Resist film forming method, resist film forming apparatus, and storage medium

Abstract

To improve processing efficiency when forming a resist film on a substrate by gas processing.SOLUTION: According to another embodiment of the present disclosure, there is provided a resist film forming method including forming a resist film on a substrate by setting an adjustment region including a processing space in a processing container configured to accommodate the substrate to a second atmosphere having a lower oxygen concentration and a lower humidity than a first atmosphere outside the adjustment region and having a pressure equal to or close to a pressure outside the adjustment region, and supplying a resist component-containing gas into the processing space in the second atmosphere; SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a resist film forming method, a resist film forming apparatus, and a storage medium. [Background technology]

[0002] The manufacturing process of semiconductor devices includes photolithography, which involves forming a resist film on a substrate such as a semiconductor wafer (hereinafter referred to as a wafer) and patterning it. Patent Document 1 describes that a resist film is formed by supplying gas in a vacuum atmosphere. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-538554 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can increase processing efficiency when forming a resist film on a substrate by gas processing. [Means for solving the problem]

[0005] The resist film forming method of the present disclosure includes a film forming step of: setting an adjustment region including a processing space in a processing vessel storing a substrate to a second atmosphere having a lower oxygen concentration and lower humidity than a first atmosphere outside the adjustment region and a pressure at or near the pressure of the first atmosphere outside the adjustment region; and supplying a resist component-containing gas into the processing space in the second atmosphere to form a resist film on the substrate; a heating step of heating the substrate on which the resist film is formed before exposure in the processing space set to the second atmosphere; Equipped with. [Effects of the Invention]

[0006] The present disclosure can improve processing efficiency when forming a resist film on a substrate by gas processing. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view of a wafer processing system according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a longitudinal sectional front view of the wafer processing system. [Figure 3] FIG. 2 is a vertical cross-sectional side view of the wafer processing system. [Figure 4] FIG. 2 is a vertical sectional side view of a resist film forming apparatus in the wafer processing system. [Figure 5] FIG. 2 is a vertical cross-sectional side view of a thermal processing apparatus for PAB in the wafer processing system. [Figure 6] FIG. 2 is an explanatory diagram showing the operation of the resist film forming apparatus. [Figure 7] FIG. 2 is an explanatory diagram showing the operation of the resist film forming apparatus. [Figure 8] FIG. 2 is an explanatory diagram showing the operation of the resist film forming apparatus. [Figure 9] FIG. 2 is an explanatory diagram showing the operation of the resist film forming apparatus. [Figure 10] FIG. 10 is a vertical cross-sectional side view showing a first modified example of the resist film forming apparatus. [Figure 11] FIG. 2 is a schematic diagram showing a vertical cross-sectional side view of a wafer. [Figure 12] FIG. 2 is a schematic diagram showing a vertical cross-sectional side view of a wafer. [Figure 13] FIG. 2 is a schematic diagram showing a vertical cross-sectional side view of a wafer. [Figure 14] FIG. 10 is a vertical cross-sectional side view showing a first modified example of the heat treatment apparatus. [Figure 15] FIG. 10 is a vertical cross-sectional side view showing a second modified example of the resist film forming apparatus. [Figure 16] FIG. 10 is a graph showing a change in wafer temperature. [Figure 17] FIG. 10 is a plan view of a wafer processing system according to a second embodiment. [Figure 18]FIG. 3 is a vertical sectional side view of the wafer processing system according to the second embodiment. [Figure 19] FIG. 10 is a plan view of a wafer processing system according to a third embodiment. [Figure 20] FIG. 10 is a perspective view showing a buffer device provided in the wafer processing system according to the third embodiment. [Figure 21] FIG. 2 is a perspective view showing the buffer device. [Figure 22] FIG. 2 is a perspective view showing the buffer device. [Figure 23] FIG. 2 is a schematic vertical cross-sectional side view of the buffer device. [Figure 24] FIG. 10 is a vertical sectional side view of a wafer processing system according to a fourth embodiment. [Figure 25] FIG. 10 is a plan view of a wafer processing system according to a fifth embodiment. [Figure 26] FIG. 10 is a vertical cross-sectional side view showing a third modified example of the resist film forming apparatus. [Figure 27] 4 is a time chart showing a process of the resist film forming apparatus according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] [First embodiment] Hereinafter, a wafer processing system as a substrate processing apparatus according to this embodiment will be described with reference to the drawings. In this specification, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0009] <Wafer processing system> First, the configuration of a wafer processing system according to this embodiment will be described. Figures 1 and 2 are a plan view and a front view, respectively, that schematically show the configuration of a wafer processing system 1. In this embodiment, the wafer processing system 1 will be described as an example of a photolithography processing system that performs a resist film forming process and a development process on wafers W.

[0010] 1, a wafer processing system 1, which is a substrate processing system, includes a cassette station 2 into which a cassette C containing a plurality of wafers W is loaded and unloaded, and a processing station 3 equipped with a plurality of various processing devices that perform predetermined processing on the wafers W. The wafer processing system 1 has a configuration in which the cassette station 2, the processing station 3, and an interface station 4 that transfers the wafers W between them and an exposure device (not shown) adjacent to the opposite side of the processing station 3 are integrally connected. Note that, as shown in FIG. 1, two processing stations 3 are installed between the cassette station 2 and the interface station 4, but one, or three or more processing stations 3 may be installed.

[0011] The cassette station 2 is provided with a plurality of cassette mounting tables 21 and wafer transfer devices 22 and 23. The cassette station 2 uses the wafer transfer device 22 or 23 to transfer wafers between the cassette C placed on the cassette mounting table 21 and the processing station 3. To this end, the wafer transfer devices 22 and 23 are each provided with a drive mechanism having movement paths in each direction, such as the horizontal direction (X direction and Y direction), the up-down direction (Z direction), and around the vertical axis (θ direction), as needed, and may also be provided with a drive mechanism having movement paths in all directions. At least one of wafer transfer devices 22 and 23 is capable of transferring wafers to and from cassette C, and is also capable of transferring wafers to and from processing station 3. Note that the transfer of wafers to and from processing station 3 refers to, for example, transferring wafers to and from third block G3, which includes a transfer device accessible by wafer transfer device 33 in processing station 3, which will be described later. Third block G3 may include multiple transfer devices (not shown) arranged vertically.

[0012] An inspection device (not shown) for inspecting the wafer W may be provided at a position accessible to either the wafer transfer device 22 or 23.

[0013] The processing station 3 is provided with multiple blocks, e.g., three blocks G1, G2, and G4 (first, second, and fourth blocks). Also, as shown in FIG. 2, multiple layers 31 each including the first and second blocks G1 and G2 are stacked vertically. For example, the first block G1 is provided on the front side of the processing station 3 (the negative X-direction side in FIG. 1), and the second block G2 is provided on the back side of the processing station 3 (the positive X-direction side in FIG. 1). The fourth block G4 is provided on the interface station 4 side of the processing station 3 (the positive Y-direction side in FIG. 1) or at a connection portion with another adjacent processing station 3. The fourth block G4 may be provided with multiple transfer devices arranged vertically. The aforementioned third block G3 may also be provided within the processing station 3.

[0014] The first block G1 is provided with a plurality of processing devices, such as a patterning film forming device and a development processing device, both of which are not shown. The patterning film forming device may include, for example, a resist film forming device and an anti-reflection film forming device. For example, a plurality of processing devices are arranged horizontally. The number, arrangement, and type of these processing devices can be selected arbitrarily.

[0015] In these patterning film forming apparatuses and developing treatment apparatuses, for example, a predetermined processing liquid or a predetermined gas is supplied onto the wafer W. In this manner, the patterning film forming apparatus forms a resist film used as a mask when forming a pattern on an underlying film, or forms an anti-reflection film for efficiently performing a light irradiation process, such as an exposure process. Meanwhile, in the developing treatment apparatus, a portion of the exposed resist film is removed to form a concave-convex shape as the mask. Note that in the contents of this specification, the various gases supplied in the patterning forming apparatus and developing treatment apparatus may be mist as well as gaseous fluids.

[0016] For example, in the second block G2, heat treatment devices (not shown) that perform heat treatment such as heating and cooling of the wafer W are arranged in a vertical and horizontal direction. Also, in the second block G2, although neither is shown, a hydrophobization treatment device that performs a hydrophobization treatment to improve the adhesion of the resist to the wafer W, and a peripheral exposure device that exposes the peripheral portion of the wafer W are arranged in a vertical and horizontal direction (Z direction in FIG. 2). The number and arrangement of these heat treatment devices, hydrophobization treatment devices, and peripheral exposure devices can also be selected as desired.

[0017] 1, a wafer transfer area 32 is formed in an area sandwiched between a first block G1 and a second block G2 in a plan view. In the wafer transfer area 32, for example, a wafer transfer device 33 is disposed.

[0018] The wafer transfer device 33 has a transfer arm 92 that is movable in, for example, the Y direction, the front-to-rear direction, the θ direction, and the up-and-down direction. The wafer transfer device 70 moves within the wafer transfer area 32 and can transfer the wafer W to predetermined devices in the surrounding first block G1, second block G2, third block G3, and fourth block G4. When there are multiple processing stations 3 as shown in FIG. 1, the wafer transfer device 33 provided in the processing station 3 located on the interface station 4 side can transfer the wafer W to predetermined devices in the first, second, and fourth blocks G1, G2, and G3, as well as the fifth block G5 described below.

[0019] A plurality of wafer transfer devices 33 are arranged one above the other, for example, as shown in FIG. 2. One wafer transfer device 33 can transfer wafers W to a predetermined device located at the height of the upper layers 31 among the multiple layers 31 stacked one above the other. Another wafer transfer device 33 can transfer wafers W to a predetermined device located at the height of the multiple layers 31 located below the layers 31. A plurality of wafer transfer areas 32 are provided to enable such transfer of wafers W. Note that the number of wafer transfer devices 33 and the number of layers 31 corresponding to one wafer transfer device 33 can be selected arbitrarily, such as by providing a wafer transfer device 33 for each layer 31.

[0020] The wafer transfer area 32, the first block G1, or the second block G2 may also include a shuttle transfer device (not shown). The shuttle transfer device linearly transfers the wafer W between a space adjacent to one side of the processing station 3 and another space adjacent to the opposite side.

[0021] The interface station 4 is provided with a fifth block G5 equipped with multiple transfer devices and wafer transfer devices 41 and 42. The interface station 4 uses the wafer transfer device 41 or 42 to transfer the wafer W between the fifth block G5, where the wafer W is transferred by the wafer transfer device 33, and the exposure device. To this end, the wafer transfer devices 41 and 42 are each provided with a drive mechanism having movement paths in the horizontal direction (X direction, Y direction), the vertical direction (Z direction), and around the vertical axis (θ direction) as needed, or may be provided with a drive mechanism having movement paths in all directions. At least one of the wafer transfer devices 41 and 42 can support the wafer W and transfer the wafer W between the transfer device in the fifth block G5 and the exposure device.

[0022] A cleaning device for cleaning the surface of the wafer W and the aforementioned peripheral exposure device may be provided in the interface station 4 at a position accessible to either of the wafer transfer devices 41 and 42 .

[0023] The inspection device may be provided in cassette station 2 as described above, but it may also be provided in processing station 3 and interface station 4 at a position accessible to any of the transport arms (33, 41, 42 in Figure 1 or Figure 2) provided inside each station.

[0024] The wafer processing system 1 described above is provided with a control device 100, which serves as a control unit. The control device 100 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of wafers W in the wafer processing system 1. The program storage unit also stores a program for controlling the operation of drive systems such as the various processing devices and transfer devices described above to realize wafer processing in the wafer processing system 1. The program includes steps required to transfer and process wafers W in the wafer processing system 1. The program causes the control device 100 to output control signals to each unit of the wafer processing system 1, which controls each unit as described above to perform the transfer and processing. The program may be recorded on a computer-readable storage medium H and installed in the control device 100 from the storage medium H. The storage medium H may include a ROM, a RAM, or a hard disk, but the structure and type are not limited, and the storage medium H may be temporary or non-temporary. The control device 100 may include a section for storing, reading, and executing a program for realizing wafer processing and for performing communications related thereto, and each section may be located either inside or outside the wafer processing system 1. The control device 100 may be one or more circuits, or may be provided as an integrated unit or as separate parts.

