Substrate processing method and substrate processing apparatus

Abstract

The present application provides a kind of substrate processing method and substrate processing device, can inhibit the consumption of processing liquid and improve the in-plane uniformity of liquid processing.Substrate processing method includes the following processes: substrate heating process, the temperature of substrate is heated to rise;Liquid film forming process, after the substrate heating process, the substrate is heated, and while the substrate is rotated at a first rotational speed, a pre-wetting liquid is supplied to the first surface of the substrate to form a liquid film of the pre-wetting liquid on the first surface of the substrate;Chemical liquid processing process, after the liquid film forming process, the substrate is heated, and while the substrate is rotated at a second rotational speed lower than the first rotational speed, a chemical liquid is supplied to the first surface of the substrate to process the first surface of the substrate by the chemical liquid;And substrate cooling process, after the chemical liquid processing process, the temperature of the substrate is lowered.

Description

Technical Field

[0001] This disclosure relates to a substrate processing method and a substrate processing apparatus. Background Technology

[0002] In the manufacturing process of semiconductor devices, there is a liquid processing step that involves supplying a processing liquid to a substrate such as a semiconductor wafer. One type of liquid processing includes liquid cleaning or wet etching, which involves supplying a heated liquid to the center of the surface of a rotating substrate. The heated liquid supplied to the center of the substrate cools down as it diffuses to the periphery. Furthermore, the substrate tends to cool down more easily at its periphery where the circumferential speed is high. Therefore, supplying a heated liquid, such as water, to the back side of the substrate achieves temperature uniformity (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent Document 1

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-057816 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] This disclosure provides a technique for suppressing the consumption of processing liquid and improving the in-plane uniformity of liquid processing in liquid processing of supplying a liquid solution to a rotating substrate.

[0008] Solution for solving the problem

[0009] One aspect of this disclosure relates to a substrate processing method comprising the following steps: a substrate heating step, wherein the substrate is heated to raise its temperature; a liquid film formation step, wherein after the substrate heating step, the substrate is heated and a pre-wetting liquid is supplied to a first surface of the substrate while the substrate is rotated at a first rotational speed to form a liquid film of the pre-wetting liquid on the first surface of the substrate; a chemical treatment step, wherein after the liquid film formation step, the substrate is heated and a chemical treatment step is supplied to the first surface of the substrate while the substrate is rotated at a second rotational speed lower than the first rotational speed to treat the first surface of the substrate with the chemical treatment; and a substrate cooling step, wherein after the chemical treatment step, the temperature of the substrate is lowered.

[0010] The effects of the invention

[0011] According to this disclosure, the in-plane uniformity of liquid treatment can be improved in liquid treatment that supplies liquid to a rotating substrate. Attached Figure Description

[0012] Figure 1 This is a longitudinal sectional side view of a substrate processing system according to one embodiment of the substrate processing apparatus.

[0013] Figure 2 This indicates that it is set in Figure 1 A schematic longitudinal cross-sectional view of an example of the structure of a processing unit in a substrate processing system.

[0014] Figure 3 This is a piping system diagram illustrating an example of a temperature adjustment DIW supply mechanism that supplies temperature adjustment DIW to the nozzles on the back of the processing unit.

[0015] Figure 4A This is a diagram illustrating the process of liquid treatment involved in one embodiment.

[0016] Figure 4B This is a diagram illustrating the process of liquid treatment involved in one embodiment.

[0017] Figure 4C This is a diagram illustrating the process of liquid treatment involved in one embodiment.

[0018] Figure 5A This is a diagram illustrating the process of liquid treatment involved in one embodiment.

[0019] Figure 5B This is a diagram illustrating the process of liquid treatment involved in one embodiment.

[0020] Figure 5C This is a diagram illustrating the process of liquid treatment involved in one embodiment.

[0021] Figure 6 This is a diagram illustrating the process of liquid treatment involved in one embodiment.

[0022] Figure 7 This is a diagram illustrating the process of liquid treatment involved in one embodiment.

[0023] Figure 8 This is a diagram illustrating the process of liquid treatment involved in one embodiment.

[0024] Figure 9 This is a graph illustrating an example of the temperature shift of the wafer between the wafer heating process and the rinsing process.

[0025] Figure 10 This is a schematic diagram of an example of a piping system, illustrating the HDIW and DIW piping system within a substrate processing system.

[0026] Figure 11This is a schematic diagram of other examples of piping systems within a substrate processing system, such as HDIW piping systems.

[0027] Explanation of reference numerals in the attached figures

[0028] W: Substrate; S1: Substrate heating process; S2: Liquid film formation process; S3: Chemical treatment process; S4: Substrate cooling process. Detailed Implementation

[0029] An embodiment of the substrate processing apparatus will be described with reference to the accompanying drawings.

[0030] Figure 1 This is a diagram showing the outline structure of the substrate processing system according to this embodiment. Hereinafter, in order to make the positional relationships clear, the X-axis, Y-axis and Z-axis are defined as mutually orthogonal, and the positive direction of the Z-axis is set as the vertical upward direction.

[0031] like Figure 1 As shown, the substrate processing system 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 and the processing station 3 are arranged adjacent to each other.

[0032] The loading / unloading station 2 includes a carrier placement section 11 and a conveying section 12. Multiple carriers C are placed on the carrier placement section 11, and these multiple carriers C are used to accommodate multiple substrates, which in this embodiment are semiconductor wafers (hereinafter referred to as wafers W) in a horizontal state.

[0033] The transport section 12 is disposed adjacent to the carrier placement section 11, and a substrate transport device 13 and a transfer section 14 are provided inside the transport section 12. The substrate transport device 13 is provided with a wafer holding mechanism for holding the wafer W. In addition, the substrate transport device 13 can move in both the horizontal and vertical directions while rotating around the vertical axis, and uses the wafer holding mechanism to transport the wafer W between the carrier C and the transfer section 14.

[0034] Processing station 3 is arranged adjacent to conveying section 12. Processing station 3 includes conveying section 15 and multiple processing units 16. Multiple processing units 16 are arranged on both sides of conveying section 15.

[0035] The substrate transport device 17 is provided inside the transport section 15. The substrate transport device 17 is provided with a wafer holding mechanism for holding the wafer W. In addition, the substrate transport device 17 can move in both the horizontal and vertical directions while rotating around the vertical axis, and uses the wafer holding mechanism to transport the wafer W between the transfer section 14 and the processing unit 16.

[0036] The processing unit 16 performs a specified substrate processing on the wafer W transported by the substrate transport device 17.

[0037] Furthermore, the substrate processing system 1 includes a control device 4. The control device 4 is, for example, a computer, which includes a control unit 18 and a storage unit 19. The storage unit 19 stores programs that control various processes performed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the storage unit 19.

[0038] Furthermore, the program can also be stored in a computer-readable storage medium and installed from that storage medium into the storage unit 19 of the control device 4. Examples of computer-readable storage media include hard disks (HD), floppy disks (FD), optical disks (CD), optical discs (MO), and memory cards.

[0039] In the substrate processing system 1 configured as described above, firstly, the substrate transport device 13 of the transport station 2 removes the wafer W from the carrier C placed in the carrier placement section 11 and places the removed wafer W in the transfer section 14. The substrate transport device 17 of the processing station 3 removes the wafer W placed in the transfer section 14 from the transfer section 14 and transports it into the processing unit 16.

[0040] After the wafer W is processed by the processing unit 16, it is removed from the processing unit 16 by the substrate transfer device 17 and placed in the transfer section 14. Then, the processed wafer W placed in the transfer section 14 is returned to the carrier C of the carrier placement section 11 by the substrate transfer device 13.

[0041] Next, refer to Figure 2 The structure of processing unit 16 is explained.

[0042] The processing unit 16 includes a chamber 20, a substrate holding and rotating mechanism 30, a first processing fluid supply unit 40, a second processing fluid supply unit 50, and a recovery cup 60.

[0043] The substrate holding and rotating mechanism 30 and the recovery cup 60 are housed in the chamber 20. An FFU (Fan Filter Unit) 21 is provided at the top of the chamber 20. The FFU 21 is used to form a downward flow within the chamber 20.

[0044] The substrate holding and rotating mechanism 30 includes a substrate holding section 31, a support section 32, and a rotation drive section 33. The substrate holding section 31 is configured as a mechanical chuck having a disk-shaped base 31a and a plurality of gripping claws 31b, which are spaced apart circumferentially at the outer periphery of the base 31a. The substrate holding section 31 holds the wafer W horizontally by means of the gripping claws 31b. When the gripping claws 31b hold the substrate, a gap is formed between the upper surface of the base 31a and the lower surface of the wafer W.

