Substrate processing method and substrate processing system

Abstract

A substrate processing method according to one embodiment includes: a step of carrying a substrate subjected to liquid processing by being supplied with a processing liquid into a vacuum chamber; and a vacuum baking step in which the substrate is heated at a predetermined processing temperature in a state in which the inside of the vacuum chamber is set to a predetermined processing pressure that is lower than normal pressure, thereby removing deposits adhering to the surface of the substrate due to the liquid processing, the processing temperature is a temperature lower than the boiling point of the deposit at atmospheric pressure.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing method and a substrate processing system. Background Art

[0002] Patent Document 1 describes dry cleaning of a substrate that has been wet cleaned in a semiconductor device manufacturing process. In Patent Document 1, the substrate that has been wet cleaned is firstly dry cleaned at a temperature of 600°C to 800°C and a pressure of 1×10 -6 Pa~1×10 -8 The first thermal cleaning is performed in a high vacuum atmosphere of 1000 Pa to remove the oxide film remaining on the substrate. Next, the second thermal cleaning is performed in a hydrogen atmosphere at a temperature of 750°C to 800°C (800°C to 900°C depending on the situation) and a pressure of 133.3 Pa to 1000 Pa to remove contaminants such as carbon. The dry cleaning in Patent Document 1 is performed as a pretreatment for the process of epitaxially growing a crystalline layer on the substrate from which the oxide film has been removed, and at least the second thermal cleaning in the hydrogen atmosphere and the epitaxial growth process are performed continuously in the same chamber.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent document 1: International Publication WO01 / 033618 Summary of the invention

[0006] The present disclosure provides a technology capable of removing deposits attached to a substrate after liquid processing.

[0007] According to one embodiment of the present disclosure, a substrate processing method is provided, comprising: a process of moving a substrate that has been liquid-treated by supplying a processing liquid into a vacuum chamber; and a vacuum baking process of heating the substrate at a predetermined processing temperature while setting the vacuum chamber to a predetermined processing pressure lower than normal pressure, thereby removing attachments attached to the surface of the substrate due to the liquid treatment, wherein the processing temperature is a temperature lower than the boiling point of the attachments under atmospheric pressure.

[0008] According to the present disclosure, it is possible to remove deposits attached to a substrate after liquid processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a schematic cross-sectional view of a substrate processing system according to one embodiment of a substrate processing apparatus.

[0010] Figure 2 It is shown Figure 1 A schematic longitudinal cross-sectional view of a structural example of a liquid processing unit included in a substrate processing system.

[0011] Figure 3 It is shown Figure 1 A schematic longitudinal cross-sectional view of a structural example of a vacuum processing area included in a substrate processing system.

[0012] Figure 4 It is shown that the Figure 4 A schematic longitudinal cross-sectional view of a structural example of a vacuum baking unit in a vacuum treatment zone.

[0013] Figure 5 This is a diagram schematically showing a COX diagram for explaining a method of determining processing conditions for a vacuum baking process.

[0014] Figure 6 This is a schematic longitudinal sectional view showing another structural example of the vacuum baking unit. DETAILED DESCRIPTION

[0015] Hereinafter, a configuration of a substrate processing system as one embodiment of a substrate processing apparatus will be described with reference to the drawings. Figure 1 1 is a diagram showing a schematic configuration of a substrate processing system according to the present embodiment. In order to clarify the positional relationship, mutually orthogonal X-axis, Y-axis, and Z-axis are defined, and the positive direction of the Z-axis is defined as the vertical upward direction.

[0016] like Figure 1 As shown, the substrate processing system 1 includes a loading / unloading block 2 and a processing block 3. The loading / unloading block 2 and the processing block 3 are disposed adjacent to each other.

[0017] The loading and unloading block 2 has a carrier loading area 11 and a substrate transfer area 12. The carrier loading area 11 is also called a loading port, etc., and a plurality of carriers C (substrate transfer containers) can be loaded in the carrier loading area 11. In each carrier C, a plurality of substrates W (e.g., semiconductor wafers) are stored in a horizontal position at equal intervals in the vertical direction.

[0018] The substrate transport area 12 is provided with a substrate transport device 13 and a delivery portion 14. The substrate transport device 13 can be configured as a multi-joint transport robot, for example, and has a substrate holder, for example, in a fork shape, as an end effector for holding the substrate W. The substrate transport device 13 can transport the substrate W between the delivery portion 14 and any carrier C placed in the carrier placement area 11. The delivery portion 14 is configured to temporarily place the substrate W. It is also possible to separate the delivery portion 14 for placing an unprocessed substrate W and the delivery portion 14 for placing a processed substrate W and to arrange them in a stacked manner.

