Substrate processing method, substrate processing apparatus, computer readable storage medium, and computer program product

Abstract

The invention provides a substrate processing method, a substrate processing apparatus, a computer readable storage medium, and a computer program product. A substrate processing method for heat-treating a metal-containing resist film formed on the surface of a substrate, the method comprising: a first heat-treating step of supplying a first gas to the substrate; and a second heat treatment step for supplying a second gas after the first step, the humidity of the first gas being higher than the humidity of the second gas.

Description

[0001] This application is a divisional application of a Chinese patent application with an application date of March 15, 2021, an application number of 202180021355.7, and an invention title of "Heat Treatment Apparatus and Heat Treatment Method". Technical Field

[0002] The present disclosure relates to a heat treatment apparatus and a heat treatment method. Background Art

[0003] In a lithography process in a semiconductor device manufacturing process, for example, a resist is coated on a semiconductor wafer (hereinafter referred to as "wafer") to form a resist film. Next, an exposure process of exposing the wafer on which the resist film is formed to a predetermined circuit pattern is performed. And, the wafer on which the exposed resist film is formed is heat-treated, whereby the chemical reaction of the exposed portion or the unexposed portion of the resist film is promoted, and it dissolves or does not dissolve in the developer. After that, the soluble portion of the resist film is removed by supplying the developer to the heat-treated wafer W, and a predetermined resist pattern is formed on the wafer.

[0004] In recent years, further high integration of semiconductor devices has been required. Therefore, in order to achieve miniaturization of the resist pattern, an exposure process using EUV (Extreme Ultraviolet) has been proposed. In the exposure process using EUV, in order to achieve high sensitivity of the resist film to exposure, a metal-containing resist as described in Patent Document 1 is used, for example.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016-530565 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] The present disclosure provides a technique capable of promoting a change in solubility when heat-treating a substrate having an exposed resist film formed on its surface, wherein the solubility of the exposed portion or the unexposed portion of the resist film changes with respect to the developer by reacting with water and being heated.

[0010] Solutions to the Problems

[0011] The heat treatment apparatus of the present disclosure includes: a stage for placing a substrate having an exposed resist film formed on its surface and heating the substrate, wherein the solubility of the exposed portion or the unexposed portion of the exposed resist film changes with respect to the developer by reacting with water and being heated;

[0012] A lifting mechanism that relatively lifts and lowers the substrate between a first position where the substrate is placed on the placement table and a second position away from the placement table; and

[0013] A gas supply unit that supplies a first gas to the substrate located at the second position before moving to the first position, and the humidity of the first gas is higher than the humidity of the atmosphere in which the placement table is provided.

[0014] Effects of the Invention

[0015] According to the present disclosure, when heat-treating a substrate having an exposed resist film on its surface where the solubility of the exposed or unexposed portion changes with respect to the developer by reacting with water and being heated, the change in solubility can be promoted. Description of the Drawings

[0016] Figure 1 is a longitudinal sectional side view of the heat treatment apparatus according to the first embodiment.

[0017] Figure 2 is an operation diagram showing the operation of the heat treatment apparatus.

[0018] Figure 3 is an operation diagram showing the operation of the heat treatment apparatus.

[0019] Figure 4 is an operation diagram showing the operation of the heat treatment apparatus.

[0020] Figure 5 is a longitudinal sectional side view of the processing chamber provided in the heat treatment apparatus according to the second embodiment.

[0021] Figure 6 is an operation diagram showing the operation of the heat treatment apparatus according to the second embodiment.

[0022] Figure 7 is an operation diagram showing the operation of the heat treatment apparatus according to the second embodiment.

[0023] Figure 8 is an operation diagram showing the operation of the heat treatment apparatus according to the second embodiment.

[0024] Figure 9 is a bottom surface side elevation view of the gas supply unit according to the third embodiment.

[0025] Figure 10 is a longitudinal sectional side view of the processing chamber provided in the heat treatment apparatus according to the third embodiment.

[0026] Figure 11 is an explanatory diagram showing an example of the supply of gas in the third embodiment.

[0027] Figure 12 It is a longitudinal sectional side view showing another example of the heat treatment apparatus according to the third embodiment.

[0028] Figure 13 It is a functional diagram showing the function of another example of the heat treatment apparatus.

[0029] Figure 14 It is a functional diagram showing the function of another example of the heat treatment apparatus.

[0030] Figure 15 It is a longitudinal sectional view showing a coating and developing apparatus.

[0031] Figure 16 It is a top view showing a coating and developing apparatus.

