JP2011003819A - Method of processing substrate, program, computer storage medium, and substrate processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a predetermined pattern on a film to be processed on a substrate uniformly in a substrate plane.SOLUTION: In-plane tendencies of measurement sizes of a resist pattern and a pattern of the film to be processed on a wafer for inspection are calculated (step S5). A target in-plane tendency of the size of the resist pattern is calculated using expression (1) ΔXt=ΔX1-ΔXe (step S6). A heating temperature of PEB processing is corrected using expression (2) ΔT=1/α×F-1(ΔXt-ΔX1) (steps S7, S8). After the correction, photolithography processing and etching processing are carried out to form the predetermined pattern on the film to be processed on the wafer (steps S9, S10). In expression (1) and expression (2), ΔXt is the target in-plane tendency of the resists pattern, ΔX1 the in-plane tendency of the resist pattern, ΔXe the in-plane tendency of the pattern of the film to be processed, ΔT a correction value of the heating temperature, α resist thermal sensitivity, and F the relation between the amount of variation in heating temperature and the amount of variation of the size of the pattern.

Description

  The present invention relates to a substrate processing method, a program, a computer storage medium, and a substrate processing system for forming a predetermined pattern on a film to be processed on a substrate such as a semiconductor wafer.

  For example, in the manufacturing process of a semiconductor device, for example, a resist coating process for coating a resist solution on a semiconductor wafer (hereinafter referred to as “wafer”) to form a resist film, an exposure process for exposing a predetermined pattern on the resist film, A post-exposure baking process (hereinafter referred to as “PEB process”) for heating to promote the chemical reaction of the resist film after the exposure, a photolithography process for sequentially developing the exposed resist film, and the like are performed. A predetermined resist pattern is formed on the wafer. Using the resist pattern as a mask, the processing target film on the wafer is etched, and then the resist film is removed to form a predetermined pattern on the processing target film.

  The resist pattern described above determines the pattern shape of the underlying film to be processed and needs to be formed with strict dimensions. Therefore, after performing a photolithography process to form a resist pattern on the wafer and measuring dimensions such as the line width of the resist pattern, based on the dimension measurement results, for example, correcting the heating temperature of the PEB process, It has been proposed to optimize the dimensions of the resist pattern. In such a case, the correction of the heating temperature is performed, for example, by correcting the temperature of the hot plate that places and heats the wafer. For example, a heater that generates heat by power feeding is incorporated in the hot plate, and the hot plate is adjusted to a predetermined temperature by adjusting the temperature of the heater (Patent Document 1).

  In addition, when correcting the heating temperature of the PEB process, it is proposed to calculate the in-plane tendency of the dimension from the measured resist pattern dimension and adjust the temperature of the hot plate based on the in-plane tendency. Has been. (Patent Document 2).

JP 2006-228816 A JP 2008-118041 A

  However, for example, when the wafer is continuously processed, a parameter that affects only the pattern size of the film to be processed formed after the etching process may change over time. In this case, even if the resist pattern after the photolithography process can be optimized as described above, the pattern of the film to be processed after the etching process may not be formed uniformly on the wafer surface.

  The present invention has been made in view of this point, and an object of the present invention is to uniformly form a predetermined pattern on a substrate to be processed on a substrate.

In order to achieve the above object, the present invention is a substrate processing method for forming a predetermined pattern on a film to be processed on a substrate, wherein the substrate is subjected to a photolithography process, and a resist is formed on the film to be processed on the substrate. After forming the pattern, measuring the dimension of the resist pattern, calculating an in-plane tendency of the measured dimension of the resist pattern, etching the processed film using the resist pattern as a mask, and processing the processed film Forming a pattern on the substrate, measuring a pattern dimension of the film to be processed, calculating an in-plane tendency of the measurement dimension of the pattern of the film to be processed, and an in-plane tendency of the measurement dimension of the resist pattern and A step of calculating a target in-plane tendency of the dimension of the resist pattern using the following formula (1) based on the in-plane tendency of the measured dimension of the pattern of the film to be processed; Based on the target in-plane tendency of the dimension of the pattern, using the following formula (2), calculating the correction value of the processing temperature of the heat treatment in the photolithography processing, and the processing temperature based on the correction value of the processing temperature And a step of performing a photolithography process including a heat treatment at the corrected processing temperature and an etching process to form a predetermined pattern on a film to be processed on the substrate. In addition, the dimension of a resist pattern means the line width of a resist pattern, for example.
ΔXt = ΔX1−ΔXe (1)
ΔT = 1 / α × F ⁻¹ (ΔXt−ΔXl) (2)
However, ΔXt: target in-plane tendency of resist pattern dimension, ΔXl: in-plane tendency of measurement dimension of resist pattern, ΔXe: in-plane tendency of measurement dimension of film pattern to be processed, ΔT: correction value of processing temperature, α : Conversion coefficient between processing temperature variation and resist pattern dimension, F: Function of processing temperature variation and pattern dimension variation

  According to the present invention, in the above equation (1), the in-plane tendency of the measured dimension of the film to be processed is subtracted from the in-plane tendency of the measured dimension of the resist pattern to calculate the target in-plane tendency of the dimension of the resist pattern is doing. That is, the target in-plane tendency of the resist pattern dimension is set so that the in-plane tendency of the pattern dimension of the film to be processed becomes zero. And using the said Formula (2), the process temperature of heat processing is correct | amended so that the in-plane tendency of the dimension of a resist pattern may turn into the said target in-plane tendency. After that, heat treatment is performed at the processing temperature corrected as described above, and photolithography processing and etching processing are performed on the substrate, so that a resist pattern can be formed with a target in-plane tendency dimension, and the pattern of the film to be processed The in-plane tendency of the dimension can be made zero. Therefore, a predetermined pattern can be uniformly formed on the substrate to be processed on the substrate surface. This also improves the product yield.

  The heat treatment may be performed using a heat treatment plate partitioned into a plurality of regions, and the treatment temperature may be corrected for each region of the heat treatment plate.

  The heat treatment may be a heat treatment performed after the exposure process in the photolithography process and before the development process.