[0045] The support portion 32 is a hollow member extending in the vertical direction. The upper end of the support portion 32 is connected to the base 31a. The rotation drive portion 33 rotates the support portion 32 by rotating the substrate holding portion 31 and the wafer W held therein about the vertical axis.

[0046] The recovery cup 60 is arranged to surround the substrate holding portion 31. The recovery cup 60 collects the processing liquid that spills from the wafer W, which is held in the substrate holding portion 31 and rotated. A drain port 61 is formed at the bottom of the recovery cup 60. The processing liquid collected by the recovery cup 60 is discharged from the drain port 61 to the outside of the processing unit 16. An exhaust port 62 is formed at the bottom of the recovery cup 60. The internal space of the recovery cup 60 is drawn in through the exhaust port 62. Gas supplied from the FFU 21 is drawn into the interior of the recovery cup 60 and then discharged to the outside of the processing unit 16 through the exhaust port 62.

[0047] The first processing fluid supply unit 40 supplies various processing fluids (liquid, gas, gas-liquid mixture, etc.) to the upper surface (typically the surface of the wafer W where devices are formed) of the wafer W held in the substrate holding unit 31. The first processing fluid supply unit 40 has a plurality of surface nozzles 41 that eject processing fluid toward the upper surface (first surface) of the wafer W. The number of surface nozzles 41 is set to the number required for the processing performed by the processing unit 16. Figure 2 Five surface nozzles 41 are depicted, but the number is not limited to that.

[0048] The first processing fluid supply unit 40 has one or more (two in the example shown) nozzle arms 42. Each nozzle arm 42 carries at least one of a plurality of surface nozzles 41. Each nozzle arm 42 is capable of moving the carried surface nozzle 41 between a position approximately directly above the rotation center of the wafer W (processing position) and a retracted position further outward than the upper opening of the recovery cup 60.

[0049] Processing fluid is supplied to each surface nozzle 41 from the corresponding processing fluid supply mechanism 43. The processing fluid supply mechanism 43 can be composed of a processing fluid supply source such as a tank, bottle, or factory power source, a supply pipeline for supplying processing fluid from the processing fluid supply source to the surface nozzle 41, and flow regulating devices such as on / off valves and flow control valves installed in the supply pipeline. In order to discharge the processing fluid (especially processing liquid) stagnating in and around the surface nozzle 41, the discharge pipeline can be connected to the supply pipeline. Such a processing fluid supply mechanism 43 is well known in the field of semiconductor manufacturing apparatus, and a diagram and detailed description of its structure are omitted. A liquid receiving device (not shown) is provided in the processing unit 16 to enable virtual distribution when each surface nozzle 41 is in the retracted position.

[0050] The second processing fluid supply unit 50 supplies various processing fluids (processing liquids, processing gases, etc.) to the lower surface (typically the back side of the wafer W without devices) held in the substrate holding unit 31. The second processing fluid supply unit 50 has one or more (two in the example) back nozzles 51A and 51B that eject processing fluid toward the lower surface (second surface) of the wafer W. Figure 2 As shown in the abstract, a processing fluid supply pipe 52 extends vertically inside the hollow support portion 32. The upper openings of two flow paths extending vertically within the processing fluid supply pipe 52 function as back nozzles 51A and 51B. The processing fluid supply pipe 52 is positioned within the support portion 32 in a manner that allows it to remain in a non-rotating state even when the substrate holding portion 31 and the support portion 32 are rotating.

[0051] Temperature-adjusting DIW (pure water) for temperature adjustment of wafer W is supplied from temperature-adjusting DIW supply mechanism 53A to back nozzle 51A (heating fluid nozzle). Back nozzle 51A and temperature-adjusting DIW supply mechanism 53A constitute the supply mechanism for heating fluid (temperature-adjusting fluid). Temperature-adjusting DIW supply mechanism 53B (only available from CDIW supply mechanism 53B)... Figure 2 (The text indicates that) cooling fluid (CDIW) for cooling wafer W is supplied to the back nozzle 51B. The back nozzle 51B and the CDIW supply mechanism 53B constitute the cooling fluid supply mechanism. The CDIW supply mechanism 53B may, for example, have the same generally known structure as the processing fluid supply mechanism 43 for the surface nozzle 41 described earlier.

[0052] In this specification, to distinguish it from heated DIW, i.e., "HDIW", DIW at room temperature (e.g., 24°C) is referred to as "CDIW".

[0053] Next, refer to Figure 3 The structure of the temperature adjustment DIW supply mechanism 53A for the rear nozzle 51A will be explained. One temperature adjustment DIW supply mechanism 53A is provided for each of the multiple processing units 16 (16-1, 16-2, 16-3, ...). The structures of each temperature adjustment DIW supply mechanism 53A are substantially identical.

[0054] The substrate processing system 1 has an HDIW main pipe 23 connected to a supply source for HDIW and a CDIW main pipe 24 connected to a supply source for CDIW. The main pipes 23 and 24 supply HDIW and CDIW to all processing units 16 of the plurality of processing units 16 included in the substrate processing system 1. A temperature sensor 25 is provided in the HDIW main pipe 23, and a temperature sensor 26 is provided in the CDIW main pipe 24.

[0055] The supply sources of HDIW and CDIW are most commonly found as essential factory capabilities in a semiconductor device manufacturing plant that houses the substrate processing system 1. However, the supply source of HDIW can also be, for example, a tank for storing HDIW, which is a component of the substrate processing system 1. DIW is supplied to the tank from the HDIW and CDIW supply sources, which are essential factory capabilities. In this case, a circulation pipeline connected to the tank and equipped with a pump and a heater corresponds to the HDIW main pipe 23. The supply source of HDIW can also be a hot water generator that heats and delivers the DIW supplied from the HDIW and CDIW supply sources, which are essential factory capabilities.

[0056] The temperature-regulating DIW supply mechanism 53A has a main pipe 531 (heating fluid line) branching off from the main HDIW pipe 23. In the main pipe 531, from the upstream side, are arranged in sequence: a flow meter 532, a pressure regulating valve 533, an on / off valve 534, a first confluence point 535, a second confluence point 536, a first branch point 537, an on / off valve 538, and a second branch point 539. The downstream end of the main pipe 531 is connected to the back nozzle 51A via a flow path within the processing fluid supply pipe 52.

[0057] Flow meter 532 and pressure regulating valve 533 constitute a flow regulating section for adjusting the flow rate of HDIW flowing in main pipe 531. Pressure regulating valve 533 has a pilot port (details not shown). Pressure regulating valve 533 operates by implementing a secondary side pressure corresponding to the operating pressure (air pressure) supplied to the pilot port by an electro-pneumatic regulator (not shown). This is controlled by a control device ( Figure 1 The control device 4 or its subordinate controller performs feedback control on the operating pressure supplied to the pilot port of the pressure regulating valve 533 so that the detected flow rate of the flow meter 532 becomes the desired value (set value).

[0058] The temperature-regulating DIW supply mechanism 53A also includes a diluent line 540 branching from the CDIW main pipe 24. The diluent line 540 branches into a first branch diluent line 542 and a second branch diluent line 543 at a branch point 541. A throttle valve 544 and an on / off valve 545 are provided in the first branch diluent line 542. A throttle valve 546 and an on / off valve 547 are provided in the second branch diluent line 543. In the illustrated example, the throttle valves 544 and 546 are configured as throttle elements with check valves (fixed throttle valves). The first branch diluent line 542 and the second branch diluent line 543 are connected to the main pipe 531 at a first confluence point 535 and a second confluence point 536, respectively.

[0059] A flow meter 548 and a pressure regulating valve 549 are installed upstream of the branch point 541 in the diluent pipeline 540. The flow meter 548 and the pressure regulating valve 549 have the same structure and function as the flow meter 532 and the pressure regulating valve 533.

[0060] At the first branch point 537, a first discharge line 550 branches off from the main line 531. In the first discharge line 550, starting from the upstream side, an on / off valve 551, a temperature sensor 552, and a throttle valve 553 (in the example shown, a throttle element with a check valve (fixed throttle valve)) are arranged in sequence.

[0061] At the second branch point 539, a second discharge line 554 branches off from the main line 531. In the second discharge line 554, an on / off valve 555 and a throttle valve 556 (in the example shown, a throttle element with a check valve (fixed throttle valve)) are arranged sequentially from the upstream side.

[0062] A temperature sensor 557 is installed on the downstream side of the main road 531, which is closer to the second branch point 539.