[0025] <Wafer Processing System Operation> The wafer processing system 1 is configured as described above. An example of wafer processing performed using the wafer processing system 1 will be described.

[0026] First, a cassette C containing a plurality of wafers W is carried into the cassette station 2 of the wafer processing system 1 and placed on the cassette mounting table 21. Next, each wafer W in the cassette C is sequentially removed by the wafer transfer device 22 or 23 and transferred to the delivery device in the third block G3.

[0027] The wafer W transferred to the transfer device in the third block G3 is supported by the wafer transfer device 33 and transferred to the hydrophobization treatment device provided in the second block G2, where it is subjected to hydrophobization treatment. The wafer W is then transferred by the wafer transfer device 33 to the resist film deposition device, where a resist film is formed on the wafer W. The wafer W is then transferred to the heat treatment device, where it is pre-baked, and then transferred to the transfer device in the fifth block G5. If there are multiple processing stations 3 as shown in FIGS. 1 and 2, the wafer W is temporarily placed in the transfer device in the fourth block G4 before being transferred to the transfer device in the fifth block G5, and then transferred between multiple wafer transfer devices 33. If necessary, the wafer W may also be transferred by the wafer transfer device 33 to a peripheral exposure device, where the peripheral edge of the wafer is exposed. The above-described processes, from resist film formation to pre-baking, will be described in detail later.

[0028] The wafer W transferred to the delivery device in the fifth block G5 is transferred to the exposure device by wafer transfer devices 41 and 42, and is exposed to a predetermined pattern. Note that the wafer W may be cleaned in a cleaning device before the exposure process.

[0029] The exposed wafer W is transferred to a transfer device in the fifth block G5 by wafer transfer devices 41 and 42. Thereafter, the wafer W is transferred to a heat treatment device by wafer transfer device 33, where it is subjected to post-exposure baking.

[0030] After the exposure and baking process, the wafer W is transferred to a developing treatment device by the wafer transfer device 33 and developed. After the development process is completed, the wafer W is transferred to a heat treatment device 40 by the wafer transfer device 33 and subjected to a post-baking process.

[0031] Thereafter, the wafer W is transferred by the wafer transfer device 33 to the delivery device in the third block G3, and then transferred by the wafer transfer device 22 or 23 in the cassette station 2 to the cassette C on the predetermined cassette mounting table 21. In this way, a series of photolithography steps is completed.

[0032] It should be noted that the wafer processing system of the present disclosure is not limited to the configuration and operation described above. For example, in the above-described embodiment, the wafer processing system is directly connected to the exposure apparatus, and wafers W are transferred between the interface station 4 and the exposure apparatus. However, the wafer processing system does not have to be directly connected to the exposure apparatus. In that case, for example, the wafer W is transferred from the cassette station 2 to the processing station 3, where it undergoes the necessary processing, and then transferred back to the cassette station 2 for removal from the system. Furthermore, unnecessary processing devices listed above may not be provided in the wafer processing system, or processing may not be performed in those devices.

[0033] [About MOR] The wafer processing system 1 is located in a clean room in a semiconductor device manufacturing factory. There is no limitation on the type of resist film formed on the wafer W by the wafer processing system 1, but for example, it is a resist film made of metal oxide resist (MOR), and the wafer processing system 1 is configured to be particularly effective for forming such MOR resist films. This MOR is a negative resist containing, for example, tin (Sn) as a metal. Note that "containing metal" here means containing metal as a constituent component, not containing metal as an impurity. In the following description, unless otherwise specified, when referring to a resist film, it is assumed to be a resist film made of MOR.

[0034] The MOR reacts with an appropriate amount of water or oxygen between the time it is applied to the wafer W and the time it is subjected to the pre-exposure heat treatment (PAB: Pre-Apply Bake). This releases some of the ligands coordinated to the metal, and a condensation reaction occurs in which the metals contained in the MOR bond together via oxygen. In other words, an appropriate amount of metal oxide is produced. The PAB is a process previously described as pre-baking, and the PAB hardens the resist film. After hardening, the resist film becomes less susceptible to condensation reactions caused by water or oxidizing gases.

[0035] After PAB, the resist film loses more ligands due to exposure, for example, using an exposure device, and hydroxyl groups bond to the metal in their place. Then, through the post-exposure bake (PEB) process, these hydroxyl groups undergo dehydration condensation, forming even more oxygen-mediated metal-metal bonds, making the exposed portions of the resist film insoluble during development.

[0036] If the resist film is exposed to an atmosphere with a relatively high oxygen concentration or a relatively high humidity before being cured by PAB, unwanted reactions such as excessive ligands being detached from the metal are likely to occur. If such unwanted reactions occur, the reactions during exposure and PEB described above may not proceed normally, resulting in the resist pattern's line width (critical dimension: CD) deviating from the desired value or reduced hardness. To prevent such problems, the wafer processing system 1 is configured to adjust the low-oxygen and low-humidity atmospheres in the processing spaces within each processing chamber where the resist film is formed and PAB is performed, and in the wafer transfer area connecting these processing spaces.

[0037] To create such a low-oxygen and low-humidity atmosphere, it is possible to evacuate the processing space and the transfer path to create a vacuum atmosphere. If the processing space and wafer transfer area are to be transferred and processed in this vacuum state, a load-lock module must be installed in the wafer processing system 1 to transfer the wafer W between the area including the processing space and wafer transfer area and other areas within the system. Transferring the wafer W through this load-lock module requires time to change the air pressure within the load-lock module containing the wafer W, which may reduce the efficiency of loading and unloading the wafer W into and from the resist film deposition apparatus and PAB thermal processing apparatus. This reduced loading and unloading efficiency may reduce the processing efficiency (throughput) of the wafer W in the resist film deposition apparatus and PAB thermal processing apparatus, and ultimately the processing efficiency of the wafer W in the wafer processing system 1.

[0038] [Regarding atmosphere adjustment in the adjustment area] To prevent such a decrease in processing efficiency, the wafer processing system 1 forms a vacuum atmosphere in the processing space and wafer transfer region within the processing vessel, achieving a low oxygen concentration and low humidity, and then increases the pressure by supplying an inert gas to adjust the pressure. This allows wafers W to be quickly loaded and unloaded from the processing space and wafer transfer region, preventing a decrease in processing efficiency of wafers W in the resist film deposition apparatus and PAB heat treatment apparatus. In the following embodiments, the region where the oxygen concentration, humidity, and pressure are adjusted by exhaust and inert gas supply is referred to as an adjustment region R0. In the first embodiment, the processing spaces 60 and 80 and wafer transfer region 90, described below, correspond to this adjustment region R0.

[0039] It is possible to create a low-oxygen-concentration, low-humidity atmosphere in the adjustment region R0 by simultaneously supplying and exhausting an inert gas, thereby reducing the pressure difference with the surroundings. However, doing so would result in the exhausted gas containing a large amount of inert gas, which would require a long time to form the atmosphere. To create a low-oxygen-concentration, low-humidity atmosphere in a relatively short time, the adjustment region R0 is first evacuated as described above to reduce the pressure and form a vacuum atmosphere, and then an inert gas is supplied to increase the pressure.

[0040] In the conditioning region R0, the atmosphere in a state in which the oxygen concentration, humidity, and pressure are adjusted by exhausting the air and supplying an inert gas as described above is referred to as the second atmosphere. As mentioned above, the second atmosphere has a low oxygen concentration and low humidity. Specifically, the oxygen concentration and humidity of the second atmosphere are set lower than those of the first atmosphere outside the conditioning region R0. The area outside the conditioning region R0 refers to a wafer W transfer area connected to the conditioning region R0 within the wafer processing system 1, where wafers W are transferred to and from the conditioning region R0. This area corresponds to the wafer transfer area 32. The area outside the conditioning region R0 may be an external space (e.g., a floor space) of the wafer processing system 1, an internal space of the cassette station 2 (e.g., a space where the wafer transfer device 22 is installed), or an internal space of the interface station 4 (e.g., a space where the wafer transfer device 41 is installed).

[0041] The oxygen concentration and humidity of the second atmosphere are lower than those of the atmosphere in the area where the cassette C is transported in the clean room where the wafer processing system 1 is installed. More specifically, for example, the second atmosphere has an oxygen concentration of 5% or less and a humidity (relative humidity) of 5% or less. The pressure of the second atmosphere is set to the same pressure as the first atmosphere or a pressure close to the pressure of the first atmosphere so that the load lock module described above is not required. The pressure close to the pressure of the first atmosphere is specifically a pressure within the range of -5 kPa to +5 kPa of the pressure of the first atmosphere.

[0042] The pressure inside the clean room in which the wafer processing system 1 is installed is atmospheric pressure (101.3 kPa) or a pressure close to atmospheric pressure. In the wafer transfer area 32, which is outside the adjustment area R0 that forms the first atmosphere, gas is supplied and exhausted to prevent particles from adhering to the wafer W, and the pressure may deviate from that inside the clean room, but by installing the wafer processing system 1 in the clean room, the pressure is set to atmospheric pressure or a pressure relatively close to atmospheric pressure. Therefore, the pressure of the first atmosphere described above is, for example, 96.3 kPa to 106.3 kPa.

[0043] As described above, the second atmosphere is formed in the adjustment region R0 by first evacuating the air to a vacuum pressure and then supplying gas. To achieve a sufficiently low oxygen concentration and low humidity, the air is evacuated to a pressure of, for example, 10 Torr (1.3 kPa) or less, and then gas is supplied to increase the pressure. Note that the gas supplied to increase the pressure in the adjustment region R0 is an inert gas, as described above, and therefore does not contain moisture and is a dry gas. "Moisture-free" here does not mean that it does not contain moisture that is inevitably mixed in. While there are no limitations on the type of inert gas supplied to the adjustment region R0, this example will be described assuming that N2 (nitrogen) gas is supplied.

[0044] [Equipment and wafer transfer area layout] The processing station 3 will be described in more detail with reference to the longitudinal side view of FIG. 3 . The processing station 3 includes a housing, the interior of which is divided into upper and lower sections by a partition wall. The upper side of the partition wall is configured as an upper region R1, in which various devices for processing the wafer W after exposure by the exposure device, such as a thermal processing device for PEB and a development processing device, are provided. The lower side of the partition wall is configured as a lower region R2, in which various devices for processing the wafer W before exposure by the exposure device, such as a resist film forming device and a thermal processing device for PAB, are provided. The above-mentioned multiple layers 31, wafer transfer region 32, and wafer transfer device 33 are provided in each of the upper region R1 and lower region R2, and the upper region R1 and lower region R2 can transport the wafer W between the cassette station 2 side and the interface station 4 side, respectively.

[0045] By regarding the partition wall as part of the housing, the processing station 3 can also be viewed as having two housings that respectively define the upper region R1 and the lower region R2. Hereinafter, the housing that defines the lower region R2 will be referred to as housing 91, and the configuration of the lower region R2 will be described. As described above, each layer 31 includes a first block G1 and a second block G2, sandwiching the wafer transfer region 32, in which processing devices for wafers W are respectively arranged. Therefore, the processing devices are stacked on the front and rear sides of the wafer transfer region 32. As described above, the processing devices for processing wafers W are arranged in the first block G1 at each height, so that the processing devices are stacked. A plurality of these stacked processing devices are arranged in the Y direction (left-right direction), forming a processing device group arranged in a matrix in a front view facing the wafer transfer region 32. The processing devices that make up this processing device group include a resist film deposition device 6 and a heat treatment device 8.

