SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD

Abstract

To excellently perform predetermined processing to a substrate by irradiating one main surface of the substrate with irradiation light with an appropriate light quantity and efficiently heating the substrate in a situation where the reflectance of a thin film is fluctuated according to the film thickness of the thin film.SOLUTION: A processing liquid is supplied to one main surface of the substrate, while heating the substrate by irradiating one main surface of the substrate rotating around a rotation axis with light. Thus, the irradiation light quantity of the light to one main surface of the substrate is adjusted corresponding to that the reflectance of the thin film is fluctuated according to the film thickness of the thin film during processing, while the predetermined processing is performed to the thin film formed on one main surface. Therefore, the temperature of the substrate during processing is controlled.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] This invention relates to a substrate processing technology for performing processing such as etching on a thin film formed on a substrate by irradiating one main surface of the substrate rotating around a rotation axis with light to heat the substrate while supplying a processing liquid to the substrate. Here, the substrate includes a semiconductor wafer, a glass substrate for a liquid crystal display device, a glass substrate for a plasma display device, a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, a glass substrate for a photomask, a substrate for a solar cell, and the like (hereinafter simply referred to as "substrate"). [Background technology]

[0002] As a substrate processing apparatus that performs chemical processing, cleaning processing, etc. by supplying a processing liquid to a processing surface of a substrate such as a semiconductor wafer while applying a heat treatment to the substrate, there is known an apparatus described in Patent Document 1. In this substrate processing apparatus, in order to heat the bottom surface (heated surface) of the substrate opposite to the top surface (processed surface), an annular heater incorporating a heating element extends in the circumferential direction of the substrate along the peripheral edge of the bottom surface of the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-11015 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the use of light-emitting elements such as LEDs (Light Emitting Diodes) instead of heating elements as a heat source for heating a substrate in a non-contact manner has been considered. For example, an ultraviolet-emitting LED (model number NVCUQ096A-D4) manufactured by Nichia Corporation can be used as a heat source for a substrate heating device. In the above-mentioned LED, a plurality of light-emitting elements are arranged in a matrix on one main surface of an element substrate.

[0005] By using the LED configured in this way, an excellent heating effect can be obtained. Therefore, for example, by supplying a chemical solution (etching solution) as a processing solution to the lower surface (corresponding to the "one main surface" of the present invention) or the upper surface (corresponding to the "other main surface" of the present invention) of the substrate, the thin film formed on the substrate can be etched at an excellent etching rate. However, if the temperature of the substrate is raised too much, bumping of the chemical solution may be caused. This bumping is one of the causes of liquid splash, particles, residue, etc. Therefore, there is a technical problem of controlling the amount of irradiation light (hereinafter referred to as "irradiation amount") irradiated from the LED to the lower surface of the substrate while preventing the temperature of the substrate from rising excessively. In particular, the thin film formed on the substrate has a characteristic that the reflectance varies depending on the film thickness of the thin film, that is, the so-called film thickness dependency, as will be described later with reference to FIG. 7. Therefore, in order to solve the technical problem, it is desirable to control the amount of irradiation light while taking into account the film thickness dependency. However, in conventional devices incorporating light-emitting parts such as LEDs, there is no one that takes this point into consideration, and it has been difficult to efficiently heat the substrate while preventing the occurrence of bumping.

[0006] The present invention has been made in consideration of the above-mentioned problems, and has an object to perform a predetermined process on a substrate well by irradiating one main surface of the substrate with an appropriate amount of irradiation light to efficiently heat the substrate under circumstances in which the reflectance of the thin film varies depending on the film thickness of the thin film. [Means for solving the problem]

[0007] One aspect of the present invention is a substrate processing apparatus comprising: a substrate holding section that holds a substrate and is rotatable about a predetermined rotation axis; a rotation mechanism that rotates the substrate holding section about the rotation axis; a heating mechanism having a light-emitting section that irradiates irradiation light onto one main surface of a substrate that is rotated about the rotation axis by being held by the substrate holding section rotated by the rotation mechanism, and that heats the substrate with the irradiated light; a processing liquid supply section that supplies a processing liquid to the one main surface of the substrate heated by the heating mechanism, thereby performing a predetermined processing on a thin film formed on the one main surface; and a control section that controls the temperature of the substrate during processing by adjusting the amount of irradiation light irradiated onto the one main surface of the substrate in response to the reflectance of the thin film varying depending on the film thickness during processing.

[0008] Another aspect of the present invention is a substrate processing method comprising: a processing step of applying a predetermined processing to a thin film formed on one main surface by irradiating one main surface of the substrate rotating about a rotation axis with light while heating the substrate and supplying a processing liquid to the one main surface of the substrate; and a temperature control step of controlling the temperature of the substrate during processing by adjusting the amount of light irradiated to the one main surface of the substrate in response to the reflectance of the thin film varying during processing depending on the film thickness of the thin film, in parallel with the processing step.

[0009] In the invention configured as described above, the substrate is heated by irradiating one main surface of the substrate with light, and a processing liquid is supplied to the one main surface of the substrate. In this way, a predetermined processing is performed, and in parallel with this, the amount of light irradiated onto the one main surface of the substrate is adjusted in response to the reflectance of the thin film varying during processing according to the film thickness of the thin film. In this way, the temperature of the substrate during processing is controlled. Effect of the Invention

[0010] According to the invention configured in this manner, an appropriate amount of irradiation light can be applied to one main surface of the substrate to efficiently heat the substrate, and as a result, the predetermined processing of the substrate can be performed satisfactorily. [Brief description of the drawings]

[0011] [Figure 1] 1 is a view showing a first embodiment of a substrate processing apparatus according to the present invention; [Diagram 2] 2 is a plan view of the substrate processing apparatus shown in FIG. 1, viewed from above. [Diagram 3] 2 is a plan view of a heating mechanism provided in the substrate processing apparatus shown in FIG. 1, as viewed in a vertical direction. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] 4 is a graph showing temperature rise characteristics of a peripheral portion of a substrate heated by a heating mechanism. [Figure 6] 2 is a block diagram showing a part of the electrical configuration of the substrate processing apparatus shown in FIG. 1. [Figure 7] 1 is a graph showing film thickness dependency of reflectance. [Figure 8] 4 is a flowchart showing an etching process performed in the first embodiment. [Figure 9A] FIG. 11 is a diagram showing the configuration of a heating mechanism provided in a second embodiment of a substrate processing apparatus according to the present invention. [Figure 9B] 9B is a perspective view showing the structure of a heat sink which is one component of the heating mechanism shown in FIG. 9A. [Figure 10] 1 is a graph showing temperature rise characteristics when a substrate is heated by various heating mechanisms in a substrate processing apparatus. [Figure 11] 11 is a graph showing the effect of the separation distance on the substrate temperature after a certain time has elapsed since the substrate was heated by the heating mechanism. [Figure 12] FIG. 11 is a block diagram showing an electrical configuration of a third embodiment of a substrate processing apparatus according to the present invention. [Figure 13] FIG. 13 is a block diagram showing an electrical configuration of a fourth embodiment of a substrate processing apparatus according to the present invention. [Figure 14] 13 is a flowchart showing an etching process performed in a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Fig. 1 is a diagram showing a first embodiment of a substrate processing apparatus according to the present invention. Fig. 2 is a plan view of the substrate processing apparatus shown in Fig. 1 as seen from above. In each of the drawings referred to below, the dimensions and numbers of each part may be exaggerated or simplified for ease of understanding. The up-down direction is the vertical direction, and the substrate side is upper with respect to the spin chuck.