[0032] Figure 17 It is a graph showing the results of the examples. Detailed Description of the Invention

[0033] [First Embodiment]

[0034] The heat treatment apparatus 1 according to the present disclosure will be described. The heat treatment apparatus 1 is a device for heating a wafer W on which a resist film is formed, and the resist film is, for example, exposed by EUV along a circuit pattern. Therefore, the heat treatment apparatus 1 is a device for performing so-called post-exposure bake (PEB). The resist constituting the resist film contains, for example, a metal, and an example of the metal is tin. When the resist is further described, the ligand detaches from the metal due to irradiation with radiation such as the above-mentioned EUV, and in this state, the resist is introduced with a hydroxyl group by reacting with water. Then, by heating, dehydration condensation occurs between the hydroxyl groups, and as a result, the resist becomes insoluble in the developer.

[0035] The heat treatment apparatus 1 performs the above-described introduction of the hydroxyl group (hydrophilic treatment) and dehydration condensation. Therefore, as a result of the treatment by the heat treatment apparatus 1, the exposed areas in the resist film become insoluble in the developer, and the unexposed areas are dissolved in the developer and removed, thereby forming a pattern in the resist film. Refer to Figure 1 the longitudinal sectional side view to describe the structure of the heat treatment apparatus 1. The heat treatment apparatus 1 includes a housing 10, and a transfer port 10A for the wafer W is provided on the side wall of the housing 10. In addition, the heat treatment apparatus 1 is provided in an air atmosphere, and both the inside and outside of the housing 10 are the air atmosphere. Inside the housing 10, when viewed from the side where the transfer port 10A is opened, a chamber (processing chamber) 20 for heat-treating the wafer W is provided on the distal side.

[0036] The processing chamber 20 includes a lid portion 21 that constitutes the top and a lower portion 22 that is located below the lid portion 21 and includes a bottom. The lid portion 21 that constitutes the upper portion of the processing chamber 20 is connected to a lifting mechanism 28 for the chamber via a support portion 29. Further, by the lifting mechanism 28, the lid portion 21 is raised relative to the lower portion 22, thereby separating and opening the processing chamber 20, and the processing chamber 20 is closed by lowering the lid portion 21.

[0037] A stage 23 is provided inside the lower portion 22. In addition, Figure 1 Reference numeral 25 in the figure is a holding member for holding the stage 23. A heater 24 is embedded in the stage 23, and is configured to heat the wafer W placed on the stage 23 at a temperature of, for example, 50°C to 210°C. Through holes 23a that penetrate the stage 23 in the thickness direction are provided at three positions in the circumferential direction of the stage 23. A vertical lift pin 26 passes through each of the through holes 23a. Each lift pin 26 is connected to a lift mechanism 27 provided at the bottom of the lower portion 22. Further, each lift pin 26 is lifted and lowered by the lift mechanism 27, and the tip of the lift pin 26 protrudes or retracts from the surface of the stage 23. The wafer W is lifted and lowered between a first position where it is placed on the stage 23 and a second position away from the stage 23 by the lift pins 26 that protrude or retract from the surface of the stage 23.

[0038] In addition, regarding the resist film formed on the wafer W, if the above-mentioned hydrophilic treatment is insufficient, dehydration condensation may not be sufficiently performed. Therefore, there is a risk that the line width (width of the convex portion) of the resist pattern formed after the development process is thinner than the desired width. Therefore, the heat treatment apparatus 1 according to the present disclosure includes a gas supply unit 3 that supplies moist air containing moisture to the wafer W to reliably hydrophilize the resist film and promote dehydration condensation.

[0039] The gas supply unit 3 is provided inside the lid portion 21 and includes a shower head 30 that has an opposing portion with an opposing surface that faces the wafer W placed on the stage 23. The inside of the shower head 30 forms a diffusion space for gas diffusion. Further, gas ejection holes 31 for supplying gas toward the wafer W are dispersedly formed on the entire surface of the lower surface (opposing surface facing the wafer W) of the shower head 30.

[0040] One end of a gas supply pipe 32 is connected to the upper surface of the showerhead 30 in a manner communicating with the diffusion space. The other end of the gas supply pipe 32 is provided with a gas supply source 33 via a valve V32, and the gas supply source 33 is configured to supply a first gas having a humidity higher than that of the atmosphere where the stage 23 is disposed. The first gas is, for example, humid air having a humidity of 68%. In addition, the humidity used in this specification represents relative humidity. Further, the atmosphere where the stage 23 is disposed refers to the atmosphere above the stage 23 when the first gas is not supplied from the gas supply unit 3 toward the wafer W. Therefore, the above-described first gas as humid air is a gas for increasing the humidity of the atmosphere above the stage 23.

[0041] As the gas supply source 33, for example, a module capable of adjusting the moisture contained in the air to supply air having a desired humidity is used. For example, the gas supply source 33 can be configured to include a bubbler, a first pipeline for supplying the water vapor generated by the bubbler to the downstream side, and a second pipeline for supplying air having an arbitrary flow rate to the water vapor flowing in the first pipeline for mixing. Moreover, by adjusting the flow rate of the air in the second pipeline, air having a desired humidity can be supplied to the showerhead 30. However, the structure of the gas supply source 33 is not limited to such a structure and can be set to any structure.