[0063] When the supply sources of HDIW and CDIW are sufficient for the plant's needs, the temperature of the HDIW flowing in the HDIW main pipe 23 is, for example, 70°C, and the temperature of the CDIW flowing in the CDIW main pipe 24 is, for example, 24°C. These temperatures may vary slightly depending on factors such as changes in external air temperature and cleanroom temperature, and are therefore monitored by temperature sensors 25 and 26.

[0064] As described below, for the primary purpose of temperature regulation of wafer W, temperature-regulating HDIW is supplied to the back side of wafer W from the back nozzle 51A. The temperature-regulating DIW supply mechanism 53A can supply only HDIW or a mixture of HDIW and CDIW to the back side of wafer W from the back nozzle 51A. The temperature of the DIW supplied to wafer W from the back nozzle 51A can be adjusted by changing the mixing ratio of HDIW and CDIW (the ratio of the flow rate of HDIW flowing into the main pipeline 531 to the flow rate of CDIW flowing into the main pipeline 531 via the diluent pipelines 540 (542, 543)).

[0065] As an example, the flow rate of the DIW to be supplied from the back nozzle 51A to the back side of wafer W is set to 1500 ml / min, and the temperature is set to 65°C. In this case, it can be easily calculated that the flow rate of the HDIW at 70°C should be set to 1340 ml / min, and the flow rate of the CDIW at 24°C should be set to 160 ml / min.

[0066] Control device 4 performs the aforementioned calculations. Furthermore, control device 4 provides the calculated HDIW flow rate as a setpoint (target value) SV to the HDIW flow feedback control system, which includes flow meter 532, pressure regulating valve 533, and an electro-pneumatic regulator (not shown). Similarly, control device 4 provides the calculated CDIW flow rate as a setpoint (target value) SV to the CDIW flow feedback control system, which includes flow meter 548, pressure regulating valve 549, and an electro-pneumatic regulator (not shown), and also outputs signals to specify the opening and closing valves (545 or 547) of the branch diluent lines (542 or 543) that should be opened.

[0067] Furthermore, in the aforementioned HDIW flow feedback control system and CDIW flow feedback control system, the detected flow rate obtained by flow meters 532 and 548 is the measured value PV, and the operating pressure supplied from the electro-pneumatic regulator to the pressure regulating valves 533 and 549 is the operating amount MV. The control device 4 adjusts the operating amount MV according to the deviation of the measured value PV from the set value SV.

[0068] To broaden the mixing ratio range (maximum / minimum ratio), the opening area of ​​the throttle valve 544 of the first branch diluent line 542 (first cryogenic fluid line) is set to be significantly larger than the opening area of ​​the throttle valve 546 of the second branch diluent line 543 (second cryogenic fluid line). Therefore, by selectively opening either the on / off valve 545 of the first branch diluent line 542 or the on / off valve 547 of the second branch diluent line 543, a flow range significantly larger than the flow rate range (maximum / minimum flow rate ratio) achievable by the pressure regulating valve 549 alone can be achieved, and flow rate regulation can be performed with high precision.

[0069] The number of branch diluent lines (542, 543, ...) is not limited to the two shown in the figure, and can also be three or more. In this case, each branch diluent line is connected in parallel to the main line 531, and each branch diluent line is equipped with an on / off valve (545, 547, ...) and a throttle valve (544, 546, ...). From the viewpoint of expanding the range of mixing ratios, it is preferable that the opening areas of the throttle valves are different from each other.

[0070] The first discharge line 550 is used to discard the DIW from the wafer W during the period before the temperature stabilizes (also known as "discarding" or "virtual distribution").

[0071] The second discharge line 554 is used to discard the DIW remaining in the flow path of the back nozzle 51A, the processing liquid supply pipe 52 connected to the back nozzle 51A, and the pipes nearby. This prevents the immediate discharge of DIW without temperature control after the temperature-adjusting DIW begins to be discharged from the back nozzle 51A.

[0072] The temperature-regulating DIW supply mechanism 53A can also operate by spraying CDIW (CDIW not mixed with HDIW) separately from the back nozzle 51A. In this case, the back nozzle 51B and the CDIW supply mechanism 53B can be omitted. However, in this case, the temperature of the back nozzle 51 and the pipe connected to it becomes unstable. Therefore, it is preferable to install the back nozzle 51B and the CDIW supply mechanism 53B separately from the back nozzle 51A and the temperature-regulating DIW supply mechanism 53A.

[0073] Next, refer to Figures 3-8 The liquid processing performed on wafer W within processing unit 16 will be described. Wafer W is held horizontally by substrate holding and rotating mechanism 30 with the surface to be processed as the upper surface, and is capable of rotating about a vertical axis. The rotation of wafer W continues until the end of a series of processes.

[0074] Furthermore, in the following description of liquid processing, the liquid landing point of the processing liquid supplied from the surface nozzle 41 to the surface of the wafer W is the rotation center of the wafer W or its vicinity, unless otherwise stated. This meaning will be stated each time when the surface nozzle 41 is scanned at the periphery of the wafer, provided that the liquid landing point of the processing liquid supplied from the surface nozzle 41 to the surface of the wafer W is the wafer periphery.

[0075] [Wafer heating process]

[0076] First, a wafer heating process (substrate heating process) is performed to heat the wafer W to a temperature suitable for liquid processing. The wafer heating process is performed by supplying a temperature-adjusting fluid (heated fluid), which is different from the liquid used in the main processing step (liquid processing step) described later, to the back side of the wafer W. The temperature-adjusting fluid is supplied through a temperature-adjusting fluid supply unit (heating fluid supply unit), which consists of a back-side nozzle 51A and a temperature-adjusting DIW supply mechanism 53A.

[0077] Regarding the fluid used for temperature adjustment, water is preferred due to its low cost and high heat capacity. However, other fluids besides water (DIW) can also be used for temperature adjustment, such as gases (specifically, heated nitrogen).

[0078] Before the wafer heating process, the on / off valve 555 is opened while the on / off valve 538 is closed, and the DIW remaining between the branch point 539 and the back nozzle 51A is discarded via the second discharge line 554.

[0079] On the other hand, with the on / off valve 551 open, the on / off valve 534 is opened, allowing the HDIW to flow into the main pipeline 531 at a controlled flow rate. Additionally, the on / off valves 545 and 547 are opened, allowing the CDIW to flow into the main pipeline 531 via the confluence point 535 or 536 at a controlled flow rate. At this time, as previously explained, the HDIW flow rate calculated by the control device 4 is provided as an initial setpoint to the HDIW flow feedback control system, and the CDIW flow rate calculated by the control device 4 is also provided as an initial setpoint to the CDIW flow feedback control system.

[0080] Within the main channel 531, HDIW and CDIW are mixed to produce temperature-controlled DIW. To promote mixing, a mixing-promoting device such as an inline mixer can be installed between the second confluence point 536 and the first branch point 537.

[0081] Initially, the flow rate and temperature of the temperature-regulating DIW tend to be unstable after it begins to be generated. The temperature instability is mainly due to the cooling of the piping before the HDIW (especially the main pipe 531). Therefore, with the on / off valve 538 closed, the on / off valve 551 is opened, and the initially generated temperature-regulating DIW is discarded (virtually distributed) via the first discharge line 550. The temperature of the temperature-regulating DIW flowing in the first discharge line 550 is monitored by the temperature sensor 552.

[0082] After a predetermined time has elapsed since the on / off valve 551 was opened and the temperature has stabilized, the control device 4 can also correct the (initial) setpoints (SV) of the HDIW flow rate and the (initial) setpoints (SV) of the CDIW flow rate based on the detection value of the temperature sensor 552, so that the detection value of the temperature sensor 552 becomes the target temperature. That is, if the detection value of the temperature sensor 552 does not rise to the target value, for example, corrections can be made to increase the setpoint (SV) of the HDIW flow rate and decrease the setpoint (SV) of the CDIW flow rate to continue feedback control of the HDIW flow rate and the CDIW flow rate.

[0083] After the temperature detected by temperature sensor 552 stabilizes at the target value, on / off valve 551 is closed and on / off valve 538 is opened. On / off valve 555 can be closed immediately after the discharge of residual DIW via the second discharge line 554 is completed, or it can be closed simultaneously with closing on / off valve 551. Thus, temperature-adjusting DIW at a predetermined temperature is ejected from back nozzle 51A toward the center of the back side of wafer W (the center of rotation of the wafer or its vicinity) at a predetermined flow rate. The ejection flow rate of the temperature-adjusting DIW from back nozzle 51A can, for example, be set to 1500 ml / min.

