JP2004172573A - Processing apparatus for substrate and processing method for substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing technique capable of reducing the processing time while minimizing the amount of etching for the substrate surface. <P>SOLUTION: A cleaning process for the substrate is taken place by feeding an alkaline processing liquid with an ultrasonic vibration and subsequently feeding an acidic processing liquid to the surface of the rotating substrate. Contaminative particles on the substrate are released from the substrate surface by the ultrasonic vibration of the alkaline processing liquid, and since the electric potentials of the contaminative particles and that of the substrate surface are of the same polarity in the alkaline processing liquid, re-adhesion of the once released contaminative particles is prevented. Therefore, the contaminative particles are efficiently removed. Since metallic contaminants on the substrate surface are changed to hydroxides by the alkaline processing liquid, they are removed by being rapidly dissolved by the subsequent acidic processing liquid. Therefore the processing time is reduced. With this method, the amount of etching for the substrate is minimized, since the metallic contaminants are removed by the acidic processing liquid of weak etching power. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a substrate processing technique for cleaning a surface of a semiconductor substrate or the like (hereinafter, simply referred to as “substrate”).

  In the substrate manufacturing process, particulate foreign substances (hereinafter referred to as “contaminated particles”) and various metal contaminants (hereinafter referred to as “metal contaminants”) adhere to the surface of the substrate. Therefore, it is necessary to clean the surface of the substrate at an appropriate stage. As a method of cleaning a substrate, a batch type method in which a large number of substrates are immersed in a cleaning liquid at a time and a processing method, and a single-wafer method in which a substrate is rotated one by one and a cleaning liquid is supplied to a substrate surface to be processed. There is a method.

  Single wafer processing equipment has many advantages over batch processing equipment in process performance, such as processing uniformity, particle reduction, and prevention of transfer of metal contaminants from other substrates. ing. Therefore, in recent years, a single-wafer-type substrate processing apparatus is becoming mainstream. However, in such a single-wafer-type substrate processing apparatus, since substrates are processed one by one, it is necessary to perform processing in a shorter time than a batch-type substrate processing apparatus from the viewpoint of productivity.

  As an attempt to reduce the processing time in a single-wafer-type substrate processing apparatus, for example, Japanese Patent Application Laid-Open No. Hei 10-256211 discloses a method using ozone water and dilute hydrofluoric acid as a cleaning liquid. According to this prior art, particles and metal contamination on the substrate surface are removed by a process including a treatment for about 15 seconds with ozone water and a treatment for about 20 seconds with dilute hydrofluoric acid, thereby shortening the cleaning process. I have.

JP-A-10-256211

  As described above, the single-wafer-type substrate processing apparatus has a problem that the cleaning processing time must be shortened.

  In addition, even when the method disclosed in Japanese Patent Application Laid-Open No. H10-256211 is used, the etching amount on the substrate surface is reduced by using the etching power of hydrofluoric acid to remove contaminant particles and metal contaminants. There is another problem that the number increases (for example, the etching thickness is 2.0 nm).

  In view of the foregoing, an object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of reducing a processing time while minimizing an etching amount on a substrate surface.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a substrate processing method, wherein a substrate to be processed is rotated while supplying an alkaline processing liquid to which ultrasonic vibration is applied to the substrate. And a second step of supplying the acidic processing liquid to the substrate while rotating the substrate after the first step.

  The invention according to claim 2 is the substrate processing method according to claim 1, wherein the first step supplies an alkaline processing liquid having ultrasonic vibration applied to a front surface of the substrate. Supplying an alkaline processing liquid to the back surface of the substrate; and supplying the acidic processing liquid to the front surface and the back surface of the substrate. And

  The invention according to claim 3 is the substrate processing method according to claim 1 or 2, wherein the alkaline processing liquid is diluted aqueous ammonia.

  The invention according to claim 4 is the substrate processing method according to claim 1 or 2, wherein the alkaline processing liquid is a mixed solution containing aqueous ammonia and aqueous hydrogen peroxide. .

  The invention according to claim 5 is the substrate processing method according to any one of claims 1 to 4, wherein the acidic processing liquid is dilute hydrochloric acid.

  The invention according to claim 6 is the substrate processing method according to any one of claims 1 to 4, wherein the acidic processing liquid is a mixed solution containing hydrochloric acid and hydrofluoric acid. I do.

  The invention according to claim 7 is the substrate processing method according to any one of claims 1 to 6, wherein the alkaline processing liquid and the acidic processing liquid are both liquids at room temperature. I do.

  An invention according to claim 8 is a substrate processing apparatus for performing a predetermined process while rotating a substrate to be processed in a horizontal plane, wherein the rotating means rotates the substrate about an axis along a substantially vertical direction. First supply means for supplying an alkaline processing liquid having ultrasonic vibration applied to the front surface of the substrate, and second supply means for supplying an acidic processing liquid to the front surface of the substrate And the following.

  The invention according to claim 9 is the substrate processing apparatus according to claim 8, wherein a third supply means for supplying an alkaline processing liquid to the back surface of the substrate, and an acid supply to the back surface of the substrate. And a fourth supply unit for supplying a processing liquid.

  The invention according to claim 10 is the substrate processing apparatus according to claim 8 or 9, wherein the alkaline processing liquid is diluted aqueous ammonia.

  The invention according to claim 11 is the substrate processing apparatus according to claim 8 or 9, wherein the alkaline processing liquid is a mixed solution containing ammonia water and hydrogen peroxide water. .

  A twelfth aspect of the present invention is the substrate processing apparatus according to any one of the eighth to eleventh aspects, wherein the acidic processing liquid is diluted hydrochloric acid.

  The invention according to claim 13 is the substrate processing apparatus according to any one of claims 8 to 11, wherein the acidic processing liquid is a mixed solution containing hydrochloric acid and hydrofluoric acid. I do.

  The invention according to claim 14 is the substrate processing apparatus according to any one of claims 8 to 13, wherein the alkaline processing liquid and the acidic processing liquid are both liquids at room temperature. I do.

  According to the first to fourteenth aspects of the present invention, since the alkaline treatment liquid to which ultrasonic vibration is applied is supplied to the substrate, contaminant particles attached to the substrate surface can be released from the substrate surface by ultrasonic vibration. it can. Further, once released contaminant particles are prevented from re-adhering due to repulsion of zeta potential with the substrate surface in the alkaline processing liquid, they can be efficiently removed and the processing time can be shortened. In addition, the metal contaminants attached to the substrate surface are changed to hydroxides by the supply of the alkaline processing liquid, and can be quickly dissolved and removed by the acidic processing liquid, so that the processing time can be reduced. In addition, this method makes it possible to effectively remove metal contaminants even with an acidic treatment liquid having a weak etching power, and thus it is possible to minimize the amount of etching on the substrate surface.

  In particular, according to the second or ninth aspect of the present invention, it is possible to remove contaminant particles and metal contaminants attached to the back surface of the substrate. At this time, since the ultrasonic vibration of the alkaline processing liquid supplied to the front surface of the substrate propagates to the back surface of the substrate, contaminant particles attached to the back surface of the substrate can also be released by the ultrasonic vibration. , A high removal effect can be obtained.