  The in-plane tendency may be expressed by being decomposed into a plurality of in-plane tendency components using a Zernike polynomial.

  The dimension of the pattern may be a line width of the pattern.

  According to another aspect of the present invention, there is provided a program that runs on a computer of a control device that controls the substrate processing system in order to cause the substrate processing method to execute the substrate processing method.

  According to another aspect of the present invention, a readable computer storage medium storing the program is provided.

According to still another aspect, the present invention is a substrate processing system for forming a predetermined pattern on a film to be processed on a substrate, and performing a photolithography process on the substrate to form a resist pattern on the film to be processed on the substrate. A coating and developing apparatus; an etching apparatus that performs an etching process on the film to be processed using the resist pattern as a mask; and a pattern that forms a pattern on the film to be processed; a dimension measuring apparatus that measures a dimension of the resist pattern; Another dimension measuring device for measuring the dimension of the pattern of the film to be processed, and a control device for correcting the processing temperature of the heat treatment in the photolithography process, and the control device is a resist measured by the dimension measuring device. The in-plane tendency of the measured dimension of the pattern is calculated, and the measured dimension of the resist pattern measured by the other dimension measuring device The in-plane tendency of the resist pattern is calculated, and based on the in-plane tendency of the measurement dimension of the resist pattern and the in-plane tendency of the measurement dimension of the pattern to be processed, the target of the dimension of the resist pattern is calculated using the following equation (1). An in-plane tendency is calculated, and based on a target in-plane tendency of the dimension of the resist pattern, a correction value of a processing temperature of the heat treatment performed in the coating and developing apparatus is calculated using the following formula (2), The processing temperature is corrected based on the correction value of the processing temperature.
ΔXt = ΔX1−ΔXe (1)
ΔT = 1 / α × F ⁻¹ (ΔXt−ΔXl) (2)
However, ΔXt: target in-plane tendency of resist pattern dimension, ΔXl: in-plane tendency of measurement dimension of resist pattern, ΔXe: in-plane tendency of measurement dimension of film pattern to be processed, ΔT: correction value of processing temperature, α : Conversion coefficient between processing temperature variation and resist pattern dimension, F: Function of processing temperature variation and pattern dimension variation

  The heat treatment may be performed using a heat treatment plate partitioned into a plurality of regions, and the control device may correct the treatment temperature for each of the plurality of regions of the heat treatment plate.

  The heat treatment may be a heat treatment performed after the exposure process and before the development process in the coating and developing apparatus.

  The said control apparatus may decompose | disassemble and express the said in-plane tendency into a some in-plane tendency component using a Zernike polynomial.

  The dimension measuring device and the other dimension measuring device may each measure a line width of the pattern as the dimension of the pattern.

  According to the present invention, it is possible to form a predetermined pattern uniformly on the substrate to be processed on the substrate.

It is explanatory drawing which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is a top view which shows the outline of a structure of a coating-development processing apparatus. It is a side view which shows the outline of a structure of a coating development processing apparatus. It is a side view which shows the outline of a structure of a coating development processing apparatus. It is a longitudinal cross-sectional view which shows the outline of a structure of a dimension measuring apparatus. It is explanatory drawing which shows the divided | segmented wafer area | region. It is a longitudinal cross-sectional view which shows the outline of a structure of a PEB apparatus. It is a top view which shows the structure of the hot platen of a PEB apparatus. It is a top view which shows the outline of a structure of an etching processing apparatus. It is a block diagram which shows the structure of a control apparatus. It is a determinant which shows an example of a calculation model. It is the flowchart explaining the inspection processing process of the wafer for an inspection, and the processing process of a wafer. It is explanatory drawing which shows a mode that the in-plane tendency of the measured dimension of the pattern of a to-be-processed film is subtracted from the in-plane tendency of the measured dimension of a resist pattern, and the target in-plane tendency of the dimension of a resist pattern is calculated.

  Embodiments of the present invention will be described below. FIG. 1 is an explanatory diagram showing an outline of a configuration of a substrate processing system 1 according to the present embodiment.

  As shown in FIG. 1, the substrate processing system 1 includes a coating and developing processing apparatus 2 that performs photolithography processing on a wafer as a substrate, and an etching processing apparatus 3 that performs etching processing on a film to be processed on the wafer. .

  As shown in FIG. 2, the coating and developing treatment apparatus 2 is a cassette that carries, for example, 25 wafers W in and out of the coating and developing treatment apparatus 2 from the outside in a cassette unit, and carries a wafer W into and out of the cassette C. A station 10, an inspection station 11 that performs a predetermined inspection on the wafer W, a processing station 12 in which a plurality of various processing apparatuses that perform predetermined processing in a single-wafer type in photolithography processing are arranged in multiple stages, The interface station 14 for transferring the wafer W to and from the exposure apparatus 13 provided adjacent to the processing station 12 is integrally connected.

  In the cassette station 10, a cassette mounting table 15 is provided, and the cassette mounting table 15 is capable of mounting a plurality of cassettes C in a row in the X direction (vertical direction in FIG. 2). The cassette station 10 is provided with a wafer transfer body 17 that can move on the transfer path 16 along the X direction. The wafer carrier 17 is also movable in the wafer arrangement direction (Z direction; vertical direction) of the wafers W accommodated in the cassette C, and selectively with respect to the wafers W arranged in the vertical direction in the cassette C. Accessible. The wafer carrier 17 can be rotated around a vertical axis (θ direction), and can also access a transfer unit 21 on the inspection station 11 side described later.

  The inspection station 11 adjacent to the cassette station 10 is provided with a dimension measuring device 20 that measures the dimension of the resist pattern formed on the film to be processed of the wafer W. The dimension measuring device 20 is disposed, for example, on the negative side in the X direction (downward in FIG. 2) of the inspection station 11. For example, on the cassette station 10 side of the inspection station 11, a delivery unit 21 for delivering the wafer W to and from the cassette station 10 is disposed. The delivery unit 21 is provided with a placement unit 21a on which, for example, a wafer W is placed. In the X direction positive direction (upward direction in FIG. 2) of the dimension measuring apparatus 20, for example, a wafer transfer body 23 that is movable along the X direction on the transfer path 22 is provided. The wafer transfer body 23 is movable, for example, in the vertical direction and is also rotatable in the θ direction, and each processing apparatus of the third processing apparatus group G3 to be described later on the dimension measuring apparatus 20, the transfer section 21, and the processing station 12 side. Can be accessed.