[0084] In the wafer heating process, when HDIW is supplied from the back nozzle 51A without CDIW mixed in, firstly, the on / off valve 551 is opened while the on / off valves 545, 547, and 538 are closed. Additionally, the on / off valve 555 is opened to pre-drain liquid remaining downstream of the branch point 539. Then, the HDIW flowing from the HDIW main pipe 23 into the main pipe 531 flows into the first discharge line 550. At this time, the temperature of the HDIW (temperature-adjusting DIW) flowing in the first discharge line 550 is monitored by the temperature sensor 552. After the temperature sensor 552 reading rises and stabilizes, the on / off valves 551 and 555 are closed, and the on / off valve 538 is opened. Thus, HDIW begins to be ejected from the back nozzle 51A. At this point, the portion of the main pipe 531 upstream of the branch point 537 is sufficiently heated, so the temperature of the HDIW ejected from the back nozzle 51A stabilizes within a relatively short time after it begins to be ejected.

[0085] The wafer W has already begun to rotate before the temperature-adjusting DIW is ejected from the back nozzle 51A. For example... Figure 4A As shown, the temperature-regulating DIW supplied to the center of the back side of wafer W flows towards the periphery of wafer W through centrifugal force, detaching from the outer side of wafer W. At this time, the back side of wafer W is covered by the liquid film of the temperature-regulating DIW. Wafer W is heated by the temperature-regulating DIW, thereby increasing its temperature.

[0086] The rotational speed of wafer W in the wafer warming process can be set to a suitable speed, such as 200 rpm or higher, to ensure that the temperature-adjusting DIW supplied to the center of the back side of wafer W evenly covers the back side of wafer W. However, excessively increasing the rotational speed of wafer W results in the temperature-adjusting DIW scattering to the outside of wafer W colliding violently with the recovery cup 60, causing a large amount of DIW mist to float around wafer W, which is not preferable. Furthermore, excessively increasing the rotational speed of wafer W also leads to the high circumferential speed of the wafer's periphery cooling down easily, impairing the in-plane temperature uniformity of the wafer, which is also not preferable. It is preferable to set the rotational speed of wafer W in the wafer warming process considering the above factors.

[0087] Furthermore, temperature-adjusting DIW is continuously ejected from the back nozzle 51A after the wafer heating process begins and before the wafer cooling process begins. The temperature of the temperature-adjusting DIW ejected from the back nozzle 51A can be monitored by the temperature sensor 557. Based on the detection results of the temperature sensor 557, the setpoints (SV) for the HDIW flow rate and the CDIW flow rate can be corrected as described above. This correction can also be used when the temperature of the temperature-adjusting DIW ejected from the back nozzle 51A is reduced from 70°C to 52°C, as described later.

[0088] In the wafer heating process, such as Figure 4B and Figure 4C As shown, a temperature-adjusting DIW can also be supplied to the surface of wafer W. In this case, it is preferable to perform virtual distribution before supplying the temperature-adjusting DIW to the surface of wafer W to fully heat the surface nozzle 41 for supplying the temperature-adjusting DIW and the piping connected thereto.

[0089] exist Figure 4B In this process, a surface nozzle 41 (hereinafter also referred to as "surface temperature adjusting nozzle 41A" for simplicity) supplies temperature adjusting DIW to the central portion of the surface of wafer W at a relatively large flow rate. The temperature adjusting DIW supplied to the central portion of the wafer surface flows towards the periphery of wafer W by centrifugal force and detaches (scatters) to the outside of wafer W. At this time, the entire surface of wafer W is covered by a liquid film of temperature adjusting DIW. Wafer W is also heated by the temperature adjusting DIW supplied to its surface. Therefore, compared to Figure 4A In this situation, the wafer W can be heated up rapidly.

[0090] exist Figure 4C In this process, temperature-adjusting DIW is supplied from the surface temperature adjusting nozzle 41A at a relatively small flow rate only to the peripheral area of ​​the wafer W surface. For example, the surface temperature adjusting nozzle 41A can be moved radially reciprocatingly to repeatedly change the radial position of the liquid landing point of the temperature-adjusting DIW on the wafer W surface. In this case, only the annular region at the periphery of the wafer W surface is covered by a liquid film of the temperature-adjusting DIW. Figure 4C In this case, localized heating of the periphery of the wafer W, which tends to cool down easily, can further improve the temperature uniformity within the wafer surface. Alternatively, instead of reciprocating the surface temperature adjusting nozzle 41A, the surface temperature adjusting nozzle 41A can be fixed in the same position (e.g., ...). Figure 4C The spray temperature is adjusted using DIW in the position shown.

[0091] In the wafer heating process, when using Figure 4A , Figure 4B , Figure 4C In any process described below, it is preferable to heat the wafer W to a temperature higher than the wafer temperature in the main processing step (also called the "wafer temperature during main processing," for example, 50°C). Actual trial runs have confirmed that temporarily heating the wafer to a first temperature higher than the wafer temperature during main processing before cooling it down can shorten the time required for the wafer W temperature to stabilize at the wafer temperature during main processing.

[0092] [Liquid film formation process and main processing process]

[0093] Next, a liquid film formation process is performed to form a liquid film of pre-wetting liquid on the entire surface of wafer W, followed by a main processing process (chemical treatment process) to treat the surface of wafer W with a chemical solution. The pre-wetting liquid can be the same chemical solution used in the main processing process described later, or it can be other liquids that can be easily replaced by the chemical solution used in the main processing process described later (e.g., DIW, IPA (isopropanol)).

[0094] exist Figure 4A , Figure 4B or Figure 4C After the wafer heating process is completed, temperature-adjusting DIW continues to be ejected from the back nozzle 51A onto the back side of wafer W. However, by adjusting the mixing ratio of the CDIW, the temperature of the temperature-adjusting DIW ejected from the back nozzle 51A is reduced to a temperature approximately equal to the wafer temperature during the main processing (e.g., 52°C). As a result, the temperature of wafer W decreases towards the wafer temperature during the main processing.

[0095] In the wafer heating process, such as Figure 4A In the case where the temperature-adjusting DIW is not supplied to the surface of wafer W as shown, a room-temperature solution of the same type used in the main processing step is supplied as a pre-wetting solution from the surface nozzle 41 (hereinafter also referred to as "surface solution nozzle 41B") used for supplying the solution. Figure 5A The wafer W is rotated at a first rotational speed and a room-temperature solution is supplied from the surface solution nozzle 41B to the center of the surface of the wafer W (the center of rotation of the wafer or its vicinity) at a first ejection flow rate.

[0096] At this point, in order to rapidly diffuse the solution to the entire surface of wafer W, it is preferable to use a relatively high first rotational speed (e.g., about 800 rpm). Alternatively, the first ejection flow rate can be relatively large (e.g., about 1000 ml / min). By using a relatively large first ejection flow rate, even if the rotational speed of wafer W is relatively high, the entire surface of wafer W can be reliably covered by the liquid film of the solution. In addition, by using a relatively large first ejection flow rate, it is possible to reliably prevent the evaporation of the solution supplied to the surface of wafer W, which becomes relatively hot (e.g., about 70°C) at the beginning of the liquid film formation process, thus preventing the formation of dry areas.

[0097] Furthermore, in situations where it is difficult to form a uniform liquid film, it is particularly preferable to set the first rotational speed and the first ejection flow rate to be relatively large in order to prevent fingering. Specifically, for example, this may be considered when using a solution with low wettability or high viscosity for wafer W.

[0098] In the wafer heating process, such as Figure 4B or Figure 4C When temperature-adjusting DIW is supplied to the wafer surface from the surface temperature-adjusting nozzle 41A as shown, the ejection of temperature-adjusting DIW from the surface temperature-adjusting nozzle 41A is stopped. Furthermore, the liquid film formation process is performed by supplying a room-temperature solution, the same solution used in the main processing step, as a pre-wetting solution to the center of the back side of the wafer W from the surface solution nozzle 41B. In this case, it also becomes... Figure 5A The state shown.

[0099] When from Figure 4B or Figure 4C When the process transitions to the liquid film formation step, in order to prevent the collapse of the raised and recessed patterns formed on the surface of wafer W, it is preferable to supply the solution to the surface of wafer W before the temperature adjustment DIW detaches from the pattern recess.

