Substrate processing method and substrate processing system

Abstract

A substrate treatment method according to one embodiment comprises: a step for delivering, into a vacuum chamber, a substrate that has been liquid-treated by supplying a treatment liquid thereto; and a vacuum baking step for removing adhered matter adhering to the surface of the substrate due to the liquid treatment by heating the substrate at a predetermined treatment temperature in a state where the inside of the vacuum chamber has been set to a predetermined treatment pressure which is lower than normal pressure. The treatment temperature is lower than the boiling point of the adhered matter under atmospheric pressure.

Description

[Technical Field]

[0001] This disclosure relates to a substrate processing method and a substrate processing system. [Background technology]

[0002] Patent Document 1 describes dry cleaning a substrate that has been wet-cleaned during the manufacturing process of a semiconductor device. In Patent Document 1, the wet-cleaned substrate is first subjected to a temperature of 600°C to 800°C and a pressure of 1 × 10⁻¹⁴ -6 Pa~1×10 -8 A first thermal cleaning is performed in a high vacuum atmosphere of Pa to remove any remaining oxide film on the substrate. Next, a second thermal cleaning is performed in a hydrogen atmosphere at a temperature of 750-800°C (or 800-900°C in some cases) and a pressure of 133.3-1000 Pa to remove contaminants such as carbon. The dry cleaning described in Patent Document 1 is performed as a pretreatment for the process of epitaxially growing a crystal layer on a substrate from which the oxide film has been removed, and at least the second thermal cleaning in a hydrogen atmosphere and the epitaxial growth process are performed continuously in the same chamber. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International release WO01 / 033618 [Overview of the project]

[0004] This disclosure provides a technology that can remove deposits adhering to a substrate after liquid treatment.

[0005] According to one embodiment of the present disclosure, a substrate processing method is provided, comprising the steps of: transporting a substrate that has been liquid-treated by supplying a processing liquid into a vacuum chamber; and a vacuum bake step of removing deposits adhering to the surface of the substrate by the liquid treatment by heating the substrate at a predetermined processing temperature while maintaining a predetermined processing pressure lower than atmospheric pressure inside the vacuum chamber, wherein the processing temperature is lower than the boiling point of the deposits under atmospheric pressure.

[0006] According to this disclosure, it is possible to remove any deposits adhering to the substrate after liquid treatment. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic cross-sectional view of a substrate processing system according to one embodiment of a substrate processing apparatus. [Figure 2] Figure 1 is a schematic longitudinal cross-sectional view showing an example configuration of a liquid treatment unit included in the substrate processing system. [Figure 3] Figure 1 is a schematic longitudinal cross-sectional view showing an example of the configuration of a vacuum processing area included in a substrate processing system. [Figure 4] Figure 4 is a schematic longitudinal cross-sectional view showing an example configuration of a vacuum bake unit installed in the vacuum processing area. [Figure 5] This is a schematic COX diagram illustrating the method for determining the processing conditions for vacuum baking. [Figure 6] This is a schematic longitudinal cross-sectional view showing another example of a vacuum bake unit configuration. [Modes for carrying out the invention]

[0008] The configuration of a substrate processing system, which is one embodiment of the substrate processing apparatus, will be described below with reference to the attached drawings. Figure 1 is a diagram showing the schematic configuration of the substrate processing system according to this embodiment. In the following, in order to clarify the positional relationships, the X, Y, and Z axes are defined as being orthogonal to each other, and the positive direction of the Z axis is defined as the vertically upward direction.

[0009] As shown in Figure 1, the substrate processing system 1 comprises an input / output block 2 and a processing block 3. The input / output block 2 and the processing block 3 are located adjacent to each other.

[0010] The loading / unloading block 2 has a carrier loading area 11 and a substrate transport area 12. The carrier loading area 11 is also called a load port, and multiple carriers C (substrate transport containers) can be placed there. Each carrier C contains multiple substrates W (e.g., semiconductor wafers) in a horizontal position at equal intervals in the vertical direction.

[0011] The substrate transport area 12 is provided with a substrate transport device 13 and a transfer unit 14. The substrate transport device 13 can be configured, for example, as an articulated transport robot, and has, as an end effector, a substrate holder, for example, a fork-shaped substrate holder for holding the substrate W. The substrate transport device 13 can transport the substrate W between any carrier C placed on the carrier placement area 11 and the transfer unit 14. The transfer unit 14 is configured to temporarily hold the substrate W. It is also possible to provide separate transfer units 14 for holding unprocessed substrates W and transfer units 14 for holding processed substrates W, stacked vertically.

