Heat treatment device and heat treatment method

Abstract

Provided is a technique for promoting the change in solubility when heat treating a substrate having an exposed resist film formed on its surface, the solubility of the exposed part or the unexposed part of which changes with respect to a developer by reacting with water and being heated. Therefore, the heat treatment device comprises: a stage (23) for placing and heating the substrate (W); a lifting mechanism (26) for lifting the substrate (W) relatively between a first position placed on the stage (23) and a second position away from the stage; and a gas supply unit (33) for supplying a first gas to the substrate (W) at the second position before it moves to the first position, the first gas having a higher humidity than the atmosphere in which the stage (23) is placed.

Description

Technical Field

[0001] The present disclosure relates to a heat treatment device and a heat treatment method. Background Art

[0002] In the photolithography process in the process of manufacturing semiconductor devices, for example, a resist is applied on a semiconductor wafer (hereinafter referred to as a "wafer") to form a resist film. Next, the wafer formed with the resist film is subjected to an exposure process for exposing a predetermined circuit pattern. In addition, the wafer formed with the exposed resist film is subjected to a heat treatment, whereby a chemical reaction of the exposed portion or the unexposed portion of the resist film is promoted, and the resist film is dissolved or insoluble in a developer. Afterwards, a developer is supplied to the heat-treated wafer W to remove the soluble portion of the resist film, and a predetermined resist pattern is formed on the wafer.

[0003] In recent years, semiconductor devices are required to be further highly integrated. Therefore, in order to miniaturize the resist pattern, an exposure process using EUV (Extreme Ultraviolet) has been proposed. In the exposure process using EUV, a metal-containing resist such as that described in Patent Document 1 is used in order to make the resist film highly sensitive to exposure.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-530565 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] The present disclosure provides a technology capable of promoting the change in solubility in a developer when heat-treating a substrate having an exposed resist film formed on its surface, the solubility of the exposed portion or the unexposed portion changing due to reaction with water and heating.

[0009] Solutions for solving problems

[0010] The heat treatment apparatus disclosed in the present invention comprises: a mounting table for mounting a substrate having an exposed resist film formed on its surface and heating the substrate, wherein the exposed resist film reacts with water and is heated so that the solubility of the exposed portion or the unexposed portion with respect to a developer changes;

[0011] a lifting mechanism for relatively lifting the substrate between a first position where the substrate is placed on the mounting table and a second position away from the mounting table; and

[0012] A gas supply unit supplies a first gas to the substrate located at the second position before the substrate is moved to the first position, wherein the first gas has a higher humidity than a humidity of an atmosphere in which the mounting table is installed.

[0013] Effects of the Invention

[0014] According to the present disclosure, when a substrate having an exposed resist film formed on its surface and having its solubility in a developer changed by reaction with water and heating, the change in solubility can be promoted. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a longitudinal sectional side view of the heat treatment apparatus according to the first embodiment.

[0016] Figure 2 1 is an operational diagram showing the operation of the heat treatment apparatus.

[0017] Figure 3 1 is an operational diagram showing the operation of the heat treatment apparatus.

[0018] Figure 4 1 is an operational diagram showing the operation of the heat treatment apparatus.

[0019] Figure 5 It is a longitudinal sectional side view of a processing chamber provided in the heat treatment apparatus according to the second embodiment.

[0020] Figure 6 It is an operation diagram showing the operation of the heat treatment apparatus according to the second embodiment.

[0021] Figure 7 It is an operation diagram showing the operation of the heat treatment apparatus according to the second embodiment.

[0022] Figure 8 It is an operation diagram showing the operation of the heat treatment apparatus according to the second embodiment.

[0023] Fig. 9 It is a bottom view of the lower surface of the gas supply unit according to the third embodiment.

[0024] Fig.10 It is a longitudinal sectional side view of a processing chamber provided in the heat treatment apparatus according to the third embodiment.

[0025] Fig.11 It is an explanatory diagram showing an example of gas supply in the third embodiment.

[0026] Fig.12 It is a longitudinal sectional side view showing another example of the heat treatment apparatus according to the third embodiment.

[0027] Fig.13 It is an operation diagram showing the operation of another example of the heat treatment apparatus.

[0028] Fig.14 It is an operation diagram showing the operation of another example of the heat treatment apparatus.

[0029] Fig.15 It is a longitudinal sectional view showing a coating and developing device.

[0030] Fig.16 It is a top view showing a coating and developing device.