[0019] The processing block 3 is provided with a transfer area 15, a liquid processing area 20, and a vacuum processing area 30. That is, the substrate processing system 1 is configured as a comprehensive substrate processing system 1 capable of performing both liquid processing and vacuum processing (vacuum baking processing). The substrate processing system 1 is configured as a system in which the components except for a part of the carrier mounting area 11 are accommodated in a common housing.

[0020] The substrate transfer device 16 is provided in the transfer area 15. The substrate transfer device 16 can be configured as, for example, a multi-axis transfer robot and has a substrate holder that holds a substrate as an end effector.

[0021] A plurality of single-chip liquid processing units 21 are provided in liquid processing area 20. The structure of liquid processing unit 21 is not particularly limited, and any structure known in the technical field of semiconductor manufacturing equipment can be used.

[0022] Below, refer to Figure 2 A structural example of a liquid processing unit 21 that can be used is briefly described below. The liquid processing unit 21 includes a rotating holding disk (substrate holding and rotating mechanism) 211 and one or more nozzles 212. The rotating holding disk (substrate holding and rotating mechanism) 211 can hold the substrate W in a horizontal position and rotate the substrate W around a vertical axis. The one or more nozzles 212 spray a processing fluid (processing liquid, processing gas, two fluids, etc.) toward the substrate W held and rotated by the rotating holding disk 211. The nozzle 212 is carried by an arm 213 for moving the nozzle 212. In the case where there are multiple nozzles 212, multiple arms 213 may be provided. In this case, each arm 213 may also carry one or more nozzles 212.

[0023] The liquid processing unit 21 has a liquid receiving cup 214 for recovering the processing liquid scattered from the rotating substrate W. The liquid receiving cup 214 has a discharge port 215 for discharging the recovered processing liquid to the outside of the liquid processing unit 21 and an exhaust port 216 for discharging the atmosphere in the liquid receiving cup 214. Clean gas (clean air) is blown downward from a fan filter unit 218 provided at the top of a chamber 217 of the liquid processing unit 21, introduced into the liquid receiving cup 214, and discharged at the exhaust port 216.

[0024] In order to supply the processing fluid required for liquid processing performed on the substrate W in the liquid processing unit 21 to each nozzle 212, a processing fluid supply mechanism 219 is provided. The processing fluid supply mechanism 219 can be composed of a supply source of processing fluid (chemical liquid, DIW (pure water), IPA (isopropyl alcohol), nitrogen, etc.) provided as factory energy (detailed illustration of each component is omitted), a processing fluid line for the processing fluid supplied from the supply source to the nozzle 212 to flow, and a flow control mechanism (opening and closing valve, flow control valve, etc.) provided on the processing fluid line.

[0025] Liquid processing units 21 may be stacked in multiple layers. In this case, a single substrate transfer device 16 may be configured to be able to carry substrates in and out of all liquid processing units 21 .

[0026] like Figure 1 and Figure 3 As shown, the vacuum processing zone 30 includes a load lock section 31 , a vacuum transfer section 32 , and a vacuum baking section 33 .

[0027] The load lock section 31 is provided with a first load lock unit 311 and a second load lock unit 312. The first load lock unit 311 and the second load lock unit 312 are stacked up and down, for example, the first load lock unit 311 is on the upper side and the second load lock unit 312 is on the lower side. The first load lock unit 311 is used when the substrate W is transferred from the atmospheric pressure side to the reduced pressure side, and the second load lock unit 312 is used when the substrate W is transferred from the reduced pressure side to the atmospheric pressure side.

[0028] A substrate stage (not shown) is provided inside each load lock unit (311, 312), on which a substrate W can be temporarily placed. A cooling mechanism (not shown) for cooling the substrate W is built into the substrate stage of the second load lock unit 312. The structure of each load lock unit (311, 312) can be a general structure used in a semiconductor manufacturing device having a vacuum transfer system. The pressure inside each load lock unit (311, 312) can be between atmospheric pressure (about 1×10 5 Pa) and medium vacuum (about 1 Pa).

[0029] The vacuum transfer unit 32 includes a vacuum transfer chamber 321 and a vacuum transfer machine 322 disposed in the vacuum transfer chamber 321. During operation of the substrate processing system 1, the vacuum transfer chamber 321 is vacuumed by a vacuum pump, here a rotary pump RP (see Figure 4 ) is always maintained at a medium vacuum (eg, about 1 Pa). The vacuum transporter 322 can be configured as, for example, a multi-joint transport robot having a substrate holder for holding a substrate as an end effector.