[0012] Processing block 3 includes a transport area 15, a liquid processing area 20, and a vacuum processing area 30. In other words, the substrate processing system 1 is configured as an integrated substrate processing system capable of performing both liquid processing and vacuum processing (vacuum baking). Except for a portion of the carrier mounting area 11, the substrate processing system 1 is configured as a system in which the constituent equipment is housed in a single common housing.

[0013] A substrate transport device 16 is provided in the transport area 15. The substrate transport device 16 can be configured, for example, as a multi-axis transport robot and has a substrate holder as an end effector for holding the substrate.

[0014] In the liquid treatment area 20, a plurality of single wafer type liquid treatment units 21 are provided. The configuration of the liquid treatment unit 21 is not particularly limited, and any one known in the technical field of semiconductor manufacturing apparatuses can be used.

[0015] Hereinafter, a configuration example of the available liquid treatment unit 21 will be briefly described below with reference to FIG. 2. The liquid treatment unit 21 includes a spin chuck (substrate holding and rotating mechanism) 211 that holds the substrate W in a horizontal posture and can rotate it around a vertical axis, and one or more nozzles 212 that discharge a processing fluid (processing liquid, processing gas, two-fluid, etc.) onto the substrate W held and rotated by the spin chuck 211. The nozzle 212 is carried by an arm 213 for moving the nozzle 212. When there are a plurality of nozzles 212, a plurality of arms 213 may be provided, and in this case, one or more nozzles 212 may be carried by each arm 213.

[0016] The liquid treatment unit 21 has a liquid receiving cup 214 for collecting the processing liquid scattered from the rotating substrate W. The liquid receiving cup 214 has a drain port 215 for discharging the collected processing liquid outside the liquid treatment unit 21 and an exhaust port 216 for discharging the atmosphere inside the liquid receiving cup 214. Clean gas (clean air) is blown downward from a fan filter unit 218 provided in the ceiling portion of the chamber 217 of the liquid treatment unit for the collected processing liquid is drawn into the liquid receiving cup 214 and discharged to the exhaust port 216.

[0017] In order to supply the processing fluid necessary for the liquid treatment applied to the substrate W in the liquid treatment 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 a processing fluid (chemical solution, DIW (pure water), IPA (isopropyl alcohol), nitrogen gas, etc.) provided as factory power (although detailed illustration of individual components is omitted), a processing fluid line through which the processing fluid supplied from the supply source to the nozzle 212 flows, a flow control mechanism (on-off valve, flow control valve, etc.) interposed in the processing fluid line, and the like.

[0018] The liquid treatment unit 21 may be stacked in multiple stages. Also in this case, it may be configured such that a single substrate transfer device 16 can transfer substrates into and out of all the liquid treatment units 21.

[0019] As shown in FIGS. 1 and 3, the vacuum treatment area 30 includes a load lock section 31, a vacuum transfer section 32, and a vacuum bake section 33.

[0020] 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 one above the other. 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 transferring the substrate W from the atmospheric pressure side to the reduced pressure side, and the second load lock unit 312 is used when transferring the substrate W from the reduced pressure side to the atmospheric pressure side.

[0021] Inside each load lock unit (311, 312), a substrate placement table (not shown) on which the substrate W can be temporarily placed is provided. The substrate placement table of the second load lock unit 312 incorporates a cooling mechanism (not shown) for cooling the substrate W. The configuration of each load lock unit (311, 312) may be a general one used in semiconductor manufacturing apparatuses having a vacuum transfer system. The pressure inside each load lock unit (311, 312) can be adjusted between atmospheric pressure (about 1×10 5 Pa) and medium vacuum (about 1 Pa).

[0022] The vacuum transfer unit 32 comprises a vacuum transfer chamber 321 and a vacuum transfer machine 322 installed inside the vacuum transfer chamber 321. During operation of the substrate processing system 1, the vacuum transfer chamber 321 is constantly maintained at a medium vacuum (e.g., approximately 1 Pa) by a vacuum pump, in this case a rotary pump RP (see Figure 4). The vacuum transfer machine 322 can be configured, for example, as an articulated transfer robot and has a substrate holder as an end effector for holding substrates.