[0031] Fig.17 It is a graph which shows the result of Example. DETAILED DESCRIPTION

[0032] [First embodiment]

[0033] The heat treatment device 1 involved in the present disclosure is described. The heat treatment device 1 is a device for heating a wafer W formed with a resist film, and the resist film is exposed to EUV along a circuit pattern, for example. Therefore, the heat treatment device 1 is a device for performing a 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 is detached from the metal due to the irradiation of the above-mentioned EUV and other radiation, and in this state, the resist is introduced into the hydroxyl group by reacting with water. Thereafter, by heating, dehydration condensation occurs between the hydroxyl groups, with the result that the resist is insoluble in the developer.

[0034] The heat treatment device 1 performs the above-mentioned introduction of hydroxyl groups (hydrophilization treatment) and dehydration condensation. Therefore, as a result of the treatment by the heat treatment device 1, the exposed areas in the resist film are insoluble in the developer, and the unexposed areas are dissolved in the developer and removed, thereby forming a pattern in the resist film. Figure 1 The structure of the heat treatment apparatus 1 is described with reference to a longitudinal sectional side view of FIG. The heat treatment apparatus 1 includes a housing 10, and a transfer port 10A for wafers W is provided on a 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 in the air atmosphere. In the housing 10, a chamber (processing chamber) 20 for performing heat treatment on the wafers W is provided on the far end side when viewed from the side where the transfer port 10A opens.

[0035] The processing chamber 20 includes a cover 21 constituting a top portion and a lower portion 22 located below the cover 21 and including a bottom portion. The cover 21 constituting the upper portion of the processing chamber 20 is connected to a chamber lifting mechanism 28 via a support 29. The cover 21 is raised relative to the lower portion 22 by the lifting mechanism 28, thereby separating and opening the processing chamber 20, and the cover 21 is lowered to close the processing chamber 20.

[0036] A mounting table 23 is provided inside the lower side portion 22. 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 lifting pin 26 is passed through each of the through holes 23a. Each of the lifting pins 26 is connected to a lifting mechanism 27 provided at the bottom of the lower side portion 22. In addition, each of the lifting pins 26 is lifted and lowered by the lifting mechanism 27, and the front end of the lifting pin 26 protrudes or retracts on the surface of the stage 23. By the lifting pins 26 that protrude or retract on the surface of the stage 23, the wafer W is lifted and lowered between a first position placed on the stage 23 and a second position away from the stage 23.

[0037] In addition, regarding the anti-etching film formed on the wafer W, if the above-mentioned hydrophilization is not sufficient, dehydration and condensation may not be fully performed. Therefore, there is a risk that the line width (width of the convex portion) of the anti-etching pattern formed after the development process is thinner than the desired width. Therefore, the heat treatment device 1 involved in the present disclosure is equipped with a gas supply unit 3, which is used to supply humid air containing water to the wafer W, so that the anti-etching film is reliably hydrophilized and dehydration and condensation are promoted.

[0038] The gas supply unit 3 is provided inside the cover 21 and includes a nozzle 30, which is a facing portion having a facing surface facing the wafer W placed on the mounting table 23. The interior of the nozzle 30 serves as a diffusion space for gas diffusion. In addition, gas ejection holes 31 for supplying gas toward the wafer W are dispersedly formed on the entire surface of the lower surface (facing surface facing the wafer W) of the nozzle 30.

[0039] 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. A gas supply source 33 is provided at the other end of the gas supply pipe 32 via a valve V32, and the gas supply source 33 is used to supply a first gas having a humidity higher than that of the atmosphere in which the mounting table 23 is provided. The first gas is, for example, humid air having a humidity of 68%. In addition, the humidity used in this specification represents relative humidity. In addition, the atmosphere in which the mounting table 23 is provided refers to the atmosphere above the mounting table 23 when the first gas is not supplied from the gas supply unit 3 toward the wafer W. Therefore, the above-mentioned first gas as humid air is a gas used to increase the humidity of the atmosphere above the mounting table 23.

[0040] As the gas supply source 33, for example, a module that can adjust the moisture contained in the air to supply air of a desired humidity is used. For example, the gas supply source 33 can be configured to include a bubbler, a first pipeline that supplies water vapor generated by the bubbler to the downstream side, and a second pipeline that supplies air of an arbitrary flow rate to the water vapor flowing in the first pipeline for mixing. In addition, by adjusting the flow rate of the air in the second pipeline, air of a desired humidity can be supplied to the nozzle 30. However, the structure of the gas supply source 33 is not limited to such a structure, and can be set to any structure.

[0041] 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 shower head 30. A central exhaust pipe 341 is connected to the central exhaust port 34 so as to penetrate the shower head 30. In addition, the shower head 30 is configured to have a gap between its side peripheral surface and the inner surface of the cover 21, and the gap constitutes an outer peripheral exhaust port 35 for exhausting from the outer peripheral side of the wafer W. The outer peripheral exhaust port 35 is connected to the outer peripheral exhaust pipe 351. The central exhaust pipe 341 and the outer peripheral exhaust pipe 351 are connected to the exhaust equipment 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 exhaust pipe 351 is a valve for opening and closing the outer peripheral exhaust pipe 351.