[0030] The first load lock unit 311 and the second load lock unit 312 are provided with a substrate W loading and unloading port at the portion facing the transfer area 15. A gate valve GV1 is provided at the loading and unloading port. The first load lock unit 311 and the second load lock unit 312 are provided with a substrate W loading and unloading port at the connection portion with the wall of the vacuum transfer chamber 321. A gate valve GV2 is provided at the loading and unloading port.

[0031] A plurality of vacuum baking units 34 are provided in the vacuum baking section 33. The plurality of vacuum baking units 34 are stacked in the vertical direction. Figure 4 As shown, the vacuum baking unit 34 has a substantially rectangular vacuum chamber 341. The vacuum chamber 341 is airtightly connected to the wall of the vacuum transfer chamber 321. The vacuum chamber 341 has a substrate W loading and unloading port 342 provided with a gate valve GV3 in a connection region with the vacuum transfer chamber 321.

[0032] Heaters 343 are provided on the top wall 3411 and the bottom wall 3412 of the vacuum chamber 341. The heater 343 is, for example, a lamp heater. Examples of the lamp heater include a UV heater, an LED heater, and the like. The lamp heater is provided so that light is uniformly irradiated onto the surface and back of the substrate W. A plurality of (for example, three) stationary support pins 344 extending upward therefrom are provided on the upper surface of the bottom wall 3412. The substrate W carried into the vacuum chamber 341 is supported by the support pins 344 and heated by the radiant heat from the heater 343. A radiation thermometer 345 is provided on the bottom wall 3412. The output of the heater 343 is controlled based on the deviation between the actual temperature of the substrate W measured by the radiation thermometer 345 and the target temperature, thereby controlling the temperature of the substrate W.

[0033] The bottom wall 3412 of the vacuum chamber 341 is provided with an exhaust port 346 and a gas supply port 347, preferably in the center of the bottom wall 3412. By providing the exhaust port 346 and the gas supply port 347 below the center of the substrate W, the gas flow in the vacuum chamber 341 can be made uniform during exhaust and supply.

[0034] The exhaust port 346 is connected to an exhaust line 3461 provided with an on-off valve 3462 and a vacuum pump (here, a turbomolecular pump TMP). The atmosphere in the vacuum chamber 341 is sucked through the exhaust port 346, thereby making the pressure in the vacuum chamber 341 1×10 -5 In addition, the pressure in the vacuum transfer chamber 321 is always maintained at a medium vacuum (about 1 Pa), so the pressure in the vacuum chamber 341 connected to the vacuum transfer chamber 321 does not become higher than the pressure in the vacuum transfer chamber 321. Therefore, there is no need to provide a roughing pump in addition to the turbomolecular pump TMP.

[0035] The gas supply port 347 is connected to a gas supply source 3473 (for example, a nitrogen gas supply source) via a gas supply line 3471 provided with an on-off valve 3472. An appropriate amount of gas is supplied to the vacuum chamber 341 which has been made into a high vacuum via the gas supply port 347, thereby enabling the pressure in the vacuum chamber 341 to be restored to the same pressure as the pressure in the vacuum transfer chamber 321 (in this example, a medium vacuum of about 1 Pa). The gas supplied from the gas supply source is not limited to nitrogen, but is preferably a gas with a low oxygen concentration and low humidity.

[0036] The pressure in the vacuum chamber 341 can be detected by the pressure sensor 348. The detection value of the pressure sensor 348 can be used for control when making the pressure in the vacuum chamber 341 a high vacuum or when returning the pressure to a medium vacuum.

[0037] The substrate transport device 16 of the transport area 15 can carry substrates W into or out of the load-lock units via the first load-lock unit 311 and the second load-lock unit 312 provided with the gate valve GV1. The vacuum transporter 322 of the vacuum transport section 32 can carry substrates W into or out of the load-lock units via the first load-lock unit 311 and the second load-lock unit 312 provided with the gate valve GV1. The vacuum transporter 322 of the vacuum transport section 32 can carry substrates W into or out of all the vacuum baking units 34 of the vacuum baking section 33.

[0038] like Figure 1 As shown, the substrate processing system 1 includes a control device 100. The control device 100 is composed of, for example, a computer, and includes a computing unit 101 and a storage unit 102. The storage unit 102 stores programs (including processing recipes) for controlling various processes performed in the substrate processing system 1. The computing unit 101 controls the operation of the substrate processing system 1 by reading out the program stored in the storage unit 102 and executing the program.