[0042] A central exhaust port 34 for exhausting the atmosphere inside the processing chamber 20 is opened at the center of the lower surface of the showerhead 30. A central exhaust pipe 341 is connected to the central exhaust port 34 and is provided in a manner penetrating the showerhead 30. Further, the showerhead 30 is arranged such that a gap is formed between its side peripheral surface and the inner surface of the cover portion 21, and the gap constitutes an outer peripheral side exhaust port 35 for exhausting from the outer peripheral side of the wafer W. The outer peripheral side exhaust port 35 communicates with an outer peripheral side exhaust pipe 351. The central exhaust pipe 341 and the outer peripheral side exhaust pipe 351 are connected to an exhaust device in the factory and are configured to be able to exhaust the atmosphere inside each processing chamber 20. V341 provided in the central exhaust pipe 341 is a valve for opening and closing the central exhaust pipe 341, and V351 provided in the outer peripheral side exhaust pipe 351 is a valve for opening and closing the outer peripheral side exhaust pipe 351.

[0043] A transfer mechanism 11 is provided on the proximal side (transfer port 10A side) within the housing 10. The transfer mechanism 11 includes a substantially circular plate-shaped support portion in a horizontal plane, namely, a support plate 12, on the surface of which a wafer W is placed. A temperature control mechanism (not shown) is embedded in the support plate 12 to control the temperature so that the temperature of the wafer W placed on the support plate 12 becomes uniform in the plane. The support plate 12 is moved along a guide rail 15 provided on the bottom surface of the housing 10 in a direction from the transfer port 10A side to the distal side via a moving mechanism 14 connected through a support member 13. Thus, the support plate 12 can move between the upper region above the mounting table 23 and the outer region of the processing chamber 20 that is offset in the lateral direction from the mounting table 23 ( Figure 1 the position shown).

[0044] When the transfer mechanism 11 is located in the outer region, the transfer mechanism outside the heat treatment device 1 that holds the wafer W enters the housing 10 from the transfer port 10A. And the external transfer mechanism moves up and down from above the support plate 12 to below, thereby performing the transfer of the wafer W between the transfer mechanism outside the heat treatment device 1 and the transfer mechanism 11 within the housing 10. In addition, a slit (not shown) extending from the end on the processing chamber 20 side to the other end is formed in the support plate 12. Through this slit, when the support plate 12 is located above the mounting table 23, the lift pins 26 that protrude or retract from the mounting table 23 can protrude above the support plate 12 via this slit. Then, through the cooperation of the lifting of the lift pins 26 and the advancement and retreat of the transfer mechanism 11, the transfer of the wafer W is performed between the mounting table 23 and the support plate 12.

[0045] The heat treatment device 1 includes, for example, a control unit 100 composed of a computer. The control unit 100 is configured to be able to output control signals to the chamber lifting mechanism 28, the lifting mechanism 27, the valves V32, V341, V351, and the moving mechanism 14. A program is stored in the control unit 100, and this program is incorporated into commands (step groups) to implement the sequence of wafer W transfer, lifting of the lift pins 26 and the cover portion 21, and gas supply shown in the operation of the heat treatment device 1 described later. This program is stored and installed in the control unit 100 through storage media such as compact discs, hard disks, MO (magneto-optical discs), DVDs, and memory cards.

[0046] The operation of the heat treatment device 1 according to the present disclosure will be described. The heat treatment device 1, for example, stands by in a state where the mounting table 23 is heated to 50°C to 210°C by the heater 24, and the processing chamber 20 is open and exhausted from each exhaust port 34, 35. In addition, the support plate 12 is at the position for receiving the wafer W ( Figure 1Standby at the position indicated by the solid line in []. First, a transfer mechanism (not shown) that holds the exposed wafer W is moved into the heat treatment apparatus 1 from the outside and moved downward from above the support plate 12 to place the wafer W on the support plate 12.

[0047] Next, the support plate 12 is moved directly above the mounting table 23. Then, the wafer W supported by the support plate 12 is pushed up by the lift pins 26, and the wafer W is supported at a second position above the mounting table 23, and the support plate 12 retracts to the outer region. Next, as Figure 2 shown, a first gas is supplied toward the wafer W, and exhaust is performed, for example, from the outer peripheral side exhaust port 35 among the respective exhaust ports. At this time, the lid portion 21 maintains the raised state, and the processing chamber 20 is open. Moisture is supplied to the wafer W by exposing the wafer W to the first gas, which is humid air, to hydrophilize the resist film.