  In particular, according to the fifth or twelfth aspect of the present invention, by using dilute hydrochloric acid as the acidic treatment liquid, the amount of etching of the substrate surface can be reduced.

  In particular, according to the invention described in claim 7 or claim 14, by performing the treatment at room temperature, compared with the case of performing the treatment at a high temperature, the amount of etching of the substrate by an alkaline treatment solution or an acidic treatment solution, It can be significantly reduced. In addition, since time and equipment required for temperature adjustment before and after processing are not required, processing time can be reduced and cost can be reduced.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In this specification, the “front surface” of the substrate refers to an outer surface with respect to the inside of the substrate, and the front and back surfaces of the substrate are referred to as “front surface” and “back surface”, respectively.

<Main Configuration of Substrate Processing Apparatus 1>
FIG. 1 is a longitudinal sectional view showing a configuration of a substrate processing apparatus 1 according to the present invention. The substrate processing apparatus 1 is a single-wafer-type substrate processing apparatus that performs a cleaning process on a substrate W that is a semiconductor wafer (more specifically, a silicon wafer). The substrate processing apparatus 1 mainly includes a spin base 10 that rotates while holding the substrate W, an alkaline processing liquid nozzle 68 that supplies an alkaline processing liquid to which ultrasonic vibration is applied to the substrate W held on the spin base 10, An acid processing liquid nozzle 78 for supplying an acid processing liquid to the substrate W held on the spin base 10, a pure water nozzle 36 for supplying pure water to the substrate W held on the spin base, and post-use processing. A receiving member 26 that constitutes a drainage tank or the like for discarding or recovering a liquid (alkaline processing liquid, acidic processing liquid, pure water, etc.), and a processing liquid shaken off from a rotating substrate W held on the spin base 10 And a control unit 90 for controlling the operation of the entire apparatus.

  FIG. 2 is a schematic diagram illustrating a configuration of piping and the like attached to the substrate processing apparatus 1. Hereinafter, the configuration of the substrate processing apparatus 1 will be described with reference to FIGS. 1 and 2.

  First, the configuration around the spin base 10 will be described.

  The spin base 10 is a disk-shaped member having an opening at the center, and a plurality of chuck pins 14 for holding a peripheral portion of the circular substrate W are provided upright on an upper surface thereof. At least three (for example, six) chuck pins 14 may be provided in order to securely hold the circular substrate W, and the chuck pins 14 are provided at equal angular intervals (for example, at 60 ° intervals) along the periphery of the spin base 10. It is arranged in. Each of the chuck pins 14 includes a substrate supporting portion 14a that supports a peripheral portion of the substrate W from below, a substrate holding portion 14b that presses an outer peripheral end surface of the substrate W supported by the substrate supporting portion 14a to hold the substrate W, It has. Each of the chuck pins 14 is configured to be switchable between a pressing state in which the substrate holding unit 14b presses the outer peripheral end surface of the substrate W and an open state in which the substrate holding unit 14b is separated from the outer peripheral end surface of the substrate W. The switching between the pressed state and the released state of the plurality of chuck pins 14 can be realized by various known mechanisms. For example, a link mechanism disclosed in Japanese Patent Publication No. 3-9607 may be used. .

  When the substrate W is transferred to the spin base 10, the plurality of chuck pins 14 are released, and when various processes are performed on the substrate W, the plurality of chuck pins 14 are pressed. By being in the pressed state, the plurality of chuck pins 14 can grip the peripheral portion of the substrate W and hold the substrate W in a substantially horizontal posture at a predetermined interval from the spin base 10. The substrate W is held with its front surface (surface on which an electronic circuit pattern is formed) WS1 facing the upper surface and the back surface WS2 facing the lower surface.

  On the lower surface side of the center of the spin base 10, a rotating shaft 11 is vertically provided. The rotating shaft 11 is a hollow cylindrical member, and a back surface treatment liquid nozzle 15 is inserted into a hollow portion inside the rotating shaft 11. An electric motor 20 is interlockingly connected to a lower end of the rotating shaft 11 via a belt driving mechanism 21. That is, the belt 21c is wound around the driven pulley 21a fixedly provided on the outer periphery of the rotating shaft 11 and the driven pulley 21b connected to the rotating shaft of the electric motor 20. By driving the electric motor 20, the driving force is transmitted to the rotating shaft 11 via the belt driving mechanism 21, and the substrate W held by the chuck pins 14 together with the rotating shaft 11 and the spin base 10 is vertically moved in a horizontal plane. It can be rotated about a rotation axis J along the direction.

  The rotating shaft 11, the belt driving mechanism 21, the electric motor 20, and the like are accommodated in a covered cylindrical casing 25 provided on the base member 24.

  The back surface processing liquid nozzle 15 penetrates the rotating shaft 11, and the tip 15 a thereof is located immediately below the center of the substrate W held on the spin base 10. The base end 15b of the back surface processing liquid nozzle 15 is connected to the processing liquid piping 16 shown in FIG. The base end of the processing liquid pipe 16 is branched into three pipes, one of which is connected to an alkaline processing liquid supply source 17a, and the other is connected to another branch pipe 16b. A source 17b is connected in communication, and a further branch pipe 16c is connected in communication with a pure water supply source 17c. The branch pipes 16a, 16b, and 16c are provided with valves 12a, 12b, and 12c, respectively. By switching the opening and closing of the valves 12a, 12b, and 12c, the spinning from the front end 15a of the back surface processing liquid nozzle 15 is performed. An alkaline processing liquid (here, diluted ammonia water), an acidic processing liquid (here, diluted hydrochloric acid), and pure water are selectively switched and discharged near the center of the back surface WS2 of the substrate W held on the base 10. And can be supplied. That is, diluted ammonia water is obtained by closing the valves 12b and 12c and opening the valve 12a, diluted hydrochloric acid by closing the valves 12a and 12c and opening the valve 12b, and valve 12c by closing the valves 12a and 12b. , The pure water can be supplied from the back surface treatment liquid nozzle 15.

  A gap between the inner wall of the hollow portion of the rotating shaft 11 and the outer wall of the back surface treatment liquid nozzle 15 is a gas supply path 19. The distal end portion 19a of the gas supply path 19 has an annular opening, and is directed toward the center of the back surface WS2 of the substrate W held on the spin base 10. The base end 19 b of the gas supply path 19 is connected to the gas pipe 22. The gas pipe 22 is connected to an inert gas supply source 23, and the valve 13 is provided in the gas pipe 22 in the middle of the path. By opening the valve 13, an inert gas (here, nitrogen gas) can be supplied from the front end 19 a of the gas supply path 19 toward the center of the back surface WS <b> 2 of the substrate W held on the spin base 10. it can.

  Next, the configuration around the alkaline processing liquid nozzle 68 will be described.