[0042] A transport mechanism 11 is provided on the proximal side (transport port 10A side) in the shell 10. The transport mechanism 11 includes a horizontal, roughly circular support portion, namely a support plate 12, on the surface of which the wafer W is placed. A temperature control mechanism (not shown) is embedded in the support plate 12, which controls the temperature so that the temperature of the wafer W placed on the support plate 12 becomes uniform within the surface. The support plate 12 is moved along a guide rail 15 provided on the bottom surface of the shell 10 in a manner from the transport port 10A side to the distal side via a moving mechanism 14 connected via a supporting member 13. Thus, the support plate 12 can be moved in an area above the mounting table 23 and in an outer area (laterally) of the processing chamber 20 deviated from the mounting table 23. Figure 1 positions shown).

[0043] When the conveying mechanism 11 is located in the outer area, the external conveying mechanism of the heat treatment device 1 holding the wafer W enters the shell 10 from the conveying port 10A. And, the external conveying mechanism is raised and lowered from the upper side of the support plate 12 to the lower side, thereby transferring the wafer W between the external conveying mechanism of the heat treatment device 1 and the conveying mechanism 11 in the shell 10. In addition, a slit not shown in the figure is formed on the support plate 12 from the end of the processing chamber 20 side to the other end side. Through the slit, when the support plate 12 is located on the mounting table 23, the lifting pin 26 protruding or retracting from the mounting table 23 can protrude onto the support plate 12 through the slit. Then, by the cooperation of the lifting and lowering of the lifting pin 26 and the advance and retreat of the conveying mechanism 11, the wafer W is transferred between the mounting table 23 and the support plate 12.

[0044] The heat treatment apparatus 1 includes, for example, a control unit 100 formed by a computer. The control unit 100 is configured to output control signals to the lifting mechanism 28, the lifting mechanism 27, the valves V32, V341, V351, and the moving mechanism 14 for the chamber. A program is stored in the control unit 100, and the program is compiled into commands (step groups) to implement the sequence of the delivery of the wafer W, the lifting pins 26, the lifting and lowering of the cover 21, and the supply of gas shown in the operation of the heat treatment apparatus 1 described later. The program is stored in a storage medium such as a compact disc, a hard disk, an MO (magneto-optical disk), a DVD, a memory card, and is installed in the control unit 100.

[0045] The function of the heat treatment apparatus 1 according to the present disclosure is described. The heat treatment apparatus 1 is, for example, 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 exhaust is performed from the exhaust ports 34 and 35. In addition, the support plate 12 is in a position ( Figure 1First, an external transfer mechanism (not shown) holding the exposed wafer W is brought into the heat treatment apparatus 1 and moved downward from above the support plate 12 to place the wafer W on the support plate 12.

[0046] Next, the support plate 12 is moved to the position directly above the mounting table 23. The wafer W supported by the support plate 12 is pushed upward by the lifting pins 26, and the wafer W is supported at the second position above the mounting table 23, and the support plate 12 is retracted to the outer area. Figure 2 As shown, the first gas is supplied toward the wafer W, and exhaust is performed from, for example, the outer peripheral exhaust port 35 among the exhaust ports. At this time, the lid 21 is maintained in the raised state, and the processing chamber 20 is opened. By exposing the wafer W to the first gas as humid air, moisture is supplied to the wafer W, and the resist film is hydrophilized.

[0047] Then, if Figure 3 As shown, while the supply of the first gas and the exhaust from the peripheral exhaust port 35 are maintained, 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, the cover 21 is lowered in parallel with the lowering of the lift pins 26 to close the processing chamber 20. In this way, the wafer W is placed on the mounting table 23 and heated to the same temperature as the mounting table 23 to be heat-treated. The temperature of the wafer W rises and the above-mentioned dehydration condensation of the hydroxyl group occurs, and the exposed portion in the resist film is insoluble in the developer.

[0048] When the heat treatment of the wafer W is completed, as shown in FIG. Figure 4 As shown, the supply of the first gas is stopped, and exhaust through the outer peripheral exhaust port 35 is stopped, and exhaust is switched to exhaust through the central exhaust port 34 .

[0049] Thereafter, the cover 21 is raised to open the processing chamber 20, and the lifting pins 26 are raised to lift the wafer W from the mounting table 23. Then, the wafer W is delivered to the transport mechanism 11 by the joint operation of the transport mechanism 11 and the lifting pins 26. The wafer W is further delivered to an external transport device and is carried out from the thermal treatment apparatus 1 to receive a development process.