[0046] The front side of the processing equipment group is surrounded by a portion of the housing 91, separating it from the surrounding area and constituting a wafer transfer area 90, which is an enclosed space. Therefore, the processing equipment group can also be seen as being arranged to separate the lower area R2 into front and rear. The wafer transfer area 90 has a height extending from the topmost layer 31 included in the lower area R2 to the bottommost layer 31, and a length extending from the leftmost processing equipment to the rightmost processing equipment of the processing equipment group. Therefore, the wafer transfer area 90 is formed to extend from the front of the resist film deposition equipment 6 to the front of each heat treatment equipment 8.

[0047] A wafer transfer device 95 is provided in the wafer transfer area 90. The wafer transfer device 95 includes a transfer arm 92, a base 93, and a movement mechanism 94, and the base 93 is configured to be movable in both the Y and Z directions and rotatable about a vertical axis by the movement mechanism 94. The transfer arm 92 supports the wafer W and is configured to be able to move forward and backward relative to the base 93.

[0048] Each of the resist film forming apparatus 6 and the heat treatment apparatus 8 includes the processing vessel described above. The transfer port for the wafer W formed in each of these processing vessels faces the wafer transfer area 90, and the wafer W can be transferred from any of the resist film forming apparatuses 6 to any of the heat treatment apparatuses 8 by a wafer transfer apparatus 95. The wafer transfer apparatus 35 provided in the wafer transfer area 32 has the same configuration as this wafer transfer apparatus 95.

[0049] To form the second atmosphere, an exhaust mechanism 96 and an N2 gas supply mechanism 97 are connected to the housing 91. The exhaust mechanism 96 includes a vacuum pump, an exhaust pipe, and a valve connected to the exhaust pipe. The exhaust mechanism 96 can switch between exhausting and stopping the exhaust of the wafer transfer region 90 via an exhaust port 96A formed in the housing 91. The exhaust volume can also be adjusted by, for example, adjusting the valve opening. The N2 gas supply mechanism 97 includes an N2 gas supply source, a pipe forming an N2 gas flow path, a valve connected to the pipe, and a flow rate adjuster such as a mass flow controller that adjusts the flow rate of N2 gas supplied downstream of the pipe. The N2 gas supply mechanism 97 can switch between supplying and stopping N2 gas to the wafer transfer region 90 via a gas supply port 97A formed in the housing 91. Note that exhaust mechanisms other than the exhaust mechanism 96 and N2 gas supply mechanisms other than the N2 gas supply mechanism 97 described below are also assumed to have the same configuration as the exhaust mechanism 96 and N2 gas supply mechanism 97.

[0050] [Configuration of resist film deposition equipment] The resist film forming apparatus 6 will be described with reference to the vertical cross-sectional side view of FIG. 4. The resist film forming apparatus 6 forms a resist film by performing CVD (Chemical Vapor Deposition) in a second atmosphere. As described above, the resist film forming apparatus 6 includes a processing vessel 61. A stage 62 is provided to separate the processing vessel 61, which is a single processing vessel, into upper and lower sections. During film formation, a wafer W is placed on the stage 62. Above the stage 62, a processing space 60 is formed for performing a film formation process on the wafer W. The processing space 60, which is a single processing space, is circular in plan view and has a relatively small, flat structure so that gas replacement can be performed quickly to prevent particle generation, as described below. As described below, the resist film forming apparatus 6 is also configured to perform cleaning, which removes a resist film formed on the wall surfaces that form the processing space 60 by supplying a cleaning gas.

[0051] Transfer ports 63 and 64 are formed in the sidewall of the processing vessel 61, and each communicates with the processing space 60. The transfer port 63 opens to the wafer transfer area 90 so that the wafer W can be transferred between the wafer transfer device 95 and the resist film deposition device 6, as described above. The transfer port 64 opens to the wafer transfer area 32 so that the wafer W can be transferred between the wafer transfer device 33 and the resist film deposition device 6, as described above. These transfer ports 63 and 64 are opened and closed by a gate valve G. The gate valve G is closed except when necessary for transferring the wafer W, making the processing space 60 airtight.

[0052] The stage 62 described above is configured as a hot plate by embedding a heater 65. The heater 65 heats the upper surface of the stage 62 to a predetermined temperature during film formation on the wafer W and during cleaning. A moving space is formed below the stage 62, in which a lifting member 66A is moved up and down by a lifting mechanism 66 provided at the bottom of the processing vessel 61. The power supply line of the heater 65 is drawn to the outside of the processing vessel 61 through the moving space and connected to a power source. The lifting member 66A is provided with three vertical pins 66B (only two are shown in the figure). The pins 66B protrude and retract above the stage 62, allowing the transfer of the wafer W between the stage 62 and the wafer transfer device 33, 95. A bellows 66C in the figure surrounds the pins 66B and is connected to the lifting member 66A and the stage 62 to maintain the airtightness of the processing space 60.

[0053] A heater 67 is embedded in the upper wall of the processing vessel 61, and heats a lower surface 68 of the upper wall (the ceiling surface forming the processing space 60) to a predetermined temperature during film formation on the wafer W and during cleaning. The heater 67 on the upper wall and the heater 65 on the stage 62 provide the thermal energy required for film formation to the wafer W and the gas supplied to the processing space 60 during film formation. During cleaning, the heater 67 on the upper wall and the heater 65 on the stage 62 provide the thermal energy required for cleaning to the resist film adhering to the wall surfaces forming the processing space 60 and the cleaning gas formed in the processing space 60. To promote cleaning, the temperatures of the lower surface 68 of the upper wall of the processing vessel 61 and the upper surface of the stage 62 are adjusted so that they are higher when the cleaning gas is supplied to the processing space 60 than when the resist component-containing gas is supplied to the processing space 60. The temperatures of the lower surface 68 of the upper wall and the upper surface of the stage 62 during the supply of the resist component-containing gas are set to, for example, 80°C to 100°C. During this supply of cleaning gas, the temperature of the lower surface 68 of the upper wall and the upper surface of the stage 62 is set to, for example, 150° C. to 190° C., which is a temperature above the boiling point of acetic acid that constitutes the cleaning gas described below.

[0054] An exhaust port 71 is formed in the lower surface 68 of the upper wall of the processing vessel 61. An exhaust mechanism 72 is connected to the processing vessel 61, and the processing space 60 can be evacuated via the exhaust port 71. Gas supply ports 73, 74, and 75 are also formed in the lower surface 68 of the upper wall. An N2 gas supply mechanism 76, a film forming gas supply mechanism 77, and a cleaning gas supply mechanism 78 are connected to the processing vessel 61, and the N2 gas supply mechanism 76, the film forming gas supply mechanism 77, and the cleaning gas supply mechanism 78 can supply gases to the processing space 60 via the gas supply ports 73, 74, and 75, respectively. The N2 gas supply mechanism 76 and the exhaust mechanism 72 form an atmosphere adjustment mechanism and serve to form a second atmosphere in the processing space 60.

[0055] The film formation gas supply mechanism 77 will now be described. The film formation gas supply mechanism 77 is composed of pipes 101 to 105, valves V1 to V5, a storage container 106, flow rate adjusters 108 and 109, and an N2 gas supply mechanism 107. The storage container 106 is a storage unit that stores a liquid (film formation raw material liquid) that serves as a film formation raw material for a resist film. The downstream end of the pipe 101 is connected to the upper wall of the processing vessel 61 so that gas can be introduced into the gas supply port (gas discharge port) 74. A valve V1 is interposed in the pipe 101, and the pipe 101 branches into pipes 102 and 103 upstream of the valve V1. Note that a pipe 104, which is shown in the drawing as being connected to the pipe 101, will be described later.

[0056] The upstream side of pipe 102 is connected to storage container 106 via valve V2, and the upstream end of pipe 102 opens to the gas phase in storage container 106. The downstream end of pipe 105 opens into the film-forming raw material liquid stored in storage container 106 so that the film-forming raw material liquid can be vaporized by bubbling to generate a resist component-containing gas. The upstream end of pipe 105 is connected to N2 gas supply mechanism 107 via flow rate adjuster 108 and valve V3 in this order. Meanwhile, the upstream end of pipe 103 is connected to the upstream side of valve V3 in pipe 105 via flow rate adjuster 109 and valve V4 in this order. The flow rate adjusters 108 and 109 are, for example, mass flow controllers, and adjust the flow rate of N2 gas supplied to the downstream sides of the pipes.

[0057] When the valves V2 to V4 are opened, N2 gas, which is a carrier gas supplied from the N2 gas supply mechanism 107 to the storage container 106, is used to bubble the storage container 106. As a result, a mixed gas of the resist component-containing gas produced by vaporization of the film-forming raw material liquid and the N2 gas, which is the carrier gas, is produced in the storage container 106 and supplied to the pipe 102. This mixed gas is supplied from the pipe 102 and N2 gas is supplied from the pipe 103 to the pipe 101, and they are mixed with each other. When the valve V1 is opened, the gas in the pipe 101 is supplied to the processing space 60.

[0058] That is, the resist component-containing gas generated from the film-forming raw material solution in the storage container 106 is diluted by the carrier gas (N2 gas) supplied to the pipe 105 and the N2 gas supplied to the pipe 103, and then supplied to the processing space 60. Therefore, in addition to the N2 gas supplied to the pipe 103, the N2 gas supplied as a carrier gas to the pipe 105 can also be considered as a dilution gas. The resist component-containing gas is diluted by 100 times or more by these dilution gases. For convenience, the gas diluted in this way will be referred to as a film-forming gas hereinafter. In other words, the film-forming gas is a gas consisting of the resist component-containing gas and the dilution gas.

[0059] The N2 gas supply mechanism 107 is a dilution gas supply mechanism. The storage container 106 forms a mixing section that mixes the resist component-containing gas with the dilution gas, and the flow path of the resist component-containing gas in the pipes 101 and 102 and the storage container 106 is equipped with a mixing section that mixes the gases in this manner. The storage container 106 not only forms a mixing section, but also serves as a resist component-containing gas supply section that vaporizes the film-forming raw material liquid to generate the resist component-containing gas, and the upstream end of the pipe 101, into which N2 gas is introduced from the pipe 103, also corresponds to a mixing section.

[0060] Meanwhile, the upstream end of the pipe 101 for supplying the film formation gas is connected to the upstream side of the position where the valve V1 is installed. The downstream end of the pipe 104 is connected via the valve V5 to, for example, an exhaust path of a factory where the wafer processing system 1 is installed. The film formation gas is first supplied to the pipe 104 by closing the valve V1 and opening the valve V5. Thereafter, the valve V5 is closed and the valve V1 is opened, so that the film formation gas is supplied to the processing space 60. By switching the supply destination in this manner, the film formation gas generated immediately after the start of bubbling is prevented from being supplied to the processing space 60, thereby suppressing fluctuations in the dilution ratio of the film formation gas supplied to the processing space 60.

[0061] Diluting the resist component-containing gas by the dilution gas by 100 times or more will be described in detail. Flow meters are provided in the pipes 105 and 102, respectively, to measure the flow rate A1 sccm of the carrier gas supplied to the storage container 106 and the flow rate A2 sccm of the mixed gas of the carrier gas and the resist component-containing gas supplied from the storage container 106 to the pipe 102. The flow rate A2 sccm - flow rate A1 sccm = flow rate A3 sccm calculated from these measurements is defined as the flow rate of the resist component-containing gas. Furthermore, a flow meter is provided in the pipe 103 to measure the flow rate A4 sccm of the N2 gas supplied from the pipe 103 to the pipe 101. The total flow rate of the film forming gases supplied to the processing space 60 via the pipe 101 is (A2 + A4) sccm. The total flow rate (A2 + A4) sccm / the flow rate A3 sccm of the resist component-containing gas is the dilution ratio, and a dilution ratio of 100 or more indicates the above-mentioned dilution of the resist component-containing gas by 100 times or more. If dilution of 100 times or more can be achieved using only the carrier gas, N2 gas does not need to be supplied to the pipe 101 via the pipe 103. In other words, the flow rate A4 sccm may be 0 sccm.