[0100] At this time, it is preferable to switch between the first processing liquid (here, a temperature adjustment DIW) supplied first and the second processing liquid (here, a chemical solution) supplied later, as follows: First, the first processing liquid is launched from the first surface nozzle 41 (here, a surface temperature adjustment nozzle 41A) at the center of rotation of the surface of the wafer W. From this state, the second processing liquid ejected from the second surface nozzle 41 (here, a surface chemical solution nozzle 41B) located near the first surface nozzle 41 lands at a position slightly separated from the center of rotation of the surface of the wafer W. Then, the first surface nozzle 41 and the second surface nozzle 41 are moved in conjunction, so that the liquid landing point of the first processing liquid is away from the center of rotation of the wafer, and the liquid landing point of the second processing liquid is close to the center of rotation of the wafer. After the liquid landing point of the second processing liquid reaches the center of rotation of the wafer, the ejection of the first processing liquid from the first surface nozzle 41 is stopped. In this case, the end of the supply period of the first processing liquid toward the wafer surface overlaps with the beginning of the chemical solution supply period. Hereinafter, the switching method of the treatment fluid will be referred to as the "overlapping (repeated) switching method" in this specification.

[0101] Alternatively, the overlapping switching method can be performed by moving the first nozzle (41) and the second nozzle (41) mounted on a common nozzle arm (42) in such a manner that the above-described relationship holds. Alternatively, the overlapping switching method can be performed by moving the first nozzle (41) mounted on the first nozzle arm (42) and the second nozzle (41) mounted on a second nozzle arm (42) different from the first nozzle arm (42) in such a manner that the above-described relationship holds.

[0102] If there is no problem even if a structure is used in which the first processing liquid (here, a temperature-adjusting DIW) and the second processing liquid (here, a chemical solution) are sprayed out from the same surface nozzle 41, then the switching of the processing liquid can be performed as follows: That is, the first processing liquid supply mechanism and the second processing liquid supply mechanism are connected in parallel for one surface nozzle 41. Moreover, almost simultaneously with stopping the supply of the first processing liquid from the first processing liquid supply mechanism to the surface nozzle 41, the supply of the second processing liquid from the second processing liquid supply mechanism to the surface nozzle 41 begins. Thus, the switching of the processing liquid can be performed without interrupting the supply of the processing liquid toward the surface of the wafer W. Alternatively, two separate surface nozzles (first surface nozzle 41 and second surface nozzle 41) can be used, and the second processing liquid can be sprayed out from the second surface nozzle 41 immediately after stopping the spraying of the first processing liquid from the first surface nozzle 41. Furthermore, for simplicity, this method of switching the processing liquid will be referred to as the "sequential switching method" in this specification below.

[0103] In the liquid film formation process, a temperature adjustment DIW with a temperature approximately equal to that of the wafer during the main processing is supplied to the back side of the wafer W from the back nozzle 51A, and a room temperature solution is supplied to the surface of the wafer W from the surface nozzle 41, thereby cooling the wafer W and reducing its temperature to the wafer temperature during the main processing.

[0104] Furthermore, in the liquid film formation process and the main processing process, a room-temperature solution (e.g., 25°C) is continuously supplied to the surface of the wafer W from the surface solution nozzle 41B. Therefore, the temperature of the temperature adjustment DIW supplied to the back side of the wafer W from the back nozzle 51A is set to a temperature slightly higher than the wafer temperature during the main processing (e.g., 50°C) (e.g., 52°C to 55°C). This allows the temperature of the wafer W (the temperature at the boundary between the wafer surface and the solution) to be maintained at the wafer temperature during the main processing. The temperature of the temperature adjustment DIW supplied to the back side of the wafer W in the main processing process can be determined by considering factors that affect the temperature of the wafer W, such as the temperature of the solution supplied to the surface of the wafer W in the main processing process, the flow rate of the solution, the specific heat of the solution, the rotational speed of the wafer W, the temperature inside the chamber 20, and the flow rate of the downward flow inside the chamber 20.

[0105] The liquid film formation process is a process that not only uniformly forms a liquid film of the solution on the entire surface of the wafer W, but also lowers and stabilizes the temperature of the wafer W at the temperature required for the main processing. Therefore, it can also be considered a "stabilization process". In this stabilization process, the atmosphere inside the chamber 20 can be adjusted to the atmosphere required for the main processing. For example, nitrogen can be supplied from the FFU 21 into the chamber 20 to make the atmosphere inside the chamber 20 have a low oxygen concentration and low humidity. In the stabilization process, the rotational speed of the wafer W can also be reduced from the first rotational speed mentioned above to the rotational speed of the wafer W in the main processing, i.e., the second rotational speed, or reduced to an appropriate rotational speed that is higher than the second rotational speed and lower than the first rotational speed.

[0106] After the temperature of wafer W stabilizes at the temperature required for the main processing, the process proceeds to the main processing step. During this transfer, while the rotational speed of wafer W is set to the second rotational speed described above, temperature adjustment DIW (e.g., 52°C) continues to be ejected from the back nozzle 51A, and room temperature (e.g., 25°C) solution continues to be ejected from the surface solution nozzle 41B onto the surface of wafer W (see reference). Figure 6 ).

[0107] By reducing the rotational speed of wafer W (set as the second rotational speed), the tendency for the periphery of wafer W to easily cool down is mitigated. This improves the uniformity of the processing results within the wafer surface. Furthermore, by reducing the rotational speed of wafer W, the liquid film can be maintained even if the flow rate of the liquid ejected from the surface liquid nozzle 41B decreases.

[0108] Preferably, the flow rate of the liquid ejected from the surface liquid nozzle 41B in the main processing step, i.e., the second ejection flow rate, is less than the flow rate of the liquid ejected from the surface liquid nozzle 41 in the liquid film formation step, i.e., the first ejection flow rate. This reduces the amount of liquid consumed. Especially when using expensive liquids, reducing liquid consumption helps lower processing costs. Furthermore, even with a lower second ejection flow rate, the wafer W can be maintained at a temperature that ensures an appropriate reaction between the wafer W and the liquid.

[0109] As the surface liquid nozzle 41B, a surface liquid nozzle for high flow rate and a surface liquid nozzle for low flow rate can be provided. Alternatively, a single surface liquid nozzle 41B can be connected to a liquid supply line for high flow rate and a liquid supply line for low flow rate that can be selectively switched. In this way, the flow rate of the liquid ejected from the surface liquid nozzle 41B can be quickly switched from a first ejection flow rate to a second ejection flow rate.

[0110] The main processing step is completed by rotating wafer W at the second rotational speed and supplying the chemical solution at the second ejection flow rate for a specified time (e.g., about 30 seconds). Furthermore, during the main processing step, the surface of wafer W is sufficiently heated, resulting in a sufficiently high temperature at the interface between the surface of wafer W and the chemical solution. Therefore, the reaction between the surface of wafer W and the chemical solution progresses sufficiently.

[0111] In one embodiment, the time required for the liquid film formation step is much shorter than that required for the main processing step, for example, less than 5 seconds, specifically, for example, about 2 to 3 seconds. Therefore, even if the liquid flow rate per unit time in the liquid film formation step (first flow rate) is greater than the liquid flow rate per unit time in the main processing step (second flow rate), it does not have a significant impact on the total amount of liquid used.

[0112] In the main processing step, the surface solution nozzle 41B can also be positioned directly above the center of the wafer W, ensuring that the solution always lands at the center of the wafer W (surface nozzle fixed). Alternatively, the main processing step (surface nozzle scanning) can be performed while moving the surface solution nozzle 41B to change the liquid landing point on the surface of the wafer W. It is desirable to determine the scanning conditions (scanning amplitude, scanning speed, scanning range) of the surface solution nozzle 41B such that no dry area is generated on the surface of the wafer W while reducing the flow rate (second flow rate) of the solution from the surface solution nozzle 41B in the main processing step.

[0113] If surface nozzle scanning is performed in the main processing step, it can also be performed in the liquid film forming step (stabilization step) under the same conditions as the main processing step.

[0114] In the liquid film formation and main processing steps, the chemical solution is supplied at room temperature, thus eliminating the need for preheating. If the chemical solution is heated for an extended period, there is a possibility of consumption due to evaporation, degradation, or other issues. At room temperature, there is no consumption, or even if consumption occurs, the degree of consumption is significantly reduced compared to when heating is involved. This is particularly advantageous from the perspective of reducing processing costs when using expensive chemical solutions. Furthermore, there are chemical solutions that, when heated, produce flammable or harmful vapors (gases). When using such chemical solutions, avoiding heating reduces the costs associated with ensuring safety.