[0050] According to the heat treatment apparatus 1, air (first gas) having a humidity higher than that of the atmosphere on the mounting table 23 is supplied to the wafer W and heat-treated. Therefore, during the heat treatment, the hydroxyl group is fully introduced into the exposed portion of the resist film, and the insolubility of the exposed portion is rapidly advanced during the heat treatment. That is, for the exposed portion, the sensitivity of the reaction based on heating is improved. The insolubility of the exposed portion is promoted in this way, so that during the development treatment, the situation in which the width of the convex portion of the resist pattern is smaller than the set value due to the insufficient insolubility is suppressed.

[0051] In addition, it is considered that after the wafer W is placed on the mounting table 23 and heated, the adhesion of the moisture contained in the first gas to the anti-etching film is reduced due to the heat of the wafer W. However, according to the heat treatment device 1, since the first gas is supplied before being placed on the mounting table 23, the heating is performed in a state where the above-mentioned hydroxyl group is reliably introduced. Therefore, the above-mentioned rapid insolubility of the exposure portion can be performed with high reliability. Moreover, since the position where the first gas is supplied is above the mounting table 23, the wafer W can be quickly placed on the mounting table 23 and heat-treated after the introduction of the hydroxyl group.

[0052] Therefore, from the supply of the first gas to the placement on the mounting table 23, the surface of the wafer W is dried by the influence of the airflow in the area where the wafer W moves. As a result, the amount of moisture permeated into the resist before being placed on the mounting table 23 is suppressed from varying within the surface of the wafer W. In other words, the introduction state of the hydroxyl group is suppressed from varying within the surface of the wafer W, so that the line width of the pattern within the surface of the wafer W after development can be suppressed.

[0053] In addition, since the wafer W is positioned at the second position and the first gas is supplied, the first gas with high humidity can be supplied to the wafer W in the state close to the nozzle 30 compared with the state in which the wafer W is placed on the mounting table 23. That is, the space between the surface of the wafer W and the first gas supply part is narrower than the space when the wafer W is subjected to heat treatment, so it becomes a state in which it is difficult to generate airflow on the wafer W, and moisture can be more uniformly infiltrated into the surface 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 heating treatment of the wafer W, the sublimates generated by the heating treatment of the wafer W are also less. Therefore, the airflow around the wafer W can also be further adjusted by setting the exhaust in the processing chamber 20 to be weaker than the exhaust during the heating treatment of the wafer W (the period in which the wafer W is placed on the mounting table 23) or setting it to be closed, so as to prevent the leakage of sublimates and avoid the airflow on the wafer W from being strengthened more than necessary.

[0054] In addition, in order to achieve the miniaturization of the resist pattern, an exposure device that irradiates EUV from a light source is sometimes used as in the present embodiment. However, as such an exposure device using EUV, the output of light from the light source is small. Therefore, as a resist, the solubility is sought to change at a lower dose, that is, high sensitivity is sought. Moreover, as described above, the metal-containing resist used in the present embodiment reacts with high sensitivity to water through the detachment of the above-mentioned ligand. As described above, the present technology utilizes the properties of the resist to change the solubility of the resist film relative to the developer. Therefore, according to the present technology, even if an exposure device with low output such as EUV is used, a pattern can be reliably formed on the resist film. In addition, according to the heat treatment device 1, the first gas is continued to be supplied after the wafer W is placed on the mounting table 23. Therefore, it is more reliable to introduce hydroxyl groups into the resist film to promote the insolubility reaction of the exposed part in the film, thereby obtaining a pattern with a desired line width.

[0055] In addition, the resist film treated by the heat treatment device 1 involved in the present disclosure is not limited to the use of a metal-containing resist, as long as the solubility of the exposed part or the unexposed part relative to the developer changes by reacting with water and being heated. Therefore, for example, a resist in which the unexposed part is soluble or insoluble by reaction, or the exposed part is soluble by reaction can also be used. Using these resists, the solubility of the resist in the exposed part or the unexposed part can also be reliably changed using this technology. In addition, a metal-containing resist does not mean that it contains metal as an impurity, but that it contains metal as a main component.

[0056] Furthermore, the humidity of the first gas is preferably higher than 60%. As shown in the embodiments described below, by making the humidity higher than 60%, the reaction rate can be greatly improved, and a great effect can be obtained. In addition, the humidity related to the gas is sometimes recorded, but the gas for which the humidity is recorded is not limited to air. Therefore, the first gas can also be a gas other than air. In addition, in the embodiments described below, sometimes a gas with high humidity and a gas with low humidity are used for processing respectively, but these gases also refer to a gas with high humidity and a gas with low humidity when measured using a hygrometer, and these gases are not limited to air.