[0013] The substrate processing apparatus 1 includes a rotating and holding mechanism 2, a scattering prevention unit 3, a surface protection unit 4, a processing unit 5, a nozzle movement mechanism 6, a heating mechanism 7, and a control unit 10. Each of these units 2 to 7 is electrically connected to the control unit 10 and operates according to instructions from the control unit 10. The control unit 10 may be, for example, a unit similar to a general computer. That is, in the control unit 10, a CPU as a main control unit performs calculation processing according to a procedure described in a program, thereby controlling each unit of the substrate processing apparatus 1. The detailed configuration and operation of the control unit 10 will be described later.

[0014] The rotating and holding mechanism 2 is a mechanism capable of rotating the substrate W while holding it in a substantially horizontal position with its surface facing upward. The rotating and holding mechanism 2 rotates the substrate W around a vertical rotation axis a1 passing through the center c1 of the main surface. The rotating and holding mechanism 2 includes a spin chuck (corresponding to an example of the "substrate holding unit" of the present invention) 21, which is a disk-shaped member smaller than the substrate W. The spin chuck 21 is provided so that its upper surface is substantially horizontal and its central axis coincides with the rotation axis a1. A cylindrical rotating shaft unit 22 is connected to the lower surface of the spin chuck 21. The rotating shaft unit 22 extends in the vertical direction with its axis line coinciding with the rotation axis a1. A rotating drive unit (e.g., a motor) 23 is connected to the rotating shaft unit 22. The rotating drive unit 23 rotates the rotating shaft unit 22 around its axis line in response to a rotation command from the control unit 10. Therefore, the spin chuck 21 can rotate around the rotation axis a1 together with the rotation shaft portion 22. The rotation drive portion 23 and the rotation shaft portion 22 form a rotation mechanism 231 that rotates the spin chuck 21 around the rotation axis a1. The rotation shaft portion 22 and the rotation drive portion 23 are housed in a cylindrical casing 24.

[0015] A through hole (not shown) is provided in the center of the spin chuck 21, and communicates with the internal space of the rotating shaft portion 22. A pump (not shown) is connected to the internal space via piping and an on-off valve (not shown). The pump and the on-off valve are electrically connected to the control portion 10. The control portion 10 controls the operation of the pump and the on-off valve. The pump can selectively apply negative pressure or positive pressure to the spin chuck 21 under the control of the control portion 10. When the pump applies negative pressure to the spin chuck 21 with the substrate W placed on the upper surface of the spin chuck 21 in a substantially horizontal position, the spin chuck 21 adsorbs and holds the substrate W from below. When the pump applies positive pressure to the spin chuck 21, the substrate W can be removed from the upper surface of the spin chuck 21.

[0016] In this configuration, when the rotation driver 23 rotates the rotation shaft 22 while the spin chuck 21 suction-holds the substrate W, the spin chuck 21 is rotated about an axis line along the vertical direction. As a result, the substrate W held on the spin chuck 21 is rotated in the direction of arrow AR1 about the vertical rotation axis a1 passing through the center c1 in the plane of the spin chuck 21.

[0017] The method of holding the substrate W is not limited to this, and may be a so-called mechanical chuck method in which the substrate W is held by a plurality of chuck pins (for example, six).

[0018] The splash prevention unit 3 receives processing liquid and the like splashed from the substrate W which is rotated together with the spin chuck 21. The splash prevention unit 3 includes a splash guard 31. The splash guard 31 is a cylindrical member with an open upper end, and is provided so as to surround the rotating holding mechanism 2. A guard drive mechanism (not shown) which moves the splash guard 31 up and down is connected to the splash guard 31, and is driven in response to a lift command from the control unit 10.

[0019] The surface protection unit 4 includes a gas discharge mechanism that discharges an inert gas flow so as to strike the peripheral portion of the upper surface (designated by symbol Wu in FIG. 4 below) of the substrate W held and rotated on the spin chuck 21. The "inert gas" is a gas that is poorly reactive with the material of the substrate W and the thin film formed on the surface thereof, such as nitrogen (N2) gas, argon gas, and helium gas. In this embodiment, gas discharge mechanisms 41 and 42 are provided. The gas discharge mechanisms 41 and 42 discharge the inert gas, for example, as a gas column-shaped gas flow. The gas discharge mechanism 42 discharges the inert gas flow so as to strike a position upstream of the position where the gas flow discharged by the gas discharge mechanism 41 strikes the peripheral portion of the substrate W in the direction of rotation of the substrate W.

[0020] The surface protection unit 4 further includes a gas discharge mechanism 43 that discharges a flow of inert gas toward the center of the upper surface of the substrate W held and rotating on the spin chuck 21. By discharging a flow of inert gas from the gas discharge mechanisms 41-43 toward the upper surface of the substrate W, the surface protection unit 4 protects a non-processing region on the upper surface of the substrate W from the processing liquid, etc., discharged so as to hit a ring-shaped processing region defined by the peripheral portion of the upper surface of the substrate W.

[0021] The gas discharge mechanisms 41 and 42 include a nozzle head 44. The gas discharge mechanism 43 includes a nozzle head 45. The nozzle heads 44 and 45 are attached to the ends of arms 61 and 62, respectively, of a nozzle movement mechanism 6, which will be described later. The arms 61 and 62 extend along a horizontal plane. The nozzle movement mechanism 6 moves the arms 61 and 62 to move the nozzle heads 44 and 45 between their respective processing positions (positions indicated by solid lines in FIG. 2) and retracted positions (positions indicated by two-dot chain lines in FIG. 2).

[0022] The nozzle head 44 has two nozzles 46 and 47, and is attached to the tip of the arm 61. The nozzles 46 and 47 have their tips (lower ends) protruding downward from the lower surface of the nozzle head 44, and their upper ends protruding upward from the upper surface. One end of a pipe 411 is connected to the upper end of one of the nozzles 46. The other end of the pipe 411 is connected to a gas supply source 412. A flow rate controller 413 and an on-off valve 414 are provided in this order from the gas supply source 412 side in the middle of the pipe 411. One end of a pipe 421 is also connected to the other nozzle 47. The other end of the pipe 421 is connected to a gas supply source 422. A flow rate controller 423 and an on-off valve 424 are provided in this order from the gas supply source 422 side in the middle of the pipe 421.

[0023] Here, when the nozzle movement mechanism 6 positions the nozzle head 44 at its processing position, the outlet of the nozzle 46 faces a part of the rotational trajectory of the peripheral edge of the substrate W rotated by the rotating and holding mechanism 2, and the outlet of the nozzle 47 faces another part of the rotational trajectory.

[0024] With the nozzle head 44 disposed at the processing position, the nozzles 46, 47 are supplied with an inert gas (nitrogen (N2) gas in the illustrated example) from the gas supply sources 412, 422. The nozzle 46 discharges the supplied inert gas flow from above so that it hits a gas target discharge position defined on the rotation trajectory of the peripheral portion of the substrate W. The nozzle 46 discharges the gas flow from the discharge port in a predetermined direction so that the discharged gas flow, after reaching the gas target discharge position, flows from the gas target discharge position toward the peripheral portion of the substrate W. The nozzle 47 discharges the supplied inert gas flow from above so that it hits a gas target discharge position defined on the rotation trajectory. The nozzle 47 discharges the gas flow from the discharge port in a predetermined direction so that the discharged gas flow, after reaching the gas target discharge position, flows from the gas target discharge position toward the peripheral portion of the substrate W.