  An alkaline processing liquid nozzle 68 is disposed above the substrate W held on the spin base 10 so that diluted ammonia water can be supplied to the front surface WS1 of the substrate W. The alkaline processing liquid nozzle 68 is connected to a nozzle moving mechanism 65 via a link member 66 bent in a convex shape. The nozzle moving mechanism 65 includes an electric motor 65a having a rotation axis extending in the vertical direction, and can rotate the link member 66 and the alkaline processing liquid nozzle 68 connected to the link member 66 around the rotation axis. it can. As a result, the alkaline processing liquid nozzle 68 moves between the facing position facing the front surface WS1 of the substrate W held by the spin base 10 and the retracted position retracted laterally from the facing position to the outside of the splash guard 50. It can move between them by a rotational movement. Also at the facing position, the alkaline processing liquid nozzle 68 can face each part from the center of the front surface WS1 of the substrate W held by the spin base 10 to the peripheral part. Further, the nozzle moving mechanism 65 is connected to a nozzle elevating mechanism 69 so that the alkaline processing liquid nozzle 68 can be moved up and down together with the nozzle moving mechanism 65. Accordingly, the alkaline processing liquid nozzle 68 can be moved between the retreat position and the opposing position, avoiding the splash guard 50.

  FIG. 3A is a perspective view of the alkaline processing liquid nozzle 68, and FIG. 3B is a longitudinal sectional view of the alkaline processing liquid nozzle 68 including the pipe 37a. As shown in these figures, the alkaline processing liquid nozzle 68 has a closed cylindrical discharge part 68b having a V-shaped lower half section and a discharge port 68a formed at the lower end surface, and a discharge part 68b. An ultrasonic vibrator 68d fixedly provided at one end of a through hole 68c formed in the upper wall surface. The ejection portion 68b is formed of a chemical-resistant material such as a fluororesin. A thin plate of quartz or high-purity SiC (silicon carbide) is attached to the surface of the ultrasonic transducer 68d. A cable 67 is electrically connected to the ultrasonic transducer 68d, and the cable 67 is electrically connected to a high-frequency oscillator (not shown). Ultrasonic waves can be emitted from the ultrasonic vibrator 68d toward dilute ammonia water filled in the discharge section 68b, and ultrasonic vibration can be applied to the dilute ammonia water discharged from the discharge port 68a. it can. A liquid inlet 70 is formed on the side wall surface of the discharge portion 68b, and the liquid inlet 70 is connected to a pipe 37a. As shown in FIG. 2, the pipe 37a is connected to the alkaline processing liquid supply source 17a via a valve 18a. That is, by opening the valve 18a, diluted ammonia water is supplied into the discharge portion 68b of the alkaline processing liquid nozzle 68, and the diluted ammonia water to which ultrasonic vibration has been applied by the ultrasonic vibrator 68d is discharged from the discharge port 68a to the substrate W. It can be discharged toward the front surface WS1.

  Subsequently, a configuration around the acidic processing liquid nozzle 78 will be described.

  An acidic processing liquid nozzle 78 is arranged above the substrate W held on the spin base 10 so that diluted hydrochloric acid can be supplied to the front surface WS1 of the substrate W. The acidic processing liquid nozzle 78 is connected to the nozzle moving mechanism 75 via a link member 76 bent in a convex shape. The nozzle moving mechanism 75 includes an electric motor 75a having a rotation axis extending in the vertical direction, and can rotate the link member 76 and the acid treatment liquid nozzle 78 connected to the link member 76 around the rotation axis. it can. As a result, the acidic processing liquid nozzle 78 moves between the facing position facing the front surface WS1 of the substrate W held on the spin base 10 and the retracted position retracted to the outside of the splash guard 50 to the side of the facing position. You can move between. Also at the facing position, the acidic processing liquid nozzle 78 can face each part from the center of the front surface WS1 of the substrate W held on the spin base 10 to the peripheral part. Further, the nozzle moving mechanism 75 is connected to a nozzle elevating mechanism 79, and is configured to move up and down the acidic processing liquid nozzle 78 together with the nozzle moving mechanism 75. Accordingly, the acidic processing liquid nozzle 78 can be moved between the retreat position and the opposing position, avoiding the splash guard 50.

  A pipe 37b is connected to the acidic processing liquid nozzle 78. As shown in FIG. 2, the pipe 37b is connected to the acidic processing liquid supply source 17b via a valve 18b. That is, by opening the valve 18b, the diluted hydrochloric acid can be discharged from the acidic processing liquid nozzle 78 toward the front surface WS1 of the substrate W.

  Subsequently, a configuration around the pure water nozzle 36 will be described.

  Above the substrate W held on the spin base 10, a disk-shaped atmosphere shielding plate 30, an annular rotating shaft 35 vertically suspended at the center of the upper surface of the atmosphere shielding plate 30, and an inside of the rotating shaft 35. The inserted pure water nozzle 36 is arranged so as to be able to ascend and descend integrally.

  An opening substantially equal to the inner diameter of the rotating shaft 35 is provided at the center of the atmosphere shielding plate 30, and a pure water nozzle 36 is inserted into a hollow portion inside the rotating shaft 35. The pure water nozzle 36 penetrates the rotation shaft 35, and the tip 36 a is located immediately above the center of the substrate W held on the spin base 10. A base end portion 36b of the pure water nozzle 36 is connected to a pure water pipe 37c, and as shown in FIG. 2, the pure water pipe 37c is connected to a pure water supply source 17c via a valve 18c. By opening the valve 18c, pure water can be supplied from the distal end portion 36a of the pure water nozzle 36 toward the center of the front surface WS1 of the substrate W held by the chuck pins.

  The gap between the inner wall of the hollow portion of the rotating shaft 35 and the inner wall of the opening at the center of the atmosphere shielding plate 30 and the outer wall of the pure water nozzle 36 is a gas supply passage 45. The distal end portion 45a of the gas supply passage 45 has an annular opening, and is directed toward the center of the front surface WS1 of the substrate W held on the spin base 10. The base end 45 b of the gas supply passage 45 is connected to the gas pipe 46. As shown in FIG. 2, the gas pipe 46 is connected to the inert gas supply source 23, and a valve 47 is provided in the middle of the gas pipe 46. By opening the valve 47, the nitrogen gas can be supplied from the front end portion 45a of the gas supply path 45 toward the center of the front surface WS1 of the substrate W held by the chuck pins.

  The rotation shaft 35 is rotatably supported by the support arm 40 via a bearing, and is connected to an electric motor 42 attached to the support arm 40 via a belt drive mechanism 41. That is, the belt 41c is wound around the driven pulley 41a fixedly provided on the outer periphery of the rotating shaft 35 and the driven pulley 41b connected to the rotating shaft of the electric motor 42. By driving the electric motor 42, the driving force is transmitted to the rotating shaft 35 via the belt driving mechanism 41, and the rotating shaft 35 and the atmosphere shielding plate 30 are centered on the rotating shaft J along the vertical direction in the horizontal plane. Can be rotated as The atmosphere blocking plate 30 rotates at substantially the same rotation speed as the substrate W. The belt drive mechanism 41 is housed in the support arm 40.