[0039] The program may be recorded in a computer-readable storage medium and installed from the storage medium to the storage unit 102 of the control device 100. Examples of computer-readable storage media include a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), and a memory card.

[0040] Next, a process flow of the substrate W in the substrate processing system 1 will be described. The substrate W is processed under the control of the control device 100 .

[0041] First, the substrate transfer device 13 of the loading / unloading block 2 takes out a substrate W from the carrier C placed in the carrier placement area 11, and places the taken-out substrate W on the delivery portion 14. The substrate W placed on the delivery portion 14 is taken out from the delivery portion 14 by the substrate transfer device 16 of the processing block 3, and is moved into a liquid processing unit 21 of the liquid processing area 20, where a predetermined liquid processing is performed.

[0042] In the liquid processing unit 21, for example, liquid processing consisting of the following steps can be implemented. First, a chemical liquid (such as DHF, SC1, etc.) is supplied from the nozzle 212 to the substrate W held and rotated by the rotating holding disk 211 to implement, for example, a chemical liquid cleaning step. Next, DIW as a rinse liquid is supplied from the nozzle 212 to the substrate W to implement a rinse step. Next, IPA is supplied to the substrate from other nozzles 212 to implement an IPA replacement step. Finally, a drying step is implemented. In this drying step, the substrate is dried by rotating the substrate at a high speed without supplying any liquid to the substrate. The substrate after the drying process has tiny attachments (such as attachments from organic matter dissolved in IPA) that are not a problem based on the previous standards. The attachments are removed by the vacuum baking process described later.

[0043] The substrate W that has been processed in the liquid processing unit 21 is taken out of the liquid processing unit 21 by the substrate transfer device 16. Next, the substrate W is transferred into the first load lock unit 311 in a state where the gate valve GV2 is closed and the gate valve GV1 is opened. Next, the gate valve GV1 is closed, and the first load lock unit 311 is evacuated to a pressure substantially equal to the pressure in the vacuum transfer chamber 321 (e.g., about 1 Pa).

[0044] Next, the gate valve GV2 is opened, and the vacuum transporter 322 takes out the substrate W from the first load lock unit 311. The vacuum transporter 322 moves the taken-out substrate W into the vacuum chamber 341 of the vacuum baking unit 34 in a state where the gate valve GV3 is opened, and places the substrate W on the support pins 344. When the vacuum transporter 322 withdraws from the vacuum chamber 341, the gate valve GV3 is closed. At this time, the pressure in the vacuum chamber 341 is about 1 Pa, which is approximately equal to the pressure in the vacuum transport chamber 321.

[0045] Next, the vacuum chamber 341 is evacuated by the turbomolecular pump TMP to, for example, 1×10 -5The high vacuum of about Pa is maintained, and the substrate W is heated to a predetermined temperature (e.g., a temperature of about 40°C to 200°C) by the heater 343. The setting of the pressure and temperature will be described later. At this time, the pressure in the vacuum chamber 341 and the temperature of the substrate W are monitored by the pressure sensor 348 and the radiation thermometer 345, respectively, and the operating states of the turbomolecular pump TMP and the heater 343 are controlled based on the monitoring results to maintain the desired process conditions.

[0046] By maintaining the above-mentioned vacuum degree and substrate temperature for a predetermined time (e.g., about 60 seconds to 600 seconds), the above-mentioned attachments attached to the surface of the substrate W are vaporized and detached from the surface of the substrate W, and are exhausted from the vacuum chamber 341 through the exhaust line 3461. Through this vacuum baking process, the cleanliness of the surface of the substrate W can be further improved.

[0047] When the vacuum baking process is finished, N2 gas is supplied to the vacuum chamber 341 through the gas supply line 3471, so that the pressure in the vacuum chamber 341 is roughly equal to the pressure (about 1 Pa) in the vacuum transfer chamber 321. At this time, for example, the following process can be adopted: N2 gas is supplied while the pressure in the vacuum chamber 341 is monitored by the pressure sensor 348, and when the pressure in the vacuum chamber 341 reaches about 1 Pa, the on-off valve 3472 is closed.

[0048] Next, the gate valve GV3 is opened, and the vacuum conveyor 322 takes out the substrate W from the vacuum chamber 341. The taken-out substrate W is moved into the second load interlock unit 312 in a state where the gate valve GV2 is open and the gate valve GV1 is closed. Next, the gate valve GV2 is closed, and the atmosphere (for example, the air in the clean room) is introduced into the second load interlock unit 312, and the pressure in the second load interlock unit 312 becomes atmospheric pressure. In the second load interlock unit 312, the temperature of the substrate W is lowered to a temperature near normal temperature (23°C) by a cooling mechanism provided on the substrate mounting table. It is not necessary to lower the temperature of the substrate W to normal temperature, and the temperature may be higher than normal temperature as long as it does not hinder the conveyance of the substrate W and the storage of the substrate into the carrier C.