[0025] The nozzle head 45 of the gas discharge mechanism 43 includes a columnar member 93 attached to the lower surface of the tip of the arm 62, a disk-shaped blocking plate 90 attached to the lower surface of the columnar member 93, and a cylindrical nozzle 48. The axis of the columnar member 93 and the axis of the blocking plate 90 coincide with each other and are aligned vertically. The lower surface of the blocking plate 90 is aligned horizontally. The nozzle 48 penetrates the columnar member 93 and the blocking plate 90 in the vertical direction so that its axis coincides with the axes of the blocking plate 90 and the columnar member 93. The upper end of the nozzle 48 also penetrates the tip of the arm 62 and opens on the upper surface of the arm 62. One end of a pipe 431 is connected to the upper opening of the nozzle 48. The other end of the pipe 431 is connected to a gas supply source 432. A flow rate controller 433 and an opening / closing valve 434 are provided in this order from the gas supply source 432 side in the middle of the pipe 431. The lower end of the nozzle 48 opens at the lower surface of the blocking plate 90. This opening is the discharge port of the nozzle 48.

[0026] When the nozzle moving mechanism 6 places the nozzle head 45 at the processing position, the discharge port of the nozzle 48 faces the vicinity of the center of the upper surface of the substrate W. In this state, the nozzle 48 is supplied with an inert gas (nitrogen (N2) gas in the illustrated example) from a gas supply source 432 via a pipe 431. The nozzle 48 discharges the supplied inert gas as a gas flow of the inert gas toward the vicinity of the center of the upper surface of the substrate W. The gas flow spreads radially from above the central portion of the substrate W toward the periphery of the substrate W. That is, the gas discharge mechanism 43 discharges the inert gas from above the central portion of the upper surface of the substrate W to generate a gas flow that spreads from above the central portion toward the periphery of the substrate W.

[0027] The processing unit 5 performs processing on a processing region on the periphery of the substrate W held on the spin chuck 21. Specifically, the processing unit 5 supplies a processing liquid to the processing region of the substrate W held on the spin chuck 21. The processing unit 5 includes a processing liquid discharge mechanism 51A that treats the periphery of the upper surface of the substrate W as the upper surface side processing region and supplies a processing liquid to the processing region to perform a predetermined processing, and a processing liquid discharge mechanism 51B that treats the periphery of the lower surface of the substrate W as the lower surface side processing region and supplies a processing liquid to the processing region to perform a predetermined processing. The processing liquid discharge mechanism 51A discharges a liquid flow of the processing liquid so as to hit a part of the periphery of the upper surface (processing surface) of the substrate W held and rotated on the spin chuck 21. The liquid flow is in the form of a liquid column. The processing liquid discharge mechanism 51A includes a nozzle head 50A. The nozzle head 50A is attached to the tip of a long arm 63 included in the nozzle movement mechanism 6. The arm 63 extends along a horizontal plane. The nozzle moving mechanism 6 moves the arm 63 to move the nozzle head 50A between the processing position (position indicated by a solid line in FIG. 2) and the retracted position (position indicated by a two-dot chain line in FIG. 2).

[0028] The nozzle head 50A has four nozzles 5a to 5d and is attached to the tip of the arm 63. The nozzles 5a to 5d are arranged in a line along the extending direction of the arm 63. In the nozzle head 50A, the tip (lower end) of the nozzles 5a to 5d protrudes downward, and the base end (upper end) thereof protrudes upward. The nozzles 5a to 5d are connected to a processing liquid supply unit 51, which is a piping system that supplies the processing liquid to the nozzles. Specifically, one end of the piping 53a to 53d of the processing liquid supply unit 51 is connected to the upper end of the nozzles 5a to 5d. The processing liquid is supplied to the nozzles 5a to 5d from the processing liquid supply unit 51, and the nozzles 5a to 5d respectively discharge the supplied processing liquid from the discharge port at the tip. The processing liquid discharge mechanism 51A discharges a liquid flow of the processing liquid from one of the nozzles 5a to 5d, which is determined by the control information set in the control unit 10, under the control of the control unit 10.

[0029] Specifically, the processing liquid supply unit 51 is configured by combining an SC-1 supply source 52a, a DHF supply source 52b, an SC-2 supply source 52c, a rinsing liquid supply source 52d, a plurality of pipes 53a, 53b, 53c, 53d, and a plurality of on-off valves 54a to 54d. SC-1, DHF, and SC-2 are chemical liquids. Therefore, the processing liquid discharge mechanism 51A is a chemical liquid discharge unit that discharges the chemical liquid to the peripheral portion of the substrate W. By this supply of the chemical liquid, the peripheral portion of the thin film (designated by symbol TF in FIG. 4) formed on the upper surface Wu of the substrate W is etched away.

[0030] The SC-1 supply source 52a is a supply source that supplies SC-1. The SC-1 supply source 52a is connected to the nozzle 5a via a pipe 53a in which an on-off valve 54a is inserted. Therefore, when the on-off valve 54a is opened, the SC-1 supplied from the SC-1 supply source 52a is discharged from the nozzle 5a.

[0031] The DHF supply source 52b is a supply source that supplies DHF. The DHF supply source 52b is connected to the nozzle 5b via a pipe 53b in which an on-off valve 54b is inserted. Therefore, when the on-off valve 54b is opened, the DHF supplied from the DHF supply source 52b is discharged from the nozzle 5b.

[0032] The SC-2 supply source 52c is a supply source that supplies SC-2. The SC-2 supply source 52c is connected to the nozzle 5c via a pipe 53c in which an on-off valve 54c is inserted. Therefore, when the on-off valve 54c is opened, the SC-2 supplied from the SC-2 supply source 52c is discharged from the nozzle 5c.

[0033] The rinse liquid supply source 52d is a supply source that supplies the rinse liquid. Here, the rinse liquid supply source 52d supplies, for example, pure water or DIW (deionized water) as the rinse liquid. The rinse liquid supply source 52d is connected to the nozzle 5d via a pipe 53d in which an on-off valve 54d is interposed. Therefore, when the on-off valve 54d is opened, the rinse liquid supplied from the rinse liquid supply source 52d is discharged from the nozzle 5d. Note that pure water, hot water, ozone water, magnetic water, reduced water (hydrogen water), various organic solvents (ionized water, IPA (isopropyl alcohol), functional water (CO2 water, etc.), etc. may be used as the rinse liquid.

[0034] The processing liquid supply unit 51 selectively supplies SC-1, DHF, SC-2, and a rinse liquid. When the processing liquid (SC-1, DHF, SC-2, or a rinse liquid) is supplied from the processing liquid supply unit 51 to a corresponding one of the nozzles 5a to 5d, the nozzle discharges a liquid flow of the processing liquid so as to hit a processing area on the peripheral portion of the upper surface of the substrate W rotating. However, each of the opening and closing valves 54a to 54d provided in the processing liquid supply unit 51 is opened and closed under the control of the control unit 10 by a valve opening and closing mechanism (not shown) electrically connected to the control unit 10. That is, the discharge mode of the processing liquid from the nozzle of the nozzle head 50A (specifically, the type of processing liquid discharged, discharge start timing, discharge end timing, discharge flow rate, etc.) is controlled by the control unit 10. That is, the processing liquid discharge mechanism 51A discharges a liquid flow of the processing liquid so as to hit a part of the rotation locus of the peripheral portion of the upper surface of the substrate W rotating around the rotation axis a1 under the control of the control unit 10.

[0035] The processing liquid discharge mechanism 51B is provided below the lower surface Wd of the substrate W held and rotated on the spin chuck 21. Basically, similar to the processing liquid discharge mechanism 51A, the processing liquid discharge mechanism 51B discharges a flow of the processing liquid under the control of the controller 10 so as to hit part of the rotation locus of the peripheral part of the lower surface of the substrate W rotating about the rotation axis a1.