  Further, the support arm 40 is connected to an arm elevating mechanism 49, and is capable of elevating. Various known mechanisms such as a feed screw mechanism using a ball screw and a mechanism using an air cylinder can be used as the arm lifting mechanism. The arm lifting / lowering mechanism 49 can raise / lower the support arm to raise / lower the rotating shaft 35 and the atmosphere shielding plate 30 connected thereto, and move the atmosphere shielding plate 30 to the substrate W held on the spin base. It can be moved between a position close to the front surface WS1 and a position separated and retreated above the substrate W. In FIG. 1, the atmosphere shielding plate 30 is in a retracted position.

  Subsequently, a configuration around the receiving member 26 will be described.

  A receiving member 26 is fixedly mounted around the casing 25 on the base member 24. On the receiving member 26, cylindrical partition members 27a and 27b are erected. A first drainage tank 28 is formed using the casing 25 and the partition member 27a as side walls, and a second drainage tank 29 is formed using the partition member 27a and the partition member 27b as side walls. A V-groove is formed at the bottom of the first drain tank 28, and a discharge port 28a connected to the waste drain 28b is provided at a part of the center of the V-groove. The used pure water and gas are discharged from the discharge port 28a of the first drainage tank 28 to the waste drain 28b, and after gas-liquid separation, can be disposed according to predetermined procedures. On the other hand, a V-groove is formed at the bottom of the second drain tank 29, and a discharge port 29a connected to the recovery drain 29b is provided at a part of the center of the V-groove. The used chemical solution is discharged from a discharge port 29a of the second drainage tank 29 to a recovery drain 29b, and once collected in a recovery tank (not shown), and then supplied to an alkaline processing liquid supply source 17a or an acidic processing liquid supply source 17b. By doing so, the chemical solution can be circulated and reused.

  Subsequently, a configuration around the splash guard 50 will be described.

  A cylindrical splash guard 50 is arranged so as to surround the spin base 10 and the substrate W held by the spin base. A first guide portion 51 is formed in the upper portion of the inner surface of the splash guard 50 and has a groove-shaped cross section and opens inward. Further, a second guide portion 52 having a quarter-arc cross section opened inward and downward is formed in a lower portion of the splash guard 50, and an annular groove 53 is formed inside the second guide portion 52. . The splash guard 50 is connected to a guard elevating mechanism 55 via a link member 56, and is movable up and down by the guard elevating mechanism 55. As the guard elevating mechanism 55, various known mechanisms such as a feed screw mechanism using a ball screw and a mechanism using an air cylinder can be adopted.

  When the guard elevating mechanism 55 lowers the splash guard 50, the partition member 27a is loosely fitted in the groove 53, and the first guide portion 51 is positioned around the spin base 10 and the substrate W held thereon. This state is a state of a rinsing process and a spin drying described later, and the pure water scattered from the rotating substrate W or the like is received by the first guide portion 51 and flows into the first drainage tank 28 along the inclination thereof. The discharge port 28a can be discharged to the waste drain 28b.

  On the other hand, when the guard elevating mechanism 55 raises the splash guard 50, the partition member 27a is separated from the groove 53, and the second guide portion 52 is positioned around the spin base 10 and the substrate W held thereon. (The state shown in FIG. 1). This state is a state at the time of the cleaning processing using the alkaline processing liquid or the acidic processing liquid, and the alkaline processing liquid or the acidic processing liquid scattered from the rotating substrate W is received by the second guide portion 52, and the second processing is performed along the curved surface. 2 The liquid can be poured into the drainage tank 29 and discharged from the discharge port 29a to the collection drain 29b.

  Further, the substrate processing apparatus 1 includes a control unit 90 in addition to the above-described configuration, and controls the electric motors 20 and 42, the arm elevating mechanism 49, the guard elevating mechanism 55, the nozzle moving mechanisms 65 and 75, the nozzle elevating mechanisms 69 and 79, and the valve. The operation of 12a, 12b, 12c, 13, 18a, 18b, 18c, 47, and the like can be controlled by the control unit 90.

<Cleaning procedure in substrate processing apparatus 1>
Hereinafter, a procedure for cleaning the substrate W using the substrate processing apparatus 1 will be described. FIG. 4 is a flowchart illustrating the operation of the substrate processing in the substrate processing apparatus 1. As shown in FIG. 4, the cleaning process of the substrate W in the substrate processing apparatus 1 includes loading of the substrate W (Step S1), supply of an alkaline processing liquid to which ultrasonic vibration is applied (Step S2), and supply of an acidic processing liquid. (Step S3), a rinsing process (Step S4), spin drying (Step S5), and unloading of the substrate W (Step S6).

  In step S <b> 1, the splash guard 50 is first moved up and down by the guard elevating mechanism 55 so that the upper end of the splash guard 50 is at the same height or slightly lower than the spin base 10. Further, the alkaline processing liquid nozzle 68, the acidic processing liquid nozzle 78, and the atmosphere blocking plate 30 are moved to the retreat position. In this state, the substrate W before the cleaning process is carried onto the spin base 10 by a transfer robot (not shown), and the peripheral edge of the substrate W is gripped by changing the plurality of chuck pins 14 from the released state to the pressed state. Thereby, the substrate W is held in a horizontal posture.

  In step S2, the splash guard 50 is raised by the guard lifting mechanism 55, and the position is adjusted so that the second guide 52 surrounds the spin base 10 and the substrate W held thereon. Further, the nozzle moving mechanism 65 and the nozzle elevating mechanism 69 are also driven to move the alkaline processing liquid nozzle 68 to a position facing the substrate W. Then, by driving the electric motor 20 and the belt driving mechanism 21, the rotation of the substrate W together with the spin base 10 is started. In this state, the dilute ammonia water to which ultrasonic vibration is applied is directed from the alkaline processing liquid nozzle 68 toward the front surface WS1 of the substrate W, and the dilute ammonia water is discharged from the back surface processing liquid nozzle 15 to the back surface of the substrate W. Each is discharged toward WS2. FIG. 5A is an operation state diagram schematically showing the state of the supply of the diluted ammonia water in step S2 only in the vicinity of the substrate W.

  FIG. 6 is a schematic plan view for explaining the movement of the alkaline processing liquid nozzle 68 with respect to the substrate W held on the spin base 10. The alkaline processing liquid nozzle 68 reciprocates between the peripheral edges N1 and N2 of the substrate W on an arc trajectory (two-dot chain line in FIG. 6) centering on the rotation axis of the nozzle moving mechanism 65 and passing through the rotation axis J of the substrate W. Scan. By discharging the dilute aqueous ammonia toward the front surface WS1 of the rotating substrate W while performing such an arc-shaped scan, the dilute aqueous ammonia is supplied to the entire front surface WS1 of the substrate W. However, the entire front surface WS1 of the substrate W can be uniformly processed. The dashed line in FIG. 6 indicates the movement locus of the acidic processing liquid nozzle 78 described later.

  Further, the dilute ammonia water discharged from the back surface treatment liquid nozzle to the vicinity of the center of the back surface WS2 of the substrate W diffuses outward due to centrifugal force accompanying rotation, and as shown in FIG. It is supplied over the entire back surface WS2.