[0062] The reason for setting the dilution ratio of the resist component-containing gas to the above-mentioned relatively large value will be explained. As described above, the processing space 60 is maintained in a relatively high-pressure second atmosphere, which is atmospheric pressure or a pressure close to atmospheric pressure, during film formation. If a film formation gas with a low dilution ratio of the resist component-containing gas is supplied to the processing space 60 at such a high pressure, the partial pressure of the resist component-containing gas in the processing space 60 will be relatively high. In such a high partial pressure environment, the resist components in the gas react with each other in the gas phase before adsorbing onto the wafer W to form a resist film, which can result in particles, potentially preventing normal film formation. Therefore, by setting the dilution ratio to a relatively large value of 100 times or more, the partial pressure of the resist component-containing gas in the processing space 60 is kept relatively low, thereby suppressing the generation of particles due to the above-mentioned reaction between the resist components.

[0063] The cleaning gas supply mechanism 78 has the same configuration as the film formation gas supply mechanism 77, except that a cleaning gas source liquid is stored in the storage container 106 instead of the film formation source liquid, and the dilution ratio of the gas generated from this source liquid is different from the dilution ratio of the resist component-containing gas. As described above, the cleaning gas is acetic acid gas, and the source liquid is, for example, acetic acid, but there are no particular limitations on the type of cleaning gas as long as it is a gas that can dissolve and remove the resist film.

[0064] [Configuration of heat treatment equipment for PAB] Next, the configuration of the heat treatment apparatus 8 for PAB will be described. Since this heat treatment apparatus 8 includes components configured similarly to the resist film deposition apparatus 6, the description will focus on the differences from the resist film deposition apparatus 6 and refer to the vertical side view of FIG. 5. The processing vessel provided in the heat treatment apparatus 8 is referred to as a processing vessel 81. The processing space within this processing vessel 81, which is another processing vessel, is referred to as a processing space 80, and this processing space 80, which is another processing space, has the same configuration as the processing space 60 in the resist film deposition apparatus 6. Like the processing vessel 61, the processing vessel 81 is formed to face wafer transfer regions 90 and 32, respectively, and is provided with transfer ports 63 and 64 that are opened and closed by gate valves G.

[0065] In the heat treatment apparatus 8, in order to heat the stage 62 to a relatively high temperature, an annular heat insulator 82 is provided surrounding the stage 62, and the heat insulator 82 and the stage 62 divide the interior of the processing vessel 81 into upper and lower sections, thereby forming a processing space 80 above the heat insulator 82 and the stage 62. The temperature of the upper surface of the stage 62 of the heat treatment apparatus 8 is set to a temperature higher than the temperature of the upper surface of the stage 62 of the resist film forming apparatus 6 when the film forming gas is supplied, specifically, a temperature higher than 100°C, for example.

[0066] In the illustrated example, the heater 67 is not provided on the upper wall of the processing vessel 81, but the heater 67 may be provided. This processing vessel 81 differs from the processing vessel 61 of the resist film forming apparatus 6 in that, of the gas supply ports 73 to 75 and the exhaust port 71, only the N2 gas supply port 73 and the exhaust port 71 are provided on the lower surface 68 of the upper wall. An exhaust mechanism 72 and an N2 gas supply mechanism 76 are connected to the processing vessel 81, and the second atmosphere can also be created in the processing space 80 by exhausting air and supplying N2 gas via the exhaust port 71 and the gas supply port 73, respectively.

[0067] [Operation of each device] Next, the operations of the resist film forming apparatus 6, the heat treatment apparatus 8, and the wafer transfer apparatus 95 when the wafer W is transferred and processed in the wafer processing system 1 as described above will be described in detail. Of these apparatuses, the operation of the resist film forming apparatus 6 will be described with reference to the schematic diagrams of FIGS. 6 to 9. The processing space 60 of the resist film forming apparatus 6 begins to be evacuated by the exhaust mechanism 72 before the wafer W is transferred (time t1, FIG. 6), forming a vacuum atmosphere. When the processing space 60 reaches the predetermined pressure described above (time t2), the exhaust mechanism 72 stops evacuation and the N2 gas supply mechanism 76 starts supplying N2 gas (FIG. 7). Thereafter, the pressure increase is completed, forming a second atmosphere (time t3). After time t3, the exhaust mechanism 72 resumes evacuation, and the exhaust mechanism 72 and the N2 gas supply mechanism 76 simultaneously perform evacuation and supply N2 gas, thereby maintaining the second atmosphere. In this manner, the second atmosphere is formed in the processing space 60 before the film formation process on the wafer W is started.

[0068] In the processing space 80 and wafer transfer region 90 of the heat treatment apparatus 8, similarly to the processing space 60, before the wafer W is transferred, evacuation by the exhaust mechanisms 72 and 96 and supply of N2 gas by the N2 gas supply mechanisms 76 and 97 are performed in that order to form a second atmosphere. After the second atmosphere is formed, evacuation and supply of N2 gas are performed together to maintain the second atmosphere.

[0069] In the resist film forming apparatus 6, the upper surface of the stage 62 and the lower surface 68 of the upper wall of the processing vessel 61 are adjusted by the heaters 65 and 67 to have predetermined temperatures within the aforementioned range for film formation. In the heat treatment apparatus 8, the upper surface of the stage 62 is also adjusted by the heater 65 to have a predetermined temperature within the aforementioned range.

[0070] The wafer W is transferred from the cassette C to the wafer transfer region 32, and the gate valve G on the wafer transfer region 32 side of the processing vessel 61 of the resist film forming apparatus 6 is opened. The wafer W is then transferred by the wafer transfer device 33 to the processing space 60, which is set to the second atmosphere, and placed on the stage 62. The wafer W is heated to the same temperature as the upper surface of the stage 62. A film formation gas is supplied from the film formation gas supply mechanism 77 to the processing space 60, which is made airtight by closing the gate valve G. A resist film is formed on the surface of the wafer W while the processing space 60 is maintained in the second atmosphere (FIG. 8). Because the processing space 60 is in the second atmosphere, i.e., the low oxygen concentration and low humidity described above, unwanted reactions of the resist film are suppressed, and film formation on the wafer W proceeds.

[0071] When the resist film on the surface of the wafer W reaches a predetermined thickness, the supply of film forming gas to the processing space 60 is stopped, the gate valve G on the wafer transfer region 90 side of the processing vessel 61 is opened, and the wafer W is removed from the processing space 60 to the wafer transfer region 90 by the wafer transfer device 95. Then, the gate valve G on the wafer transfer region 90 side of the processing vessel 81 of the heat treatment device 8 is opened, and the wafer W is transferred to the processing space 80 within the processing vessel 81. Because the wafer transfer region 90 and the processing space 80 are in the second atmosphere, unwanted reactions of the resist film are suppressed even during this transfer.

[0072] The wafer W is then placed on the stage 62 and heated, and PAB is performed. Closing the gate valve G makes the processing space 80 airtight, and PAB proceeds while the processing space 80 is maintained at the second atmosphere. Thereafter, the gate valve G on the wafer transfer region 32 side of the processing vessel 81 is opened, and the wafer W is removed from the processing space 80 under the second atmosphere to the wafer transfer region 32 by the wafer transfer device 33. The wafer W removed to the wafer transfer region 32 in this manner is transferred within the wafer processing system 1, and subjected to the various processes described above as being performed after PAB, such as exposure, PEB, and development, before being returned to the cassette C.

[0073] The resist film forming apparatus 6 from which the wafer W has been unloaded has a resist film M formed on the wall surfaces that define the processing space 60. In this resist film forming apparatus 6, the heaters 65, 67 adjust the upper surface of the stage 62 and the lower surface 68 of the upper wall of the processing vessel 61 to predetermined temperatures within the ranges described above for cleaning. Then, the processing space 60 is evacuated by the exhaust mechanism 72, and a cleaning gas is supplied to the processing space 60 by the cleaning gas supply mechanism 78 (FIG. 9). This dissolves the resist film M formed on the wall surfaces, and the dissolved material is exhausted and removed. Thereafter, the supply of cleaning gas to the processing space 60 is stopped, and cleaning is completed.

[0074] 6 and 7, the atmosphere in the processing space 60 is exhausted and N2 gas is supplied to form the second atmosphere again in the processing space 60, and then the wafer W is loaded and processed. Note that the frequency of cleaning is not limited to every time one wafer W is processed in the resist film forming apparatus 6, and cleaning may be performed every time multiple wafers W are processed.

[0075] As described above, the processing spaces 60, 80 and wafer transfer region 90 constituting the adjustment region R0, which forms the transfer path along which the wafer W is transferred from the wafer transfer region 32, subjected to resist film formation and PAB, and returned to the wafer transfer region 32, are set to the second atmosphere, and the pressure difference with the first atmosphere in the wafer transfer region 32 is suppressed. Therefore, when the wafer W is transferred between the wafer transfer region 32 and the processing spaces 60, 80, the wafer W does not stagnate, as occurs in the configuration provided with the load lock module described above, and the transfer can be performed quickly. Similarly, the transfer within the adjustment region R0 (transfer between the processing spaces 60, 80 and the wafer transfer region 90) can be performed quickly without stagnation of the wafer W. Therefore, a decrease in the processing efficiency of resist film formation and PAB is prevented, and the throughput of the wafer processing system 1 can be relatively high.

[0076] 6 and 7, during the period from time t1 to t3 when the second atmosphere is formed in the processing space 60 of the resist film forming apparatus 6, only one of evacuation and N2 gas supply is performed. However, this is not limited to this. Specifically, to prevent the time required to form the second atmosphere from being extended due to the N2 gas being exhausted together with water and oxygen in the processing space 60 as described above, N2 gas is supplied to the processing space 60 at a first flow rate from time t1 to t2, and N2 gas is supplied to the processing space 60 at a second flow rate greater than the first flow rate from time t2 to t3. While the first flow rate is described as 0 in the description of FIG. 6, it may be a flow rate greater than 0.

[0077] Furthermore, in order to quickly increase the pressure in the processing space 60 from time t2 to t3, the processing space 60 is evacuated at a first exhaust rate from time t1 to t2, and at a second exhaust rate smaller than the first exhaust rate from time t2 to t3. Although the second exhaust rate is described as 0 in the description of FIG. 7, it is not limited to being 0. Similarly to the processing space 60, the formation of the second atmosphere in the processing space 80 and wafer transfer region 90 of the heat treatment device 8 is not limited to only one of exhaust and N2 gas supply.

[0078] [First Modification of Resist Film Forming Apparatus] 10 shows a longitudinal sectional side view of a resist film forming apparatus 6A, which is a first modified example of the resist film forming apparatus. The resist film forming apparatus 6A differs from the resist film forming apparatus 6 in that an organic compound gas supply mechanism 79 is connected to the processing vessel 61. The organic compound gas supply mechanism 79 has a configuration similar to that of the cleaning gas supply mechanism 78 and the film forming gas supply mechanism 77, except that a liquid organic compound is stored in, for example, a storage vessel 106, and a gas containing the vaporized organic compound is supplied to the processing space 60 through a gas supply port 69 provided on the lower surface 68 of the upper wall of the processing vessel 61. There are no particular limitations on the organic compound as long as it can be supplied to the wafer W as a gas and can constitute part of the resist film M.

[0079] Note that, being configured in the same manner as the film formation gas supply mechanism 77, the organic compound gas supply mechanism 79 supplies a mixed gas of vaporized organic compound and dilution gas to the processing space 60. In the following description, the flow rate of the organic compound gas refers to the flow rate of the vaporized organic compound in the mixed gas, and is calculated in the same manner as the flow rate of the resist component-containing gas in the film formation gas described above.