[0036] The processing liquid discharge mechanism 51B includes a nozzle head 50B fixedly disposed below the peripheral portion of the lower surface of the substrate W. The nozzle head 50B has three nozzles 5a1, 5b1, and 5d1. The nozzles 5a1, 5b1, and 5d1 are arranged in a row along the rotation direction of the substrate W. In the nozzle head 50B, the tip end (upper end) of the nozzles 5a1, 5b1, and 5d1 protrudes upward, and the base end (lower end) thereof protrudes downward. The nozzle 5a1 is connected to a pipe 53a1 branched from the pipe 53a on the nozzle side of the opening / closing valve 54a. Therefore, when the opening / closing valve 54a is opened according to the control of the control unit 10, the SC-1 supplied from the SC-1 supply source 52a is discharged from the nozzle 5a1 to the peripheral portion of the lower surface of the substrate W. The nozzle 5b1 is also connected to a pipe 53b1 branched from the pipe 53b on the nozzle side of the opening / closing valve 54b. Therefore, when the on-off valve 54b is opened under the control of the control unit 10, the DHF supplied from the DHF supply source 52b is discharged from the nozzle 5b1 to the lower peripheral portion of the substrate W. Furthermore, a pipe 53d1 branched from the pipe 53d on the nozzle side of the on-off valve 54d is connected to the nozzle 5d1. Therefore, when the on-off valve 54d is opened under the control of the control unit 10, the rinse liquid supplied from the rinse liquid supply source 52d is discharged from the nozzle 5d1. Note that, in this embodiment, the on-off valves 54a, 54b, and 54d are controlled to open and close so that three types of processing liquid are simultaneously supplied to the upper peripheral portion and the lower peripheral portion of the substrate W, but an on-off valve for controlling the discharge of the processing liquid from the nozzles 5a, 5b, and 5d and an on-off valve for controlling the discharge of the processing liquid from the nozzles 5a1, 5b1, and 5d1 may be provided in parallel. In this case, the discharge of the processing liquid from the nozzles 5a, 5b, and 5d and the discharge of the processing liquid from the nozzles 5a1, 5b1, and 5d1 can be controlled individually. That is, the processing liquid can be supplied to the upper surface peripheral portion and the lower surface peripheral portion simultaneously as in the present embodiment, or can be supplied at different timings.

[0037] The nozzle movement mechanism 6 is a mechanism for independently moving the nozzle heads 44, 45, 50A between their respective processing positions and retracted positions. The nozzle movement mechanism 6 includes horizontally extending arms 61-63, nozzle bases 64-66, and drive units 67-69. The nozzle heads 44, 45, 50A are attached to the tips of the arms 61-63, respectively.

[0038] The base ends of the arms 61-63 are connected to the upper end portions of the nozzle bases 64-66. The nozzle bases 64-66 are arranged around the casing 24 in a distributed manner with their axes aligned vertically. The nozzle bases 64-66 each include a rotating shaft that extends vertically along its axis and is rotatable around the axis. The axis of the nozzle bases 64-66 coincides with the axis of each rotating shaft. The upper end portions of the nozzle bases 64-66 are attached to the upper ends of the rotating shafts. When each rotating shaft rotates, the upper end portions of the nozzle bases 64-66 rotate around the axis of each rotating shaft, i.e., the axis of the nozzle bases 64-66. The nozzle bases 64-66 are provided with driving units 67-69 that rotate the respective rotating shafts around their axes. The driving units 67-69 are each configured to include, for example, a stepping motor or the like.

[0039] The driving units 67-69 rotate the upper end portions of the nozzle bases 64-66 via the rotation shafts of the nozzle bases 64-66. As the upper end portions rotate, the nozzle heads 44, 45, 50A also rotate around the axis of the nozzle bases 64-66. As a result, the driving units 67-69 move the nozzle heads 44, 45, 50A horizontally between the respective processing positions and the retracted positions.

[0040] When the nozzle head 44 is positioned in the processing position, the outlet of the nozzle 46 faces part of the rotational trajectory of the peripheral edge of the substrate W rotated by the rotating and holding mechanism 2, and the outlet of the nozzle 47 faces another part of the rotational trajectory.

[0041] When the nozzle head 45 is placed in the processing position, the nozzle 48 is located above the center c1 of the substrate W, and the axis of the nozzle 48 coincides with the rotation axis a1 of the spin chuck 21. The discharge outlet (lower opening) of the nozzle 48 faces the center of the substrate W. In addition, the lower surface of the shielding plate 90 faces and is parallel to the upper surface of the substrate W. The shielding plate 90 is close to the upper surface of the substrate W in a non-contact state.

[0042] When the nozzle head 50A is disposed at the processing position, the nozzles 5a to 5d are disposed at the processing positions. The retracted positions of the nozzle heads 44, 45, 50A are positions where they do not interfere with the transport path of the substrate W and do not interfere with each other. Each retracted position is, for example, a position outside and above the splash guard 31.

[0043] In addition to the processing liquid discharge mechanism 51B configured as described above, a heating mechanism 7 is provided below the peripheral portion of the lower surface of the substrate W. The configuration and operation of the heating mechanism 7 will be described in detail below with reference to Figures 3 and 4. Figure 3 is a plan view of the heating mechanism provided in the substrate processing apparatus shown in Figure 1, viewed from the vertical direction. Figure 4 is a cross-sectional view taken along line IV-IV in Figure 3. In order to clarify the internal structure of the heating mechanism 7, the heating housing 71 is omitted in Figure 3.

[0044] The heating mechanism 7 has a resin heating housing 71 having a substantially sector shape in a plan view from above. The heating housing 71 has a resin box member 711 with an opening at the top, and a transparent member 712 arranged so as to close the annular opening of the box member 711 from above. The light emitting unit 72 functioning as a heating source, the heat sink 73, the base member 74, and the light receiving unit 8 described later are stored in a storage space 713 formed by the box member 711 and the transparent member 712. That is, the light emitting unit 72 and the like are protected from an atmosphere such as a chemical solution by the heating housing 71. Then, as described later, when the light emitting unit 72 is turned on, light from the light emitting unit 72 (in this embodiment, ultraviolet light with a wavelength of about 365 nm) is irradiated toward the lower surface Wd of the substrate W through the transparent member 712. Also, the reflected light RL reflected by the substrate W is guided to the light receiving unit 8 through the transparent member 712. Thus, in the first embodiment, the entire transparent member 712 functions as a transmission window.

[0045] A base member 74 having an annular shape is disposed on the inner bottom of the storage space 713 in correspondence with the heating housing 71. The base member 74 is made of, for example, an aluminum plate. A heat sink 73 is disposed on the base member 74 and serves to cool the light-emitting unit 72 from below. More specifically, the heat sink 73 has a metal plate having the same planar shape as the base member 74, that is, an annular shape. Cooling water is circulated inside the metal plate by a cooling water circulation supply unit (not shown). This cools the light-emitting unit 72.

[0046] On the upper surface of the heat sink 73, the light emitting unit 72 such as the ultraviolet light emitting LED described above is arranged so as to face the lower surface Wd of the substrate W via a transparent member (transmission window) 712. In the first embodiment, in order to heat the peripheral portion of the substrate under a preset heating condition (for example, to raise the temperature to a target temperature of 80° C. in 10 seconds), nine light emitting units 72 are arranged in an arc shape corresponding to the shape of the peripheral portion of the substrate. That is, the light emitting units 72 are arranged with the rotational symmetry axis a71 of the heating housing 71 as a reference. Each light emitting unit 72 has an element substrate 721, a light emitting element 722 that emits light (ultraviolet light), and a connector 723 for transmitting and receiving a control signal of the light emitting element 722 and a temperature detection signal between the control unit 10 and the element substrate 721. The light emitting element 722 and the connector 723 are attached adjacent to each other on one main surface of the element substrate 721. The light emitting unit 72 is fixed to the upper surface of the heat sink 73 so that the light emitting element 722 and the connector 723 face the lower surface Wd of the substrate W via the transparent member 712.