  Here, since the ultrasonic vibration is applied to the diluted ammonia water discharged from the alkaline processing liquid nozzle 68, the shock of the ultrasonic vibration promotes the release of the contaminant particles attached to the surface of the substrate W. Further, the back surface treatment liquid nozzle does not have a function of imparting ultrasonic vibration, but the ultrasonic vibration of the diluted ammonia water supplied to the front surface WS1 of the substrate W causes the inside of the substrate W to move in the thickness direction. To the back surface WS2, thereby promoting the release of the contaminant particles attached to the back surface WS2 of the substrate W. On the other hand, the potential (zeta potential) of the main contaminant particles such as PSL (polystyrene latex), SiN, SiO, and Si is negatively (-) in an alkaline aqueous solution, and the surface of the substrate (silicon wafer) W The zeta potential is also negatively charged (−) when in contact with an alkaline aqueous solution. In this case, since the zeta potential on the surface of the substrate W and the surface of the contaminated particles have the same polarity, a repulsive force is generated between the substrate W and the contaminated particles. Therefore, on the surface of the substrate W, the contaminant particles once released from the surface of the substrate W by the ultrasonic vibration of the dilute ammonia water are prevented from re-adhering due to the repulsive force of the zeta potential, and the contaminant particles are efficiently removed.

  In step S2, a metal contaminant such as Fe or Cu attached to the substrate surface is converted into a hydroxide by supplying diluted ammonia water. This makes it possible to easily dissolve metal contaminants in step S3 described below.

  The dilute ammonia water supplied to the surface of the substrate W is shaken off to the side of the substrate W by the centrifugal force due to the rotation of the substrate W, as shown by the arrow in FIG. It is received by the unit 52. Then, the diluted ammonia water flows down into the second drain tank 29 and is discharged from the discharge port 29a to the recovery drain 29b. The dilute ammonia water discharged to the recovery drain 29b is recovered in a recovery tank (not shown), and then supplied again to the alkaline processing liquid supply source 17a to be recycled.

  After supplying the dilute aqueous ammonia for a predetermined time, the supply of the dilute aqueous ammonia from the alkaline processing liquid nozzle 68 and the back surface processing liquid nozzle 15 is stopped.

  In step S3, first, by driving the nozzle moving mechanisms 65 and 75, the nozzle elevating mechanisms 69 and 79, the guard elevating mechanism 55, and the like, the alkaline processing liquid nozzle 68 is moved to the retracted position, and the acidic processing liquid nozzle 78 is replaced. Each is moved to the opposing position. Then, the acidic treatment liquid nozzle 78 is directed toward the front surface WS1 of the substrate W rotating the dilute hydrochloric acid, and the back surface treatment liquid nozzle 15 is directed toward the back surface WS2 of the substrate W rotating the diluted hydrochloric acid. , Respectively. FIG. 5B is an operation state diagram schematically showing the state of the supply of the dilute hydrochloric acid in step S3 only in the vicinity of the substrate W.

  The acidic processing liquid nozzle 78 reciprocates between the peripheral edges N3 and N4 of the substrate W on an arc trajectory (dashed line in FIG. 6) passing the rotation axis J of the substrate W around the rotation axis of the nozzle moving mechanism 75. I do. By discharging the dilute hydrochloric acid toward the front surface WS1 of the rotating substrate W while performing such an arc-shaped scan, the dilute hydrochloric acid is supplied to the entire front surface WS1 of the substrate W, and the substrate W The entire front surface WS1 can be uniformly processed.

  Further, the diluted hydrochloric acid discharged from the back surface treatment liquid nozzle to the vicinity of the center of the back surface WS2 of the substrate W diffuses outward due to centrifugal force accompanying rotation, and as shown in FIG. It will be supplied over the entire surface of WS2.

  The dilute hydrochloric acid supplied to the surface of the substrate W dissolves (ionizes) metal contaminants adhering to the surface of the substrate W and is removed. Here, since the metal contaminants adhering to the surface of the substrate W have been converted into hydroxides in advance in step S2, the dissolution with dilute hydrochloric acid in step S3 can be performed more quickly.

  In step S3, the diluted hydrochloric acid supplied to the surface of the substrate W is shaken off to the side of the substrate W by the centrifugal force due to the rotation of the substrate W, as indicated by the arrow in FIG. It is received by the second guide section 52. Then, the diluted hydrochloric acid flows down into the second drain tank 29 and is discharged from the discharge port 29a to the recovery drain 29b. The dilute hydrochloric acid discharged to the recovery drain 29b is recovered in a recovery tank (not shown), and then supplied again to the acid processing liquid supply source 17b to be circulated and reused.

  After the diluted hydrochloric acid is supplied for a predetermined time, the supply of the diluted hydrochloric acid from the acidic processing liquid nozzle 78 and the back surface processing liquid nozzle 15 is stopped.

  In step S4, first, the acidic processing liquid nozzle 78 is moved to the retreat position by driving the nozzle moving mechanism 75, the nozzle elevating mechanism 79, and the guard elevating mechanism 55. Thereafter, the splash guard 50 is moved by the guard elevating mechanism 55, and the position is adjusted so that the first guide portion 51 surrounds the spin base 10 and the substrate W held thereon. Further, the arm elevating mechanism 49 is driven to lower the atmosphere blocking plate 30 to a position close to the front surface WS1 of the substrate W held on the spin base 10. Then, the electric motor 42 and the belt driving mechanism 41 are driven to rotate the atmosphere blocking plate 30 together with the rotating shaft 35, and the nitrogen gas is discharged from the gas supply path 45 toward the front surface WS1 of the substrate W. On the other hand, nitrogen gas is discharged from the gas supply path 19 toward the back surface WS2 of the substrate W. Thereby, the space between the atmosphere blocking plate 30 and the substrate W and the space between the spin base 10 and the substrate W are each made to have a low oxygen partial pressure. In this state, from the pure water nozzle 36 toward the front surface WS1 of the substrate W rotating the pure water, and from the back surface treatment liquid nozzle 15, the back surface WS2 of the substrate W rotating the pure water is rotating. Then, a rinsing process is performed to discharge dilute hydrochloric acid and the like remaining on the surface of the substrate W, respectively. FIG. 5C is an operation state diagram schematically showing the state of pure water supply in step S4 only in the vicinity of the substrate W.

  In step S4, the pure water supplied to the surface of the substrate W is shaken off to the side of the substrate W by the centrifugal force due to the rotation of the substrate W, as indicated by an arrow in FIG. It is received by the first guide section 51. Then, the pure water flows down into the first drain tank 28, is discharged from the discharge port 28a to the waste drain 28b, and is discarded.

  After supplying pure water for a predetermined time, supply of pure water from the pure water nozzle 36 and the back surface treatment liquid nozzle 15 is stopped.

  In step S5, after the supply of the pure water in step S4 is completed, the supply of the nitrogen gas from the gas supply passages 45 and 19 and the rotation of the substrate W are continued, and the water attached to the surface of the substrate W is shaken off to dry the substrate W. (Spin drying).