[0057] In addition, the supply flow rate of the first gas supplied to the wafer W may be reduced when the processing chamber 20 is open, and the supply flow rate of the first gas supplied to the wafer W may be increased when the processing chamber 20 is closed. Figure 1 In the heat treatment apparatus 1 shown in FIG. 1 , a flow rate adjustment unit is provided in the gas supply pipe 32 so as to be able to adjust the flow rate of the gas ejected from the shower head 30. Figure 2When the processing chamber 20 is opened as shown, the wafer W is placed at the second position on the mounting table 23 and the first gas is supplied, the flow rate of the first gas is set to the first flow rate. Figure 3 As shown, after wafer W is placed on mounting table 23 and lid 21 is lowered to seal processing chamber 20 , the flow rate of the first gas is set to a second flow rate that is larger than the first flow rate described above.

[0058] By reducing the flow rate of the first gas supplied to the wafer W when the processing chamber 20 is open, the amount of the first gas flowing out of the processing chamber 20 can be suppressed. As a result, it is possible to suppress condensation due to the high humidity atmosphere outside the processing chamber 20. In addition, 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.

[0059] In addition, the timing for lowering the cover 21 of the processing chamber 20 may be simultaneous with the lowering of the lift pins 26 or later than the lowering of the lift pins 26. In addition, the exhaust port of the processing chamber 20 is not limited to being set to be able to exhaust from above the center of the wafer W and from the periphery of the wafer W, and may be set to be exhausted from only one of them.

[0060] [Second Embodiment]

[0061] Next, a heat treatment apparatus 1A according to the second embodiment will be described. In the drawings of the heat treatment apparatus 1A and the heat treatment apparatuses 1B and 1C described later, the same parts as those of the heat treatment apparatus 1 according to the first embodiment are omitted, and only the processing chamber 20 is shown. Figure 5 As shown, the other end side of the gas supply pipe 300 connected to the diffusion space of the nozzle 30 is branched into two pipes. In addition, a first gas supply source 301 for supplying a 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 side. 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%.

[0062] Reference numeral 303 provided on the gas supply pipe 300 is a three-way valve for switching the gas supplied to the nozzle 30 between the first gas and the second gas. Alternatively, a mixing box may be provided instead of the three-way valve 303 to supply the first gas and the second gas by changing the mixing ratio of the high-humidity gas and the low-humidity gas.

[0063] First, before the wafer W is placed on the mounting table 23, as shown in FIG. Figure 6As shown in FIG. 1 , the first gas is supplied to the second position. Figure 7 As shown in FIG. 1 , while the first gas is being supplied, the wafer W is placed on the mounting table 23 (moved to the first position) and heat treatment is started, and the processing chamber 20 is sealed. Thereafter, while the wafer W is being heat treated, the gas supplied to the wafer W is switched to the second gas ( Figure 8 ).

[0064] The reaction rate can be increased by supplying high-humidity gas while performing heat treatment, but there is a risk of degradation of the roughness of the resist film surface and the in-plane uniformity of the line width of the resist pattern if excessive moisture is supplied to the wafer W and heat treatment is performed. Therefore, when the wafer W is heat treated, the humidity of the supplied gas is reduced as the reaction of the resist film progresses, and the amount of moisture supplied to the wafer W is adjusted, thereby suppressing degradation of the roughness of the resist film surface and degradation of the in-plane uniformity of the line width of the resist pattern.

[0065] In addition, when the wafer W is subjected to heat treatment, it is difficult to make the moisture content uniform within the surface of the wafer W. When the wafer W is heated while being supplied with high-humidity humid air, there is a risk that the moisture content within the surface of the wafer W is easily different. Figure 5 After the first gas is supplied to the wafer W at the second position before the wafer W is placed on the mounting table 23 as shown in FIG. 1 , the gas supplied to the wafer W is switched to the second gas before the wafer W is placed on the mounting table 23. Then, the wafer W supplied with the second gas may be placed on the mounting table 23, as shown in FIG. Figure 8 As shown, the wafer W is heat-treated while the second gas is supplied.

[0066] Alternatively, the second gas having a lower humidity than the first gas may be, for example, nitrogen (N 2 In order to sufficiently change 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.

[0067] [Third Embodiment]

[0068] In addition, the humidity of the gas supplied to the wafer W may be adjusted within the surface of the wafer W. Fig. 9 1 is a bottom side view of an example of a shower head 30 provided in such a heat treatment apparatus 1B. For example, when the shower head 30 is viewed from the bottom side, five gas supply regions 300A to 300E are provided, namely, a central gas supply region 300A and gas supply regions 300B to 300E obtained by dividing the region surrounding the central region into four in the circumferential direction, and gas ejection holes 31 are formed in each gas supply region 300A to 300E. Fig.10As shown, the inside of the showerhead 30 is formed into five partitions 301A to 301E corresponding to each area, and each partition 301A to 301E is connected to a gas supply source 33A to 33E via a gas supply pipe 32A to 32E. Fig.10 In FIG. 5 , for convenience, five partitions 301A to 301E are shown side by side in the horizontal direction.