[0049] Next, the gate valve GV1 is opened, and the substrate transfer device 16 of the transfer area 15 takes out the substrate W from the second load lock unit 312 and transfers it to the interface 14. Next, the substrate transfer device 13 of the substrate transfer area 12 takes out the substrate W from the interface 14 and stores it in the original carrier C. Through the above processing, a series of transfer and processing of a substrate W in the substrate processing system 1 is completed.

[0050] According to the above-mentioned embodiment, it is possible to remove the attachments (particle-causing substances) at the molecular level that have become a problem in recent years and that are attached to the surface of the substrate. Of course, it is also possible to remove the attachments that are attached to the inside of the pattern formed on the surface of the substrate. In addition, according to the above-mentioned embodiment, the removal of contaminants is performed by vacuum baking treatment as a dry process that is separate from the wet process (processing performed in the liquid processing unit 21), so the possibility of new contaminants attaching to the substrate is low.

[0051] In addition, according to the above-mentioned embodiment, since the liquid processing unit 21 and the vacuum baking unit 34 are arranged in a substrate processing system 1 with a common shell, the substrate W after liquid processing can be moved from the liquid processing unit 21 to the vacuum baking unit 34 in a short time. Therefore, concerns about Q time (Q-time) can be eliminated. The attachments attached to the substrate W in the liquid processing unit 21 may grow over time by adsorbing substances in the atmosphere around the substrate, or may be fixed or crystallized due to drying. In other words, as time passes, it may become difficult to remove the attachments. According to the above-mentioned embodiment, such problems can be solved and the removal efficiency of the attachments can be improved.

[0052] As an attachment to be removed by vacuum baking treatment, for example, organic matter at the molecular level dissolved in IPA (isopropyl alcohol) supplied to the substrate just before the final drying process in the wet cleaning process (liquid treatment) is exemplified. Such organic matter dissolved in IPA is different from particles (resin or metal powder) generated by dust caused by sliding between parts, etc., and cannot be removed by the filter provided in the IPA supply line. Sometimes, organic matter is eluted from a new filter provided in the IPA supply line, which is particularly significant when using HOT-IPA. When IPA dissolved with organic matter is supplied to the substrate, the organic matter remains on the substrate when the IPA evaporates and becomes particles. The particles generated in this way are, for example, less than 20nm in size, but such small particles have also become a problem with the miniaturization of semiconductor devices in recent years. In addition, in the wet treatment of the substrate, a treatment liquid containing organic acids such as fatty acids is sometimes supplied to the substrate, and the organic acid may also become the cause of the particles.

[0053] In addition, the liquid supplied to the substrate immediately before the final drying process in the wet cleaning process is not limited to IPA as long as it has a lower surface tension than the surface tension of the rinse liquid (DIW), is easily replaced with the rinse liquid, and has a relatively high volatility. For example, it can also be an alcohol other than IPA. However, in the current semiconductor manufacturing process, IPA is actually used in most cases.

[0054] In the above-mentioned embodiment, the above-mentioned organic matter (attached matter) is removed from the surface of the substrate by gasifying (or decomposing and gasifying), for example. The principle is briefly described below.

[0055] If the substrate is placed at a position that is closer to the vapor pressure line of the COX diagram of the deposit (refer to Figure 5 In an atmosphere with a pressure lower than the oblique line VP) and a temperature higher than the detachment limit temperature, organic matter attached to the surface of the substrate can be removed. Here, the "detachment limit temperature" refers to a temperature below which the removal target substance cannot be detached from the substrate even if the pressure is lower than the vapor pressure line of the COX diagram of the removal target substance at a temperature lower than this temperature, and the "detachment limit temperature" varies for each substance.