[0080] In the resist film forming apparatus 6A, a film forming gas is supplied to the processing space 60, which is set to the second atmosphere, as in the resist film forming apparatus 6, and a film is formed by CVD on the wafer W. During this film formation by CVD, the flow rate ratio of the resist component-containing gas and the organic compound gas supplied to the processing space 60 is changed midway by changing the vaporization efficiency, for example, by changing the flow rate of the carrier gas.

[0081] This will be described in detail with reference to the schematic diagram of a vertical cross-sectional side of a wafer W in FIG. 11. The supply of a film-forming gas and an organic compound gas into the processing space 60 is started. The flow rate of the resist component-containing gas contained in the film-forming gas is A3 sccm, and the flow rate of the organic compound gas is B1 sccm. After a predetermined time has elapsed since the start of the supply of each gas, the flow rate of the resist component-containing gas is kept at A3 sccm, while the flow rate of the organic compound gas is changed to B2 sccm, which is larger than B1 sccm, and film formation is continued. After a predetermined time has elapsed since this flow rate change, the supply of the film-forming gas and the organic compound gas into the processing space 60 is stopped. As a result, the resist film M formed on the wafer W has a lower content of metal M1 per unit volume in the upper side than in the lower side, as shown in FIG. 11.

[0082] Instead of increasing the flow rate of the organic compound gas relative to the flow rate of the resist component-containing gas as described above, the flow rate of the resist component-containing gas may be decreased relative to the flow rate of the organic compound gas, thereby making the content ratio of the metal M1 different between the upper and lower sides of the resist film M.

[0083] The reason for changing the content ratio of metal M1 in the resist film in this manner will be explained using FIGS. 12 and 13, which are schematic diagrams showing the longitudinal cross-section of a wafer W to be developed. The upper part of FIG. 12 is a schematic diagram showing a wafer W before development, in which the proportion of metal M1 contained in the resist film M is the same between the upper and lower sides. When the resist film M is exposed using an exposure device, light is less readily supplied to the lower side of the resist film M than to the upper side. Therefore, during this exposure, the reaction in the resist film M progresses more rapidly in the upper side, promoting bonding between metal M1 molecules via oxygen. As a result, during development, the dissolution reaction of the resist film M progresses more rapidly in the lower side than in the upper side, which can result in a resist pattern having a smaller opening width in the upper side than in the lower side, as shown in the lower part of FIG. 12.

[0084] However, if the resist film M is formed so that the content of metal M1 is smaller on the upper side than on the lower side as shown in Fig. 11, the reaction on the upper side during exposure is suppressed, and the amount of metal that bonds via oxygen becomes more uniform between the upper and lower sides of the resist film M. As a result, the progress of the dissolution reaction on the upper and lower sides of the resist film M during development becomes uniform, which is preferable because it makes it possible to uniform the opening widths of the resist pattern on the upper and lower sides as shown in Fig. 13.

[0085] [First Modification of Heat Treatment Apparatus] 14 is a vertical cross-sectional side view of a heat treatment apparatus 8A, which is a first modified example of the heat treatment apparatus for PAB. The following description will focus on the differences between this heat treatment apparatus 8A and the heat treatment apparatus 8. The side of the stage 62 in the heat treatment apparatus 8A is spaced apart from the side wall of the processing vessel 81. The wafer W can be transferred between the wafer transfer apparatuses 33 and 94 and the stage 62 by the lifting and lowering operations of these wafer transfer apparatuses 33 and 94.

[0086] In the heat treatment apparatus 8A, a light irradiation unit 111 is provided instead of the heater 65 of the stage 62, and the wafer W is heated by the light irradiation unit 111. The light irradiation unit 111 includes a plurality of light sources 112, each of which is configured with, for example, an LED. The light sources 112 are connected to a power supply unit 119 that supplies power to the light sources 112, and the intensity of light irradiated from the light sources 112 can be freely changed by adjusting the amount of power supplied from the power supply unit 119. The light sources 112 and the power supply unit 119 are configured as a light irradiation unit. The light irradiation unit 111 is provided above the processing vessel 61, and the light source 112 is disposed on the upper wall of the processing vessel 61. Light irradiated downward from the light source 112 (shown by a chain line in the figure) is supplied to the wafer W on the stage 62.

[0087] As with the heat treatment apparatus 8, the processing space 80 of the heat treatment apparatus 8A is set to the second atmosphere before the wafer W is loaded. The wafer W is then transferred into the processing space 80 under the second atmosphere and placed on, for example, the stage 62. Light irradiation from the light source 112 is then initiated, and the PAB of the wafer W is performed. In the illustrated example, the exhaust port 71 and the N2 gas supply port 73 for forming the second atmosphere are opened in the side and bottom surfaces of the processing vessel 81, respectively. As described above, the PAB performed in the second atmosphere is not limited to being performed by placing the wafer W on a hot plate.

[0088] [Second Modification of Resist Film Forming Apparatus] 15 is a vertical cross-sectional side view of a resist film forming apparatus 6B, which is a second modified example of the resist film forming apparatus. The resist film forming apparatus 6B is configured to perform a film forming process similar to that performed in the resist film forming apparatus 6 and PAB by light irradiation on the wafer W. Therefore, the film forming process and PAB on the wafer W are performed in the same processing space 60.

[0089] The resist film forming apparatus 6B differs from the resist film forming apparatus 6 in that it includes a light irradiation unit 113. The light irradiation unit 113 has a configuration generally similar to the light irradiation unit 111 described in FIG. 14 and includes a light source 112 and a window 114. The window 114 forms part of the upper wall of the processing vessel 61, and light from the light source 112 passes through the window 114 and is supplied to the wafer W placed on the stage 62. The gas supply ports 73 to 75 and the exhaust port 71 are opened at positions away from the window 114 on the lower surface of the upper wall of the processing vessel 61. Note that the heater 67 is not provided on the upper wall of this processing vessel 61, and the upper wall is heated during cleaning by light irradiation from the light irradiation unit 111 instead of the heater 67, for example.

[0090] The differences from the other resist film forming apparatuses 6 are as follows: in the resist film forming apparatus 6B, the wafer W is heated to a relatively high temperature to perform PAB, and therefore the stage 62 reaches a relatively high temperature, and therefore the stage 62 is surrounded by a heat insulating material 82, similar to the stage 62 of the heat treatment apparatus 8 shown in Fig. 5. Furthermore, when processing is performed in this resist film forming apparatus 6B, there is no need to transfer the wafer W from the resist film forming apparatus 6B to the wafer transfer area 90, and therefore the processing vessel 61 of the resist film forming apparatus 6B does not have a transfer port 63 that opens into the wafer transfer area 90.

[0091] The processing procedure for the wafer W in the resist film forming apparatus 6B will be described. First, the processing space 60 is set to the second atmosphere, and the wafer W is transferred from the wafer transfer region 32 to the processing space 60 by the wafer transfer device 33. Then, the wafer W is placed on the stage 62 and heated, and the supply of film formation gas to the processing space 60 begins (time t11). The temperature of the wafer W during film formation is set to the same temperature as the temperature described as the temperature of the wafer W during film formation in the resist film forming apparatus 6.

[0092] After a predetermined time has elapsed since the start of the supply of the film formation gas, the supply of the film formation gas is stopped, thereby ending the film formation process (time t12), and light irradiation from the light irradiation unit 113 to the wafer W on the stage 62 is started. This light irradiation and the state in which the wafer W is exposed to heat from the heater 65 of the stage 62 cause the temperature of the wafer W to rise to the same temperature as the temperature of the wafer W when heated in the heat treatment device 8, and PAB is then performed. After a predetermined time has elapsed since the start of the light irradiation, the light irradiation is stopped, ending the PAB (time t13), and the temperature of the wafer W drops. Thereafter, the wafer W is transferred from the processing chamber 61 to the wafer transfer area 32 by the wafer transfer device 33. Note that during the period from the transfer of the wafer W to the transfer of the wafer W, the processing space 60 is maintained in the second atmosphere, and the above-described series of processes are performed in the second atmosphere.

[0093] In this resist film forming apparatus 6B, the temperature of the wafer W for PAB is raised by the light irradiation unit 113, eliminating the need to raise the temperature of the heater 65 of the stage 62. Therefore, after PAB, there is no need to wait, or the time required to lower the temperature of the upper surface of the stage 62 to a predetermined temperature for film formation can be relatively short. This allows the subsequent wafer W to be placed on the stage 62 and film formation processing to begin promptly. Therefore, the resist film forming apparatus 6B including the light irradiation unit 113 is preferable from the viewpoint of increasing the throughput of the wafer processing system 1. However, this does not prohibit the PAB from being performed by raising the temperature of the heater 65 after the supply of film formation gas has been completed.

[0094] As described above, the resist film forming apparatus is provided with a heating mechanism for heating the wafer W. In the resist film forming apparatus 6, the heater 65 corresponds to the heating mechanism, and in the resist film forming apparatus 6B, the heater 65 and the light irradiation unit 113 correspond to the heating mechanism. The heating mechanism of the resist film forming apparatus may be provided in the resist film forming apparatus and used to perform film formation and PAB, as shown as an example of the resist film forming apparatus 6B, or may be used only to perform film formation, as shown as an example of the resist film forming apparatus 6. When used only for film formation, a heating mechanism for PAB may be provided in a location separate from the resist film forming apparatus, as shown as the heater 65 of the heat treatment apparatus 8, so that the wafer W can be heated.

[0095] In the resist film forming apparatus 6B, the light irradiation unit 113 starts irradiating the wafer W with light after the supply of the film forming gas to the processing space 60 is stopped, but the light irradiation may start while the film forming gas is being supplied to the processing space 60. For example, the wafer W may be irradiated with light at a first intensity while the film forming gas is being supplied to the processing space 60, and after the supply of the film forming gas is stopped, the wafer W may be irradiated with light at a second intensity greater than the first intensity for PAB.

[0096] Furthermore, after the start of the film formation gas supply, the light intensity is increased in multiple stages. As a result, as shown in FIG. 16 , the temperature of the wafer W is increased in multiple stages between times t11 and t12, from the start of the film formation gas supply until it is stopped, and the temperature of the wafer W may also be increased in multiple stages between times t12 and t13, from the stop of the film formation gas supply until the light irradiation by the light irradiation unit 113 is stopped and the PAB is completed. When the temperature of the wafer W is increased during the film formation gas supply as shown in FIG. 16 , the energy imparted to the wafer W is increased, thereby increasing the reaction efficiency (i.e., film formation efficiency) between the wafer W and the resist component-containing gas during the film formation gas supply, thereby shortening the film formation gas supply time. Furthermore, as shown in FIG. 16 , by increasing the temperature of the wafer W even after the film formation gas supply is stopped, the PAB can be completed quickly. Note that the light intensity is not limited to being increased in multiple stages. For example, the light intensity may be gradually increased so that the light intensity is proportional to the time elapsed since the start of the light irradiation.

[0097] [Second embodiment of wafer processing system] A wafer processing system 1A, which is a second embodiment of the wafer processing system, will be described below, focusing on the differences from the wafer processing system 1, with reference to Fig. 17, which is a plan view, and Fig. 18, which is a longitudinal side view. The lower region R2 of the processing station 3 of the wafer processing system 1A does not have a wafer transfer area 90 or a wafer transfer device 95. The first block G1 and the second block G2 are respectively provided with a PAB heat treatment device 8 and a resist film deposition device 6, and wafers W processed in the resist film deposition device 6 are transferred by the wafer transfer device 33 to the heat treatment device 8 via the wafer transfer area 32.

[0098] A transfer opening for wafer W is formed in the side wall of the housing 91 provided in the processing station 3 at a position facing the wafer transfer area 32, and this transfer opening for wafer W is opened and closed by a shutter 122. When the shutter 122 is open, the wafer transfer area 32 communicates with the transfer area for wafer W in a station adjacent to the processing station 3 in which the wafer transfer area 32 is provided, and wafers W can be transferred between the wafer transfer area 32 and the transfer area for wafer W in the adjacent station. When the shutter 122 is closed, the wafer transfer area 32 is separated from the transfer area for wafer W in the adjacent station and is formed as an enclosed space. The shutter 122 is closed except when necessary for transferring wafer W.