[0048] Next, as Figure 3 shown, while maintaining the supply of the first gas and the exhaust from the outer peripheral side exhaust port 35, the lift pins 26 are lowered, and the wafer W is moved to the mounting position (first position) of the mounting table 23. For example, in parallel with the lowering of the lift pins 26, the lid portion 21 is lowered to close the processing chamber 20. In this way, the wafer W is heated to the same temperature as the mounting table 23 by being placed on the mounting table 23, and heat treatment is performed. The temperature of the wafer W rises, and dehydration condensation of the above-described hydroxyl groups occurs, and the insolubility of the exposed portion in the resist film with respect to the developer progresses.

[0049] When the heat treatment of the wafer W is completed, as Figure 4 shown, the supply of the first gas is stopped, and the exhaust using the outer peripheral side exhaust port 35 is stopped, and the exhaust is switched to the central exhaust port 34.

[0050] After that, the lid portion 21 is raised to open the processing chamber 20, and the lift pins 26 are raised to raise the wafer W from the mounting table 23. Then, the wafer W is transferred to the transfer mechanism 11 by the combined action of the transfer mechanism 11 and the lift pins 26. The wafer W is further transferred to an external transfer device and carried out of the heat treatment apparatus 1 to be subjected to development processing.

[0051] According to the heat treatment apparatus 1, air (first gas) having a humidity higher than the humidity of the atmosphere above the humidity ratio stage 23 is supplied to the wafer W and heat treatment is performed. Therefore, during the heat treatment, a state is achieved in which hydroxyl groups are sufficiently introduced into the exposed portions of the resist film, and during the heat treatment, the insolubilization of the exposed portions progresses rapidly. That is, for the exposed portions, the sensitivity of the reaction based on heating is increased. Since the insolubilization of the exposed portions is promoted in this way, during the development process, a situation where the width of the convex portions of the resist pattern is smaller than the set value due to insufficient insolubilization is suppressed.

[0052] In addition, it is considered that after the wafer W is placed on the stage 23 and heated, the adhesion of the moisture contained in the first gas to the resist film is reduced due to the heat of the wafer W. However, according to the heat treatment apparatus 1, since the first gas is supplied from before the wafer W is placed on the stage 23, heating is performed in a state where the above-described introduction of hydroxyl groups has been reliably performed. Thus, the rapid insolubilization of the above-described exposed portions can be performed with high reliability. Moreover, since the position where the first gas is supplied is above the stage 23, after the introduction of hydroxyl groups, the wafer W can be quickly placed on the stage 23 and heat treatment can be performed.

[0053] Therefore, from the supply of the first gas until the wafer W is placed on the stage 23, drying occurs in the plane of the wafer W due to the influence of the air flow in the area where the wafer W moves. Thereby, the deviation of the penetration amount of the moisture of the resist in the plane of the wafer W before being placed on the stage 23 is suppressed. That is, the deviation of the introduction state of hydroxyl groups in the plane of the wafer W is suppressed, and thus the deviation of the line width of the pattern in the plane of the wafer W after development can be suppressed.

[0054] In addition, since the wafer W is positioned at the second position and the first gas is supplied, compared with the state where the wafer W is placed on the stage 23, the first gas having a high humidity can be supplied to the wafer W in a state closer to the nozzle 30. That is, the space between the surface of the wafer W and the first gas supply portion is smaller than this space during the heat treatment of the wafer W, so a state is achieved in which it is difficult for an air flow to be generated above the wafer W, and moisture can penetrate more uniformly in the plane of the wafer W. In addition, when the wafer W is positioned at the second position and the first gas is supplied, since it is before the heat treatment of the wafer W, the amount of sublimates generated due to the heat treatment of the wafer W is also small. Therefore, the exhaust gas in the processing chamber 20 can be made weaker than the exhaust gas during the period of heat treatment of the wafer W (the period when the wafer W is placed on the stage 23) or set to be closed, etc., to further adjust the air flow around the wafer W, thereby preventing the leakage of sublimates and avoiding an excessive increase in the air flow above the wafer W beyond the requirement.

[0055] In addition, in order to miniaturize the resist pattern, an exposure apparatus that irradiates EUV from a light source is sometimes used as in the present embodiment. However, as such an exposure apparatus that uses EUV, the output of the light from the light source is small. Therefore, as the resist, it is desired that the solubility changes at a low dose, that is, a high sensitivity is desired. Moreover, as described above, the metal-containing resist used in the present embodiment reacts highly sensitively to moisture through the dissociation of the above-described ligand. As described above, the present technique utilizes the properties of this resist to change the solubility of the resist film with respect to the developer. Therefore, according to the present technique, even when using an exposure apparatus with a low output such as EUV, a pattern can be reliably formed on the resist film. In addition, according to the heat treatment apparatus 1, the first gas is continuously supplied even after the wafer W is placed on the placement table 23. Therefore, hydroxyl groups are more reliably introduced into the resist film to promote the insoluble reaction of the exposed portion in the film, and thus a pattern with a desired line width can be obtained.