[0056] As an example, erucic acid amide (C 22 H 43 NO). Figure 5 The COX diagram of erucic acid amide is schematically shown in FIG. The boiling point (at atmospheric pressure) of erucic acid amide is about 480°C, and the release limit temperature is about 40°C. In other words, the treatment temperature of the vacuum baking treatment needs to be set to at least about 40°C. On the COX diagram, the vapor pressure at 200°C is about 8 Pa, and the vapor pressure at 50°C is about 2×10 -5 When the treatment is performed at a temperature near the vapor pressure line VP, the treatment time becomes longer. Therefore, when the treatment temperature is 200°C, the vacuum baking treatment is performed at a treatment pressure of, for example, 1 Pa, and when the treatment temperature is 50°C, the vacuum baking treatment is performed at a treatment pressure of, for example, 1×10 -5 The vacuum baking treatment can be performed at a treatment pressure of 1000 Pa. If there is no concern that the heat may have an adverse effect on the semiconductor device components already formed on the substrate, the treatment temperature can be higher than 200°C, for example, to an upper limit of about 300°C. However, in general, from the perspective of avoiding thermal damage or surface oxidation to the substrate and the semiconductor device components already formed on the substrate, it is considered that the upper limit of the treatment temperature is preferably about 200°C.

[0057] Furthermore, although the processing pressure can be lowered, this may increase the vacuuming time, resulting in reduced productivity and / or requiring a higher performance vacuum pump. Therefore, in current practical applications, it is preferred that the processing pressure be set to a minimum of 1×10 -5 Pa. That is, the upper limit of the processing temperature can be determined based on whether there is an adverse effect on the substrate, and the lower limit of the processing pressure can be determined based on productivity, operating costs, device manufacturing costs, etc. The lower limit of the processing temperature can be higher than the above-mentioned separation limit temperature. Figure 5It is sufficient to determine the processing conditions (processing temperature and processing pressure) that are within the triangular area surrounded by the vapor pressure line VP and the two straight lines indicating the upper limit value of the processing temperature and the lower limit value of the processing pressure determined based on the above concept.

[0058] Erucic acid amide has a large molecular weight and is one of the substances that are particularly difficult to remove among the substances that are considered to be removed by vacuum baking treatment. Therefore, if the treatment conditions are determined in a manner that matches erucic acid amide, it is possible to remove attachments composed of other substances while removing erucic acid amide by vacuum baking treatment.

[0059] The vacuum baking treatment can also remove organic compounds such as higher fatty acids and activators whose molecular weight is smaller than that of erucamide. In addition, not limited to organic compounds, residues of inorganic liquid chemicals (such as hydrofluoric acid) used for liquid treatment (which adhere to the surface of the substrate at the molecular level) can also be removed. Substances whose vapor pressure lines are closer to the upper left side of the graph than the vapor pressure line of erucamide can be removed by treatment conditions of lower temperature and higher pressure (low vacuum degree). Since the substances attached to the substrate can be predicted based on the process performed on the substrate in the liquid treatment unit, it is sufficient to determine the treatment conditions that can cope with the predicted attachments. Figure 5 In the case of the material on the upper left side of the graph of , the processing pressure may be, for example, a pressure of about 1 Pa (medium vacuum). In addition, when the processing pressure is excessively increased, the removal efficiency of the attached matter decreases, so the processing pressure is preferably set to about 1 Pa or less.

[0060] In addition, as attachments suitable for removal by vacuum baking, attachments physically adsorbed on the surface of the substrate and attachments attached to the surface of the substrate as a result of the entanglement of molecules inhibiting vaporization can be cited. As attachments physically adsorbed on the surface of the substrate, attachments obtained by polar attraction bonding such as hydrogen bonds and attachments obtained by van der Waals bonding are included. Most of the attachments derived from the processing liquid used in the wet process (especially the cleaning process) of the semiconductor substrate are consistent with the above. On the other hand, it is difficult to remove substances adsorbed (chemically adsorbed) on the surface of the substrate through bonds with very high bond energy such as chemical bonds (ionic bonds, covalent bonds, metallic bonds), so these substances are not included in the objects to be removed by vacuum baking. In addition, it is difficult to remove completely solidified (crystallized) attachments (however, attachments that are easily decomposed at the above-mentioned processing temperature, such as around 200°C, are excluded), and as attachments to be removed, attachments in liquid or semi-solid states are mainly the objects.

[0061] <Deformation of Vacuum Chamber>

[0062] Next, refer to Figure 6 The vacuum baking unit 34 is described in detail below. Figure 4 The difference of the vacuum baking unit 34 shown is that a lifting pin 349 capable of lifting and lowering, a lifting mechanism 3491 of the lifting pin 349, and a cover 3492 of the lifting mechanism 3491 are provided instead of the fixed support pin 344, and the other structures are all the same. It should be noted that in FIG. 7, in order to avoid complicating the drawing, the structure (structure for exhaust and gas supply, radiation thermometer 345, etc.) provided near the bottom wall 3412 of the vacuum chamber 341, the pressure sensor 348, the vacuum pump for the vacuum transfer chamber 321, etc. are omitted.