[0023] The first load lock unit 311 and the second load lock unit 312 are provided with loading / unloading ports for substrates W in the portions facing the transport area 15. A gate valve GV1 is provided at these loading / unloading ports. The first load lock unit 311 and the second load lock unit 312 are provided with loading / unloading ports for substrates W at the connection points with the walls of the vacuum transport chamber 321. A gate valve GV2 is provided at these loading / unloading ports.

[0024] The vacuum baking section 33 is provided with a plurality of vacuum baking units 34. The plurality of vacuum baking units 34 are stacked vertically. As shown in Figure 4, the vacuum baking unit 34 has a vacuum chamber 341 that is roughly rectangular. The vacuum chamber 341 is hermetically connected to the wall of the vacuum transport chamber 321. The vacuum chamber 341 has a substrate W loading / unloading port 342 in the connection area with the vacuum transport chamber 321, where a gate valve GV3 is provided.

[0025] Heaters 343 are provided on the ceiling wall 3411 and the bottom wall 3412 of the vacuum chamber 341. The heaters 343 are, for example, lamp heaters. Examples of lamp heaters include UV heaters and LED heaters. The lamp heaters are installed so that lamp light is evenly irradiated onto the front and back surfaces of the substrate W. Multiple (for example, three) immovable support pins 344 are provided on the upper surface of the bottom wall 3412, extending upward from there. The substrate W, when brought into the vacuum chamber 341, is supported by the support pins 344 and heated by radiant heat from the heaters 343. A radiation thermometer 345 is provided on the bottom wall 3412. The temperature of the substrate W is controlled by controlling the output of the heaters 343 based on the deviation between the actual temperature of the substrate W measured by the radiation thermometer 345 and the target temperature.

[0026] An exhaust port 346 and an air supply port 347 are provided in the bottom wall 3412 of the vacuum chamber 341, preferably in the central part of the bottom wall 3412. By providing the exhaust port 346 and the air supply port 347 below the central part of the substrate W, the airflow inside the vacuum chamber 341 during exhaust and air supply can be made uniform.

[0027] An exhaust line 3461, which includes an on / off valve 3462 and a vacuum pump (in this case, a turbomolecular pump TMP), is connected to the exhaust port 346. By sucking the atmosphere inside the vacuum chamber 341 through the exhaust port 346, the pressure inside the vacuum chamber 341 is reduced to 1 × 10⁻¹⁰ -5 A high vacuum of approximately Pa can be achieved. Furthermore, since the pressure inside the vacuum transfer chamber 321 is constantly maintained at a medium vacuum (approximately 1 Pa), the pressure inside the connected vacuum chamber 341 will never exceed this. Therefore, there is no need to install a separate pump for roughing alongside the turbomolecular pump TMP.

[0028] The air supply port 347 is connected to a gas supply source 3473 (for example, a nitrogen gas supply source) via an air supply line 3471, which has an on / off valve 3472 interposed therein. By supplying an appropriate amount of gas to the vacuum chamber 341, which has been under high vacuum, through the air supply port 347, the pressure inside the vacuum chamber 341 can be returned to the same pressure as the pressure inside the vacuum transport chamber 321 (a medium vacuum of about 1 Pa in this example). The gas supplied from the gas supply source is not limited to nitrogen gas, but a gas with a low oxygen concentration and low humidity is preferred.

[0029] The pressure inside the vacuum chamber 341 can be detected by the pressure sensor 348. The value detected by the pressure sensor 348 can be used, for example, to control the pressure inside the vacuum chamber 341 when creating a high vacuum and when returning the pressure to a medium vacuum.

[0030] The substrate transport device 16 in the transport area 15 can transport substrates W to and from the first load lock unit 311 and the second load lock unit 312, which are equipped with gate valves GV1, through their respective inlets and outlets. The vacuum transporter 322 in the vacuum transport section 32 can transport substrates W to and from the first load lock unit 311 and the second load lock unit 312, which are equipped with gate valves GV1, through their respective inlets and outlets. The vacuum transporter 322 in the vacuum transport section 32 can transport substrates W to and from all of the vacuum bake units 34 in the vacuum bake section 33.