[0099] In order to facilitate partitioning each wafer transfer area 32 of the two processing stations 3 into an enclosed space using the housing 91, the fourth block G4 in the wafer processing system 1A is disposed in one of the two adjacent processing stations 3. However, as long as each wafer transfer area 32 can be partitioned, the fourth block G4 may be disposed so as to straddle the two processing stations 3, similar to the wafer processing system 1 shown in FIG.

[0100] An exhaust mechanism 96 and an N2 gas supply mechanism 97 are connected to the housing 91, and an exhaust port 96A and an N2 gas supply port 97A open to the wafer transfer region 32. When the shutter 122 is closed, the wafer transfer region 32 is exhausted and supplied with N2 gas, thereby creating a second atmosphere in the wafer transfer region 32, similar to the wafer transfer region 90 of the first embodiment. Therefore, the adjustment region R0 in which the second atmosphere is created in this wafer processing system 1A is composed of the wafer transfer region 32, the processing space 60 of the resist film deposition apparatus 6, and the processing space 80 of the heat treatment apparatus 8. The first atmosphere outside this adjustment region R0 corresponds to the atmosphere in the wafer W transfer region in the cassette station 2 and the interface station 4 to which the wafer transfer region 32 is connected, and is set to a pressure similar to that of the wafer transfer region 32 described in the first embodiment, for example.

[0101] In this wafer processing system 1A, the wafer transfer area 32, the processing space 60 of the resist film deposition apparatus 6, and the processing space 80 of the heat treatment apparatus 8 are each set to the second atmosphere before the wafer W is transferred. Then, the wafer W transferred from the cassette station 2 to the wafer transfer area 32 undergoes film formation processing in the resist film deposition apparatus 6, is transferred via the wafer transfer area 32 to the heat treatment apparatus 8, receives PAB, and is transferred to the interface station 4.

[0102] In the wafer processing system 1A described above, there is no need to provide a place such as a load lock module for changing the pressure for transfer between the cassette station 2 and the interface station 4, and to stop the transfer of the wafer W at that place. Therefore, like the wafer processing system 1, the processing efficiency of the wafer processing system 1A can be improved.

[0103] [Third embodiment of wafer processing system] A wafer processing system 1B, which is a third embodiment of the wafer processing system, will be described with reference to the plan view of Fig. 19. This wafer processing system 1B has a configuration substantially similar to that of the wafer processing system 1A, which is the second embodiment, and in the lower region R2 of the processing station 3, a heat treatment device 8 and a resist film deposition device 6 are provided in the first block G1 and the second block G2, respectively. However, the second atmosphere is not formed in the wafer transfer region 32 of this lower region R2, and instead, for example, an atmospheric atmosphere at or near atmospheric pressure is used.

[0104] In this wafer processing system 1B, a buffer apparatus 130 is provided in each of the fourth block G4 and the fifth block G5, which are accessible by the wafer transfer apparatus 33 in the wafer transfer region 32 of the lower region R2. The buffer apparatus 130 can store a large number of wafers W in its internal sealed space, and this sealed space can be used as a second atmosphere. Therefore, in this wafer processing system 1B, an adjustment region R0 in which the second atmosphere is formed is composed of the inside of the buffer apparatus 130, the processing space 60 of the resist film deposition apparatus 6, and the processing space 80 of the heat treatment apparatus 8. The wafer transfer region 32, which is connected to the inside of the buffer apparatus 130, the processing space 60 of the resist film deposition apparatus 6, and the processing space 80 of the heat treatment apparatus 8, is outside the adjustment region R0, and the atmosphere in this wafer transfer region 32 corresponds to the first atmosphere.

[0105] In the wafer processing system 1B, the wafer W that has undergone film formation processing in the resist film forming apparatus 6 is transferred to the buffer apparatus 130 via the wafer transfer area 32, and then transferred from the buffer apparatus 130 to the heat treatment apparatus 8 via the wafer transfer area 32 to undergo PAB. Therefore, the interior of the buffer apparatus 130 forms part of the transfer area for transferring the wafer W from the resist film forming apparatus 6 to the heat treatment apparatus 8.

[0106] To describe in more detail the transfer of the wafer W via the buffer apparatus 130, there are cases where a wafer W (hereinafter referred to as a later wafer W) transferred to the buffer apparatus 130 cannot be transferred to the heat treatment apparatus 8 because a wafer W (hereinafter referred to as a first wafer W) is currently being transferred to the heat treatment apparatus 8. In such cases, the later wafer W waits in the buffer apparatus 130 until the first wafer W is transferred from the heat treatment apparatus 8 and becomes available for transfer to the heat treatment apparatus 8, and after that wait, the later wafer W is transferred to the heat treatment apparatus 8. By transferring the wafer W in this manner, the time that the later wafer W is exposed to an atmosphere other than the second atmosphere from the time of forming the resist film until the PAB is performed is reduced, thereby suppressing the reaction of the resist film with water and oxygen.

[0107] An example of the configuration of the buffer device 130 will be described with reference to the perspective views of FIGS. 20 to 22 and the schematic vertical cross-sectional side view of FIG. 23. The buffer device 130 includes a rectangular housing 131, which has one of its four side walls removed. A shutter 134 is provided in place of the removed side wall, allowing the interior of the housing 131 to be an airtight space, as described above. In the following description of the buffer device 130, the side from which the side wall has been removed will be referred to as the front side. This front side is the side facing the wafer transfer area 32, where the wafer W is transferred by the wafer transfer device 33.

[0108] Support portions 132 for supporting wafers W are provided in multiple stages on the side wall of the housing 131. Four support portions 132 positioned at the same height form a group to support the peripheral edge of the backside of one wafer W while it waits. A waiting area for wafers W formed by the same group of support portions 132 is called a slot. Four shutters 134 are provided on the front side of the housing 131, with the front and rear positions different from each other. Each shutter 134 has four horizontally elongated through-holes 135 aligned vertically. Portions of the shutter 134 located above and below the through-holes 135 are called bridge portions 136. Each shutter 134 can be raised and lowered by a lifting mechanism provided in the housing 131. The positions of the bridge portions 136 shown in Figures 23(a), 23(b), and 23(c) correspond to the positions of the bridge portions 136 in Figures 20, 21, and 22, respectively.

[0109] Depending on the combination of height positions of the shutters 134, a state in which some slots are open to the wafer transfer region 32 through the through-holes 135 (the state shown in FIGS. 20 and 21 ) and a state in which the interior of the housing 131 is sealed and all slots are separated from the exterior of the housing 131 (the state shown in FIG. 22 ) can be switched. As shown in FIGS. 20 and 21 , the slots that are open can be changed by changing the height of the shutters 134. The interior of the housing 131 is sealed except when necessary for transporting the wafer W. An exhaust mechanism 96 and an N2 gas supply mechanism 97 are connected to the housing 131, and exhaust and supply of N2 gas can be performed while the interior of the housing 131 is sealed to create the second atmosphere inside the housing 131. Note that when a wafer W is transferred to a slot, only a portion of the slot is open to the wafer transfer region 32, preventing the interior of the housing 131 from being separated from the second atmosphere due to this opening.

[0110] As in the above-described wafer processing system 1B, the entire area through which the wafer W is transferred from the resist film forming apparatus 6 to the heat treatment apparatus 8 does not have to be under the second atmosphere, and only a portion may be under the second atmosphere to suppress the reaction of the resist film with water and oxygen. By using only a portion as the second atmosphere in this manner, the area through which N2 gas is supplied and exhausted is prevented from becoming large, thereby reducing the manufacturing and operating costs of the wafer processing system. Note that, from the viewpoint of more reliably suppressing the reaction of the resist film, it is preferable to use the second atmosphere in the entire area through which the wafer W is transferred from the resist film forming apparatus 6 to the heat treatment apparatus 8, as in the wafer processing system 1A.

[0111] [Fourth embodiment of wafer processing system] A wafer processing system 1C, which is a fourth embodiment of the wafer processing system, will be described below, focusing on the differences from wafer processing system 1B. Figure 24 is a vertical cross-sectional side view of lower region R2 in processing station 3 of this wafer processing system 1C. In first block G1 of this lower region R2, a resist film forming apparatus 6B capable of performing PAB as described in Figure 15 and a resist film removing apparatus 141 performing a process called EBR (Edge Bead Removal) are stacked one on top of the other.

[0112] The resist film removal apparatus 141 includes a cup 142 that accommodates a wafer W, a stage 143 that can rotate while holding the wafer W by suction within the cup 142, and a nozzle 144 that can move inside and outside the cup 142. A thinner liquid is supplied from the nozzle 144 to the peripheral edge of the wafer W that is placed on the stage 143 and rotating, thereby removing the resist film. Since such liquid processing makes it difficult to form a vacuum atmosphere, the second atmosphere is not formed in the resist film removal apparatus 141.

[0113] The second block G2 is provided with a heat treatment device 149. The heat treatment device 149 is configured to heat the wafer W by using a hot plate (stage 62 equipped with heater 65) on which the wafer W is placed, similar to the heat treatment device 8 described in FIG. 5, or by using the light irradiation unit 111 described in FIG. 14 to irradiate the wafer W on the stage 62 with light. The wafer W is transported by the wafer transport device 33 in the order of the resist film deposition device 6B, the resist film removal device 141, and the heat treatment device 149, and processed therein. PAB is performed in each of the resist film deposition device 6B and the heat treatment device 149. That is, PAB is performed separately before and after EBR.

[0114] The heat treatment device 149, which is a post-film removal heat treatment device, is an apparatus for heating the wafer W processed in the resist film removal device 141, and therefore the second atmosphere is not formed in this heat treatment device 149 either, as in the resist film removal device 141. In this wafer processing system 1C, the adjustment region R0 in which the second atmosphere is formed is the processing space 60 of the resist film deposition device 6B, and the first atmosphere is the atmosphere in the wafer transfer region 32 connected to this adjustment region R0.

[0115] As the PAB progresses, the resist film becomes less soluble in thinner. Therefore, as described above, PAB is performed separately before and after EBR. The PAB before EBR (referred to as the "early-stage PAB") performed in the resist film forming apparatus 6B is performed to reduce the reactivity of the resist film with water and oxygen while hardening the resist film so as to ensure the solubility of the resist film with thinner. The post-heating process, the PAB after EBR (referred to as the "late-stage PAB") performed in the heat treatment apparatus 149, heats the wafer W so as to sufficiently harden the resist film so as to further reduce its reactivity with water and oxygen. To harden the resist film at each stage, the late-stage PAB in the heat treatment apparatus 149 heats the wafer W for a longer heating time or at a higher heating temperature than the early-stage PAB performed in the resist film forming apparatus 6B.

[0116] The reason why the heating time of the wafer W in the latter PAB is longer than that in the former PAB will be described in detail below. The heating time of the wafer W in the resist film deposition apparatus 6B, which performs the former PAB and film deposition process, starts when the supply of film deposition gas to the processing space 60 is stopped and the film deposition process ends. The heating time of the wafer W in the resist film deposition apparatus 6B ends when the wafer W leaves the stage 62 and is no longer heated by the heater 65 in the stage 62, nor is it heated by light irradiation.

[0117] The starting point of the heating time of the wafer W in the heat treatment apparatus 149 that performs the post-stage PAB is the time when heating is started by the heater 65 in the stage 62 upon placement on the stage 62, or the time when heating is started by the light irradiation of the light irradiation unit 111. If the heat treatment apparatus 149 includes both the stage 62 equipped with the heater 65 and the light irradiation unit 111, the starting point of heating is the earlier of the heating start time by the stage 62 and the heating start time by the light irradiation. And the end point of the heating time in the heat treatment apparatus 149 is the same as the end point of the heating time in the resist film forming apparatus 6B, which is the time when heating by placement on the stage 62 and heating by light irradiation are no longer performed.