[0115] To prepare heated chemical solutions in advance, a heated chemical solution supply system is required, consisting of a chemical solution storage tank, a circulation pipeline connected to the chemical solution storage tank, and equipment such as pumps and heaters installed in the circulation pipeline. In contrast, a chemical solution supply system for supplying room temperature chemical solutions requires fewer components compared to a heated chemical solution supply system, which helps reduce the cost of the substrate processing equipment.

[0116] Furthermore, the supply temperature of the medicine solution is not limited to room temperature; it can be a temperature at which the consumption of the medicine solution will not be a problem, or it can be a temperature higher than room temperature.

[0117] One of the most effective processes in this embodiment is the organic solvent treatment process included in the BEOL process of semiconductor manufacturing. In this organic solvent treatment process, a high-cost organic solvent is supplied to the wafer in a heated state. With the increasing sophistication of patterns in recent years, the required cleanliness of the organic solvent has increased, and once supplied to the wafer, the organic solvent cannot be recycled. Therefore, the organic solvent must be used only once. Furthermore, to reduce processing costs, it is necessary to reduce the amount of solvent required to process one wafer. In this embodiment, the solvent treatment process (main processing process) is performed while the back side of the wafer is heated using a temperature-adjusting DIW, thus eliminating the need to supply the heated organic solvent at a high flow rate to ensure wafer heating and in-plane temperature uniformity. In contrast, in prior art where the back side of the wafer is not heated using a temperature-adjusting DIW, the heated organic solvent is supplied at a high flow rate (e.g., approximately 1500 ml / min). Therefore, the entire wafer is rapidly heated to the temperature required for the reaction between the solution and the wafer, and the tendency for the temperature to drop at the periphery of the wafer is mitigated. In the case of the organic solution processing step included in the BEOL process, according to this embodiment, even when using an organic solution to perform the liquid film formation step, the ejection flow rate of the organic solution is, for example, about 150 ml / min. In the solution processing step (main processing step), the ejection flow rate of the organic solution is equal to or less than the aforementioned flow rate. That is, according to this embodiment, the amount of organic solution used can be reduced to about 1 / 10 of that in the prior art. Furthermore, in this embodiment, the temperature required for the reaction between the solution and the wafer is maintained by heating the back side of the wafer W using a temperature-adjusting DIW, thus eliminating the need for preheating the organic solution as described above. Therefore, the consumption of expensive organic solutions can be suppressed, thereby further reducing the amount of organic solution used.

[0118] In addition, the liquid supply unit is formed by the surface liquid nozzle 41B and the liquid supply mechanism (processing fluid supply mechanism) 43 connected thereto.

[0119] [Modified implementations of the liquid film formation process and the main processing process]

[0120] After adopting Figure 4B or Figure 4C In wafer heating processes where the temperature-adjusting DIW can be easily replaced by a chemical solution (e.g., where the DIW is miscible with the chemical solution), the temperature-adjusting DIW supplied to the surface of wafer W can be used as a pre-wetting solution during the wafer heating process. The ejection flow rate and temperature shift of the temperature-adjusting DIW supplied from the back nozzle 51A to the back side of wafer W can be compared with those described previously. Figure 4A The process is the same as the wafer heating process.

[0121] After adopting Figure 4B In the case of a wafer heating process, after the wafer heating process is completed, the surface temperature adjustment nozzle 41A continues to be positioned directly above the center of the wafer W, and the temperature of the temperature adjustment DIW ejected from the surface temperature adjustment nozzle 41A is reduced from the first temperature (e.g., 70°C) in the wafer heating process to a second temperature (e.g., 52°C) lower than that (see reference). Figure 5B As a result, the temperature of wafer W drops to near the wafer temperature during main processing (e.g., 50°C).

[0122] After adopting Figure 4C In the case of a wafer heating process, after the wafer heating process is completed, the surface temperature adjustment nozzle 41A is moved to directly above the center of the wafer W, so that the temperature of the temperature adjustment DIW ejected from the surface temperature adjustment nozzle 41A is reduced to a second temperature (e.g., 52°C). (Refer to...) Figure 5C ).

[0123] In any of the above cases, the temperature-adjusting DIW is used as a pre-wetting liquid. That is, in this case, the wafer heating process can be regarded as a liquid film formation process, and the process of ejecting the temperature-adjusting DIW from the surface temperature-adjusting nozzle 41A at a second temperature (e.g., 52°C) can also be regarded as a stabilization process.

[0124] The processing fluid supply mechanism 43 that supplies temperature adjustment DIW to the surface temperature adjustment nozzle 41A can be configured to have the same structure as the temperature adjustment DIW supply mechanism 53A that supplies temperature adjustment DIW to the back nozzle 51A (that is, the structure that adjusts the temperature by adjusting the mixing ratio of HDIW and CDIW).

[0125] After the temperature of wafer W stabilizes to the wafer temperature required for main processing, the ejection of temperature adjustment DIW from surface temperature adjustment nozzle 41A stops, and the ejection of chemical solution from surface chemical solution nozzle 41B begins, thus initiating the main processing step (see reference). Figure 6 In this case, the aforementioned overlapping switching method can also be used to switch the processing fluid to be supplied from the temperature adjustment DIW to the chemical solution. Alternatively, a sequential switching method can be used to switch the processing fluid to be supplied from the temperature adjustment DIW to the chemical solution.

[0126] Alternatively, at a point slightly earlier than when the wafer temperature of the main processing wafer W is stable, the ejection of temperature adjustment DIW from the surface temperature adjustment nozzle 41A is stopped, and the ejection of liquid from the surface liquid nozzle 41B begins.

[0127] In the main processing step, the liquid landing point of the liquid medicine ejected from the surface liquid medicine nozzle 41B can be set to the rotation center of the wafer surface or its vicinity. In the main processing step, the liquid landing point of the liquid medicine can also be moved by causing the surface liquid medicine nozzle 41B to perform a scanning action.

[0128] Also in the above-described modified embodiment, it is preferable that the rotation speed (second rotation speed) of the wafer W in the main processing step is smaller than the rotation speed (first rotation speed) of the wafer W in the liquid film forming step. Thereby, the tendency for the peripheral portion of the wafer W to become cold easily can be reduced.

[0129] Also in the above-described modified embodiment, the ejection flow rate of the liquid medicine from the surface liquid medicine nozzle 41B in the main processing step can be the same as the second ejection flow rate in the foregoing embodiment.

[0130] The main processing step is completed by supplying the liquid medicine from the surface liquid medicine nozzle 41B to the surface of the wafer W for a predetermined time.

[0131] [Wafer Cooling Step (Substrate Cooling Step)]

[0132] The wafer cooling step is performed by supplying a fluid for adjusting the temperature (for cooling), which is different from the liquid medicine used in the main processing step (liquid medicine processing step), to the back surface of the wafer W. It is preferable that the fluid for adjusting the temperature has a low price and a large heat capacity, and the most suitable fluid for temperature adjustment is CDIW.

[0133] The wafer cooling step is performed as follows. After the main processing step is completed, the temperature adjustment DIW ejected from the back surface nozzle 51A is stopped, and CDIW is ejected from the back surface nozzle 51B to the back surface of the wafer W. Thereby, the temperature of the wafer W decreases, and the reaction rate between the object to be removed (or reaction object) on the surface of the wafer W and the liquid medicine decreases. Before the rinsing step ends, the ejection of CDIW from the back surface nozzle 51B is continued.

[0134] [Rinsing Step]

[0135] In parallel with the ejection of CDIW from the back surface nozzle 51B, a rinsing liquid is supplied from the surface nozzle 41 for supplying the rinsing liquid to the surface of the wafer W to perform a rinsing step on the wafer surface (refer to Figure 7 ). In addition, if the temperature of the wafer W has sufficiently decreased, the ejection of CDIW from the back surface nozzle 51B can be stopped.

[0136] In the case where DIW cannot be used as the rinsing liquid, for example, in the case where an organic solvent such as IPA is used as the rinsing liquid, the rinsing step can be performed according to the following process.

[0137] <First Process of IPA Rinsing>

[0138] In the first process, the supply of the liquid chemical from the surface liquid chemical nozzle 41B is stopped, and the liquid chemical is removed from the surface of the wafer W by shaking for a predetermined time (e.g., several seconds). After that, IPA is ejected from the surface nozzle 41 for supplying IPA (hereinafter also simply referred to as "surface IPA nozzle 41C"). Then, IPA is supplied to the wafer W from the surface IPA nozzle 41C for a predetermined time, thereby performing a rinsing process on the surface of the wafer W.