[0069] Moreover, for example, in Figure 3 When the first gas is supplied toward the wafer W mounted on the mounting table 23 (moved to the first position) and being heated, as shown in FIG. Fig.11 As shown, the humidity of the first gas supplied from each area 300A to 300E is adjusted so that the humidity decreases in the order of, for example, the gas supply areas 300B, 300D, 300A, 300C, and 300E. By adjusting the humidity of the supplied humid air in the surface of wafer W in this way, the amount of moisture supplied to the resist film can be adjusted in the surface of wafer W. By adjusting the moisture supplied to wafer W in the surface, the reaction speed of the resist can be adjusted in the surface of wafer W. In addition, when performing heat treatment while supplying the first gas to wafer W located at the second position before being placed on the mounting table 23, the humidity of the first gas supplied to wafer W can also be adjusted in the surface of wafer W.

[0070] In addition, assuming that the process is performed as described in the first embodiment and a resist pattern is formed on the wafer W, the line width of the resist pattern tends to be thinner at the peripheral portion of the wafer W than at the central portion. In order to eliminate this tendency, in addition to supplying the first gas to the entire surface of the wafer W, the first gas may be further supplied toward the periphery of the wafer W. Fig.11 The processing chamber 20 provided in such a heat treatment apparatus 1C is shown. Figure 1 The heat treatment apparatus 1 shown in the figure similarly includes a showerhead 30A (hereinafter referred to as an "opposing gas supply unit") that supplies the first gas from an opposing portion that faces the wafer W placed on the mounting table 23. In addition, the heat treatment apparatus 1C includes a peripheral gas supply unit 30B that supplies the first gas from the outer peripheral side of the wafer W toward the center of the wafer W.

[0071] The peripheral gas supply part 30B is formed of, for example, a pipe 310 having a square cross section in an annular shape and provided along the inner surface of the lower end of the cover 21. A plurality of gas ejection holes 311 are formed on the inner wall of the pipe 310 along the circumferential direction of the wafer W, and the gas ejection holes 311 are used to supply the first gas from the outer peripheral side of the wafer W placed on the mounting table 23 when the cover 21 is lowered to seal the processing chamber 20. One end of the pipe 310 is connected to a gas supply pipe 312, and the other end of the gas supply pipe 312 is connected to a gas supply pipe 32 for supplying gas to the opposite gas supply part 30A, and is configured to be supplied with the first gas from the gas supply source 33. Fig.12 V312 in the figure is a valve.

[0072] The heat treatment apparatus 1C is, for example, Figure 2 Similarly, the first gas is supplied from the opposing gas supply unit 30A toward the wafer W located at the second position before being placed on the mounting table 23. Fig.13 As shown, while the gas is ejected from the opposing gas supply unit 30A, the wafer W is lowered to be placed on the mounting table 23, and the cover 21 is lowered to close the processing chamber 20. Thus, the first gas is supplied to the entire surface of the wafer W while the heat treatment of the wafer W is performed. Fig.14 As shown, in a state where the wafer W is placed on the mounting table 23, the supply of the first gas in the opposite gas supply part 30A is stopped, and the supply of the first gas from the peripheral gas supply part 30B is started. Then, this process is repeated multiple times. Fig.13 process and Fig.14 The process shown.

[0073] Thus, the supply amount of the first gas in the area on the outer peripheral side of the wafer W can be made greater than the supply amount of the first gas in the area on the central side of the wafer W. Therefore, the moisture content in the area on the outer peripheral side of the wafer W can be increased, and the reaction speed can be improved. Thus, the reduction in the line width of the resist pattern on the outer peripheral side of the wafer W can be suppressed.

[0074] Next, a coating and developing apparatus provided with the above-mentioned heat treatment apparatuses 1 and 1A to 1C will be described. Fig.15 This is a schematic longitudinal sectional side view of a coating and developing device. Fig.16 1 is a top view of a coating and developing device. The coating and developing device is composed of a carrier block D1, a processing block D2, and an interface block D3 connected in a straight line in this order. Regarding the interface block D3, an exposure device D4 is connected to the side opposite to the connection direction of the processing block D2. The carrier block D1 has the function of moving the carrier C in and out of the coating and developing device, and has a carrier C placement table 91, an opening and closing part 92 that is raised and lowered to open and close the cover of the carrier C, and a transfer mechanism 93 for transferring the wafer W from the carrier C via the opening and closing part 92.