[0056] In addition, the resist film processed by the heat treatment apparatus 1 according to the present disclosure is not limited to using a metal-containing resist, as long as it is a resist whose solubility with respect to the developer changes in the exposed portion or the unexposed portion by reacting with water and being heated. Therefore, for example, a resist in which the unexposed portion becomes soluble or insoluble by reaction, or a resist in which the exposed portion becomes soluble by reaction can also be used. By using these resists, the solubility of the resist in the exposed portion or the unexposed portion can also be reliably changed by the present technique. In addition, the metal-containing resist does not mean containing metal as an impurity, but means containing metal as a main component.

[0057] Moreover, the humidity of the first gas is preferably higher than 60%. As shown in the examples described later, by making the humidity higher than 60%, the reaction rate can be significantly increased, and a large effect can be obtained. In addition, the humidity related to the gas is sometimes described, but the gas for which the humidity is described is not limited to air. Therefore, the first gas can also be a gas other than air. In addition, in the embodiments described later, gases with high humidity and gases with low humidity are sometimes used for processing separately, but regarding these gases, they also refer to gases with high humidity and gases with low humidity measured using a hygrometer, and these gases are not limited to air.

[0058] In addition, the supply flow rate of the first gas supplied to the wafer W can be reduced when the processing chamber 20 is open, and the supply flow rate of the first gas supplied to the wafer W can be increased when the processing chamber 20 is closed. For example, in Figure 1 the heat treatment apparatus 1 shown, a flow rate adjustment unit is provided in the gas supply pipe 32, and it is configured to be able to adjust the flow rate of the gas ejected from the nozzle 30. Moreover, in Figure 2When the processing chamber 20 is opened as shown, the wafer W is placed at the second position above the stage 23, and when the first gas is supplied, the flow rate of the first gas is set to the first flow rate. And, after the wafer W is placed on the stage 23 as shown in Figure 3 and the lid portion 21 is lowered to close the processing chamber 20, the flow rate of the first gas is set to a second flow rate that is larger than the above-mentioned first flow rate.

[0059] By reducing the flow rate of the first gas supplied to the wafer W when the processing chamber 20 is open in this way, the amount of the first gas flowing out of the processing chamber 20 can be suppressed. Thereby, dew condensation generated due to the high-humidity atmosphere outside the processing chamber 20 can be suppressed. Moreover, by increasing the flow rate of the first gas after the processing chamber 20 is closed, a sufficient amount of the first gas can be supplied to the wafer W, and the resist film can be sufficiently hydrophilized.

[0060] In addition, as the timing when the lid portion 21 of the processing chamber 20 is lowered, it can be either simultaneous with the lowering of the lift pins 26 or later than the lowering of the lift pins 26. Further, as the exhaust port of the processing chamber 20, it is not limited to being provided so as to be able to exhaust from above the central portion of the wafer W and the outer periphery of the wafer W, and it can also be provided to exhaust from only one of them.

[0061] [Second Embodiment]

[0062] Next, the heat treatment apparatus 1A according to the second embodiment will be described. In addition, regarding the drawings of the heat treatment apparatus 1A and the heat treatment apparatuses 1B and 1C described later, the display of the parts having the same structure as those of the heat treatment apparatus 1 of the first embodiment is omitted, and only the part of the processing chamber 20 is shown. The heat treatment apparatus 1A is as shown in Figure 5 One end of the gas supply pipe 300 that communicates with the diffusion space of the shower head 30 is branched into two pipes on the other end side. And, a first gas supply source 301 for supplying the first gas is provided at one end of the other end side of the gas supply pipe 300, and a second gas supply source 302 for supplying a second gas having a lower humidity than the first gas is provided at the other end. The first gas is, for example, air with a humidity of 68%, and the second gas is, for example, air with a humidity of 20%.

[0063] The reference numeral 303 provided in the gas supply pipe 300 is a three-way valve for switching the gas supplied to the shower head 30 between the first gas and the second gas. Alternatively, a mixing box may be provided instead of the three-way valve 303, and the first gas and the second gas may be supplied by changing the mixing ratio of the high-humidity gas and the low-humidity gas.

[0064] First, before the wafer W carried into the heat treatment apparatus 1A is placed on the stage 23, as shown in Figure 6The first gas is supplied at the second position as shown. Next, as Figure 7 shown, with the first gas being supplied, the wafer W is placed on the placement table 23 (moved to the first position) and heat treatment is started, and the processing chamber 20 is closed. After that, in a state where the wafer W has been heat-treated, the gas supplied to the wafer W is switched to the second gas ( Figure 8 ).