  The processing station 12 adjacent to the inspection station 11 includes, for example, five processing device groups G1 to G5 in which a plurality of processing devices are arranged in multiple stages. A first processing device group G1 and a second processing device group G2 are arranged in this order from the inspection station 11 side on the X direction negative direction (downward direction in FIG. 2) side of the processing station 12. A third processing device group G3, a fourth processing device group G4, and a fifth processing device group G5 are sequentially arranged from the inspection station 11 side on the X direction positive direction (upward direction in FIG. 2) side of the processing station 12. Has been placed. A first transfer device 30 is provided between the third processing device group G3 and the fourth processing device group G4. The first transfer device 30 can selectively access each device in the first processing device group G1, the third processing device group G3, and the fourth processing device group G4 to transfer the wafer W. A second transport device 31 is provided between the fourth processing device group G4 and the fifth processing device group G5. The second transfer device 31 can selectively access each device in the second processing device group G2, the fourth processing device group G4, and the fifth processing device group G5 to transfer the wafer W.

  As shown in FIG. 3, in the first processing unit group G1, a liquid processing apparatus that supplies a predetermined liquid to the wafer W and performs processing, for example, a resist coating that forms a resist film by applying a resist solution to the wafer W Apparatuses 40, 41, and 42, and bottom coating apparatuses 43 and 44 that form an antireflection film for preventing reflection of light during the exposure process are stacked in five stages in order from the bottom. In the second processing unit group G2, liquid processing units, for example, development processing units 50 to 54 for supplying a developing solution to the wafer W and performing development processing are stacked in five stages in order from the bottom. Further, chemical chambers 60 and 61 for supplying various processing liquids to the liquid processing apparatuses in the processing apparatus groups G1 and G2 are provided at the lowermost stage of the first processing apparatus group G1 and the second processing apparatus group G2. Are provided.

  As shown in FIG. 4, the third processing unit group G3 includes, for example, a temperature control unit 70, a transition unit 71 for transferring the wafer W, and a high-precision temperature control for adjusting the wafer temperature under high-precision temperature control. The apparatuses 72 to 74 and the high temperature heat treatment apparatuses 75 to 78 that heat-treat the wafer W at a high temperature are sequentially stacked in nine stages from the bottom.

  The fourth processing unit group G4 includes, for example, a high-accuracy temperature control unit 80, pre-baking units (hereinafter referred to as “PAB units”) 81 to 84 that heat-treat the resist-coated wafer W, and post-development processing units. Post-baking apparatuses (hereinafter referred to as “POST apparatuses”) 85 to 89 that heat-process the wafer W are stacked in 10 stages in order from the bottom.

  In the fifth processing apparatus group G5, a plurality of heat processing apparatuses for heat-treating the wafer W, for example, high-precision temperature control apparatuses 90 to 93, and a post-exposure baking apparatus (hereinafter referred to as “PEB apparatus”) for performing heat treatment as heat treatment on the wafer W. 94-99 are stacked in 10 steps from the bottom.

  As shown in FIG. 2, a plurality of processing devices are arranged on the positive side in the X direction of the first transfer device 30, and an adhesion device 100 for hydrophobizing the wafer W as shown in FIG. 101, heat treatment apparatuses 102 and 103 for heat-treating the wafer W are stacked in four stages in order from the bottom. As shown in FIG. 2, a peripheral exposure device 104 that selectively exposes only the edge portion of the wafer W, for example, is disposed on the positive side in the X direction of the second transfer device 31.

  As shown in FIG. 2, the interface station 14 is provided with a wafer transfer body 111 that moves on a transfer path 110 that extends in the X direction, and a buffer cassette 112. The wafer transfer body 111 is movable in the Z direction and rotatable in the θ direction, and accesses the exposure apparatus 13 adjacent to the interface station 14, the buffer cassette 112, and the fifth processing apparatus group G5. The wafer W can be transferred.

  Next, the configuration of the above-described dimension measuring apparatus 20 will be described. As shown in FIG. 5, the dimension measuring device 20 has a casing 20 a in which a wafer W is loaded and unloaded (not shown) on the side surface. In the casing 20a, a mounting table 120 for mounting the wafer W horizontally and an optical surface shape measuring instrument 121 are provided. The mounting table 120 can move, for example, in a two-dimensional direction in the horizontal direction. The optical surface shape measuring instrument 121 includes, for example, a light irradiation unit 122 that irradiates light on the wafer W from an oblique direction, a light detection unit 123 that detects light irradiated from the light irradiation unit 122 and reflected by the wafer W, A measurement unit 124 that calculates the size of the resist pattern on the wafer W based on the light reception information of the light detection unit 123 is provided. The dimension measuring apparatus 20 measures the dimension of the resist pattern using, for example, a scatterometry method. In the measuring unit 124, the light intensity distribution in the wafer surface detected by the light detecting unit 123, and The size of the resist pattern can be measured by checking the virtual light intensity distribution stored in advance and obtaining the size of the resist pattern corresponding to the virtual light intensity distribution thus checked. In the present embodiment, for example, the line width of the resist pattern is measured as the dimension of the resist pattern.

In addition, the dimension measuring apparatus 20 moves the wafer W relatively horizontally with respect to the light irradiation unit 122 and the light detection unit 123, so that a plurality of regions in the wafer surface, for example, each wafer region W as shown in FIG. it can be measured dimension of the resist pattern at a plurality of measuring points for every ₁ to _W-5. The wafer regions W _{1 to} W ₅ correspond to hot plate regions R _{1 to} R ₅ of PEB apparatuses 94 to 99 described later. The number and shape of the regions in the wafer surface are not limited to the regions shown in FIG. 6 and can be arbitrarily selected.