[0118] It is described that the heating temperature of the wafer W in the post-stage PAB is higher than that in the pre-stage PAB. This heating temperature is the temperature of the wafer W during the above-described heating time. When the output of the light irradiation unit or the heater is changed and the temperature of the wafer W during the heating time is changed, the maximum temperatures are compared. That is, if the maximum temperature during the above-described heating time in the pre-stage PAB is X °C and the maximum temperature during the above-described heating time in the post-stage PAB is Y °C, and X < Y, then the heating temperature of the wafer W in the post-stage PAB is higher than that in the pre-stage PAB.

[0119] In the wafer processing system 1C described above, the resist film deposition apparatus 6B is installed, so that the first-stage PAB in the second atmosphere is performed in the same processing vessel as the first-stage PAB, subsequent to the first-stage PAB. However, the first-stage PAB is not limited to being performed in the same processing vessel. For example, as described in the first to third embodiments, after the first-stage PAB is performed in the resist film deposition apparatus, the wafer W may be transferred to a heat treatment apparatus located separately from the resist film deposition apparatus, and the first-stage PAB may be performed in the heat treatment apparatus. That is, by providing the resist film removal apparatus 141 and the heat treatment apparatus 149 for heating after EBR in the first to third embodiments, the first-stage PAB may be performed in the second atmosphere, and the EBR and the second-stage PAB may be performed after the first-stage PAB. When the substrate is transported to a processing vessel other than the one where the film formation processing is performed and the PAB is performed thereon, the starting point of the heating time for the PAB is the earlier of the time when the substrate is placed on the hot plate in the processing vessel to which the substrate is transported or the time when heating by light irradiation begins.

[0120] [Fifth embodiment of wafer processing system] Next, a wafer processing system 1D, which is a fifth embodiment of the wafer processing system, will be described with reference to a plan view of FIG. 25, focusing on differences from the previously described wafer processing systems 1, 1A to 1C. The wafer processing system 1D includes an upstream transfer chamber 152, and a plurality of cassette mounting stages 21 are arranged side by side in the left-right direction in front of the upstream transfer chamber 152. A door 153 is provided on the side wall of the upstream transfer chamber 152, and the door 153 can attach and detach the lid of the cassette C on the cassette mounting stage 21. The upstream transfer chamber 152 is provided with a first transfer device 154, which is a vertically movable articulated arm. The first transfer device 154 can transfer wafers W between the cassette C on the cassette mounting stage 21 and relay chambers 155 and 156, which will be described later.

[0121] In the upstream transfer chamber 152, on the opposite side (rear side) of the cassette mounting table 21, intermediate chambers 155 and 156 are arranged side by side, and a downstream transfer chamber 161 is arranged rearward of the intermediate chambers 155 and 156. A gate valve 158 is interposed between the intermediate chambers 155 and 156 and the upstream transfer chamber 152, and a gate valve 159 is interposed between the intermediate chambers 155 and 156 and the downstream transfer chamber 161. The intermediate chambers 155 and 156 are each equipped with a mounting table on which a wafer W is placed, and the mounting table has pins that protrude and retract from the upper surface of the mounting table to raise and lower the wafer W so that the wafer W can be delivered to and from each of the first transfer device 154 and a second transfer device 163 (described later).

[0122] Two resist film forming apparatuses 6 and two heat treatment apparatuses 8 are connected to the subsequent transfer chamber 161 via gate valves 162, and these resist film forming apparatuses 6 and heat treatment apparatuses 8 are arranged to surround the subsequent transfer chamber 161 in a plan view. A second transfer device 163 consisting of an articulated arm is provided in the subsequent transfer chamber 161, and is capable of transferring wafers W to and from the resist film forming apparatuses 6, heat treatment apparatuses 8, and relay chambers 155 and 156. The gate valves 158, 159, and 162 are closed except when necessary to transfer the wafers W, and separate the respective apparatuses from the respective chambers.

[0123] With the gate valves 159 and 162 closed, the downstream transfer chamber 161 forms an airtight space. An exhaust mechanism 96 and an N2 gas supply mechanism 97 are connected to the downstream transfer chamber 161, and the interior thereof is set to a second atmosphere. In this wafer processing system 1D, the downstream transfer chamber 161, the processing space 60 of the resist film forming apparatus 6, and the processing space 80 of the heat treatment apparatus 8 form an adjustment region R0 in which the second atmosphere is formed. The relay chambers 155 and 156 connected to the downstream transfer chamber 161 are outside the adjustment region R0, and the atmosphere in these relay chambers 155 and 156 is the first atmosphere.

[0124] In this wafer processing system 1D, a wafer W transferred from a cassette C is transferred in the following order: pre-stage transfer chamber 152 → relay chamber 155 → post-stage transfer chamber 161 → resist film deposition device 6 → post-stage transfer chamber 161 → heat treatment device 8 → post-stage transfer chamber 161 → relay chamber 156 → pre-stage transfer chamber 152, and then returned to the cassette C. By being transferred in this manner, the wafer W is subjected to resist film deposition and PAB, as in the wafer processing system 1, and the second atmosphere is created around the wafer W between the deposition and PAB. In the wafer processing system 1D, as in the wafer processing systems 1 and 1A-1C, stagnation in wafer W transfer can be suppressed, and high throughput can be achieved.

[0125] [Other configurations] The layout of each device in each of the wafer processing systems described above is not limited to the examples described above and is arbitrary. For example, the number of devices stacked for processing wafers W and the order of stacking can be changed as appropriate. The number of devices arranged along the Y direction (left-right direction) of the stack formed by stacking devices is also arbitrary and is not limited to the examples shown in the drawings. Furthermore, devices described as being installed in the first block G1 may be installed in the second block G2, and devices described as being installed in the second block G2 may be installed in the first block G1. Although the arrangement of devices other than the resist film forming device and heat treatment device is not explicitly shown in the diagrams showing the processing station 3, such as Figure 3, these devices may be installed in the first block G1 or the second block G2 as appropriate.

[0126] In addition, in the wafer processing systems 1, 1A-1C, resist film deposition, PAB, and wafer W transport in the second atmosphere are shown to occur in the lower region R2 of the processing station 3. However, these processes and transport may occur in the upper region R1. That is, the upper region R1 may be used to process wafers W before exposure, and the lower region R2 may be used to process wafers W after exposure. Furthermore, the wafer processing systems 1, 1A-1C may not have an upper region R1. That is, like the wafer processing system 1D, these wafer processing systems 1, 1A-1C may be configured to perform only resist film deposition and PAB on wafers W before returning them to the cassette C. In such a configuration where only pre-exposure processing is performed, the interface station 4 is not provided, and wafers W processed in the processing station 3 can simply be returned to the cassette C from the cassette station 2.

[0127] Furthermore, the positions and numbers of exhaust ports and N2 gas supply ports opening into the processing apparatus and the transfer region for forming the second atmosphere are not limited to the examples described above and can be any configuration. Incidentally, in a resist film forming apparatus, if the resist component-containing gas remains in the processing space 60 for a long time, the generation of particles is promoted due to reactions between the gases. In order to prevent the generation of particles by increasing the gas replacement efficiency in the processing space 60 after film formation is completed and preventing the resist component-containing gas from remaining in the processing space 60 for a long time, in the examples described above, no irregularities are formed on the wall surfaces forming the processing space 60 other than the gas supply ports 73-75 and the exhaust port 71.

[0128] In order to supply each gas with high uniformity into the processing space 60, a shower head may be provided on the ceiling of the processing vessel 61, and the gases supplied from each gas supply port 73 to 75 may be supplied from the supply port of this shower head into the processing space 60. In other words, the shower head may form part of the wall surface that defines the processing space 60, and the outlet of the shower head may face the processing space 60.

[0129] 13, when forming a resist film on the wafer W using an organic compound gas with different metal M1 content ratios on the upper and lower sides, the upper and lower sides may be formed using different film forming apparatuses. The supply destination of the organic compound gas is not limited to the processing space 60, but may be a flow path formed by the piping constituting the film forming gas supply mechanism 77. That is, the organic compound gas may be supplied to the processing space 60 in a state mixed with the film forming gas or a dilution gas or resist component-containing gas constituting the film forming gas. Furthermore, the method for vaporizing the film forming raw material liquid is not limited to bubbling. The dilution ratio may be calculated from the flow rate of the mixed gas containing the carrier gas and the resist component-containing gas and the flow rate of the dilution gas containing the carrier gas, as in the case of bubbling described above.

[0130] Furthermore, the film forming liquid in the storage container 106 of the film forming gas supply mechanism 77 is not limited to being vaporized and supplied to the processing space 60 as a resist component-containing gas as described above, but may be supplied to the processing space 60 in the form of a mist together with an inert gas such as N2 gas. Therefore, the resist component-containing gas in the present technology also includes a liquid containing a mist of resist components.

[0131] [Mist treatment] FIG. 26 shows a longitudinal side view of a resist film forming apparatus 6C, which is an example of an apparatus for performing film formation processing using mist. Regarding this resist film forming apparatus 6C, differences from the resist film forming apparatus 6 of the first embodiment will be described. A nozzle 171 is provided in the ceiling of a processing vessel 61. The nozzle 171 is connected to a liquid supply mechanism 172 via a pipe 174 for supplying the film forming raw material liquid to the nozzle 171. The liquid supply mechanism 172 includes a flow rate adjuster such as a valve or a mass flow controller, a reservoir for storing the film forming raw material liquid, and a pressurizing mechanism for pressurizing the reservoir to pressure-feed the film forming raw material liquid. The film forming raw material liquid is configured to flow through the pipe 174 at a desired flow rate and be supplied to the nozzle 171. A heater 175 is provided in the pipe 174, which can heat the flowing film forming raw material liquid.

[0132] The nozzle 171 is connected to an N2 gas supply mechanism 76 via a pipe, and the N2 gas supply mechanism 76 can independently supply N2 gas to the gas supply port 73 and the nozzle 171. The N2 gas supplied from the N2 gas supply mechanism 76 and the film-forming raw material liquid supplied from the liquid supply mechanism 172 are mixed in the nozzle 171 and discharged as a mist from a discharge port 176 provided below the nozzle 171, and the mist is supplied to the wafer W on the stage 62 to form a film. Hereinafter, this mist may be referred to as a mist containing resist components.

[0133] The resist component-containing mist generated in the nozzle 171 is heated to a desired temperature by the action of the heater 175 of the pipe 174 and the heater 67 on the upper wall of the processing vessel 61, and is then discharged from the discharge port 176. The resist film forming apparatus 6C operates in the same manner as the resist film forming apparatus 6, except that the film-forming raw material is supplied to the processing space 60 as a mist instead of a gas. Therefore, before the resist component-containing mist is supplied to the wafer W, the processing space 60 is set to a low-oxygen, low-humidity second atmosphere.

[0134] When forming a film on a wafer W in this resist film forming apparatus 6C, the temperature of the upper surface of the stage 62 is set to be higher than the temperature of the resist component-containing mist at the discharge port 176, for example. FIG. 26 schematically shows droplets 170 of the resist component-containing mist when the temperature is set in this manner. As the droplets 170 approach the stage 62 and the wafer W, evaporation progresses, causing the droplets 170 to become smaller or disappear, as shown. Therefore, as the droplets move from the discharge port 176 toward the wafer W on the stage 62, the density of the liquid constituting the resist component-containing mist decreases. Therefore, in this resist film forming apparatus 6C, the film forming material is supplied to the processing space 60 as a resist component-containing mist, and at least a portion of the mist is vaporized and supplied to the wafer W, thereby forming a film on the wafer W. In other words, a resist component-containing gas produced by vaporization of the resist component-containing mist or a mixed fluid of the resist component-containing mist and the resist component-containing gas produced by vaporization of the mist is supplied to the wafer W, thereby forming a film on the wafer W. As mentioned above, FIG. 26 is a schematic illustration of droplets 170 of the film-forming raw material supplied into the processing space 60 to clearly illustrate the change in density of the liquid described above, and therefore the size ratio of each droplet 170 to the processing space 60 is not limited to that shown in FIG. 26.