[0031] As shown in Figure 1, the substrate processing system 1 includes a control device 100. The control device 100 is, for example, a computer and includes an arithmetic unit 101 and a storage unit 102. The storage unit 102 stores programs (including processing recipes) that control various processes performed in the substrate processing system 1. The arithmetic unit 101 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the storage unit 102.

[0032] The program may be one that was recorded on a computer-readable storage medium and installed from that storage medium to the storage unit 102 of the control device 100. Examples of computer-readable storage mediums include hard disks (HDs), flexible disks (FDs), compact disks (CDs), magnetic optical disks (MOs), and memory cards.

[0033] Next, the processing flow of the substrate W within the substrate processing system 1 will be described. The processing of the substrate W is carried out under the control of the control device 100.

[0034] First, the substrate transport device 13 in the loading / unloading block 2 takes one substrate W from the carrier C placed in the carrier placement area 11 and places the removed substrate W on the transfer section 14. The substrate W placed on the transfer section 14 is then taken out of the transfer section 14 by the substrate transport device 16 in the processing block 3 and transported to one of the liquid treatment units 21 in the liquid treatment area 20, where it undergoes predetermined liquid treatment.

[0035] The liquid treatment unit 21 can perform liquid treatment consisting of the following steps, for example. First, a chemical solution (e.g., DHF, SC1, etc.) is supplied from the nozzle 212 to the substrate W, which is held and rotated by the spin chuck 211, to perform a chemical cleaning step, for example. Next, DIW is supplied to the substrate W as a rinse solution from the nozzle 212 to perform a rinsing step. Then, IPA is supplied to the substrate from another nozzle 212 to perform an IPA replacement step. Finally, a drying step is performed in which the substrate is rotated at high speed without supplying any liquid to the substrate to dry it. After the drying process, the substrate has minute deposits (e.g., organic matter dissolved in IPA) that are not problematic by conventional standards. These deposits are removed by the vacuum bake treatment described later.

[0036] After processing in the liquid treatment unit 21, the substrate W is removed from the liquid treatment unit 21 by the substrate transport device 16. Next, the substrate W is transported into the first load lock unit 311, where the gate valve GV2 is closed and the gate valve GV1 is open. Then, the gate valve GV1 is closed and the first load lock unit 311 is evacuated until the pressure inside the vacuum transport chamber 321 is approximately equal to the pressure inside the vacuum transport chamber 321 (for example, about 1 Pa).

[0037] Next, the gate valve GV2 is opened, and the vacuum conveyor 322 removes the substrate W from the first load lock unit 311. The vacuum conveyor 322 then carries the removed substrate W into the vacuum chamber 341 of one vacuum bake unit 34, where the gate valve GV3 is open, and places it on the support pins 344. When the vacuum conveyor 322 exits the vacuum chamber 341, the gate valve GV3 is closed. At this time, the pressure inside the vacuum chamber 341 is approximately 1 Pa, which is about the same as the pressure inside the vacuum conveying chamber 321.

[0038] Next, the inside of the vacuum chamber 341 is evacuated by the turbomolecular pump TMP, for example, 1 × 10⁻¹⁶ -5 A high vacuum of approximately Pa is maintained, and the substrate W is heated to a predetermined temperature (for example, a temperature of approximately 40°C to 200°C) by the heater 343. The pressure and temperature settings 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 state of the turbomolecular pump TMP and the heater 343 is controlled based on the monitoring results so that the desired process conditions are maintained.

[0039] By maintaining the above-mentioned vacuum level and substrate temperature for a predetermined time (for example, about 60 to 600 seconds), the aforementioned deposits adhering to the surface of the substrate W are vaporized, detached from the surface of the substrate W, and discharged from the vacuum chamber 341 via the exhaust line 3461. This vacuum bake treatment can further increase the cleanliness of the surface of the substrate W.

[0040] Once the vacuum baking process is complete, N2 gas is supplied into the vacuum chamber 341 via the air supply line 3471 to bring the pressure inside the vacuum chamber 341 to approximately equal the pressure inside the vacuum transfer chamber 321 (approximately 1 Pa). At this time, for example, a procedure can be adopted in which the pressure inside the vacuum chamber 341 is monitored by the pressure sensor 348 while supplying N2 gas, and the on / off valve 3472 is closed when the pressure inside the vacuum chamber 341 reaches approximately 1 Pa.