[0075] The processing block D2 is composed of unit blocks E1 to E6 stacked in order from bottom to top. The unit blocks E1 to E3 are provided with a resist coating device as a liquid processing device 8 for coating a resist to form a resist film on the wafer W. The unit blocks E4 to E6 have substantially the same structure as the unit blocks E1 to E3, but are provided with a developing device for supplying a developing solution to the wafer for developing processing instead of the resist coating device. Fig.16 A unit block E5 is shown.

[0076] A conveying mechanism F5 that moves on a linear conveying path from the carrier block D1 side to the interface block D3 is provided in the unit block E5. When viewed from the carrier block D1 side, a developing device as a liquid processing device 8 is arranged in parallel on the right side of the conveying path. In addition, when viewed from the carrier block D1 side, a heat treatment device 1 involved in the present disclosure is arranged in parallel on the left side of the conveying path. A shelf unit U7 composed of a plurality of modules stacked on each other is provided on the carrier block B1 side of the conveying path. The transfer of the wafer W between the conveying arm 103 and the conveying mechanism A5 is performed via the transfer module of the shelf unit U7 and the conveying arm 104.

[0077] In addition, if Fig.15 As shown, a filter 101 is provided at the top of the conveying path. Through an FFU (FanFilter Unit) not shown in the figure, the air of the clean room where the coating and developing devices are provided is sucked into the filter 101 and supplied to the filter 101, and is supplied downward from the filter 101. The supplied air is exhausted at the cover 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. In other words, the atmosphere around the mounting table 23 is formed by the air. Therefore, the first gas supplied to the wafer W in the heat treatment device 1 is a gas having a higher humidity than the air supplied through the filter 101.

[0078] Fig.15 The tower T1 shown is arranged on the side of the carrier block D1 and extends in the vertical direction so as to cross each unit block E1 to E6. Moreover, a transfer module TRS is provided at each height of the unit blocks E1 to E6. In addition, a freely elevating transfer arm 95 for transferring wafers W to the tower T1 is provided on the side of the carrier block D1. Fig.15 In FIG. 1 , the transport mechanisms 11 of the unit blocks E1 to E6 are represented by F1 to F6 .

[0079] The interface block D3 includes towers T2, T3, and T4 extending in the vertical direction in a manner spanning the unit blocks E1 to E6. A freely elevating interface arm 96 is used for the transfer of wafers W between towers T2 and T3, and a freely elevating interface arm 97 is used for the transfer of wafers W between towers T2 and T4. In addition, an interface arm 98 is provided for the transfer of wafers W between tower T2 and exposure device D4. Modules such as the transfer module TRS are stacked on each other in tower T2. In addition, modules are also provided in towers T3 and T4, but the description is omitted here.

[0080] In the coating and developing device, the wafer W transported by the carrier C is transported to the unit blocks E1 to E3, and receives the resist film forming process and heating process in sequence as described above. Then, the wafer W is transported to the exposure device D4 via the handover module TRS at each height of the unit blocks E1 to E3 of the tower T2 of the interface block D3, and receives the exposure process. The exposed wafer W is transported to the handover module TRS at each height of the unit blocks E4 to E6 of the tower T2. Next, the wafer W is transported to the heat treatment device 1 in the unit blocks E4 to E6 and undergoes the aforementioned heat treatment, and then is transported to the developing device, receives the development process in sequence, and returns to the carrier C after the resist pattern is formed.

[0081] As discussed above, the embodiments disclosed herein should be considered in all respects as illustrative rather than restrictive. The embodiments described above may be omitted, replaced, modified, and combined in various ways without departing from the scope of the appended claims and the gist thereof.

[0082] [Example]

[0083] In order to verify the effect of the heat treatment apparatus involved in the present disclosure, the heat treatment apparatus 1 shown in the first embodiment was used, the humidity of the first gas was set to 20%, 50% and 68%, and the examples of processing the wafer W in the same manner as 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.

[0084] Fig.17The results are shown, and the black dots in the figure represent the measured values ​​of the line width of the anti-etching pattern measured in Examples 1 to 3. In addition, the diamond part in each example is a mean diamond, the horizontal line located in the center represents the average value of each Example 1 to 3, and the upper and lower points of the diamond part represent the upper and lower limits of the 95% confidence interval on both sides of each example. In addition, in the mean diamond, the line drawn at a position away from the average value of Examples 1 to 3 in the up and down direction represents an overlap mark. In addition, the bars extending from the average value in the up and down direction are average error bars, and the dotted lines represent standard deviation lines. In addition, the right side of the chart shows the comparison circles of the Student's t-test (Student's t-test, significant difference 0.05) of each combination.

[0085] According to 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 than that of Examples 1 and 2, and a difference of about 0.4 nm in the 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, so it can be said that by setting the humidity of the first gas to more than 60%, the reaction rate can be greatly increased and the line width can be increased.