[0139] <Second process of IPA rinsing>

[0140] In the second process, the state of ejecting the liquid chemical from the surface liquid chemical nozzle 41B is switched to the state of ejecting IPA from the surface IPA nozzle 41C by using the aforementioned overlapping switching method. Then, the surface of the wafer W is rinsed by supplying IPA from the surface IPA nozzle 41C to the wafer W for a predetermined time.

[0141] [Drying process]

[0142] After performing IPA rinsing through the above first process or second process, a drying process is performed. While supplying a drying gas such as nitrogen, a gas with a low oxygen concentration and low humidity, to the surface of the wafer W, for example, the liquid landing point of the IPA ejected from the surface IPA nozzle 41C on the wafer surface is moved from the central portion of the wafer W to the peripheral portion, whereby this drying process can be performed (refer to Figure 8 ). The drying gas can be ejected from the surface nozzle 41 for supplying the drying gas (hereinafter also simply referred to as "surface gas nozzle 41D"). In this case, it is preferable to move the surface IPA nozzle 41C and the surface gas nozzle 41D in such a manner that the blowing position of the drying gas onto the wafer surface is maintained at a position slightly radially inward from the liquid landing point of the IPA from the surface IPA nozzle 41C on the wafer surface.

[0143] The drying process is not limited to the above description. It is also possible to simply stop ejecting IPA from the surface IPA nozzle 41C after performing the above first process and second process (of IPA rinsing), and dry the wafer W by shaking drying.

[0144] In the case where DIW is used as the rinsing liquid, the surface nozzle 41 for supplying CDIW to the surface of the wafer W (hereinafter, for simplicity, also referred to as "surface rinsing nozzle 41E") can be used, and the rinsing process can be performed through the following process.

[0145] During the drying process, it is also possible to stop ejecting CDIW from the back nozzle 51B. In addition, it is also possible to eject HDIW from the back nozzle 51A to promote drying.

[0146] <Process of DIW rinsing>

[0147] Using surface cleaning nozzle 41B and surface rinsing nozzle 41E, the process switches from supplying cleaning solution to the surface of wafer W to supplying room-temperature DIW (CDIW) via the aforementioned overlapping switching method. CDIW is supplied from surface rinsing nozzle 41E for a predetermined time (see reference). Figure 7 DIW rinsing complete.

[0148] Subsequently, using the surface rinsing nozzle 41E and the surface IPA nozzle 41C, the process switches from supplying CDIW to supplying IPA to the surface of wafer W via the aforementioned overlapping switching method. By supplying IPA from the surface IPA nozzle 41C at predetermined intervals, the CDIW on the surface of wafer W is replaced with IPA.

[0149] Then, perform the same drying process as described above.

[0150] Furthermore, when DIW cannot be used as a rinsing fluid, the cooling of wafer W after the chemical treatment process is mainly achieved by CDIW supplied to the back side of wafer W. High-cost IPA is typically not supplied at high flow rates, therefore the contribution of IPA supplied to the surface of wafer W to the cooling of wafer W is small. When DIW can be used as a rinsing fluid, CDIW is supplied at high flow rates not only to the back side of wafer W but also to the surface of wafer W, thereby enabling rapid cooling of wafer W.

[0151] With the completion of the drying process, the series of liquid processing steps for a wafer W is finished. Afterwards, wafer W is removed from processing unit 16.

[0152] The processing liquid present on the surface of wafer W at the start of the drying process is not limited to IPA, and may also be other solvents besides IPA that have low surface tension (at least lower than the surface tension of DIW) to the extent that they can prevent the collapse of the pattern on the surface of wafer W. The processing liquid present on the surface of wafer W at the start of the drying process is preferably a liquid with higher volatility than DIW.

[0153] According to the above-described embodiment, the temperature of the interface between the surface of the wafer W and the chemical solution is controlled by supplying a temperature-adjusting DIW (HDIW, CDIW, or a mixture thereof) to the back side of the wafer W. Therefore, even if a chemical solution that should react with the surface of the wafer W at a high temperature is supplied at room temperature, the desired reaction can be achieved. As a result, chemical solution consumption can be prevented, the amount of chemical solution consumed can be reduced, and high in-plane uniformity processing can be achieved.

[0154] Reference Figure 9Here is an example illustrating the temperature progression of the wafer during the wafer warming process and the rinsing process. In the wafer warming process (S1), HDIW at 70°C is supplied to the back side of wafer W as a temperature conditioning solution. After 10 seconds from the start of the wafer warming process (S1), the temperature of wafer W reaches approximately 70°C. Then, in the liquid film formation process (S2), HDIW at 52°C is supplied to the back side of wafer W as a temperature conditioning solution, and a chemical solution (CHM) at room temperature (25°C) is supplied to the front side of wafer W. After approximately 3 seconds from the start of the liquid film formation process (S2), the wafer temperature stabilizes at the main processing wafer temperature of 50°C. Then, in the main processing process (S3), i.e., the chemical solution treatment process, HDIW at 52°C continues to be supplied to the back side of wafer W, and a chemical solution (CHM) at room temperature (25°C) is supplied to the front side of wafer W. However, as previously described, the wafer rotation speed and chemical spraying flow rate in the main processing step (S3) are lower than in the liquid film formation step (S2). The main processing step (S3) lasts approximately 17 seconds. Afterwards, in the wafer cooling step (S4), CDIW at 24°C is supplied to the back side of wafer W, and the temperature of wafer W drops to room temperature after approximately 2 seconds. Figure 9 In the example, along with the start of the wafer cooling process (S4), CDIW at 24°C is supplied to the surface of wafer W as a rinsing fluid. This CDIW is a coolant that lowers the temperature of wafer W and also serves as a rinsing fluid to wash away the chemical residue on the surface of wafer W. After the temperature of wafer W stabilizes at room temperature, CDIW at 24°C continues to be supplied to the surface of wafer W as a rinsing fluid for the rinsing process (S5). Figure 9 In the example, the wafer cooling process (S4) is also included as part of the rinsing process (S5).

[0155] In the above embodiments, different processing liquids are supplied through separate surface nozzles 41, but this is not a limitation. For example, two or more processing liquids can be supplied from a single surface nozzle 41 without causing problems even when supplied through the same nozzle. Furthermore, in the above embodiments, only DIW for regulating the temperature of wafer W is supplied from the back nozzles 51A and 51B, but it is also possible to configure a structure that allows other processing liquids, such as pharmaceutical solutions, to be supplied from the back nozzle 51A. Moreover, when multiple processing liquids are supplied from the same nozzle, multiple processing liquid supply mechanisms that can be switched via a switching valve (or multiple on / off valves) are connected in parallel with a single surface nozzle 41. Such structures are known and therefore will not be described in detail in this specification.

[0156] Next, refer to Figure 10Here is a simplified illustration of an example of the piping system for HDIW and CDIW within substrate processing system 1. Processing station 3 of substrate processing system 1 has a two-layer structure comprising an upper layer 3A and a lower layer 3B. Figure 10 In the diagram, 71 indicates an HDIW supply source that is a necessary capability for the plant, and 72 indicates a CDIW supply source that is a necessary capability for the plant.

[0157] HDIW supply source 71 is connected to the upstream end of HDIW pipeline 711. HDIW pipeline 711 branches at branch point 712 into branch pipeline 713A for upper layer 3A and branch pipeline 713B for lower layer 3B. Upstream of branch point 712, an on / off valve 710 and a temperature sensor 716 are installed in HDIW pipeline 711. Branch pipelines 713A and 713B merge again at confluence point 714 to form a single HDIW pipeline 711. The downstream end of HDIW pipeline 711 is connected to the plant discharge line (DR). A back pressure valve 715 is installed downstream of confluence point 714.

[0158] CDIW supply source 72 is connected to the upstream end of CDIW pipeline 721. CDIW pipeline 721 branches at branch point 722 into branch pipeline 723A for upper layer 3A and branch pipeline 723B for lower layer 3B. Upstream of branch point 722, a CO2 bubbler 720 and a temperature sensor 726 are installed in CDIW pipeline 721. Branch pipelines 723A and 723B merge again at confluence point 724 to form a single CDIW pipeline 721. The downstream end of CDIW pipeline 721 is connected to the plant discharge line (DR). At the downstream end of branch pipelines 723A and 723B (the portion further downstream than the connection point with the downstream processing unit 16), pressure-controlling throttling devices 727A and 727B (fixed throttling valves) are installed.