[0047] In the light-emitting unit 72 thus configured, when a lighting signal is given from the control unit 10 via the connector 723, the light-emitting element 722 lights up and emits ultraviolet light L toward the bottom surface Wd of the substrate W. The ultraviolet light L is irradiated onto the bottom surface Wd of the substrate W rotating around the rotation axis a1 via the transparent member 712. This heats up the substrate peripheral portion to a desired temperature. For example, when all nine light-emitting units 72 are turned on in response to a command from the irradiation light amount control unit (see FIG. 6, which will be described later) of the control unit 10, the ultraviolet light L is irradiated onto the bottom surface Wd of the rotating substrate W, and as a result, the temperature of the peripheral portion of the substrate W is raised to 80° C. or higher in a relatively short time (about 10 seconds from the start of lighting) as shown by the curve C(9) in FIG. 5. If a processing liquid is supplied to the substrate W at that point, the temperature of the substrate W drops slightly, but the temperature of the peripheral portion of the substrate W can be maintained at about 75° C. by continuing to irradiate the ultraviolet light L even during the supply of the processing liquid.

[0048] Here, by changing the number of the light-emitting parts 72 that are turned on, the amount of ultraviolet light L irradiated to the lower surface Wd of the substrate W, that is, the amount of irradiation light, is adjusted. As shown by the curves C(8), C(6), C(4), and C(2) in the figure, by decreasing the number of the light-emitting parts 72 that are turned on to 8, 6, 4, and 2, the temperature of the peripheral part of the substrate W during the supply of the processing liquid (10 seconds after the start of the supply) can be gradually reduced. In other words, by changing the number of light-emitting parts that are turned on, the amount of ultraviolet light L irradiated to the lower surface Wd of the substrate W per unit time varies, and the temperature of the peripheral part of the substrate W can be controlled. In consideration of this point, the number of light-emitting parts that are turned on at the start of the etching process may be set to a number less than the maximum number (9 in this embodiment). In other words, when the temperature of the substrate W decreases due to an increase in reflectance during the etching process, it is desirable to continue the etching process while leaving room for increasing the number of light-emitting parts that are turned on.

[0049] In this way, a part of the ultraviolet light L is reflected from the underside of the substrate onto which the ultraviolet light L is irradiated as the "irradiation light" of the present invention, and returns to the heating mechanism 7 as reflected light RL. In order to receive the reflected light RL and detect the amount of the reflected light RL (hereinafter referred to as the "amount of reflected light"), in this embodiment, a light receiving unit 8 is provided on the upper surface of the heat sink 73. The light receiving unit 8 has a light receiving element 81 (FIG. 6) such as a photodiode, and outputs a signal corresponding to the amount of reflected light to the control unit 10 as the "reflected light amount information" of the present invention. In this way, the light receiving unit 8 corresponds to an example of the "reflected light receiving unit" of the present invention.

[0050] In this embodiment, as shown in FIG. 3, the light receiving unit 8 is provided outside and close to the light emitting unit 72 in the radial direction of the substrate W. Therefore, the following action and effect are obtained. The ultraviolet light L is emitted from the light emitting unit 72 with a certain spread as shown in FIG. 4. Then, as shown in FIG. 4, the thin film TF formed from the upper peripheral portion of the substrate W through the substrate end face to the lower peripheral portion of the substrate W is also irradiated with the component of the ultraviolet light L spreading toward the lower peripheral portion, and the reflected light RL of the component advances radially outward. Therefore, in this embodiment, as described above, the light receiving unit 8 is disposed near the radial outside of the light emitting unit 72. Therefore, the reflected light RL can be efficiently received, and as a result, the reflectance of the thin film TF on the lower surface side of the substrate W can be detected with high accuracy. However, there is a concern that the light receiving unit 8 may be deteriorated by directly receiving the reflected light RL due to the large amount of reflected light. In this case, as shown by the dashed line in Fig. 6 described next, it is desirable to additionally dispose an optical filter 82 near the light receiving surface 81a of the light receiving element 81 to attenuate the reflected light RL incident on the light receiving element 81. Furthermore, the light receiving unit 8 may be provided away from the heating mechanism 7. In this case, the light receiving unit 8 receives the reflected light RL extracted from the heating mechanism 7 and detects the amount of reflected light. Furthermore, the number of light receiving units 8 is not limited to one, and two or more may be provided.

[0051] 6 is a block diagram showing a part of the electrical configuration of the substrate processing apparatus shown in FIG. 1. The control unit 10 of the substrate processing apparatus 1 has a general computer system configuration in which a calculation processing unit 11 such as a CPU for performing various calculation processes and a storage unit 12 for storing basic programs and various information are connected to a bus line. A fixed disk 13 (e.g., a hard disk drive) for storing control software, data, etc. is further connected to the bus line. Furthermore, an input display unit 14 is appropriately connected via an interface (I / F). The input display unit 14 displays various information and accepts input from an operator, and is configured, for example, with a touch panel display. Of course, instead of the input display unit 14, a display for displaying various information and a keyboard or mouse for accepting input from an operator may be used.

[0052] In the control unit 10, a bevel etching program stored in advance in the fixed disk 13 is copied to the memory unit 12 (for example, RAM, etc.), and the calculation processing unit 11 executes calculation processing according to the bevel etching program in the memory unit 12. As a result, similar to the device described in Patent Document 1, the substrate W is heated by rotating the substrate W around the rotation axis a1 and irradiating the lower surface Wd of the substrate W with ultraviolet light L. After the temperature of the substrate W reaches a certain temperature, a processing liquid is supplied to the upper surface Wu and the lower surface Wd of the substrate W, so that the thin film TF on the periphery of the substrate W is etched. So-called bevel etching is performed. Here, the film thickness of the thin film TF gradually decreases as the etching process progresses. At this time, the reflectance of the thin film TF varies with the decrease in the film thickness of the thin film TF. For example, when the thin film TF is made of silicon nitride (SiN) or silicon oxide (SiO2), when the thin film TF is irradiated with ultraviolet light L, the reflectance varies greatly according to the film thickness variation, as shown by the curve CV1 (SiN) and the curve CV3 (SiO2) in FIG. 7. In addition to the above, a thin film TF such as titanium nitride (TiN), copper (Cu), cobalt (Co), or tungsten (W) may be formed on the upper surface Wu of the substrate W, and a thin film TF may also be formed on the lower surface Wd of the substrate W as the processing liquid flows around to the lower surface Wd of the substrate W via the edge of the substrate. However, as shown in the same figure, these thin films TF also have a film thickness dependency in which the reflectance varies depending on the film thickness.

[0053] If the above bevel etching is performed while maintaining a constant amount of irradiated light without taking this into consideration, the reflectance will fluctuate during the etching, and the proportion of the ultraviolet light L that is reflected by the lower surface Wd of the substrate W and becomes the reflected light RL will also change with the above-mentioned fluctuation in reflectance. As a result, as the reflectance decreases, excessive ultraviolet light L will be applied to the lower surface Wd of the substrate W, which may cause bumping. Conversely, as the reflectance increases, the ultraviolet light L applied to the lower surface Wd of the substrate W will decrease, causing the temperature of the substrate W to decrease, resulting in a decrease in the etching rate.

[0054] Therefore, in this embodiment, the control unit 10 causes the calculation processing unit 11 to function as an "irradiation light amount control unit 111" and a "reflectance calculation unit 112" to perform a temperature control process corresponding to an example of the "temperature control step" of the present invention in parallel with the etching process corresponding to an example of the "predetermined processing step" of the present invention. Hereinafter, the etching process will be described with reference to FIG. 8.