  Next, the configuration of the above-described PEB devices 94 to 99 will be described. As shown in FIG. 7, the PEB apparatus 94 has a casing 94a in which a loading / unloading port (not shown) for the wafer W is formed on the side surface. In the casing 94a, there are provided a lid body 130 that is located on the upper side and is movable up and down, and a hot plate housing part 131 that is located on the lower side and forms the processing chamber K integrally with the lid body 130. .

  The lid 130 has a substantially cylindrical shape with an open bottom surface. An exhaust part 130 a is provided at the center of the upper surface of the lid 130. The atmosphere in the processing chamber K is uniformly exhausted from the exhaust part 130a.

  The hot plate accommodating portion 131 includes an annular holding member 141 that holds a hot plate 140 as a heat treatment plate and holds the outer peripheral portion of the hot plate 140, and a substantially cylindrical support ring 142 that surrounds the outer periphery of the holding member 141. I have.

As shown in FIG. 8, the hot plate 140 is divided into a plurality of, for example, five hot plate regions R ₁ , R ₂ , R ₃ , R ₄ , R ₅ . The hot plate 140 is, for example, positioned in the center when viewed from the plane, and is divided into a circular hot plate region R ₁ and hot plate regions R _{2 to} R ₅ whose periphery is divided into four arcs.

Each of the hot plate regions R _{1 to} R ₅ of the hot plate 140 has a built-in heater 143 that generates heat by power feeding, and can be heated for each of the hot plate regions R _{1 to} R ₅ . The amount of heat generated by the heater 143 in each of the hot plate regions R _{1 to} R ₅ is adjusted by the temperature controller 144. The temperature control device 144 can control the temperature of each of the hot plate regions R _{1 to} R ₅ to a heating temperature as a predetermined processing temperature by adjusting the amount of heat generated by the heater 143. The setting of the heating temperature in the temperature control device 144 is performed by, for example, the control device 400 described later.

  As shown in FIG. 7, elevating pins 150 for supporting the wafer W from below and elevating it are provided below the hot plate 140. The elevating pin 150 can be moved up and down by an elevating drive mechanism 151. A through-hole 152 that penetrates the hot plate 140 in the thickness direction is formed near the center of the hot plate 140, and the lift pins 150 rise from below the hot plate 140 and pass through the through-hole 152, It can protrude above the plate 140.

  Note that the configuration of the PEB devices 95 to 99 is the same as that of the PEB device 94 described above, and a description thereof will be omitted.

  As shown in FIG. 9, the etching processing apparatus 3 includes a cassette station 200 that carries a wafer W into and out of the etching processing apparatus 3, a common transport unit 201 that transports the wafer W, and a film to be processed on the wafer W in a predetermined pattern. And etching apparatus 202 and 203 for etching, and dimension measuring apparatuses 204 and 205 as other dimension measuring apparatuses for measuring the dimension of the pattern of the film to be processed (hereinafter referred to as “processed film pattern”). In the present embodiment, for example, the line width of the film pattern to be processed is measured as the dimension of the film pattern to be processed.

  The cassette station 200 has a transfer chamber 211 in which a wafer transfer mechanism 210 for transferring the wafer W is provided. The wafer transfer mechanism 210 has two transfer arms 210a and 210b that hold the wafer W substantially horizontally, and is configured to transfer the wafer W while holding it by either of the transfer arms 210a and 210b. . A cassette mounting table 212 on which a cassette C capable of accommodating a plurality of wafers W arranged side by side is mounted on the side of the transfer chamber 211. In the illustrated example, a plurality of, for example, three cassettes C can be mounted on the cassette mounting table 212.

  The transfer chamber 211 and the common transfer unit 201 are connected to each other via two load lock devices 213a and 213b that can be evacuated.

  The common transfer unit 201 includes, for example, a transfer chamber chamber 214 having a sealable structure formed so as to have a substantially polygonal shape (in the illustrated example, a hexagonal shape) when viewed from above. In the transfer chamber 214, a wafer transfer mechanism 215 for transferring the wafer W is provided. The wafer transfer mechanism 215 has two transfer arms 215a and 215b that hold the wafer W substantially horizontally, and is configured to transfer the wafer W while holding it by either of the transfer arms 215a and 215b. .

  Etching devices 202 and 203, dimension measuring devices 204 and 205, and load lock devices 213 b and 213 a are arranged outside the transfer chamber chamber 214 so as to surround the periphery of the transfer chamber chamber 214. The etching devices 202 and 203, the dimension measuring devices 204 and 205, and the load lock devices 213b and 213a are arranged in this order in the clockwise direction when viewed from above, for example, and with respect to the six side surfaces of the transfer chamber 214, respectively. They are arranged so as to face each other.

In addition, about the structure of the dimension measuring apparatuses 204 and 205, since it is the same as that of the dimension measuring apparatus 20 in the coating and developing treatment apparatus 2 described above, the description thereof is omitted. In these linear measurement apparatus 204 can measure the size of the target film pattern at a plurality of measurement points in each wafer region W ₁ to _W-5.

  Next, the control device 400 that controls the heating temperature in the PEB devices 94 to 99 and the exposure amount in the exposure device 13 will be described. The control device 400 is constituted by, for example, a general-purpose computer including a CPU, a memory, and the like, and includes a measurement unit 124 of the dimension measurement device 20 shown in FIG. 5, a temperature control device 144 shown in FIGS. Connected to the devices 204 and 205.

  As shown in FIG. 10, the control device 400 includes, for example, an input unit 401 that receives the dimension measurement results from the dimension measurement devices 20, 204, and 205, and correction values for the heating temperatures of the PEB devices 94 to 99 from the dimension measurement results. A data storage unit 402 storing various information necessary for calculation, a program storage unit 403 storing various programs for calculating the correction value of the heating temperature, and executing the various programs An arithmetic unit 404 that calculates a correction value, an output unit 405 that outputs the calculated heating temperature correction value to the PEB devices 94 to 99, and the like are provided.