[0041] Next, the gate valve GV3 is opened, and the vacuum transfer machine 322 removes the substrate W from the vacuum chamber 341. The removed substrate W is then loaded into the second load lock unit 312, where the gate valve GV2 is open and the gate valve GV1 is closed. Subsequently, the gate valve GV2 is closed, and air (e.g., air from the cleanroom) is introduced into the second load lock unit 312, bringing the pressure inside the second load lock unit 312 to atmospheric pressure. Inside the second load lock unit 312, the temperature of the substrate W is lowered to around room temperature (23°C) by a cooling mechanism provided on the substrate mounting platform. It is not necessarily required to lower the temperature of the substrate W to room temperature; a temperature higher than room temperature is acceptable as long as it does not hinder the transport of the substrate W and its storage in the carrier C.

[0042] Next, the gate valve GV1 opens, and the substrate transport device 16 in the transport area 15 removes the substrate W from the second load lock unit 312 and transports it to the transfer section 14. Then, the substrate transport device 13 in the substrate transport area 12 removes the substrate W from the transfer section 14 and stores it back in the original carrier C. With this, the series of transport and processing operations for one substrate W within the substrate processing system 1 is completed.

[0043] According to the above embodiment, molecular-level deposits (particle-causing substances) adhering to the substrate surface, which have become a problem in recent years, can be removed. Of course, it is also possible to remove deposits adhering to the inside of patterns formed on the substrate surface. Furthermore, according to the above embodiment, since contaminants are removed by vacuum baking, which is a dry process separated from the wet process (processing performed in the liquid treatment unit 21), the possibility of new contaminants adhering to the substrate is low.

[0044] Furthermore, according to the above embodiment, since the liquid treatment unit 21 and the vacuum bake unit 34 are installed in a single substrate processing system 1 that shares a housing, the substrate W after liquid treatment can be transferred from the liquid treatment unit 21 to the vacuum bake unit 34 in a short time. This eliminates concerns regarding Q time. Deposits adhering to the substrate W in the liquid treatment unit 21 may grow over time by adsorbing substances from the surrounding atmosphere, or they may solidify or crystallize as they dry. In other words, it may become difficult to remove the deposits over time. According to the above embodiment, this problem can be solved and the efficiency of deposit removal can be improved.

[0045] Examples of deposits that can be removed by vacuum baking include molecular-level organic matter dissolved in IPA (isopropyl alcohol) supplied to the substrate immediately before the final drying step in wet cleaning (liquid treatment). Unlike particles (fine powder of resin or metal) generated due to dust generation from sliding between components, such organic matter dissolved in IPA cannot be removed by filters installed in the IPA supply line. Organic matter may also leach from new filters installed in the IPA supply line, which is particularly noticeable when HOT-IPA is used. When IPA containing dissolved organic matter is supplied to the substrate, the organic matter remains on the substrate as the IPA evaporates, becoming particles. These particles, for example, are less than 20 nm in size, but even such small particles are becoming a problem with the miniaturization of semiconductor devices in recent years. In addition, in wet treatment of substrates, treatment solutions containing organic acids such as fatty acids may be supplied to the substrate, and these organic acids can also cause particles.

[0046] Furthermore, the liquid supplied to the substrate immediately before the final drying step in the wet cleaning process is not limited to IPA, as long as it has a lower surface tension than the rinse solution (DIW), is easily replaceable with the rinse solution, and is relatively volatile. For example, other alcohols besides IPA may be used. However, in current semiconductor manufacturing processes, IPA is actually used in almost all cases.

[0047] In the above embodiment, for example, the organic matter (adhered material) is removed from the surface of the substrate by vaporization (or decomposition and vaporization). The principle is briefly explained below.

[0048] If the substrate is placed in an atmosphere at a pressure below the vapor pressure line of the COX diagram of the adhering substance (refer to the diagonal VP in Fig. 5) and at a temperature higher than the detachment limit temperature, the organic substances adhering to the surface of the substrate can be removed. Here, the "detachment limit temperature" means a temperature at which, even if the pressure is below the vapor pressure line of the COX diagram of the substance to be removed at a temperature lower than this temperature, it cannot be detached from the substrate, and this varies for each substance.