[0055] FIG. 8 is a flow chart showing an etching process executed by the substrate processing apparatus shown in FIG. Before the etching process, the arithmetic processing unit 11 reads out a recipe that specifies the type of substrate W, the chemicals to be used, and the processing procedure, and sets the etching conditions and operation conditions (step S1). Then, when the substrate W to be processed is placed on the spin chuck 21 from outside the substrate processing apparatus 1, the arithmetic processing unit 11 controls each unit of the apparatus to start the etching process in the same procedure as the apparatus described in Patent Document 1 (step S2). Then, this etching process is executed until the arithmetic processing unit 11 determines in step S3 that the etching removal of the thin film TF formed on the upper surface Wu and the lower surface Wd at the periphery of the substrate W is completed. That is, when the determination in step S3 is "YES", the etching process ends (step S4), the progress of the etching conditions is analyzed, and the analysis result is stored in the fixed disk 13 (step S5).

[0056] On the other hand, while the result of the determination in step S3 is "NO", that is, while the etching process is not completed, the arithmetic processing unit 11 continuously or intermittently executes a temperature control process (step S6). In this temperature control process, the arithmetic processing unit 11 receives a signal related to the amount of reflected light detected by the light receiving unit 8. Then, the reflectance calculation unit 112 of the arithmetic processing unit 11 acquires reflected light amount information from the signal, and acquires irradiation light amount information related to the amount of irradiation light (= (amount of light emitted from each light emitting unit 72) × (number of light emitting units 72 turned on)) based on the etching conditions set in step S1. Then, the reflectance calculation unit 112 calculates the reflectance of the thin film TF based on the irradiation light amount information and the reflected light amount information (step S61). The reflectance actually measured using the light receiving unit 8 in this way (hereinafter referred to as "actual reflectance") is provided to the irradiation light amount control unit 111.

[0057] The irradiation light amount control unit 111 judges whether the measured reflectance of the received thin film TF falls within a preset reflectance range (step S62). If the measured reflectance falls within the preset reflectance range ("YES" in step S62), the irradiation light amount control unit 111 returns to step S3 while maintaining the irradiation light amount, i.e., the number of light-emitting units 72 to be turned on.

[0058] On the other hand, if the measured reflectance is out of the preset reflectance range ("NO" in step S62), the process proceeds to step S63, where the irradiation light amount control unit 111 determines whether the measured reflectance is below the preset reflectance range (below the preset reflectance range) or above the preset reflectance range (above the preset reflectance range). Here, if the measured reflectance is below the preset reflectance ("YES" in step S63), bumping may occur due to excessive ultraviolet light L being applied to the lower surface Wd of the substrate W. Therefore, the irradiation light amount control unit 111 reduces the irradiation light amount, that is, the number of light-emitting units 72 to be turned on (step S64), and then returns to step S3. This optimizes the irradiation light amount applied to the lower surface Wd of the substrate W, and bumping can be prevented in advance. Conversely, if the measured reflectance is above the preset reflectance range ("NO" in step S63), only ultraviolet light L less than the set amount is applied to the lower surface Wd of the substrate W, and there is a concern that the etching rate may decrease. Therefore, the irradiation light amount control unit 111 increases the irradiation light amount, that is, the number of the light-emitting units 72 to be turned on (step S65), and then returns to step S3. This optimizes the irradiation light amount provided to the lower surface Wd of the substrate W, and prevents a decrease in the etching rate.

[0059] As described above, in the first embodiment, the adjustment of the amount of irradiation light is performed in parallel with the etching process for the peripheral portion of the thin film TF formed on the lower surface Wd by passing through the upper surface Wu and the substrate edge surface to the lower surface Wd, that is, the so-called bevel etching. Therefore, even if the film thickness of the thin film TF decreases with the progress of the bevel etching and the reflectance varies, the amount of irradiation light is adjusted accordingly, and the temperature of the substrate W is prevented from changing significantly. As a result, the occurrence of bumping can be effectively prevented. Moreover, the stabilization of the temperature of the substrate W suppresses the variation in the time required for the etching process, and the etching process can be completed at the optimal time for each process. This makes it possible to improve the number of wafers processed per hour and suppress the amount of chemicals and power used.

[0060] Furthermore, if the temperature of the substrate W fluctuates during the etching process, warping may occur in the substrate W. However, according to the present embodiment, the substrate temperature is stabilized, so that the substrate W can be satisfactorily etched without warping.

[0061] In this embodiment, the thin film TF is formed from the upper peripheral edge of the substrate W through the substrate end face to the lower peripheral edge of the substrate W, so that, as shown in FIG. 4, the thin film TF is formed on the outer side in the radial direction of the substrate W within the range where the ultraviolet light L emitted from the light emitting unit 72 is irradiated onto the lower surface Wd of the substrate W, but the thin film TF is not formed on the inner side. Therefore, in this embodiment, as shown in FIG. 3, the light receiving unit 8 is provided outside and close to the light emitting unit 72 in the radial direction of the substrate W. Therefore, the reflected light RL reflected in the region where the thin film TF is formed within the above range can be reliably received, and the reflectance of the thin film TF can be accurately detected. As a result, the substrate W can be satisfactorily etched.

[0062] As described above, in order to reliably receive the reflected light RL reflected in the region where the thin film TF is formed and to increase the heating efficiency of the peripheral portion of the substrate W, it is preferable to dispose the light emitting unit 72 at a position directly below the peripheral portion of the lower surface of the substrate W or in the vicinity thereof. However, in an actual substrate processing apparatus 1, various configurations, such as a splash guard 31, are disposed around the substrate W. Therefore, the space in which the light emitting unit 72 can be disposed is limited to a position directly below the lower surface of the substrate W and away from the edge of the substrate W toward the rotation axis a1 side, and even in the first embodiment, the center position of the range in which the ultraviolet light L from the light emitting unit 72 is irradiated onto the lower surface Wd of the substrate W is 30 mm away from the edge of the substrate. Therefore, as a result of intensive studies, the inventors of the present application have concluded that it is possible to move the center position toward the edge of the substrate by configuring the heating mechanism 7 as follows. Hereinafter, the substrate processing apparatus 1 according to the second embodiment of the present invention will be described with reference to FIGS. 9A, 9B, 10, and 11.

[0063] Fig. 9A is a diagram showing the configuration of a heating mechanism provided in a second embodiment of a substrate processing apparatus according to the present invention. Fig. 9B is a perspective view showing the structure of a heat sink, which is one component of the heating mechanism shown in Fig. 9A, with dots added to clarify the heat sink structure and auxiliary lines shown by dashed dotted lines. The second embodiment is significantly different from the first embodiment in the configuration of a heat sink 73 provided in the heating mechanism 7. The following description will focus on the differences, and the same components will be denoted by the same reference numerals and description of the configuration will be omitted.

[0064] In the second embodiment, the heat sink 73 has the same planar shape as the base member 74, that is, a bottom surface 731 having a substantially sector shape, as shown in FIG. 9B. The side surface of the heat sink 73 is an inclined surface 732, which is finished with a downward inclination from the axis of rotational symmetry 733 in the circumferential direction. The inclination angle θ can be set to 10° to 20°, and by adjusting the inclination angle θ, the center position of the range in which the ultraviolet light L from the light emitting unit 72 is irradiated onto the lower surface Wd of the substrate W can be displaced in the radial direction of the substrate W. For example, when the inclination angle θ is set to 10°, the distance from the substrate end surface to the above-mentioned center position (hereinafter referred to as the "separation distance") is about 20 mm. Furthermore, when the inclination angle θ is increased to 20°, the separation distance becomes about 10 mm.