[0063] The lifting pin 349 passes through a through hole provided in the bottom wall 3412 of the vacuum chamber 341. The lower end of the lifting pin 349 is supported by a disk-shaped or spider-arm-shaped pin support 3493. The pin support 3493 can be raised and lowered by a linear actuator such as a cylinder. The cover 3492 is airtightly connected to the bottom wall 3412 to prevent the atmosphere from flowing into the vacuum chamber 341 through the through hole of the bottom wall 3412 through which the lifting pin 349 passes.

[0064] According to this modified embodiment, the substrate W can be brought into close contact with the bottom wall 3412 of the vacuum chamber 341 by lowering the lift pins 349 supporting the substrate W. In this case, the substrate W can also be heated by heat conduction from the heater 343, so that the substrate can be quickly heated. Alternatively, when the temperature of the substrate W rises to a certain degree, the lift pins 349 are raised, and then the vacuum baking process is performed while heating the substrate W by heat radiation. Alternatively, the substrate W can be kept in close contact with the bottom wall 3412 of the vacuum chamber 341, and the substrate can be continuously heated by heat conduction.

[0065] The following trade-off relationship holds: From the viewpoint of reducing particles, it is more preferable to Figure 4 As shown, the back surface of the substrate W is in contact with only the support pins 344 , but from the viewpoint of shortening the processing time, it is more preferable that the back surface is in surface contact with the heating member as in this modified embodiment.

[0066] In this case, as the heater 343 , in particular, as the heater provided on the bottom wall 3412 , a resistance heating heater, for example, a rubber heater can be used.

[0067] exist Figure 3In the embodiment and the modified embodiment of FIG. 7 , the heater 343 may also be a resistance heating heater. The resistance heating heater may be attached to the surface of the wall (3411, 3412) of the vacuum chamber 341, or may be buried inside the wall. In the case where a lamp heater is used as the heater 343, the lamp heater may be disposed on the vacuum side surface of the wall (3411, 3412) (the inner surface of the wall facing the processing space), or the wall may be made of a light-transmitting material such as quartz, and the lamp heater may be disposed on the outside of the wall (the outside of the vacuum chamber 341).

[0068] It is also possible to adopt a structure in which the substrate W is directly carried from the atmospheric space to the vacuum chamber 341 of the vacuum baking unit 34 without passing through the load lock unit. In this case, a rotary pump and a turbomolecular pump can be connected to the vacuum chamber 341, and rough pumping can be performed by the rotary pump first, and then vacuuming can be performed by the turbomolecular pump.

[0069] In addition, depending on the type of the deposits to be removed, high vacuum may not be required. In this case, it is not necessary to use a vacuum pump for high vacuum such as a turbomolecular pump, and only a vacuum pump for medium vacuum such as a rotary pump may be used.

[0070] It is also possible to store a plurality of combinations of processing pressure and processing temperature of the vacuum baking process prepared in advance in the storage unit 102 of the control device 100. In this case, for example, the control device 100 may display a plurality of combinations on a user interface (not shown) such as a display of the substrate processing system 1, and the operator may select one combination from the plurality of combinations through a keyboard or a touch panel. The control device 100 controls the operation of the vacuum baking unit 34 based on the selected combination to perform the vacuum baking process. Preferably, in the plurality of combinations, the lower the processing pressure, the lower the processing temperature is set.

[0071] like Figure 1 As shown, the substrate processing system 1 includes a control device 100. The control device 100 is composed of, for example, a computer, and includes a computing unit 101 and a storage unit 102. The storage unit 102 stores programs (including processing recipes) for controlling various processes performed in the substrate processing system 1. The computing unit 101 controls the operation of the substrate processing system 1 by reading out the program stored in the storage unit 102 and executing the program.

[0072] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the appended claims and the gist thereof.

[0073] The substrate is not limited to a semiconductor wafer, and may be other types of substrates used in manufacturing semiconductor devices, such as a glass substrate and a ceramic substrate.

[0074] Description of Reference Numerals

[0075] W: substrate; 341: vacuum chamber.

Claims

1. A substrate processing method, comprising: A step of carrying a substrate that has been subjected to liquid processing by supplying a processing liquid into a vacuum chamber; as well as The vacuum baking step is to heat the substrate at a predetermined processing temperature while setting the vacuum chamber to a predetermined processing pressure lower than normal pressure, thereby removing the attached matter attached to the surface of the substrate due to the liquid treatment. The treatment temperature is a temperature lower than the boiling point of the deposits under atmospheric pressure.