[0135] By creating a state in which the density of the liquid constituting the mist decreases as it flows from the discharge port 176 opening into the processing space 60 toward the wafer W, the following advantages are achieved. Because the film-forming source material is supplied to the processing space 60 as a mist, the molecules constituting the film-forming source material are more cohesive immediately after supply to the processing space 60 than when it is supplied as a gas. Therefore, even if gases such as oxygen or water vapor remain in the processing space 60, the number of molecules constituting the film-forming source material that can come into contact with these gases is reduced, thereby suppressing unwanted reactions of the film-forming source material with the gases. Furthermore, because the film-forming source material is in a gaseous state on the surface of the wafer W on the stage 62 and has high fluidity, it is supplied with high uniformity over the entire surface of the wafer W. Therefore, creating a state in which the density of the liquid constituting the mist decreases as it flows from the discharge port 176 toward the wafer W is preferable because it can suppress deterioration of the resist film formed on the wafer W due to oxygen and water while achieving a highly uniform film thickness across the wafer W.

[0136] Note that, in order to create a state in which the density of the liquid constituting the mist decreases from the discharge port 176 toward the wafer W as described above, it is not limited to controlling the outputs of the heaters 65, 67, and 175 respectively provided on the stage 62, the ceiling of the processing vessel 61, and the pipe 174 through which the film-forming raw material flows. For example, a plurality of heaters may be embedded in the sidewall of the processing vessel 61 and disposed at different heights. The heaters disposed at lower positions, i.e., closer to the stage 62, may have higher outputs, thereby increasing the temperature of the processing space 60 from the ceiling of the processing vessel 61 where the discharge port 176 is provided toward the stage 62, thereby creating the above state.

[0137] As shown in the film formation example of the resist film forming apparatus 6C above, the film forming raw material is not limited to being supplied to the wafer W in either a gas state or a mist state, but may be supplied to the wafer W as a mixture of these gases and mist. Note that the mist is not limited to being formed by using N2 gas, but may be formed by mixing an inert gas other than N2 gas with the film forming raw material liquid.

[0138] [Modification of film formation process] Next, another example of a film formation process using the resist film formation apparatus 6 in the first embodiment will be described with reference to the timing chart of FIG. 27, focusing on differences from the film formation process described in FIG. 8. The processing space 60 is exhausted from the exhaust port 71 and N2 gas is supplied from the gas supply port 73 by the N2 gas supply mechanism 76. While the processing space 60 is maintained in a second atmosphere with low oxygen and low humidity, a film formation gas (resist component-containing gas + dilution gas) is supplied to the processing space 60, and film formation on the wafer W on the stage 62 begins (time t21 in the chart). Thereafter, the supply of the film formation gas is stopped (time t22), while the processing space 60 continues to be exhausted from the exhaust port 71 and the supply of N2 gas from the gas supply port 73. While the supply of the film formation gas is stopped, the wafer W remains stored in the processing space 60.

[0139] Thereafter, the supply of the film formation gas to the processing space 60 is resumed (time t23). Thereafter, the supply of the film formation gas is stopped, and the film formation process on the wafer W is completed (time t24). Therefore, in the example shown in Figure 27, the film formation gas is intermittently supplied to the wafer W, and the film formation process is repeatedly performed on the same wafer W. Then, during the period when the film formation gas is not supplied (from time t22 to time t23), the processing space 60 is evacuated and the film formation gas is removed from the processing space 60.

[0140] In the film formation process example shown in FIG. 27 , a film formation gas containing a resist component-containing gas is repeatedly supplied to the wafer W, and the processing space 60 is evacuated between the time when the supply of the film formation gas is stopped and the time when the next supply of the film formation gas is started. This prevents problems such as a decrease in the diffusibility of the film formation gas due to an excessively high concentration of the film formation source in the processing space 60, resulting in large variations in film thickness across the wafer W. Furthermore, in the film formation process example shown in FIG. 27 , an inert gas (N gas) is supplied to the processing space 60 while the film formation gas is not being supplied, serving as a purge gas, thereby quickly removing the film formation source from the processing space 60. Furthermore, supplying N gas in this manner prevents a large pressure difference from occurring between the time when the supply of the film formation gas is stopped and the time when the supply of the film formation gas is resumed, thereby suppressing variations in film quality across the film thickness. Furthermore, the evacuation of the processing space 60 during the time when the film formation gas is not being supplied may be performed within a range that creates a low vacuum in the processing space 60, as described below. If the exhaust at this time is performed so that the processing space 60 is at a high vacuum, it takes a long time for the degree of vacuum to stabilize, and production efficiency is significantly reduced. In other words, by performing the exhaust at this time in a low vacuum range, the exhaust and the subsequent supply of film formation gas can be quickly switched and performed.

[0141] In this manner, when the film formation gas is intermittently supplied, the number of times the film formation gas is supplied to one wafer W may be three or more times. Although the process is described as being performed using the resist film formation apparatus 6 in the first embodiment, the same process may be performed using a resist film formation apparatus having any of the other configurations described above. When the wafer W is processed using the mist described above, the mist may be supplied intermittently, as in the case of processing using the film formation gas, and the processing space 60 may be evacuated during the period when the mist is not supplied.

[0142] In each embodiment, the processing space 60 is set to atmospheric pressure or a pressure close to atmospheric pressure during the film forming process. 5 Pa~10 2Pa). Here, a supplementary explanation will be given to the film formation process using mist described in FIG. 26. When performing the process using mist in this manner, the processing space 60 is set to such a relatively high pressure, which suppresses vaporization of the mist immediately after it is discharged into the processing space 60, thereby more reliably suppressing the unwanted reaction between the film formation raw material and oxygen, etc., as described above. Therefore, setting the processing space 60 to such a relatively high pressure during the film formation process is preferable from the viewpoint of forming a resist film with good film quality using the mist.

[0143] [Regarding the membrane] Although Sn has been used as an example of a metal contained in the MOR, the metal is not limited to Sn and may be, for example, zinc or tungsten. Furthermore, while the examples described above have shown the formation of a negative resist film and subsequent processing of the negative resist film, a positive resist film may be formed and subsequently processed. Furthermore, although bubbling has been used to generate a resist component-containing gas during resist film formation, the apparatus configuration is not limited to the aforementioned generation of the resist component-containing gas by bubbling. As a specific example, an inert gas and a film-forming raw material liquid are supplied to a vaporizer from separate flow paths, and the inert gas and the film-forming raw material liquid are mixed and heated in the vaporizer to generate a resist component-containing gas. The resist film formation apparatus may then be configured so that the resist component-containing gas is supplied to a supply path connecting the vaporizer and the processing chamber 61.

[0144] This technology is not limited to application to resist films and PAB after resist film deposition, but may also be applied to the deposition of films formed below the resist film and the heat treatment performed after the deposition of this film and before the deposition of the resist film. That is, a film that is etched using the resist film as a mask after a pattern is formed on the resist film may also be subjected to the same deposition process as the resist film and the same heat treatment as the PAB after the resist film deposition. If this film is referred to as an underlayer film, this underlayer film may be a film (inorganic film) composed of an inorganic compound, such as an anti-reflective SiARC film, or a film (organic film) composed of an organic substance, such as SOC (spin on carbon). Other underlayer films may include a film containing both inorganic and organic elements, such as an SiOC film, that has properties intermediate between an inorganic film and an organic film, or a film composed of an organic-inorganic hybrid material, such as polysiloxane.

[0145] Furthermore, in each embodiment, the substrate to be processed is not limited to a wafer, but may be, for example, a substrate for manufacturing a flat panel display or a mask substrate for manufacturing an exposure mask. Therefore, a rectangular substrate may be processed.

[0146] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and various omissions, substitutions, modifications, and combinations may be made to the above-described embodiments without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0147] M resist film R0 adjustment area W wafer 60, 80 processing space 61, 81 Treatment vessel

Claims

1. a film formation process in which an adjustment region including a processing space in a processing vessel storing a substrate is set to a second atmosphere having a lower oxygen concentration and lower humidity than a first atmosphere outside the adjustment region and a pressure at or near the pressure of the first atmosphere outside the adjustment region, and a resist component-containing gas is supplied to the processing space in the second atmosphere to form a resist film on the substrate; a heating step of heating the substrate on which the resist film is formed before exposure in the processing space set to the second atmosphere; A resist film forming method comprising:

2. 2. The resist film forming method according to claim 1, further comprising the step of forming the second atmosphere by evacuating the adjustment region and supplying an inert gas thereto before the film forming step.

3. The step of forming the second atmosphere includes: an exhaust step of reducing the pressure in the adjustment region by exhaust to create a pressure atmosphere lower than the pressure of the second atmosphere; a step of supplying an inert gas to the adjustment region to increase the pressure to the second atmosphere, the step being performed following the evacuation step; The resist film forming method according to claim 2, further comprising:

4. a step of causing the resist component-containing gas to flow through a flow path connected to a discharge port provided in the processing vessel so as to open into the processing space in order to supply the resist component-containing gas into the processing space; a dilution step of supplying a dilution gas to a mixing section provided in the flow path to dilute the resist component-containing gas by 100 times or more, 4. The resist film forming method according to claim 1, wherein the resist component-containing gas supplied to the substrate is a resist component-containing gas diluted in the dilution step.

5. The adjustment area is a processing space for performing the film forming step, another processing space for performing the heating step, and a transfer area for transferring the substrate between the processing space and the other processing space, 4. The resist film forming method according to claim 1, further comprising the step of transporting the substrate from the one processing space to the other processing space through the transport region in the second atmosphere.

6. 4. The resist film forming method according to claim 1, further comprising a cleaning step of supplying a cleaning gas into the processing space after the film forming step to remove the resist film inside the processing vessel.

7. the resist film is a resist film containing a metal, 4. The resist film forming method according to claim 1, wherein the film forming step is a step of forming the resist film so that the proportion of the metal contained in an upper portion of the resist film is smaller than that in a lower portion of the resist film.

8. 4. The resist film forming method according to claim 1, wherein the heating step includes a step of placing the substrate on a hot plate or a step of irradiating the substrate with light.

9. 4. The resist film forming method according to claim 1, wherein the film forming step and the heating step are performed on the substrate in the same processing space.

10. removing the resist film from the peripheral edge of the substrate after the heating step; a post-heating step of heating the substrate from which the resist film on the peripheral edge has been removed at a temperature higher than that in the heating step or for a heating time longer than that in the heating step; The resist film forming method according to any one of claims 1 to 3, comprising:

11. supplying the resist component-containing gas as a mist from a discharge port opening into the processing space toward the substrate in the processing space; a step of forming a state in which the density of the liquid constituting the mist decreases as the liquid moves from the discharge port toward the substrate; The resist film forming method according to any one of claims 1 to 3, comprising:

12. The film forming step includes: repeatedly supplying the resist component-containing gas to the substrate; evacuating the processing space during a period from when the supply of the resist component-containing gas to the substrate is stopped until the next supply of the resist component-containing gas to the substrate; The resist film forming method according to any one of claims 1 to 3, comprising:

13. a processing vessel for storing the substrate; an atmosphere adjusting mechanism that adjusts an adjustment region including a processing space in the processing container to a second atmosphere having a lower oxygen concentration and lower humidity than a first atmosphere outside the adjustment region and a pressure at or near the pressure of the first atmosphere outside the adjustment region; a gas supply mechanism that supplies a resist component-containing gas to the processing space in the second atmosphere to form a resist film on the substrate; a heating mechanism that heats the substrate on which the resist film is formed before exposure in the processing space set to the second atmosphere; A resist film forming apparatus comprising:

14. A storage medium for storing a computer program used in a resist film forming apparatus, 4. A storage medium in which the computer program is configured to include steps for executing the resist film forming method according to claim 1.

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