The program storage unit 403 stores, for example, a plurality of in-plane tendency components ΔX _i (i = 1 to n, where n is 1 or more) of the measurement dimension of the pattern from the dimension measurement result of the resist pattern or the film pattern to be processed in the wafer surface Is stored in the program P1. The plurality of in-plane tendency components ΔX _i are expressed by decomposing the in-plane tendency ΔX (the variation tendency in the wafer surface) of the pattern measurement dimension into a plurality of components using, for example, a Zernike polynomial. is there.

  The Zernike polynomial is explained here. The Zernike polynomial is a complex function on a unit circle with a radius of 1 often used in the optical field (practically used as a real function), and a polar coordinate argument ( r, θ). This Zernike polynomial is mainly used in the field of optics to analyze the aberration component of a lens. By decomposing the wavefront aberration using the Zernike polynomial, each wavefront has an independent shape such as a mountain shape or a saddle shape. Can be known.

In the present embodiment, for example, the dimension measurement values of a large number of points in the wafer surface are shown in the height direction on the wafer surface, and the points of the dimension measurement values are connected by a smooth curved surface. The in-plane tendency ΔX is regarded as a wavefront that undulates up and down. Then, the in-plane tendency ΔX of the measurement dimension of the pattern is determined by using a Zernike polynomial, such as a vertical deviation component in the ΔX direction, an X direction inclination component, a Y direction inclination component, a curved component that curves in a convex shape or a concave shape, etc. It is decomposed into a plurality of in-plane tendency components ΔX _i . The magnitude of each in-plane tendency component ΔX _i can be expressed by a Zernike coefficient.

The Zernike coefficient representing each in-plane tendency component ΔX _i is specifically expressed by the following equation using polar coordinate arguments (r, θ).

ΔX ₁ (1)
ΔX ₂ (r · cos θ)
ΔX ₃ (r · sin θ)
ΔX ₄ (2r ² -1)
ΔX ₅ (r ² · cos 2θ)
ΔX ₆ (r ² · sin 2θ)
ΔX ₇ ((3r ³ -2r) · cos θ)
ΔX ₈ ((3r ³ -2r) · sin θ)
ΔX ₉ (6r ⁴ -6r ² +1)
ΔX ₁₀ (r ³ · cos 3θ)
ΔX ₁₁ (r ³ · sin 3θ)
ΔX ₁₂ ((4r ⁴ −3r ² ) · cos 2θ)
ΔX ₁₃ ((4r ⁴ −3r ² ) · sin 2θ)
ΔX ₁₄ ((10r ⁵ -12r ³ + 3r) · cos θ)
ΔX ₁₅ ((10r ⁵ -12r ³ + 3r) · sin θ)
ΔX ₁₆ (20r ⁶ -30r ⁴ + 12r ² -1)
・
・

In the present embodiment, for example, the Zernike coefficient ΔX ₁ is a dimension average value (ΔX direction deviation component) in the wafer surface, the Zernike coefficient ΔX ₂ is an X direction inclination component, the Zernike coefficient ΔX ₃ is an Y direction inclination component, and the Zernike coefficient ΔX _4. , ΔX ₉ indicates a curved component.

Further, the program storage unit 403 uses the following equation (1) based on the in-plane tendency ΔXl of the measurement dimension of the resist pattern and the in-plane tendency ΔXe of the dimension of the film pattern to be processed. The program P2 for calculating the target in-plane tendency ΔXt of the resist pattern dimensions is stored.
ΔXt = ΔX1−ΔXe (1)

Further, the program storage unit 403 uses the following equation (2) to heat the hot plate regions R _{1 to} R ₅ in the PEB apparatuses 94 to 99 based on the above-described target in-plane tendency ΔXt of the resist pattern dimensions. A program P3 for calculating the temperature correction value ΔT is stored.
ΔT = 1 / α × F ⁻¹ (ΔXt−ΔXl) (2)
Where ΔT is a correction value of the heating temperature, α is a resist thermal sensitivity that is a conversion coefficient between the variation amount of the heating temperature and the dimension of the resist pattern, and F is a function of the variation amount of the heating temperature and the variation amount of the pattern dimension.

The function F in the above equation (2) is a calculation model M that is a matrix of, for example, the variation amount of the heating temperature and the variation amount of the pattern dimension. Here, as described above, the in-plane tendency ΔX of the measurement dimension of a pattern such as a resist pattern or a film pattern to be processed is expressed by using a plurality of in-plane tendency components ΔX _i decomposed by the Zernike polynomial. Therefore, for example, as shown in FIG. 11, the calculation model M is a determinant of n (number of in-plane tendency components) rows × m (number of hot plate regions) columns expressed using Zernike coefficients under specific conditions. The calculation model M is stored in the data storage unit 402, for example.

In the calculation model M, for example, the temperature of each of the hot plate regions R _{1 to} R ₅ of the hot plate 140 is raised by 1 ° C. in order, and the dimensions of the pattern of multiple points in the wafer surface in each case are measured. From the measured dimensions, the dimensional fluctuation amount of the pattern in the wafer surface corresponding to each in-plane tendency component ΔX _i (Zernike coefficient) is calculated, and the dimensional fluctuation per unit temperature fluctuation of the hot plate regions R _{1 to} R ₅ The quantity is expressed as each element M _{i, j} (1 ≦ i ≦ n, 1 ≦ j ≦ m (m = 5, which is the number of hot plate regions in the present embodiment)) of the determinant.

In addition, the program storage unit 403 uses the following equation (3) to heat the hot plate regions R _{1 to} R ₅ based on the correction value ΔT of the heating temperature of the hot plate regions R _{1 to} R ₅ described above. A program P4 for correcting the temperature is stored.
T = Tl + ΔT (3)
Where T: corrected heating temperature, Tl: heating temperature before correction

  The programs P1 to P4 for realizing the functions of the control device 400 are, for example, a computer-readable hard disk (HD), flexible disk (FD), compact disk (CD), magnetic optical desk (MO), memory card, etc. May be recorded in a computer-readable storage medium and installed in the control device 400 from the storage medium.

  Next, the processing process of the wafer W in the substrate processing system 1 configured as described above will be described together with the inspection processing of the inspection wafer E. FIG. 12 is a flowchart for explaining the inspection processing step for the inspection wafer E and the processing step for the wafer W. In the present embodiment, a film to be processed is formed on the wafer W in advance.