[0049] As an example, assume erucamide (C 22 H 43 NO), which is a kind of fatty acid, as the substance to be removed. The COX diagram of erucamide is schematically shown in Fig. 5. The boiling point of erucamide (under atmospheric pressure) is about 480°C, and the detachment limit temperature is about 40°C. That is, the treatment temperature of the vacuum bake treatment needs to be at least about 40°C or higher. 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 Pa. When the treatment is carried out at a temperature near the vapor pressure line VP, the treatment time becomes long. Therefore, when the treatment temperature is 200°C, for example, the treatment pressure can be 1 Pa, and when it is 50°C, for example, the treatment pressure can be 1×10 -5 Pa for the vacuum bake treatment. If there is no risk of adversely affecting the semiconductor device components already formed on the substrate due to heat, it is also possible to raise the treatment temperature further above 200°C, for example, up to about 300°C at the upper limit. However, generally, from the perspective of avoiding thermal damage or surface oxidation to the substrate and the semiconductor device components already formed on the substrate, the upper limit of the treatment temperature is preferably considered to be about 200°C.

[0050] Furthermore, it is possible to lower the treatment pressure, but doing so may lead to a longer evacuation time and a decrease in throughput, and / or may require a more high-performance vacuum pump, etc. Therefore, at present, in practical use, the treatment pressure is preferably at least 1×10 -5It is preferable to set the pressure to approximately Pa. In other words, the upper limit of the processing temperature can be determined by whether or not it adversely affects the substrate, and the lower limit of the processing pressure can be determined by considering throughput, running costs, equipment manufacturing costs, etc. The lower limit of the processing temperature should be higher than the aforementioned release limit temperature. In other words, in Figure 5, the processing conditions (processing temperature and processing pressure) should be determined such that they are located within the triangular area enclosed by the vapor pressure line VP and the two lines indicating the upper limit of the processing temperature and the lower limit of the processing pressure determined based on the above considerations.

[0051] Elkaamide has a large molecular weight and is one of the substances that is particularly difficult to remove by vacuum baking. Therefore, by determining the treatment conditions to suit elkaamide, it is possible to remove elkaamide and other deposits simultaneously by vacuum baking.

[0052] Vacuum baking can also remove organic compounds such as higher fatty acids and surfactants, which have smaller molecular weights than erukaamide. Furthermore, it can remove not only organic compounds but also residual inorganic chemicals (e.g., hydrofluoric acid) used in liquid treatment (which adhere to the substrate surface at a molecular level). Substances whose vapor pressure curve is higher and to the left of the graph than erukaamide can be removed under lower temperature and higher pressure (lower vacuum) processing conditions. Since the substances adhering to the substrate can be predicted from the processes performed on the substrate in the liquid treatment unit, processing conditions that can address the predicted adhering substances should be determined. For substances whose vapor pressure curve is higher and to the left of the graph in Figure 5 than erukaamide, the processing pressure may be, for example, around 1 Pa (medium vacuum). However, since excessively high processing pressure reduces the efficiency of adhering substance removal, it is preferable to keep the processing pressure at around 1 Pa or less.

[0053] Suitable deposits for removal by vacuum baking include those physically adsorbed on the substrate surface and those adhering to the substrate surface as a result of vaporization being suppressed due to molecular entanglement. Physically adsorbed deposits on the substrate surface include those bonded by polar attractive forces such as hydrogen bonds, and those bonded by van der Waals forces. Most deposits originating from processing solutions used in wet processes (especially cleaning processes) of semiconductor substrates fall into this category. On the other hand, substances adsorbed on the substrate surface by very high-energy bonds such as chemical bonds (ionic bonds, fertile bonds, metallic bonds) are difficult to remove and are therefore not included in the targets for removal by vacuum baking. Furthermore, removal of completely solidified (crystallized) deposits is difficult (except for those that decompose easily at the aforementioned processing temperature, for example, around 200°C), and the main targets for removal are liquid or semi-solid deposits.

[0054] <Modified Vacuum Chamber Embodiment> Next, a modified embodiment of the vacuum bake unit 34 will be described with reference to Figure 6. The vacuum bake unit 34 in the modified embodiment differs from the vacuum bake unit 34 shown in Figure 4 only in that it is provided with a liftable lift pin 349, a lifting mechanism 3491 for the lift pin 349, and a cover 3492 for the lifting mechanism 3491, instead of the immovable support pin 344. All other components are the same. Note that in Figure 7, in order to avoid complexity in the drawing, the configuration provided near the bottom wall 3412 of the vacuum chamber 341 (configuration for exhaust and supply air, radiant thermometer 345, etc.), pressure sensor 348, vacuum pump for vacuum transport chamber 321, etc. have been omitted.