[0065] By performing heat treatment while supplying a gas with high humidity, the reaction rate can be increased. However, if moisture is excessively supplied to the wafer W and heat treatment is performed, there is a risk of deterioration in the surface roughness of the resist film and the in-plane uniformity of the line width of the resist pattern. Therefore, when heat-treating the wafer W, as the reaction of the resist film progresses, the humidity of the supplied gas is reduced, and the amount of moisture supplied to the wafer W is adjusted, thereby suppressing deterioration in the surface roughness of the resist film and deterioration in the in-plane uniformity of the line width of the resist pattern.

[0066] In addition, when heat-treating the wafer W, it is difficult to make the moisture amount uniform within the plane of the wafer W. When heating while supplying humid air with high humidity to the wafer W, there is a risk that the moisture amount is likely to vary within the plane of the wafer W. Therefore, it is also possible to switch the gas supplied to the wafer W to the second gas before placing the wafer W, which is located at the second position, on the placement table 23 as shown, after supplying the first gas to the wafer W. Then, the wafer W in a state where the second gas is being supplied can be placed on the placement table 23, and heat treatment can be performed on the wafer W while supplying the second gas as shown Figure 5 shown. Figure 8 shown.

[0067] In addition, the second gas having a humidity lower than that of the first gas may be an inert gas such as nitrogen (N2) gas, for example. In addition, from the viewpoint of sufficiently changing the humidity of the gas supplied to the wafer W, the humidity difference between the first gas and the second gas is preferably 20% or more, for example.

[0068] [Third Embodiment]

[0069] In addition, it is also possible to be able to adjust the humidity of the gas supplied to the wafer W within the plane of the wafer W. Figure 9 is a bottom surface side elevation view of an example of the showerhead 30 provided in such a heat treatment apparatus 1B. For example, when observing the showerhead 30 from the bottom surface direction, five gas supply regions 300A to 300E are provided, that is, the central gas supply region 300A and each gas supply region 300B to 300E obtained by circumferentially dividing the region surrounding the central region into four, and gas ejection holes 31 are formed in each gas supply region 300A to 300E. And, as Figure 10As shown, five zones 301A to 301E are formed inside the nozzle 30 corresponding to the respective regions, and the zones 301A to 301E are respectively connected to gas supply sources 33A to 33E via gas supply pipes 32A to 32E. In addition, in Figure 10 for convenience, the five zones 301A to 301E are shown side by side in the horizontal direction.

[0070] Moreover, for example, when supplying the first gas toward the wafer W placed on the placement table 23 (moved to the first position) and being heat-treated as Figure 3 shown, the humidity of the first gas supplied from the respective regions 300A to 300E is adjusted as Figure 11 shown so that the humidity decreases, for example, in the order of the gas supply regions 300B, 300D, 300A, 300C, and 300E. By adjusting the humidity of the supplied moist air in the plane of the wafer W in this way, the amount of moisture supplied to the resist film can be adjusted in the plane of the wafer W. By adjusting the moisture supplied to the wafer W in the plane, the reaction rate of the resist can be adjusted in the plane of the wafer W. In addition, when performing heat treatment while supplying the first gas to the wafer W located at the second position before being placed on the placement table 23, the humidity of the first gas supplied to the wafer W can also be adjusted in the plane of the wafer W.

[0071] In addition, assuming that a resist pattern is formed on the wafer W after processing as described in the first embodiment, the line width of the resist pattern tends to be thinner at the peripheral portion of the wafer W than at the central portion. To eliminate this tendency, in addition to supplying the first gas to the entire surface of the wafer W, the first gas can also be further supplied toward the periphery of the wafer W. Figure 11 The processing chamber 20 provided in such a heat treatment apparatus 1C is shown. This processing chamber 20 Figure 1 similarly includes a nozzle 30A (hereinafter referred to as the "opposing gas supply portion") that supplies the first gas from the opposing portion facing the wafer W placed on the placement table 23, as in the heat treatment apparatus 1 shown in

[0072] Regarding the outer peripheral gas supply unit 30B, for example, a pipe 310 with a square cross-section is formed in a ring shape and disposed along the inner surface of the lower end of the lid portion 21. On the inner wall portion of the pipe 310, a plurality of gas ejection holes 311 are formed in the circumferential direction of the wafer W. The gas ejection holes 311 are used to supply a first gas from the outer peripheral side of the wafer W placed on the placement table 23 when the lid portion 21 is lowered to seal the processing chamber 20. One end of a gas supply pipe 312 is connected to the pipe 310, and the other end of the gas supply pipe 312 is connected to the gas supply pipe 32 that supplies gas to the opposing gas supply unit 30A, and is configured to be supplied with the first gas from the gas supply source 33. Figure 12 V312 in it is a valve.