  First, in order to correct the heating temperature of the PEB apparatuses 94 to 99, a series of photographic processes are performed on the inspection wafer E by the coating and developing processing apparatus 2, and a resist pattern is formed on the film to be processed on the inspection wafer E. (Step S1 in FIG. 12). Details of the photolithography process will be described in the process of the wafer W described later. The inspection wafer E on which the resist pattern is formed is transferred to the dimension measuring device 20 of the inspection station 11.

In the dimension measuring apparatus 20, the inspection wafer E is mounted on the mounting table 120. Next, a predetermined portion of the inspection wafer E is irradiated with light from the light irradiation unit 122, and the reflected light is detected by the light detection unit 123. Then, the measurement unit 124 measures the dimension of the resist pattern on the inspection wafer E (step S2 in FIG. 12). At this time, the dimension of the resist pattern in each of the wafer regions W _{1 to} W ₅ is measured. The measurement result of the resist pattern dimension of the inspection wafer E is output to the input unit 401 of the control device 400.

  Thereafter, the inspection wafer E is transferred to the etching processing apparatus 3, and the processing target film of the inspection wafer E is etched using the resist pattern as a mask to form a pattern on the processing target film (FIG. 12). Step S3). Thereafter, the inspection wafer E is transferred to the dimension measuring device 204 in the etching processing apparatus 3.

In the dimension measuring apparatus 204, the dimension of the film pattern to be processed is measured by the same method as the measurement of the dimension of the resist pattern in the dimension measuring apparatus 20 described above (step S4 in FIG. 12). At this time, the dimension of the film pattern to be processed in each of the wafer regions W _{1 to} W ₅ is measured. The dimension measurement result of the film pattern to be processed on the inspection wafer E is output to the input unit 401 of the control device 400.

  In the control device 400, first, the calculation unit 404 calculates an in-plane tendency ΔXl of the measurement dimension of the resist pattern using the program P1 based on the measurement dimension of the resist pattern of the inspection wafer E. Similarly, the in-plane tendency ΔXe of the measurement dimension of the film to be processed is calculated based on the measurement dimension of the resist pattern of the film to be processed (step S5 in FIG. 12).

  Subsequently, based on the in-plane tendency ΔXl of the measured dimension of the resist pattern and the in-plane tendency ΔXe of the dimension of the film pattern to be processed, a target in-plane tendency ΔXt of the dimension of the resist pattern is calculated using the program P2. Specifically, as shown in FIG. 13, the in-plane tendency ΔXe of the measurement dimension of the film pattern to be processed is subtracted from the in-plane tendency ΔXl of the measurement dimension of the resist pattern to calculate the target in-plane tendency ΔXt of the dimension of the resist pattern. (Step S6 in FIG. 12).

Thereafter, based on the target in-plane tendency ΔXt of the resist pattern dimensions, a heating temperature correction value ΔT of each of the hot plate regions R _{1 to} R ₅ in the PEB apparatuses 94 to 99 is calculated using the program P3 (FIG. 12). Step S7).

Then, based on the correction value ΔT of the heating temperature of the thermal plate regions _R 1 to R _5, the heating temperature of each of the thermal plate regions _R 1 to R ₅ with the program P4 is corrected (step S8 in FIG. 12). The corrected heating temperatures T of the hot plate regions R _{1 to} R ₅ are output from the output unit 405 to the PEB devices 94 to 99.

  Next, a series of photolithography processes are performed on the product wafer W, for example. First, the wafers W are taken out one by one from the cassette C on the cassette mounting table 15 by the wafer transfer body 17 and sequentially transferred to the transfer unit 21 of the inspection station 11. The wafer W transferred to the delivery unit 21 is transferred to the processing station 12 by the wafer transfer body 23.

  The wafer W transferred to the processing station 12 is first transferred to the temperature adjusting device 70 belonging to the third processing unit group G3, and the temperature is adjusted to a predetermined temperature. Thereafter, the wafer W is transferred to the bottom coating device 43 by the first transfer device 30, and an antireflection film is formed. The wafer W on which the antireflection film is formed is sequentially transferred to the heat treatment apparatus 102, the high temperature heat treatment apparatus 75, and the high precision temperature adjustment apparatus 80 by the first transfer apparatus 30, and is subjected to a predetermined process in each processing apparatus. The Thereafter, the wafer W is transferred to the resist coating device 40 by the first transfer device 30, and a resist film is formed on the wafer W.

  The wafer W on which the resist film is formed is transported to the PAB device 81 by the first transport device 30 and subjected to heat treatment, and then the peripheral exposure device 104 and the high-precision temperature control device 93 are transported by the second transport device 31. Are sequentially conveyed, and predetermined processing is performed in each apparatus. Thereafter, the wafer is transferred to the exposure apparatus 13 by the wafer transfer body 111 of the interface station 14, and a predetermined pattern is exposed on the resist film on the wafer W. The wafer W that has been subjected to the exposure processing is transferred to the PEB apparatus 94 of the processing station 12 by the wafer transfer body 111.

The wafer W transferred to the PEB apparatus 94 is transferred to the lift pins 150 that have been lifted and waited in advance, and after the lid 130 is closed, the lift pins 150 are lowered so that the wafer W becomes the hot plate 140. Placed on top. At this time, each of the hot plate regions R _{1 to} R ₅ of the hot plate 140 is heated to the heating temperature corrected in step S8 described above. The wafer W is heated to a predetermined temperature by the heated hot plate 140.

  The wafer W that has been subjected to the PEB processing in the PEB apparatus 94 is transferred to the high-precision temperature adjusting device 91 by the second transfer device 31 to be temperature-adjusted, and then transferred to the development processing device 50 where development processing is performed on the wafer W. The resist film is developed. Thereafter, the wafer W is transferred to the POST apparatus 85 by the second transfer apparatus 31 and post-baked, and then transferred to the high-precision temperature controller 72 by the first transfer apparatus 30 and the temperature is adjusted. Thereafter, the wafer W is transferred to the transition device 71 by the first transfer device 30, transferred to the transfer section 21 of the inspection station 11 by the wafer transfer body 23, and returned to the cassette C from the transfer section 21 by the wafer transfer body 17. . Thus, a series of wafer processing in the coating and developing treatment apparatus 2 is completed, and a predetermined resist pattern is formed on the wafer W (step S9 in FIG. 12). At this time, the resist pattern on the wafer W is formed with the above-mentioned target in-plane tendency ΔXt.