[0055] The lift pin 349 is passed through a through-hole provided in the bottom wall 3412 of the vacuum chamber 341. The lower end of the lift pin 349 is supported by a disc-shaped or spider-arm-shaped pin support 3493. The pin support 3493 can be raised and lowered by a linear actuator such as an air cylinder. The cover 3492 is hermetically connected to the bottom wall 3412 and prevents air from flowing into the vacuum chamber 341 through the through-hole in the bottom wall 3412 through which the lift pin 349 passes.

[0056] 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 that support the substrate W. In this case, the substrate W can also be heated by heat conduction from the heater 343, and the substrate can be heated rapidly. Once the temperature of the substrate W has risen to a certain extent, the lift pins 349 can be raised, and thereafter, the vacuum bake process may be performed while heating the substrate W by thermal radiation. Alternatively, the substrate W may be kept in close contact with the bottom wall 3412 of the vacuum chamber 341, and the substrate may be continued to be heated by heat conduction.

[0057] As shown in Figure 4, it is more preferable from the viewpoint of particle reduction if the back surface of the substrate W is in contact only with the support pins 344, and a trade-off relationship exists where it is more preferable from the viewpoint of shortening processing time if the back surface is in surface contact with the heating member, as in this modified embodiment.

[0058] In this case, a resistance heating heater, such as a rubber heater, can be used as the heater 343, particularly the heater provided on the bottom wall 3412.

[0059] In the embodiment shown in Figure 3 and the modified embodiment shown in Figure 7, the heater 343 may also be a resistance heater. The resistance heater may be attached to the surface of the walls (3411, 3412) of the vacuum chamber 341, or it may be embedded inside the walls. If the heater 343 is a lamp heater, the lamp heater may be provided on the vacuum-side surface of the walls (3411, 3412) (the inner surface facing the processing space of the wall), or the wall may be made of a light-transmitting material such as quartz, and the heater may be provided on the outside of the wall (outside the vacuum chamber 341).

[0060] Alternatively, a configuration may be adopted in which the substrate W is directly loaded from the atmospheric space into the vacuum chamber 341 of the vacuum bake unit 34 without going 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 vacuuming can be performed first with the rotary pump, followed by vacuuming with the turbomolecular pump.

[0061] In some cases, high vacuum may not be necessary depending on the type of deposit to be removed. In such cases, it is not necessary to use a high-vacuum vacuum pump such as a turbomolecular pump; a medium-vacuum vacuum pump, such as a rotary pump, may be used instead.

[0062] The storage unit 102 of the control device 100 may store multiple combinations of processing pressure and processing temperature for the vacuum bake process that have been prepared in advance. In this case, for example, the control device 100 may display multiple 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 multiple combinations using a keyboard or touch panel. Based on the selected combination, the control device 100 controls the operation of the vacuum bake unit 34 to perform the vacuum bake process. Preferably, in the above multiple combinations, the processing temperature is set lower as the processing pressure decreases.

[0063] As shown in Figure 1, the substrate processing system 1 includes a control device 100. The control device 100 is, for example, a computer and includes an arithmetic unit 101 and a storage unit 102. The storage unit 102 stores programs (including processing recipes) that control various processes performed in the substrate processing system 1. The arithmetic unit 101 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the storage unit 102.

[0064] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0065] The substrate is not limited to semiconductor wafers, but may also be other types of substrates used in the manufacture of semiconductor devices, such as glass substrates or ceramic substrates. [Explanation of symbols]

[0066] W board 341 Vacuum Chamber

Claims

1. The process involves supplying a processing solution to transfer the treated substrate into a vacuum chamber, A vacuum bake process is performed by heating the substrate at a predetermined processing temperature while maintaining a predetermined processing pressure lower than atmospheric pressure inside the vacuum chamber, thereby removing any deposits adhering to the surface of the substrate by the liquid treatment. Equipped with, The processing temperature is lower than the boiling point of the deposit under atmospheric pressure. The aforementioned liquid treatment method includes a solvent coating step of covering the surface of the substrate with an organic solvent having a lower surface tension than water, and a drying step of drying the substrate covered with the organic solvent, wherein the substrate dried by the drying step is transported into the vacuum chamber and subjected to the vacuum bake step. Substrate processing method.