  Here, by performing the spin drying while discharging the nitrogen gas from the gas supply passages 45 and 19, an effect of increasing the drying efficiency of the front surface WS1 and the back surface WS2 of the substrate W can be obtained. Further, the space between the atmosphere blocking plate 30 and the substrate W and the space between the spin base 10 and the substrate W are made to have a low oxygen partial pressure, respectively, so that the front surface WS1 and the back surface of the substrate W are formed. The effect of suppressing generation of a watermark in WS2 can be obtained.

  When the drying of the surface of the substrate W is completed, the supply of the nitrogen gas from the gas supply paths 45 and 19 is stopped. By stopping the electric motor 20, the rotation of the substrate W is also stopped.

  In step S6, the arm elevating mechanism is driven to raise the atmosphere blocking plate 30 to a position largely separated from the front surface WS1 of the substrate W held on the spin base 10, and to retract the same. In addition, by driving the guard elevating mechanism 55, the upper end of the splash guard 50 is set at the same height or slightly lower than the spin base 10. In this state, the plurality of chuck pins 14 gripping the peripheral portion of the substrate W are released from the pressed state, and the substrate W is carried out from the spin base 10 to the outside of the apparatus by a transfer robot (not shown). The cleaning process of the substrate W ends.

  In the above series of processes, the temperature of the diluted ammonia water and the diluted hydrochloric acid can be performed at normal temperature (20 to 30 ° C.). If the room temperature is kept at room temperature, the diluted ammonia water and the diluted hydrochloric acid can be used without adjusting the liquid temperature, so that the processing of the substrate W can be easily performed. That is, since the time and equipment required for temperature adjustment before and after the treatment are not required, the treatment time can be reduced and the cost can be reduced. Further, by performing the treatment at room temperature, the amount of etching of the substrate W by the alkaline treatment liquid or the acidic treatment liquid can be significantly reduced as compared with the case of performing the treatment at a high temperature (about 65 ° C.).

<Modification>
In the above-described embodiment, dilute ammonia water has been described as an example of the alkaline processing liquid. However, a mixed solution (SC1) of ammonia water, hydrogen peroxide water, and pure water, or a surfactant added to diluted ammonia water Alternatively, an alkaline treatment liquid or the like may be used. As described above, when the alkaline processing liquid to which the hydrogen peroxide solution or the surfactant is added is used, the effect of protecting the surface of the substrate W to be processed and suppressing the deterioration of the surface roughness can be obtained. . When dilute aqueous ammonia is used, the volume ratio of pure water to aqueous ammonia (28 to 30 wt%, the same applies hereinafter) is preferably set to 5: 0.02 to 0.6 for protecting the surface of the substrate W. When used, in order to maintain alkalinity, it is desirable that the volume ratio of pure water, aqueous ammonia, and aqueous hydrogen peroxide (30 wt%, the same applies hereinafter) be 5: 0.03 to 1: 0.03 to 1.

  Alternatively, an alkaline treatment liquid whose pH value has been increased by adding a strongly alkaline chemical to diluted ammonia water or SC1 may be used. In the above-described embodiment, by supplying an alkaline processing liquid, metal contaminants such as Fe and Cu adhering to the surface of the substrate W are converted into hydroxides, and the subsequent dissolution processing with the acidic processing liquid is promoted. The effect can be obtained, but this effect can be more remarkably obtained by supplying an alkaline treatment liquid having an increased pH value. In other words, as the pH value of the supplied alkaline processing liquid is increased, metal contaminants adhering to the surface of the substrate W can be more efficiently converted into hydroxides, so that the subsequent dissolution by the acidic processing liquid is further promoted. Can be done. The results of the test in Example 3 described below show that the use of an alkaline treatment liquid whose pH value has been increased to 12 improves the effect of removing metal contaminants.

  However, when the pH value is excessively increased, the alkaline processing liquid may obtain an etching force that cannot be ignored for the substrate W. In that case, the etching of the surface of the substrate W by the alkaline processing liquid proceeds inappropriately, which is contrary to the object of the present invention. For this reason, it is desirable to use an alkaline treatment liquid whose pH value is raised within a range that does not provide an etching power of a predetermined value or more. For example, a preferable pH value range is 11 or more and less than 13.

  In addition, in order to obtain a relatively high pH value for an alkaline treatment liquid such as dilute ammonia water or SC1, it is better to add a strongly alkaline chemical solution than to increase the pH value only by adjusting the concentration or the mixing ratio. According to the latter, not only can the pH value of the alkaline processing solution easily reach 11 or more, but also the amount of the chemical solution used is small, so that the production cost increases compared to the former. The burden on the environment is also small.

  As the strong alkaline chemical solution added to increase the pH value of the alkaline treatment liquid, for example, an aqueous solution of TMAH (tetramethylammonium hydroxide) or an aqueous solution of CHOLINE (2-hydroxyethyltrimethylammonium hydroxide) is preferably used. .

  Further, in the above-described embodiment, dilute hydrochloric acid has been described as an example of the acidic treatment liquid, but dilute hydrofluoric acid, dilute sulfuric acid, or a mixed solution of dilute hydrochloric acid and dilute hydrofluoric acid may be used in addition to dilute hydrochloric acid. When using dilute hydrochloric acid, the volume ratio of hydrochloric acid (35 wt%, the same applies hereinafter) and pure water are desirably performed at a ratio of 1: 3 to 15, and when using a mixed solution of dilute hydrochloric acid and dilute hydrofluoric acid, the etching force by hydrofluoric acid is used. It is desirable to carry out the reaction at a volume ratio of hydrofluoric acid (50 wt%, the same applies hereinafter) and dilute hydrochloric acid of 1:50 to 500 in order to suppress the concentration.

  Further, a step of cleaning the surface of the substrate W with pure water may be added between step S2 and step S3. As the nozzle for discharging pure water in this step, for example, an acidic processing liquid nozzle 78 can be used. In this case, as shown in FIG. 7, a pipe 37b connected to the acid processing liquid nozzle 78 is branched into two pipes, and one of the branch pipes 37d is connected to the acid processing liquid supply source 17b via a valve 18d. The other branch pipe 37e is connected to the pure water supply source 17c via the valve 18e. In this way, it is possible to switch the discharge from the acid processing liquid nozzle 78 between the acid processing liquid and pure water by opening and closing the valves 18d and 18e. As a processing procedure, after step S2, the alkaline processing liquid nozzle 68 is moved to the retreat position by driving the nozzle moving mechanisms 65 and 75, the nozzle raising and lowering mechanisms 69 and 79, the guard raising and lowering mechanism 55, and the like. The splash guard 50 is moved to a position where the first guide portion 51 surrounds the spin base 10 and the substrate W held thereby. Then, the acidic processing liquid nozzle 78 directs pure water toward the front surface WS1 of the rotating substrate W, and the back surface processing liquid nozzle 15 outputs pure water from the back surface WS2 of the rotating substrate W. Are ejected toward. After discharging the pure water for a predetermined time, the discharge of the pure water from the acidic processing liquid nozzle 78 and the back surface processing liquid nozzle 15 is stopped. Thereafter, the guard elevating mechanism is driven to move the splash guard 50 to a position where the second guide portion 52 surrounds the spin base 10 and the substrate W held by the spin base 10, and then proceeds to step 3.