[0159] Branch pipe 713A (713B) is equivalent to Figure 3 In the fluid loop diagram, HDIW main pipe 23. Branch pipes 723A (723B) are equivalent to... Figure 3 The CDIW supervisor is 24 in the fluid loop diagram. That is, in... Figure 10 In the example, the HDIW taken from branch line 713A (713B) and the CIWD taken from branch line 723A (723B) are supplied by the temperature-regulated DIW supply mechanism 53A (in... Figure 10 (The mixture is indicated by the dashed box) and supplied to the back nozzle 51A. Figure 10 The structure of the DIW supply mechanism 53A for temperature regulation is similar to Figure 2The structure of the temperature adjustment DIW supply mechanism 53A is the same. Each processing unit 16 has one temperature adjustment DIW supply mechanism 53A, but for the sake of simplicity in the drawings, [the following is omitted]. Figure 10 Only one is shown in the image.

[0160] Figure 11 Other examples of HDIW piping systems within substrate processing system 1 are shown. Figure 11 The description of the CDIW piping system is omitted here. In this example, the HIDW supply line 801, which is essential for the plant's capacity, is connected to the upstream end of the HDIW line 803. The HDIW line 803 branches at branch point 804 into branch line 805A for upper layer 3A and branch line 805B for lower layer 3B. Upstream of branch point 804, an on / off valve 817 and a temperature sensor 816 are installed in the HDIW line 803. Branch lines 805A and 805B merge again at confluence point 806 to form a single HDIW line 803. Downstream of confluence point 806, an on / off valve 807 and a check valve 808 are installed in the HDIW line 803. The downstream end of the HDIW line 803 is connected to the HIDW return line 802, which is part of the plant's essential capacity system. Between the confluence point 806 and the on / off valve 807, a discharge line 809 branches off from the HDIW line 803. An on / off valve 810 is installed in the discharge line 809. During normal operation of the substrate processing system 1, on / off valves 807 and 817 are opened, and on / off valve 810 is closed. For maintenance or other purposes, when the substrate processing system 1 is stopped, on / off valves 807 and 817 are closed, and on / off valve 810 is opened to discharge the DIW from the line. In this example, with... Figure 10 Unlike other examples, no back pressure valve was installed at the downstream end of HDIW line 803.

[0161] The embodiments disclosed herein are illustrative in all respects and not restrictive. The above embodiments may be omitted, substituted, or modified in various ways without departing from the claims and their spirit.

[0162] The substrate being processed is not limited to a semiconductor wafer (wafer W), and can be any substrate used in the field of semiconductor device manufacturing, such as a glass substrate or a ceramic substrate.

Claims

1. A substrate processing method comprising the following processes: a substrate warming process of heating a substrate to raise a temperature of the substrate to a first temperature; a liquid film forming process of, after the substrate warming process, heating the substrate and lowering the temperature of the substrate to a second temperature lower than the first temperature and stabilizing the second temperature, and supplying a pre-wetting liquid to a first surface of the substrate while rotating the substrate at a first rotation speed to form a liquid film of the pre-wetting liquid on the first surface of the substrate; a chemical liquid processing process of, after the liquid film forming process, heating the substrate to maintain the temperature of the substrate at the second temperature, and supplying a chemical liquid at room temperature to the first surface of the substrate while rotating the substrate at a second rotation speed lower than the first rotation speed to process the first surface of the substrate by the chemical liquid; and a substrate cooling process of, after the chemical liquid processing process, lowering the temperature of the substrate.

2. The substrate processing method according to claim 1, wherein the heating of the substrate in the substrate warming process, the liquid film forming process, and the chemical liquid processing process is performed by supplying a heated fluid different from the chemical liquid to at least a second surface on a back side of the first surface of the substrate.

3. The substrate processing method according to claim 2, wherein the substrate warming process includes supplying the heated fluid at the first temperature higher than a target temperature of the substrate in the chemical liquid processing process to the second surface of the substrate, and lowering the temperature of the heated fluid supplied to the second surface of the substrate to the second temperature before the chemical liquid processing process is started.

4. The substrate processing method according to claim 1, wherein the substrate warming process is performed by supplying a heated fluid different from the chemical liquid to only a second surface on a back side of the first surface of the substrate.

5. The substrate processing method according to claim 1, wherein the substrate warming process is performed by supplying a heated fluid different from the chemical liquid to the first surface of the substrate and a second surface on a back side of the first surface of the substrate.

6. The substrate processing method according to claim 1, wherein the substrate warming process is performed by supplying a heated fluid different from the chemical liquid to only a peripheral portion of the first surface of the substrate and supplying a heated fluid different from the chemical liquid to a second surface on a back side of the first surface of the substrate.

7. The substrate processing method according to claim 5 or 6, wherein the heated fluid different from the chemical liquid supplied to the first surface of the substrate in the substrate warming process is also continuously supplied to the first surface of the substrate in the liquid film forming process, and the heated fluid different from the chemical liquid is used as the pre-wetting liquid in the liquid film forming process.

8. The substrate processing method according to any one of claims 1 to 6, wherein ​ The pre-wetting liquid used in the liquid film forming process is the same liquid as the chemical liquid used in the chemical liquid processing process, the chemical liquid is supplied as the pre-wetting liquid to the first surface of the substrate at a first flow rate in the liquid film forming process, and the chemical liquid is supplied at a second flow rate lower than the first flow rate in the chemical liquid processing process.

9. The substrate processing method according to any one of claims 1 to 6, wherein the substrate cooling process is performed by at least supplying a fluid different from the chemical liquid to a second surface on a back side of the first surface of the substrate at a temperature lower than a target temperature of the substrate in the chemical liquid processing process.

10. A substrate processing apparatus comprising: a substrate holding section that holds a substrate having a first surface and a second surface on a back side of the first surface; a rotation drive section that rotates the substrate holding section; a chemical liquid supply section that supplies a chemical liquid to the substrate; a heated fluid supply section that supplies a heated fluid to the substrate; and a control section, wherein the control section is configured to execute the following processes: a substrate warming process that causes the temperature of the substrate to rise to a first temperature by supplying the heated fluid to the substrate by the heated fluid supply section; a liquid film forming process that, after the substrate warming process, causes the substrate to rotate at a first rotation speed by the rotation drive section, causes the temperature of the substrate to decrease to a second temperature lower than the first temperature and stabilize at the second temperature by supplying the heated fluid to the second surface of the substrate by the heated fluid supply section, and forms a liquid film of a pre-wetting liquid on the first surface of the substrate by supplying the heated fluid to the first surface of the substrate by the heated fluid supply section as the pre-wetting liquid or by supplying a chemical liquid to the first surface of the substrate by the chemical liquid supply section as the pre-wetting liquid; a chemical liquid processing process that, after the liquid film forming process, causes the substrate to rotate at a second rotation speed lower than the first rotation speed by the rotation drive section, causes the temperature of the substrate to be maintained at the second temperature by supplying the heated fluid to the second surface of the substrate by the heated fluid supply section, and processes the first surface of the substrate by the chemical liquid by supplying a chemical liquid at normal temperature to the first surface of the substrate by the chemical liquid supply section.

11. The substrate processing apparatus according to claim 10, wherein the heated fluid supply section further comprises: a heated fluid nozzle that ejects the heated fluid toward the second surface of the substrate held by the substrate holding section; a heated fluid line that has an upstream end connected to a heated fluid supply source and a downstream end connected to the heated fluid nozzle; and a low-temperature fluid line that has an upstream end connected to a low-temperature fluid supply source and a downstream end connected to the heated fluid line, the low-temperature fluid line supplying a low-temperature fluid having a temperature lower than that of the heated fluid to the heated fluid line, ​ ​ The control section adjusts the temperature of the fluid discharged from the heated fluid nozzle by adjusting the mixing ratio of the low-temperature fluid relative to the heated fluid.

12. The substrate processing apparatus according to claim 11, wherein provided with: an exhaust line that branches from the heated fluid line at a branch point on the downstream side of a position at which the low-temperature fluid and the heated fluid line join; a temperature sensor provided on the exhaust line; a first on-off valve that opens and closes the exhaust line; and a second on-off valve provided on the heated fluid line on the downstream side of the branch point, the control section opens the first on-off valve to flow the heated fluid from the exhaust line in a state in which the second on-off valve is closed until the temperature detected by the temperature sensor reaches a predetermined value, and closes the first on-off valve and opens the second on-off valve to discharge the heated fluid from the heated fluid nozzle after the temperature detected by the temperature sensor reaches the predetermined value.

13. The substrate processing apparatus according to claim 12, wherein the control section controls the mixing ratio of the low-temperature fluid relative to the heated fluid based on the temperature detected by the temperature sensor when the first on-off valve is opened to flow the heated fluid from the exhaust line in a state in which the second on-off valve is closed. ​

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