[0073] This heat treatment apparatus 1C is, for example, connected to Figure 2 Similarly, the first gas is supplied from the opposing gas supply unit 30A to the wafer W located at the second position before being placed on the placement table 23. Next, as Figure 13 shown, in a state where gas is ejected from the opposing gas supply unit 30A, the wafer W is lowered to place the wafer W on the placement table 23, and the lid portion 21 is lowered to close the processing chamber 20. Thus, the heat treatment of the wafer W is performed while supplying the first gas toward the entire surface of the wafer W. Next, as Figure 14 shown, in a state where the wafer W is placed on the placement table 23, the supply of the first gas in the opposing gas supply unit 30A is stopped, and the first gas is supplied from the outer peripheral gas supply unit 30B. Then, this Figure 13 process and Figure 14 the process shown are repeated multiple times.

[0074] Thereby, the supply amount of the first gas in the region on the outer peripheral side of the wafer W can be made larger than the supply amount of the first gas in the region on the center side of the wafer W. Therefore, the moisture content in the region on the outer peripheral side of the wafer W can be increased, and the reaction rate can be improved. Thereby, a reduction in the line width of the resist pattern on the outer peripheral side of the wafer W can be suppressed.

[0075] Next, a coating and developing apparatus provided with the above-described heat treatment apparatuses 1, 1A to 1C will be described. Figure 15 is a schematic longitudinal sectional side view of the coating and developing apparatus, Figure 16 is a top view of the coating and developing apparatus. This coating and developing apparatus is configured by linearly connecting in order of a carrier block D1, a processing block D2, and an interface block D3. Regarding the interface block D3, an exposure apparatus D4 is connected to the side opposite to the connection direction with the processing block D2. The carrier block D1 has a function of loading and unloading the carrier C into and out of the coating and developing apparatus, and includes a placement table 91 for the carrier C, an opening and closing portion 92 that moves up and down to open and close the lid portion of the carrier C, and a transfer mechanism 93 for transferring the wafer W from the carrier C via the opening and closing portion 92.

[0076] The processing block D2 is formed by stacking the unit blocks E1 to E6 in order from bottom to top. The unit blocks E1 to E3 are provided with a resist coating device for coating a resist as the liquid processing device 8, which is used to form a resist film on the wafer W. The structures of the unit blocks E4 to E6 are substantially the same as those of the unit blocks E1 to E3, but instead of the resist coating device, a developing device for supplying a developing solution to the wafer for developing processing is provided. Figure 16 The unit block E5 is shown.

[0077] In the unit block E5, a transfer mechanism F5 is provided that moves on a linear transfer path from the carrier block D1 side to the interface block D3. When viewed from the carrier block D1 side, developing devices as the liquid processing device 8 are arranged in parallel on the right side of the transfer path. In addition, when viewed from the carrier block D1 side, the heat treatment device 1 according to the present disclosure is arranged in parallel on the left side of the transfer path. A rack unit U7 composed of a plurality of mutually stacked modules is provided on the carrier block B1 side of the transfer path. The transfer of the wafer W between the transfer arm 103 and the transfer mechanism A5 is performed via the transfer module of the rack unit U7 and the transfer arm 104.

[0078] In addition, as Figure 15 shown, a filter 101 is provided at the top of the transfer path. Through an FFU (Fan Filter Unit, not shown), the air in the clean room where the coating and developing devices are provided is sucked and supplied to the filter 101, and is supplied downward from the filter 101. The supplied air is exhausted at the cover portion 21 of the processing chamber 20 of the heat treatment device 1, flows into the housing 10 of the heat treatment device 1, and is supplied onto the mounting table 23. That is, the atmosphere around the mounting table 23 is formed by this air. Therefore, the first gas supplied to the wafer W in the heat treatment device 1 is a gas with a humidity higher than that of the air supplied via the filter 101.

[0079] Figure 15 The shown tower T1 is provided on the side closer to the carrier block D1 and extends in the vertical direction so as to straddle the unit blocks E1 to E6. Moreover, transfer modules TRS are provided at each height of the unit blocks E1 to E6. In addition, a freely liftable transfer arm 95 for transferring the wafer W to and from the tower T1 is provided on the side closer to the carrier block D1. In addition, in Figure 15 this, the transfer mechanisms 11 of the unit blocks E1 to E6 are denoted as F1 to F6.

[0080] The interface block D3 has towers T2, T3, and T4 that extend in the vertical direction in a manner that spans the unit blocks E1 to E6. The transfer of the wafer W between the towers T2 and T3 is performed using the freely movable interface arm 96, and the transfer of the wafer W between the towers T2 and T4 is performed using the freely movable interface arm 97. In addition, an interface arm 98 is provided for transferring the wafer W between the tower T2 and the exposure apparatus D4. Modules such as the transfer module TRS are stacked on top of each other on the tower T2. In addition, modules are also provided on the towers T3 and T4, but the description thereof is omitted here.