  When the resist pattern is formed on the wafer W in the coating / developing apparatus 2, the cassette C containing the wafer W is unloaded from the coating / developing apparatus 2 and then loaded into the etching apparatus 3.

  In the etching processing apparatus 3, first, one wafer W is taken out from the cassette C on the cassette mounting table 212 by the wafer transfer mechanism 210 and loaded into the load lock apparatus 213a. When the wafer W is loaded into the load lock device 213a, the inside of the load lock device 213a is sealed and decompressed. After that, the inside of the load lock device 213a and the inside of the transfer chamber chamber 214 in a state where the pressure is reduced with respect to the atmospheric pressure (for example, a substantially vacuum state) are communicated. Then, the wafer transfer mechanism 215 unloads the wafer W from the load lock device 213a and loads it into the transfer chamber 214.

  The wafer W loaded into the transfer chamber 214 is then transferred into the etching apparatus 202 by the wafer transfer mechanism 215 and the film to be processed on the wafer W is etched. Thereafter, the resist pattern and the antireflection film are removed, and a predetermined pattern is formed on the film to be processed (step S10 in FIG. 12). At this time, the in-plane tendency of the dimension of the film pattern to be processed is zero. . That is, the film pattern to be processed is uniformly formed on the wafer W within the wafer surface.

  Thereafter, the wafer is returned again into the transfer chamber 214 by the wafer transfer mechanism 215. Then, the wafer is transferred to the wafer transfer mechanism 210 via the load lock device 213b and stored in the cassette C. Thereafter, the cassette C containing the wafers W is unloaded from the etching processing apparatus 3 and a series of wafer processing ends.

According to the above embodiment, in the above formula (1), the in-plane tendency ΔXe of the measurement dimension of the film pattern to be processed is subtracted from the in-plane tendency ΔXl of the measurement pattern of the resist pattern, and the target surface of the dimension of the resist pattern An internal tendency ΔXt is calculated. That is, the target in-plane tendency ΔXt of the dimension of the resist pattern is set so that the in-plane tendency of the dimension of the film pattern to be processed becomes zero. Then, using equation (2), so that plane tendency of the dimensions of the resist pattern becomes the target plane tendency .DELTA.Xt, the heating temperature of the thermal plate regions _R 1 to R ₅ in the PEB unit 94 to 99 It is corrected. Thereafter, the PEB process is performed at the heating temperature corrected as described above, and the photolithography process and the etching process are performed on the wafer W. Therefore, the resist pattern can be formed with the dimension of the target in-plane tendency ΔXt, and the film to be processed The in-plane tendency of the pattern dimension can be made zero. Therefore, a predetermined pattern can be uniformly formed on the film to be processed on the wafer W within the wafer surface. This also improves the product yield.

In the above embodiment, the heating temperature of the plurality of hot plate regions R _{1 to} R ₅ is corrected in the hot plate 140 of the PEB devices 94 to 99. By performing the PEB process at the heating temperature corrected as described above, the wafer W can be heated for each of the wafer regions W _{1 to} W ₅ . Therefore, a resist pattern can be formed on the wafer W with a target in-plane tendency ΔXt with higher accuracy.

  Note that the wafer processing method of the present embodiment can also be applied to the case where a so-called double patterning process used when forming a fine resist pattern on the wafer W is performed. In the double patterning process, first, the first exposure process and the development process are performed on the resist film on the wafer W to form a first pattern. Then, after etching the first pattern, the resist film is again subjected to a second exposure process and a development process to form a second pattern. Then, the first pattern and the second pattern are synthesized, and a fine resist pattern is formed on the wafer W.

  In this double patterning process, first, the dimension of the first pattern is measured, and an in-plane tendency (corresponding to ΔXe in the above embodiment) of the measured dimension is calculated. Thereafter, the dimension of the second pattern is measured, and an in-plane tendency (corresponding to ΔX1 in the above embodiment) of the measured dimension is calculated. Then, a target in-plane tendency (corresponding to ΔXt in the above embodiment) of the dimension of the second pattern is calculated using the above formula (1). Based on the target in-plane tendency of the dimension of the second pattern, the heating temperature of the PEB process is corrected using the above formula (2). Then, when forming the second pattern, the PEB process is performed at the corrected heating temperature.

  In this case, the in-plane tendency of the dimension of the first pattern can be matched with the in-plane tendency of the dimension of the second pattern. Accordingly, since the first pattern and the second pattern can be formed with the same in-plane tendency dimension, a predetermined resist pattern can be formed on the wafer W.

  In this case, the heating temperature of the PEB process when forming the first pattern may also be corrected. That is, similarly to the method of the above embodiment, the heating temperature of the PEB process may be corrected in consideration of the in-plane tendency of the dimension of the film pattern to be processed after the etching process of the first pattern. In such a case, after the PEB process is performed at the corrected heating temperature to form the first pattern, the film to be processed on the wafer W is etched using the first pattern as a mask, and the film pattern to be processed is formed within the wafer surface. It can be formed uniformly. Further, as described above, the in-plane tendency of the dimension of the first pattern and the in-plane tendency of the dimension of the second pattern can be matched. Therefore, when the film to be processed is etched using the second pattern as a mask. In addition, the film pattern to be processed can be uniformly formed in the wafer surface. Therefore, a predetermined pattern can be uniformly formed on the film to be processed on the wafer W within the wafer surface.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood.

  For example, in the above embodiment, the line width of the pattern is adjusted as the dimension of the resist pattern or the film pattern to be processed. Instead, the side wall angle of the pattern or the diameter of the contact hole is adjusted. Also good. In such a case, the heating temperatures of the POST devices 85 to 89 and the PAB devices 81 to 84 may be corrected instead of the heating temperatures of the PEB devices 94 to 99 corrected in the above embodiment.

