beam splitter. According to paragraph 2,
A lithography apparatus further comprising a first correction lens provided between the first beam splitter and the second beam splitter to correct light transmitted between the first beam splitter and the second beam splitter to be parallel. According to paragraph 2,
A second correction lens is provided between the first beam splitter and the mirror to change the focal length of the light incident on the mirror to adjust the degree of parallelism between the light of the first optical path and the light of the second optical path. A lithographic apparatus comprising: According to paragraph 4,
A lithographic apparatus in which the amount of light transmitted from the second optical path is adjusted to be similar to the amount of light transmitted from the first optical path by changing the material and coating of the second correction lens. According to paragraph 4,
The transmittance of the second correction lens is,
A lithographic apparatus provided so that the amount of light transmitted from the second optical path is similar to the amount of light transmitted from the first optical path. According to paragraph 2,
The mirror is,
A lithographic device provided to have a predetermined curvature. In clause 7,
The curvature is,
A lithographic apparatus provided so that the degree of parallelism between light transmitted from a second optical path and light transmitted from the first optical path is similar. According to paragraph 1,
Further comprising a third beam splitter and a fourth beam splitter,
The first beam splitter and the mirror are placed parallel to the horizontal direction below the measurement light source,
The second beam splitter, the third beam splitter, the fourth beam splitter, and the imaging lens are placed horizontally and parallel to the lower part of the first beam splitter,
The third beam splitter separates the light transmitted from the first beam splitter and transmits it to the second beam splitter and the fourth beam splitter,
The first optical path is,
Light is incident from the substrate through the first beam splitter, the third beam splitter, the second beam splitter, and the objective lens and is then reflected back to the objective lens. The second beam splitter, the third beam splitter, and the objective lens. This is the path transmitted to the imaging lens through the fourth beam splitter,
The second optical path is,
A lithography device in which light is transmitted to the imaging lens through the first beam splitter, the mirror, and the fourth beam splitter. According to clause 9,
A lithography apparatus further comprising a third correction lens provided between the second beam splitter and the third beam splitter to adjust the degree of parallelism of light transmitted between the second beam splitter and the third beam splitter to be the same. According to clause 9,
A lithography apparatus further comprising a fourth correction lens provided between the fourth beam splitter and the mirror to adjust the degree of parallelism of light incident on the fourth beam splitter. According to clause 11,
The transmittance of the fourth correction lens is,
A lithographic apparatus provided so that the amount of light transmitted from the second optical path is similar to the amount of light transmitted from the first optical path. According to paragraph 1,
The reflectance of the mirror is,
A lithographic apparatus provided between the first beam splitter and the mirror and determined to be similar to the amount of light transmitted from the second optical path and the amount of light transmitted from the first optical path. According to any one of claims 1 to 13,
A lithography apparatus further comprising a process light source that irradiates light to the second beam splitter so that the light transmitted through the second beam splitter forms a pattern on the substrate. According to clause 14,
Further comprising a controller for controlling the means of movement,
The controller is,
A lithography apparatus that determines the location of the process light source based on the image information. According to clause 15,
The substrate is,
a pattern layer in which the cured resist forms a first pattern;
and an uncured resist layer applied on the substrate to cover the first pattern,
The controller is,
Recognize the location of the first pattern based on the image information,
A lithographic apparatus for controlling the process light source to form a second pattern by curing a portion of the uncured resist layer at a predetermined location on the first pattern. According to clause 16,
A lithographic apparatus in which an alignment key is formed on the first pattern. In a method of performing a lithography process using the lithography apparatus of claim 14,
A first pattern forming step of forming a first pattern by applying and selectively curing and developing a resist on a substrate;
A resist application step of applying resist on the substrate to cover the first pattern;
A position recognition step of recognizing the position of the first pattern based on the image information;
A lithography method comprising forming a second pattern by curing a portion of an uncured resist layer at a predetermined location on the first pattern using the process light source to form a second pattern. According to clause 18,
The first pattern forming step is,
A lithographic method further comprising forming an alignment key on the first pattern. According to clause 18,
The process light source is provided with light of ultraviolet to blue wavelengths,
A lithography method in which the measurement light source is provided as light with a red to infrared wavelength that is longer than the wavelength of the process light source.