  An alkaline treatment liquid was supplied to the substrate W (silicon wafer), and a test was performed on the removal rate of Si particles and SiN particles (contaminant particles) existing on the front surface WS1 of the substrate W before and after the supply of the alkaline treatment liquid.

  In case C11, the above substrate processing apparatus 1 was used, and ultrasonic vibration was applied using diluted ammonia water (ammonia water: pure water = 1: 25 by volume ratio) as an alkaline processing liquid, and then the substrate W was treated. Supply was performed to the front surface WS1 for 20 seconds. The temperature of the dilute aqueous ammonia was normal.

  In Case C12, the above-described substrate processing apparatus 1 was used, and ultrasonic vibration was applied using SC1 (aqueous ammonia: hydrogen peroxide: pure water = 1: 1: 50 by volume) as an alkaline processing liquid. The wafer W was supplied to the front surface WS1 of the substrate W for 20 seconds. The temperature of SC1 was normal temperature.

  In case C13, a processing tank in which SC1 was stored using a batch type substrate processing apparatus and SC1 (aqueous ammonia: hydrogen peroxide: pure water = 1: 1: 50 by volume) as an alkaline processing liquid. The substrate W was immersed therein for 60 seconds. The temperature of SC1 was 60 ° C.

  In case C14, a batch-type substrate processing apparatus was used, and a processing tank in which SC1 was stored using SC1 (a volume ratio of ammonia water: hydrogen peroxide solution: pure water = 1: 1: 50) as an alkaline processing liquid. The substrate W was immersed therein for 600 seconds. The temperature of SC1 was 60 ° C.

  FIG. 8 shows the results of the test according to the first embodiment. In the case C11 and the case C12 according to the present invention, a high removal rate could be obtained in spite of the processing time being one third and the processing temperature being room temperature as compared with the case C13. In addition, in the case C11 and the case C12 according to the present invention, the same removal rate could be obtained in only 1/30 of the processing time, even though the processing temperature was room temperature, as compared with the case C14. .

  Next, a test was performed on the effect of removing Fe and Cu (metal contaminants) present on the front surface WS1 of the substrate W (silicon wafer).

  In case C21, the above-described substrate processing apparatus 1 was used. SC1 (aqueous ammonia: hydrogen peroxide: pure water = 1: 1: 50 in volume ratio) was used as the alkaline treatment liquid, and was supplied to the front surface WS1 of the substrate W for 20 seconds. Dilute hydrochloric acid (hydrochloric acid: pure water = 1: 5 in volume ratio) was used as the acidic treatment liquid, and was supplied to the front surface WS1 of the substrate W for 15 seconds.

  In case C22, the above-described substrate processing apparatus 1 was used. SC1 (aqueous ammonia: hydrogen peroxide: pure water = 1: 1: 50 by volume) was used as the alkaline treatment liquid, and was supplied to the front surface WS1 of the substrate W for 20 seconds. A mixed solution of dilute hydrofluoric acid and dilute hydrochloric acid (hydrofluoric acid: hydrochloric acid: pure water = 1: 20: 200 in volume ratio) was supplied as an acidic treatment liquid to the front surface WS1 of the substrate W for 15 seconds. .

  In case C23, the above-described substrate processing apparatus 1 was used. The supply of the alkaline processing liquid is omitted, and a mixed solution of diluted hydrofluoric acid and dilute hydrochloric acid (hydrofluoric acid: hydrochloric acid: pure water = 1: 20: 200 in volume ratio) is used as the acidic processing liquid, and the front surface of the substrate W is used. Supply was performed to the surface WS1 for 15 seconds.

  FIG. 9 shows the results of the test according to the second embodiment. The case C21 and the case C22 according to the present invention had a lower concentration of the residual metal contaminant after the treatment than the case C23, and were able to obtain an excellent removal effect. That is, by supplying the acidic treatment liquid after supplying the alkaline treatment liquid, the effect of removing metal contaminants could be enhanced.

  In the third embodiment, a comparative test was performed on the effect of removing Fe, Cu, and Ni (metal contaminants) existing on the surface of the substrate W (silicon wafer) when alkaline treatment solutions having different pH values were used. In the third embodiment, in all cases C31, C32, C41, and C42, the above-described substrate processing apparatus 1 was used, and the alkaline processing liquid was supplied to the surface of the substrate W after applying ultrasonic vibration.

  In case C31, SC1 having a pH value of 10.5 (aqueous ammonia: hydrogen peroxide: pure water = 1: 1: 100 in volume ratio) was used as the alkaline treatment liquid, and supplied to the surface of the substrate W for 10 seconds. went. In addition, a mixed solution of diluted hydrofluoric acid and diluted hydrochloric acid (hydrofluoric acid: hydrochloric acid: pure water = 1: 40: 200 in volume ratio) was supplied to the surface of the substrate W for 10 seconds as an acidic treatment liquid.

  In case C32, an alkaline treatment liquid was prepared by adding TMAH (25 wt%, the same applies hereinafter) to SC1 as an alkaline treatment liquid to adjust the pH value to 12 (by volume ratio, TMAH: ammonia water: hydrogen peroxide: pure water = 3). : 1: 1: 100) for 10 seconds to the surface of the substrate W. In addition, a mixed solution of diluted hydrofluoric acid and diluted hydrochloric acid (hydrofluoric acid: hydrochloric acid: pure water = 1: 40: 200 in volume ratio) was supplied to the surface of the substrate W for 10 seconds as an acidic treatment liquid.

  In Case C41, SC1 having a pH value of 10.5 (aqueous ammonia: hydrogen peroxide: pure water = 1: 1: 100 in volume ratio) was used as the alkaline treatment liquid and supplied to the surface of the substrate W for 10 seconds. went. In addition, dilute hydrochloric acid (hydrochloric acid: pure water = 1: 5 in volume ratio) was used as the acidic treatment liquid, and was supplied to the surface of the substrate W for 10 seconds.

  In case C42, an alkaline treatment liquid having a pH value of 12 by adding TMAH to SC1 as an alkaline treatment liquid (TMAH: ammonia water: hydrogen peroxide solution: pure water = 3: 1: 1: 100 by volume ratio) Was supplied to the surface of the substrate W for 10 seconds. In addition, dilute hydrochloric acid (hydrochloric acid: pure water = 1: 5 in volume ratio) was used as the acidic treatment liquid, and was supplied to the surface of the substrate W for 10 seconds.

  The results of the test according to the third embodiment are shown in FIGS. 10 shows the Fe ion concentration before and after the treatment under the conditions of Case C31 and Case C32, FIG. 11 shows the Cu ion concentration before and after the treatment under the conditions of Case C41 and Case C42, and FIG. The Ni ion concentrations before and after the treatment under the conditions are shown respectively.

  In any of the results of FIGS. 10 to 12, the case C32 and the case C42 using the alkaline treatment liquid whose pH value was raised to 12 were compared with the case C31 and the case C41, and the residual metal contaminants after the treatment were compared. It was confirmed that the concentration could be reduced. That is, it was confirmed that the use of the alkaline treatment liquid having an increased pH value improved the effect of removing metal contaminants.