[0081] In this coating and developing apparatus, the wafer W conveyed by the carrier C is conveyed to the unit blocks E1 to E3 and sequentially undergoes the processes of forming a resist film and heat treatment as described above. Then, the wafer W is conveyed to the exposure apparatus D4 via the transfer module TRS at each height of the unit blocks E1 to E3 of the tower T2 of the interface block D3 and undergoes an exposure process. The exposed wafer W is conveyed to the transfer module TRS at each height of the unit blocks E4 to E6 of the tower T2. Next, the wafer W is conveyed to the heat treatment apparatus 1 in the unit blocks E4 to E6 and undergoes the aforementioned heat treatment, and then is conveyed to the developing apparatus, sequentially undergoes a developing process, and returns to the carrier C after a resist pattern is formed.

[0082] As discussed above, the embodiments disclosed herein should be considered illustrative and not restrictive in all respects. The above embodiments can be omitted, replaced, changed, and combined in various ways without departing from the scope of the appended claims and their gist.

[0083] [Examples]

[0084] In order to verify the effects of the heat treatment apparatus according to the present disclosure, using the heat treatment apparatus 1 shown in the first embodiment, the humidity of the first gas was set to 20%, 50%, and 68% respectively, and the examples in which the wafer W was processed in the same manner as in the example shown in the first embodiment were set as Examples 1, 2, and 3. Each example was repeated 3 times, and the line width of the resist pattern was measured.

[0085] Figure 17The results are shown. The black dots in the figure represent the measured values of the line widths of the resist patterns measured in Examples 1 to 3. In addition, the diamond-shaped parts in each example are mean diamonds, the horizontal line in the center represents the average of Examples 1 to 3, and the points above and below the diamond-shaped parts represent the upper and lower limits of the 95% confidence intervals on both sides of each example. Further, in the mean diamond, the lines drawn at positions away from the average of Examples 1 to 3 in the vertical direction represent overlap marks. And the bars extending in the vertical direction from the average are mean error bars, and the dashed line represents the standard deviation line. In addition, the comparison circles of the Student's t-test (significance difference 0.05) for each combination are shown on the right side of the graph.

[0086] Based on the results, no significant difference in the line width of the resist pattern was observed between Example 1 and Example 2. On the other hand, in Example 3, the line width was significantly wider compared to Examples 1 and 2, and a difference of about 0.4 nm in line width was observed between Examples 1 and 2 and Example 3. As described above, the line width of the resist pattern becomes wider as the reaction rate increases. Therefore, it can be said that by setting the humidity of the first gas to be higher than 60%, the reaction rate can be significantly increased and the line width can be increased.

[0087] Description of reference numerals

[0088] 1: Heat treatment apparatus; 3: Gas supply unit; 23: Stage; 27: Lifting mechanism; W: Wafer.

Claims

1. A substrate processing method for heat-treating a metal-containing resist film formed on a substrate surface, comprising: a first heat treatment step of supplying a first gas to the substrate; and a second heat treatment step of supplying a second gas after the first heat treatment step, wherein, The humidity of the first gas is higher than that of the second gas.

2. The substrate processing method according to claim 1, wherein, The second gas is an inert gas.

3. The substrate processing method according to claim 1 or 2, wherein, The first gas is air with adjusted moisture.

4. The substrate processing method according to claim 1 or 2, wherein, In the second heat treatment step, the temperature of the substrate is made higher than that in the first heat treatment step.

5. The substrate processing method according to claim 1 or 2, wherein, At least one of the first gas and the second gas is a gas obtained by mixing two gases with different humidities.

6. A substrate processing method for heat-treating a metal-containing resist film formed on a substrate surface, comprising: a first heat treatment step of supplying a first gas to the substrate; and a second heat treatment step of supplying a second gas after the first heat treatment step, wherein, In the second heat treatment step, the temperature of the substrate is made higher than that in the first heat treatment step.

7. The substrate processing method according to claim 6, wherein, The second gas is an inert gas.

8. The substrate processing method according to claim 6 or 7, wherein, At least one of the first gas and the second gas is a gas obtained by mixing two gases with different humidities.

9. A computer-readable storage medium storing a program for executing the substrate processing method according to any one of claims 1 to 8.

10. A substrate processing apparatus for heat-treating a metal-containing resist film formed on a substrate surface, comprising: a stage for heating the substrate; a gas supply unit for supplying a first gas and a second gas; and a control unit, the control unit causes the first gas to be supplied to the substrate, and then causes the second gas to be supplied to the substrate, the humidity of the first gas is higher than the humidity of the second gas.

11. A substrate processing apparatus for heat-treating a metal-containing resist film formed on a surface of a substrate, comprising: a stage for heating the substrate; a gas supply unit for supplying a first gas and a second gas; and a control unit, wherein the control unit causes the first gas to be supplied to the substrate and then causes the second gas to be supplied to the substrate, and sets a period during which the temperature of the substrate when the second gas is supplied to the substrate is higher than the temperature of the substrate when the first gas is supplied to the substrate.

12. A computer program product including a program for executing the substrate processing method according to any one of claims 1 to 8.

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