2. The substrate processing method according to claim 1, wherein the processing temperature is 300°C or less.

3. The processing temperature is within the range of 40°C to 200°C, and the processing pressure is 1 × 10⁻⁶ －５ The substrate processing method according to claim 1, wherein the pressure is in the range of Pa to 1 Pa.

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

5. The substrate treatment method according to claim 1, wherein the deposit includes a substance derived from an organic compound that was dissolved in the organic solvent.

6. The substrate processing method according to claim 1, wherein no gas capable of reacting with the deposits is supplied to the vacuum chamber during the execution of the vacuum baking step.

7. The substrate processing method according to claim 6, wherein, after the completion of the vacuum baking process and before the substrate is removed from the vacuum chamber, no gas capable of reacting with the surface of the substrate is supplied to the vacuum chamber.

8. The substrate processing method according to claim 1, further comprising a liquid treatment step of applying the liquid treatment to the substrate, wherein the liquid treatment step is performed before the vacuum bake step.

9. A liquid treatment step of supplying a treatment liquid to a substrate and performing liquid treatment on the substrate, The process involves transferring the substrate that has undergone the aforementioned liquid treatment into a vacuum chamber, A vacuum bake step comprising heating the substrate at a predetermined processing temperature while the inside of the vacuum chamber is at a predetermined processing pressure lower than atmospheric pressure, thereby removing deposits adhering to the surface of the substrate by the liquid treatment, wherein the processing temperature is lower than the boiling point of the deposits at atmospheric pressure, A substrate processing method comprising, The aforementioned substrate processing method is performed by a substrate processing system. The substrate processing system comprises a container loading / unloading block that receives and unloads substrate transport containers containing substrates, and a processing block that processes substrates removed from the substrate transport containers located in the container loading / unloading block. The processing block includes a liquid processing area where a plurality of liquid processing units for performing the liquid processing step are arranged, a vacuum processing area where a plurality of devices for performing the vacuum baking step are provided, and a transport area where a substrate transport device for transporting the substrate between the liquid processing area and the vacuum processing area is provided, and at least the liquid processing area, the vacuum processing area and the transport area are provided within a common housing. A substrate processing method comprising: a plurality of devices provided in the vacuum processing area, a first load lock unit and a second load lock unit; a plurality of vacuum bake units for performing the vacuum bake process, each having the vacuum chamber; and a vacuum transfer machine for transporting substrates in a reduced-pressure atmosphere between the first and second load lock units and the vacuum bake units, wherein the substrate transfer device in the transfer area is provided to be able to transfer substrates to and from the first and second load lock units, and the second load lock unit has a function to cool the substrates that have undergone the vacuum bake process.

10. A liquid treatment step of supplying a treatment liquid to a substrate and performing liquid treatment on the substrate, The process involves transferring the substrate that has undergone the aforementioned liquid treatment into a vacuum chamber, A vacuum bake step comprising heating the substrate at a predetermined processing temperature while the inside of the vacuum chamber is at a predetermined processing pressure lower than atmospheric pressure, thereby removing deposits adhering to the surface of the substrate by the liquid treatment, wherein the processing temperature is lower than the boiling point of the deposits at atmospheric pressure, A substrate processing system that performs a substrate processing method comprising, The substrate processing system comprises a container loading / unloading block that receives and unloads substrate transport containers containing substrates, and a processing block that processes substrates removed from the substrate transport containers located in the container loading / unloading block. The processing block includes a liquid processing area where a plurality of liquid processing units for performing liquid processing on a substrate are arranged, a vacuum processing area where a plurality of devices for performing a vacuum bake process on a substrate are provided, and a transport area where a substrate transport device for transporting 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 transport area are provided within a common housing, and the plurality of devices provided in the vacuum processing area include at least one vacuum bake unit having a vacuum chamber for performing the vacuum bake process. A substrate processing system comprising a plurality of devices provided in the vacuum processing area, including a first load lock unit and a second load lock unit, a plurality of vacuum bake units, each having a vacuum chamber for performing the vacuum bake process, and a vacuum transfer machine for transporting substrates in a reduced-pressure atmosphere between the first and second load lock units and the vacuum bake units, wherein the substrate transfer device in the transfer area is provided to be able to transfer substrates to and from the first and second load lock units, and the second load lock unit has a function to cool the substrates that have undergone the vacuum bake process.

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