  Further, in order to suppress the amount of etching of the substrate surface, it is desirable to reduce the ratio of hydrofluoric acid in the acidic processing liquid as much as possible. However, according to the results of FIGS. It was confirmed that a very excellent removal effect on metal contaminants can be obtained using dilute hydrochloric acid containing no hydrofluoric acid. That is, by using the alkaline treatment liquid having an increased pH value, an extremely excellent effect of removing metal contaminants could be obtained without mixing hydrofluoric acid in the acidic treatment liquid.

  In the case of using an alkaline treatment solution having an increased pH value, in Example 3, a test was performed on the effect of removing metal contaminants, but in Example 4, a test was performed on the removal rate of contaminant particles. In Example 4, tests were performed on the removal rates of the five main types of contaminant particles PSL, SiN, AlO, Si, and SiO.

  In case C51, the above-described substrate processing apparatus 1 was used. Using an alkaline treatment liquid (pH ratio: TMAH: ammonia water: hydrogen peroxide water: pure water = 3: 1: 1: 100) by adding TMAH to SC1 and adjusting the pH value to 12 as an alkaline treatment liquid, After applying the vibration, supply was performed to the surface of the substrate W for 30 seconds. In addition, a mixed solution of diluted hydrofluoric acid and diluted hydrochloric acid (hydrofluoric acid: hydrochloric acid: pure water = 1: 40: 200 in volume ratio) was supplied to the surface of the substrate W for 10 seconds as an acidic treatment liquid.

  In case C52, a conventionally used batch type substrate processing apparatus was used. In case C52, first, the substrate W was immersed for 510 seconds in a treatment tank storing dilute hydrofluoric acid at normal temperature (hydrofluoric acid: pure water = 1: 50 by volume ratio), and then SC1 at 65 ° C. (volume ratio). The substrate W is immersed in a processing tank storing ammonia water: hydrogen peroxide water: pure water = 1: 1: 50) for 600 seconds, and then the substrate W is stored in a processing tank storing 65 ° C. SC2 for 600 seconds. Dipped. Note that SC2 is a mixed solution of hydrochloric acid, hydrogen peroxide solution, and pure water. In this case C52, SC2 having a volume ratio of hydrochloric acid: hydrogen peroxide solution: pure water = 1: 1: 50 was used. .

  FIG. 13 shows the results of the test according to the fourth embodiment. The case C51 according to the present invention is different from the case C52 in that the total processing time is 1/50 or less and the processing temperature is normal temperature, but the main contaminant particles PSL, SiN, AlO, Si, SiO It was confirmed that almost the same removal rate was obtained for each of the above. In other words, even when the alkaline processing liquid having an increased pH value is used, there is no particular adverse effect on the removal of the contaminant particles, and a removal rate substantially equal to that of the conventional batch-type substrate processing apparatus can be obtained. It was confirmed that.

It is a longitudinal section showing the composition of substrate processing device 1 of the present invention. FIG. 2 is a schematic diagram illustrating a configuration of piping and the like attached to the substrate processing apparatus 1. FIG. 3 is a perspective view of an alkaline processing liquid nozzle 68 and a vertical cross-sectional view including a pipe 37 a of the alkaline processing liquid nozzle 68. 5 is a flowchart illustrating an operation of substrate processing in the substrate processing apparatus 1. FIG. 9 is an operation state diagram schematically showing a state of supply of diluted ammonia water, diluted hydrochloric acid, and pure water only in the vicinity of the substrate W. FIG. 4 is an illustrative plan view for explaining movement of an alkaline processing liquid nozzle 68 with respect to a substrate W held on a spin base 10. It is a mimetic diagram showing composition of piping etc. concerning a modification. 4 is a graph showing the results of a test according to Example 1. 9 is a graph showing the results of a test according to Example 2. 13 is a graph showing the results of a test according to Example 3. 13 is a graph showing the results of a test according to Example 3. 13 is a graph showing the results of a test according to Example 3. 13 is a graph showing the results of a test according to Example 4.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 10 Spin base 15 Back surface treatment liquid nozzle 26 Receiving member 30 Atmosphere barrier plate 36 Pure water nozzle 50 Splash guard 68 Alkaline treatment liquid nozzle 68d Ultrasonic vibrator 78 Acid treatment liquid nozzle W Substrate

Claims (14)

A substrate processing method,
A first step of supplying an alkaline processing liquid having ultrasonic vibration applied to the substrate while rotating the substrate to be processed;
A second step of supplying an acidic treatment liquid to the substrate while rotating the substrate after the first step;
A substrate processing method comprising: The substrate processing method according to claim 1, wherein
The first step includes supplying an alkaline treatment liquid having ultrasonic vibration applied to the front surface of the substrate, and supplying an alkaline treatment liquid to the back surface of the substrate,
The substrate processing method according to claim 2, wherein the second step includes a step of supplying an acidic processing liquid to the front surface and the back surface of the substrate. The substrate processing method according to claim 1 or 2, wherein
The substrate processing method, wherein the alkaline processing liquid is diluted ammonia water. The substrate processing method according to claim 1 or 2, wherein
The substrate processing method, wherein the alkaline processing liquid is a mixed solution containing aqueous ammonia and aqueous hydrogen peroxide. The substrate processing method according to any one of claims 1 to 4, wherein
The substrate processing method, wherein the acidic processing liquid is dilute hydrochloric acid. The substrate processing method according to any one of claims 1 to 4, wherein
The substrate processing method, wherein the acidic processing liquid is a mixed solution containing hydrochloric acid and hydrofluoric acid. The substrate processing method according to any one of claims 1 to 6, wherein
The substrate processing method, wherein the alkaline processing liquid and the acidic processing liquid are both liquids at room temperature. A substrate processing apparatus that performs a predetermined process while rotating a substrate to be processed in a horizontal plane,
Rotating means for rotating the substrate about an axis along a substantially vertical direction,
First supply means for supplying an alkaline treatment liquid having ultrasonic vibration applied to the front surface of the substrate,
Second supply means for supplying an acidic treatment liquid to the front surface of the substrate;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 8, wherein:
Third supply means for supplying an alkaline processing liquid to the back surface of the substrate,
Fourth supply means for supplying an acidic treatment liquid to the back surface of the substrate,
A substrate processing apparatus, further comprising: The substrate processing apparatus according to claim 8, wherein:
The substrate processing apparatus, wherein the alkaline processing liquid is diluted ammonia water. The substrate processing apparatus according to claim 8, wherein:
The substrate processing apparatus, wherein the alkaline processing liquid is a mixed solution containing aqueous ammonia and aqueous hydrogen peroxide. The substrate processing apparatus according to any one of claims 8 to 11, wherein
The substrate processing apparatus, wherein the acidic processing liquid is diluted hydrochloric acid. The substrate processing apparatus according to any one of claims 8 to 11, wherein
The substrate processing apparatus, wherein the acidic processing liquid is a mixed solution containing hydrochloric acid and hydrofluoric acid. The substrate processing apparatus according to any one of claims 8 to 13, wherein
The substrate processing apparatus, wherein the alkaline processing liquid and the acidic processing liquid are both liquids at room temperature.

Images