  Further, the dimension measuring apparatus 20 is provided in the inspection station 11, but may be provided in the processing station 12. Further, the dimension measuring devices 204 and 205 are disposed in the etching processing apparatus 3, but may be provided independently outside the etching processing apparatus 3. Further, the dimension measuring devices 20, 204, 205 measure the dimensions of the resist pattern and the film pattern to be processed in the wafer surface by, for example, irradiating the wafer W with an electron beam and acquiring an image of the surface of the wafer W. Also good.

  Moreover, although the heat plate 140 whose temperature is set in the PEB devices 94 to 99 is partitioned into five regions, the number thereof can be arbitrarily selected. Further, the shape of the partition area of the hot plate 140 can be arbitrarily selected.

  Furthermore, the present invention can also be applied to a case where the substrate is another substrate such as an FPD (flat panel display) other than the wafer W, a mask reticle for a photomask, or the like.

  The present invention is useful when a predetermined pattern is formed on a film to be processed on a substrate such as a semiconductor wafer.

1 substrate processing system 2 coating and developing treatment apparatus 3 etching apparatus 94 to 99 PEB 140 hot plate 20,204,205 sizer 400 controller E test wafer P1~P4 program R ₁ to R ₅ of the thermal plate regions W wafer

Claims (12)

A substrate processing method for forming a predetermined pattern on a film to be processed on a substrate,
Performing a photolithography process on the substrate, forming a resist pattern on the target film of the substrate, measuring the dimension of the resist pattern, and calculating an in-plane tendency of the measurement dimension of the resist pattern;
Etching is performed on the film to be processed using the resist pattern as a mask, and after forming a pattern on the film to be processed, the dimension of the pattern of the film to be processed is measured. Calculating an internal trend,
Calculating a target in-plane tendency of the dimension of the resist pattern using the following equation (1) based on the in-plane tendency of the measured dimension of the resist pattern and the in-plane tendency of the measured dimension of the film to be processed; ,
Based on the target in-plane tendency of the dimension of the resist pattern, using the following formula (2), calculating a correction value for the heat treatment temperature in the photolithography process;
Correcting the processing temperature based on the correction value of the processing temperature;
Performing a photolithography process including a heat treatment at the corrected processing temperature and an etching process to form a predetermined pattern on a film to be processed on the substrate.
ΔXt = ΔX1−ΔXe (1)
ΔT = 1 / α × F ⁻¹ (ΔXt−ΔXl) (2)
However, ΔXt: target in-plane tendency of resist pattern dimension, ΔXl: in-plane tendency of measurement dimension of resist pattern, ΔXe: in-plane tendency of measurement dimension of film pattern to be processed, ΔT: correction value of processing temperature, α : Conversion coefficient between processing temperature variation and resist pattern dimension, F: Function of processing temperature variation and pattern dimension variation The heat treatment is performed using a heat treatment plate partitioned into a plurality of regions,
The substrate processing method according to claim 1, wherein the processing temperature is corrected for each region of the heat treatment plate. 3. The substrate processing method according to claim 1, wherein the heat treatment is a heat treatment performed after an exposure process in a photolithography process and before a development process. The substrate processing method according to claim 1, wherein the in-plane tendency is expressed by being decomposed into a plurality of in-plane tendency components using a Zernike polynomial. The substrate processing method according to claim 1, wherein the dimension of the pattern is a line width of the pattern. A program that operates on a computer of a control device that controls the substrate processing system in order to cause the substrate processing system to execute the substrate processing method according to claim 1. A readable computer storage medium storing the program according to claim 6. A substrate processing system for forming a predetermined pattern on a film to be processed on a substrate,
A coating and developing apparatus for performing a photolithography process on a substrate and forming a resist pattern on a film to be processed on the substrate;
An etching apparatus for performing an etching process on the film to be processed using the resist pattern as a mask, and forming a pattern on the film to be processed;
A dimension measuring device for measuring the dimension of the resist pattern;
Other dimension measuring apparatus for measuring the dimension of the pattern of the film to be processed;
A controller for correcting the processing temperature of the heat treatment in the photolithography process,
The controller is
Measure the resist pattern by calculating the in-plane tendency of the measured dimension of the resist pattern measured by the dimension measuring apparatus and calculating the in-plane tendency of the measured dimension of the resist pattern measured by the other dimension measuring apparatus. Based on the in-plane tendency of the dimension and the in-plane tendency of the measurement dimension of the pattern of the film to be processed, the target in-plane tendency of the dimension of the resist pattern is calculated using the following formula (1):
Based on the target in-plane tendency of the resist pattern dimensions, the following equation (2) is used to calculate a correction value for the processing temperature of the heat treatment performed in the coating and developing apparatus:
A substrate processing system, wherein the processing temperature is corrected based on a correction value of the processing temperature.
ΔXt = ΔX1−ΔXe (1)
ΔT = 1 / α × F ⁻¹ (ΔXt−ΔXl) (2)
However, ΔXt: target in-plane tendency of resist pattern dimension, ΔXl: in-plane tendency of measurement dimension of resist pattern, ΔXe: in-plane tendency of measurement dimension of film pattern to be processed, ΔT: correction value of processing temperature, α : Conversion coefficient between processing temperature variation and resist pattern dimension, F: Function of processing temperature variation and pattern dimension variation The heat treatment is performed using a heat treatment plate partitioned into a plurality of regions,
The substrate processing system according to claim 8, wherein the control device corrects the processing temperature for each of a plurality of regions of the heat treatment plate. 10. The substrate processing system according to claim 8, wherein the heat treatment is a heat treatment performed after the exposure processing and before the development processing in the coating and developing processing apparatus. The substrate processing system according to claim 8, wherein the control device decomposes the in-plane tendency into a plurality of in-plane tendency components using a Zernike polynomial. The substrate processing system according to claim 8, wherein the dimension measuring device and the other dimension measuring device respectively measure a line width of the pattern as the dimension of the pattern.

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