2. The substrate processing method according to claim 1, wherein: The treatment temperature is below 300°C.

3. The substrate processing method according to claim 1, wherein: The treatment temperature is in the range of 40°C to 200°C, and the treatment pressure is 1×10 -5 The pressure is in the range of Pa to 1Pa.

4. The substrate processing method according to claim 1, wherein: A plurality of combinations of processing pressure and processing temperature for the vacuum baking process are prepared in advance, one combination is selected from the prepared plurality of combinations, and the vacuum baking process is performed according to the selected combination of processing pressure and processing temperature. Among the plurality of combinations, the lower the processing pressure, the lower the processing temperature is set.

5. The substrate processing method according to claim 1, wherein: The liquid treatment includes the following steps: a solvent covering step, covering the surface of the substrate with an organic solvent having a surface tension lower than that of water; and a drying step, drying the substrate covered with the organic solvent, wherein the substrate dried by the drying step is moved into the vacuum chamber to perform the vacuum baking step.

6. The substrate processing method according to claim 5, wherein: The attached matter includes a substance derived from an organic compound dissolved in the organic solvent.

7. The substrate processing method according to claim 1, wherein: During the vacuum baking process, an active gas capable of reacting with the deposits is not supplied to the vacuum chamber.

8. The substrate processing method according to claim 7, wherein: During the period from the completion of the vacuum baking step to the removal of the substrate from the vacuum chamber, no gas having an activity capable of reacting with the surface of the substrate is supplied to the vacuum chamber.

9. The substrate processing method according to claim 1, wherein: The method further includes supplying a processing liquid to the substrate to perform a liquid treatment on the substrate, wherein the liquid treatment step is performed before performing the vacuum baking step.

10. The substrate processing method according to claim 9, wherein: The substrate processing method is performed by a substrate processing system. Regarding the substrate processing system, the substrate processing system comprises: a container loading and unloading block for receiving and delivering a substrate transport container containing substrates; and a processing block for processing substrates taken out from the substrate transport container in the container loading and unloading block, The processing block is provided with: a liquid processing area, in which a plurality of liquid processing units are arranged; a vacuum processing area, in which a plurality of devices for performing the vacuum baking process are provided; and a conveying area, in which a substrate conveying device for conveying the substrate between the liquid processing area and the vacuum processing area is provided, wherein at least the liquid processing area, the vacuum processing area and the conveying area are provided in a common shell, and the plurality of devices provided in the vacuum processing area include at least one vacuum baking unit having the vacuum chamber.

11. The substrate processing method according to claim 10, wherein: The multiple devices arranged in the vacuum processing area include: a first loading interlock unit and a second loading interlock unit; a plurality of vacuum baking units, each of which has the vacuum chamber; and a reduced pressure conveyor, which conveys the substrate between the first loading interlock unit and the second loading interlock unit and the vacuum baking unit under a reduced pressure atmosphere, wherein the substrate conveying device in the conveying area is arranged in a manner capable of transferring the substrate between the first loading interlock unit and the second loading interlock unit, and the second loading interlock unit has the function of cooling the substrate after the vacuum baking process is performed.

12. A substrate processing system comprising: a container loading and unloading block for receiving and delivering a substrate transport container containing substrates; and a processing block for processing substrates taken out of the substrate transport container in the container loading and unloading block, in, The processing block is provided with: a liquid processing area, in which a plurality of liquid processing units are arranged; a vacuum processing area, in which a plurality of devices for performing a vacuum baking process on a substrate are arranged; and a conveying area, in which a substrate conveying device for conveying the substrate between the liquid processing area and the vacuum processing area is arranged, wherein at least the liquid processing area, the vacuum processing area and the conveying area are arranged in a common shell, and the plurality of devices arranged in the vacuum processing area include at least one vacuum baking unit having a vacuum chamber for performing the vacuum baking process in the substrate processing method according to claim 1.

13. The substrate processing system according to claim 12, wherein: The multiple devices arranged in the vacuum processing area include: a first loading interlock unit and a second loading interlock unit; a plurality of vacuum baking units, each of which has the vacuum chamber; and a reduced pressure conveyor, which conveys the substrate between the first loading interlock unit and the second loading interlock unit and the vacuum baking unit under a reduced pressure atmosphere, wherein the substrate conveying device in the conveying area is arranged in a manner capable of transferring the substrate between the first loading interlock unit and the second loading interlock unit, and the second loading interlock unit has the function of cooling the substrate after the vacuum baking process is performed.

Images