[0065] Here, in the substrate processing apparatus 1, when the peripheral portion of the substrate W was heated using three types of heating mechanisms 7 with separation distances set to 10 mm (tilt angle θ=20°), 20 mm (tilt angle θ=10°), and 30 mm (tilt angle θ=0°), the temperature of the peripheral portion was measured, and the temperature rise characteristics shown in Figure 10 were obtained.

[0066] FIG. 10 is a graph showing the temperature rise characteristics when the substrate is heated by various heating mechanisms in the substrate processing apparatus. The horizontal axis of the graph shows the elapsed time from the start of lighting of the light-emitting unit 72, and the vertical axis shows the temperature of the peripheral part of the substrate W. As is clear from the figure, the temperature rise curve becomes steeper as the tilt angle θ is set larger. Also, from the graph, the temperature of the peripheral part of the substrate W at the time when 10 seconds have passed since the start of lighting is read, and the correlation between them is summarized in a graph as shown in FIG. 11. As is clear from the figure, the peripheral part of the substrate W can be efficiently heated by tilting the light-emitting element 722. As a result, the time required for the peripheral part of the substrate W to reach a predetermined temperature and stabilize can be shortened, and the tact time required for substrate processing can be shortened.

[0067] Furthermore, the reflected light RL reflected at a position closer to the substrate edge can be detected by the light receiving unit 8, improving the accuracy of reflectance detection. However, as shown in FIG. 9A, the angle of incidence of the ultraviolet light L with respect to the lower surface Wd of the substrate W becomes relatively large, and the angle of reflection of the reflected light RL reflected by the lower surface Wd also becomes large. For this reason, there is a possibility that the reflected light RL penetrates deep into the device. Therefore, in the second embodiment, the heating mechanism 7 is surrounded by a heat-resistant light-shielding member 75 having light-shielding properties, and the light receiving unit 8 is disposed in the heat-resistant light-shielding member 75.

[0068] Incidentally, in the above-mentioned first and second embodiments, the reflected light RL is received and the reflectance is actually measured, but the reflectance may be derived by other means. For example, as shown in FIG. 7, film thickness dependent characteristic information indicating the change in the reflectance of the thin film TF with respect to the film thickness of the thin film TF is known or can be obtained in advance. Therefore, after the film thickness dependent characteristic information is stored in the fixed disk 13 in advance, the film thickness of the thin film TF may be measured continuously or intermittently during the etching process, and the reflectance may be calculated based on the measured value and the film thickness dependent characteristic information (third embodiment). In other words, the etching process may be performed as follows while monitoring the film thickness of the thin film TF.

[0069] 12 is a block diagram showing an electrical configuration of a third embodiment of a substrate processing apparatus according to the present invention. The third embodiment is significantly different from the first embodiment in that a film thickness measuring unit 91 is provided instead of the light receiving unit 8, the film thickness of the thin film TF at the peripheral portion of the substrate W is measured to obtain film thickness information relating to the film thickness, and a reflectance calculating unit 112 calculates the reflectance of the thin film TF based on the film thickness information. The other configurations are basically the same as those of the first embodiment. Therefore, the following description will focus on the differences, and a description of the same configurations will be omitted.

[0070] A conventionally known device can be used as the film thickness measurement unit 91. For example, a spectroscopic ellipsometer, an interference type film thickness meter, a stylus type film thickness meter, etc. can be used. As in the embodiment described later, an image of the thin film TF can be obtained by processing an image captured by an imaging unit such as a camera in an image processing unit, and the film thickness can be calculated by the calculation processing unit 11.

[0071] In the third embodiment, film thickness-dependent characteristic information (FIG. 7) for each material constituting the thin film TF is stored in advance in the fixed disk 13. Then, in step S61 of the temperature control process (step S6), the calculation processing unit 11 reads out film thickness-dependent characteristic information corresponding to the type of the thin film TF based on the etching conditions set in step S1, and calculates the reflectance of the thin film TF based on the film thickness information output from the film thickness measurement unit 91 and the film thickness-dependent characteristic information.

[0072] Therefore, similarly to the first embodiment, the substrate W can be efficiently heated while preventing bumping, and the etching process on the substrate W can be performed satisfactorily.

[0073] In the first to third embodiments, the reflectance of the thin film TF is calculated during the etching process, but the influence of the fluctuation in reflectance is directly related to the etching rate. Therefore, instead of calculating the reflectance, the amount of irradiation light may be adjusted based on the etching rate (fourth embodiment).

[0074] Fig. 13 is a block diagram showing an electrical configuration of a fourth embodiment of a substrate processing apparatus according to the present invention. Fig. 14 is a flow chart showing an etching process performed in the substrate processing apparatus shown in Fig. 13. The fourth embodiment is significantly different from the first embodiment in the following four points. That is, the differences are: Instead of the light receiving unit 8, an imaging unit 92 that images the peripheral portion of the upper surface of the substrate W is provided. The arithmetic processing unit 11 of the control unit 10 has an image processing unit 15 that performs various image processing on the image captured by the imaging unit 92 and outputs a thin film image suitable for film thickness analysis; The calculation processing unit 11 functions as a processing progress acquisition unit 113 that acquires the progress of the etching processing, that is, the etching rate, based on the thin film image output from the image processing unit 15; and The irradiation light amount control unit 111 adjusts the amount of irradiation light L according to the etching rate. Other configurations are basically the same as those in the first embodiment, so the following description will focus on the differences and omit a description of the same configurations.

[0075] In the fourth embodiment, the substrate processing apparatus 1 sets the etching conditions (step S1) and starts the etching process (step S2) in the same manner as in the first embodiment. Then, the calculation processing unit 11 continuously or intermittently determines whether the etching removal of the thin film TF at the peripheral portion of the substrate W is completed (step S3). Then, when the calculation processing unit 11 determines "YES" in step S3, it ends the etching process (step S4) and analyzes and saves the etching conditions (step S5) to end the bevel etching.

[0076] On the other hand, while step S3 is judged as "NO", that is, while the etching process is not completed, the calculation processing unit 11 continuously or intermittently executes a temperature control process (step S6) using the etching rate. In this temperature control process, the imaging unit 92 captures an image of the upper surface Wu of the substrate W from above to obtain an image including an image of the thin film TF (hereinafter referred to as "thin film image"). The image processing unit 15 performs various image processing on this image to obtain a thin film image suitable for analyzing the thickness of the thin film TF. The calculation processing unit 11 analyzes the thin film image to obtain the thickness of the thin film TF, and calculates the etching rate based on the amount of change from the previously obtained thickness (step S66). This etching rate is provided to the irradiation light amount control unit 111.

[0077] The irradiation light amount control unit 111 judges whether the received etching rate is within a preset rate range (corresponding to an example of the "reference range" of the present invention) (step S67). If the etching rate is within the preset rate range ("YES" in step S67), the irradiation light amount control unit 111 returns to step S3 while maintaining the irradiation light amount, i.e., the number of light-emitting units 72 to be turned on.

[0078] On the other hand, if the etching rate is out of the above-mentioned preset rate range ("NO" in step S67), the process proceeds to step S68, where the irradiation light amount control unit 111 determines whether the etching rate is falling (below the above-mentioned preset rate range) or rising (above the above-mentioned preset rate range). If the etching rate is falling ("YES" in step S68), the ultraviolet light L is not applied to the lower surface Wd of the substrate W less than the set amount. Therefore, the irradiation light amount control unit 111 increases the irradiation light amount, that is, the number of the light-emitting units 72 to be turned on (step S65), and then returns to step S3. This optimizes the irradiation light amount applied to the lower surface Wd of the substrate W, thereby preventing a decrease in the etching rate.