[0086] Description of Reference Numerals

[0087] 1: heat treatment device; 3: gas supply unit; 23: mounting table; 27: lifting mechanism; W: wafer.

Claims

1. A heat treatment device comprising: A mounting table for mounting a substrate having an exposed resist film formed on its surface and heating the substrate, wherein the exposed resist film reacts with water and is heated so that the solubility of the exposed portion or the unexposed portion with respect to a developer changes; a lifting mechanism for relatively lifting the substrate between a first position where the substrate is placed on the mounting table and a second position away from the mounting table; as well as a gas supply unit for supplying a first gas to the substrate located at the second position before the substrate is moved to the first position, wherein the humidity of the first gas is higher than the humidity of an atmosphere in which the mounting table is installed, wherein the gas supply unit supplies the first gas to the substrate at the first position, When the substrate is located at the second position, the gas supply unit supplies the first gas at a first flow rate, and when the substrate is located at the first position, the gas supply unit supplies the first gas at a second flow rate greater than the first flow rate.

2. The heat treatment device according to claim 1, wherein: The gas supply unit supplies a second gas having a humidity lower than that of the first gas to the substrate at the first position or the second position.

3. The heat treatment device according to claim 2, wherein: The gas supply unit supplies the second gas to the substrate at the first position, The gas supply unit sequentially supplies the first gas and the second gas to a substrate at a first position.

4. The heat treatment device according to claim 1, wherein: The gas supply unit comprises: a peripheral gas supply unit configured to supply the first gas from the periphery of the substrate at the first position toward the center of the substrate; a facing portion, which faces the substrate at the first position; as well as An opposing gas supply unit supplies the first gas from the opposing unit to the surface of the substrate.

5. The heat treatment device according to claim 4, wherein: Regarding the first gas, supply from the peripheral gas supply unit and supply from the opposing gas supply unit are performed in this order.

6. The heat treatment device according to claim 1, wherein: The gas supply unit comprises: a facing portion facing the substrate at the first position; and A first gas supply region and a second gas supply region are provided in the facing portion and each includes a gas ejection hole to independently supply the first gas to a first region and a second region different from each other in the substrate.

7. The heat treatment device according to claim 6, wherein: The gas supply unit supplies gases having different humidity levels from the first gas supply region and the second gas supply region as the first gas.

8. The heat treatment device according to claim 4, further comprising: a chamber that surrounds the mounting table, is evacuated inside, and is opened so as to be separated into an upper side portion including the facing portion as a top portion and a lower side portion including a bottom portion; and The chamber lifting mechanism lifts and lowers the upper portion relative to the lower portion so as to close the chamber when the substrate is located at the first position and to open the chamber when the substrate is located at the second position.

9. The heat treatment device according to claim 1, wherein: The first gas is air, and the humidity of the first gas is higher than 60%.

10. The heat treatment device according to claim 1, wherein: The resist film is a resist film containing metal.

11. A heat treatment method comprising the following steps: Before a substrate having an exposed resist film formed on its surface is placed at a first position to be placed on a stage for heating the substrate, the substrate is placed at a second position above the first position, wherein: The exposed resist film reacts with water and is heated, so that the solubility of the exposed portion or the unexposed portion with respect to the developer changes; Next, in order to supply moisture to the resist film, a first gas having a humidity higher than that of an atmosphere in which the mounting table is installed is supplied to the substrate located at the second position by a gas supply unit; Then, the substrate is moved to the first position and heated. wherein the gas supply unit supplies the first gas to the substrate at the first position, When the substrate is located at the second position, the first gas is supplied at a first flow rate, and when the substrate is located at the first position, the first gas is supplied at a second flow rate greater than the first flow rate.

12. The heat treatment method according to claim 11, wherein: The gas supply unit supplies a second gas having a humidity lower than that of the first gas to the substrate at the first position or the second position.

13. The heat treatment method according to claim 12, wherein: The gas supply unit sequentially supplies the first gas and the second gas to the substrate at the first position.

14. The heat treatment method according to claim 11, further comprising the following steps: supplying the first gas from the outer periphery of the substrate at the first position toward the center of the substrate; and The first gas is supplied to the surface of the substrate from a portion facing the substrate at the first position.

15. The heat treatment method according to claim 11, wherein: The gas supply unit comprises: a facing portion facing the substrate at the first position; and a first gas supply region and a second gas supply region, wherein the first gas supply region and the second gas supply region are provided in the facing portion and each of the first gas supply region and the second gas supply region has a spray hole, The heat treatment method further includes the step of independently supplying the first gas from a first gas supply region and a second gas supply region to first and second regions of the substrate that are different from each other.

16. The heat treatment method according to claim 15, wherein: The step of independently supplying the first gas to the first region and the second region includes the step of supplying gases having different humidities from the first gas supply region and the second gas supply region.

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