[0079] Conversely, if the etching rate is above the target ("NO" in step S68), it is considered that the etching rate is increasing due to excessive ultraviolet light L being applied to the lower surface Wd of the substrate W. In this case, bumping may occur. Therefore, the irradiation light amount control unit 111 reduces the irradiation light amount, that is, the number of light-emitting units 72 to be turned on (step S64), and then returns to step S3. This optimizes the amount of irradiation light applied to the lower surface Wd of the substrate W, making it possible to prevent bumping from occurring.

[0080] As described above, according to the fourth embodiment, similarly to the first to third embodiments, a temperature control process (step S6) utilizing the etching rate is performed in parallel with the etching process for the peripheral portion of the thin film TF formed on the upper surface Wu of the substrate W, that is, the so-called bevel etching. That is, the amount of irradiation light is adjusted based on the change in the etching rate caused by the variation in the thickness of the thin film TF, and the temperature of the substrate W is prevented from changing significantly. As a result, the occurrence of bumping can be effectively prevented. Moreover, the stabilization of the temperature of the substrate W suppresses the variation in the time required for the etching process, and the etching process can be completed at the optimal time for each process. This makes it possible to improve the number of wafers processed per hour and to suppress the amount of chemicals and power used.

[0081] The present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the first and second embodiments, irradiation light amount information regarding the irradiation light amount of the ultraviolet light L irradiated from the light emitting unit 72 when the reflected light RL is received by the light receiving unit 8 is acquired based on the etching conditions, but the irradiation light amount information may be calculated by receiving a part of the ultraviolet light L by a photodiode or the like.

[0082] In the first and second embodiments, the reflectance fluctuation is directly acquired, in the third embodiment, the reflectance fluctuation is indirectly acquired based on the film thickness of the thin film TF, and in the fourth embodiment, the reflectance fluctuation is indirectly acquired based on the etching rate. In addition to these, if the amount of irradiated light is not adjusted despite the reflectance fluctuation, the temperature of the substrate W rises or falls in accordance with the reflectance fluctuation. Therefore, the reflectance fluctuation may be indirectly acquired while monitoring the temperature, and the amount of irradiated light may be adjusted.

[0083] In addition, in the above embodiment, the amount of irradiated light is adjusted by switching the number of lit light-emitting units 72, but of course the amount of irradiated light may be adjusted by increasing or decreasing the amount of light emitted or by blinking each light-emitting unit 72. In addition, although the light-emitting units 72 that emit ultraviolet light L are used, light-emitting units that emit light of other wavelengths may also be used.

[0084] In addition, in the above embodiment, the present invention is applied to a so-called bevel etching technique for etching the peripheral portion of a thin film TF formed on the upper surface Wu of a substrate W, but the application of the present invention is not limited to this, and the present invention can be applied to general processes in which the film thickness of a thin film TF varies by supplying a processing liquid to the thin film TF. [Industrial Applicability]

[0085] This invention can be applied to general substrate processing techniques in which a processing liquid is supplied to a thin film formed on a substrate while the substrate is heated by irradiating one main surface of the substrate rotating around a rotation axis with light, thereby performing processing such as etching on the thin film formed on the substrate. [Explanation of symbols]

[0086] 1...Substrate processing device 7...Heating mechanism 8...Light receiving section 10...Control section 11...Computation processing unit 21...Spin chuck (substrate holder) 72…Light emitting part 81...Photo-detector 111... Irradiation light quantity control unit 112...Reflectance calculation section 113... Processing progress acquisition unit 231...Rotation mechanism a1...Rotation axis L…Ultraviolet light (irradiation light) RL…Reflected light TF…Thin film W…Substrate Wd…Bottom surface (one of the main surfaces of the substrate) Wu: Top surface (other main surface of the substrate)

Claims

1. a substrate holder that holds a substrate and is rotatable around a predetermined rotation axis; a rotation mechanism that rotates the substrate holder around the rotation axis; a heating mechanism having a light emitting unit that irradiates irradiation light onto one main surface of the substrate that rotates around the rotation axis by being held by the substrate holding unit that is rotated by the rotation mechanism, and that heats the substrate by the irradiation light; a processing liquid supply unit that supplies a processing liquid to one main surface of the substrate heated by the heating mechanism, thereby performing a predetermined processing on the thin film formed on the one main surface; a control unit that controls a temperature of the substrate during the processing by adjusting an amount of the irradiation light onto one main surface of the substrate in response to a reflectance of the thin film varying depending on a thickness of the thin film during the processing; A substrate processing apparatus comprising:

2. The substrate processing apparatus according to claim 1 , The processing liquid supplying unit supplies the processing liquid to the other main surface of the substrate heated by the heating mechanism, thereby performing the predetermined processing on a thin film formed on the other main surface.

3. 3. The substrate processing apparatus according to claim 1, a reflected light receiving unit that receives reflected light reflected by one main surface of the substrate and outputs reflected light amount information related to the amount of reflected light, The control unit includes an irradiation light amount control unit that controls the light emitter based on the reflected light amount information output from the reflected light receiving unit to control the irradiation light amount of the irradiation light.

4. The substrate processing apparatus according to claim 3, the control unit further includes a reflectance calculation unit that calculates a reflectance of the thin film based on irradiation light amount information regarding the irradiation light amount when the reflected light is received by the reflected light receiving unit and the reflected light amount information, The irradiation light amount control unit controls the light emitting unit based on the reflectance calculated by the reflectance calculation unit.

5. 3. The substrate processing apparatus according to claim 1, a film thickness measuring unit for measuring a film thickness of the thin film, The control unit is a storage unit that stores film thickness dependent characteristic information indicating a change in reflectance of the thin film with respect to a film thickness of the thin film at a wavelength of the irradiated light; a reflectance calculation unit that calculates a reflectance of the thin film based on thickness information on the thickness of the thin film measured by the thickness measurement unit and the thickness dependent characteristic information; an irradiation light amount control unit that controls the light emitting unit based on the reflectance calculated by the reflectance calculation unit to control an irradiation light amount of the irradiation light; The substrate processing apparatus includes:

6. 3. The substrate processing apparatus according to claim 1, an imaging unit that images a thin film formed on the substrate, The control unit is a processing progress acquisition unit that acquires a progress degree of the processing based on an image captured by the imaging unit; an irradiation light amount control unit that maintains the amount of irradiation light when the degree of progress is within a predetermined reference range, and adjusts the amount of irradiation light in accordance with the degree of progress of the processing when the degree of progress is out of the reference range; The substrate processing apparatus includes:

7. 7. The substrate processing apparatus according to claim 6, The irradiation light intensity control unit adjusts the intensity of the irradiation light so that when the degree of progress falls below the reference range, the intensity of the irradiation light is increased, and when the degree of progress exceeds the reference range, the intensity of the irradiation light is decreased.

8. 8. The substrate processing apparatus according to claim 6, the treatment is an etching treatment for etching the thin film with the treatment liquid, The substrate processing apparatus, wherein the processing progress acquisition unit acquires an etching rate of the thin film as the degree of progress.

9. a processing step of applying a predetermined processing to a thin film formed on one main surface of the substrate by irradiating light onto one main surface of the substrate rotating around a rotation axis to heat the substrate, and supplying a processing liquid onto the one main surface of the substrate; a temperature control step of controlling a temperature of the substrate during the processing by adjusting an amount of light irradiated onto one main surface of the substrate in response to a change in reflectance of the thin film depending on a thickness of the thin film during the processing, in parallel with the processing step; A substrate processing method comprising:

Images