JP2018163980A - Substrate processing method and substrate processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing method capable of excellently removing a resist formed on a surface of a substrate, and a substrate processing apparatus.SOLUTION: In a substrate processing method for removing a resist from a surface of a substrate, a support step of supporting the substrate in horizontal to a support member; a mixture gas supply step (step T3) of supplying a moisture vapor and an ozone gas to the vicinity of the surface of a substrate W; and an ultraviolet radiation step (step T6) of irradiating an ultraviolet radiation to a mixture gas supplied to the vicinity of surface of the substrate W.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for processing a substrate. Examples of substrates to be processed include semiconductor wafers, liquid crystal display substrates, plasma display substrates, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, and photomasks. Substrates such as substrates for substrates, ceramic substrates, and substrates for solar cells are included.

  In the manufacturing process of semiconductor devices, for example, a resist coating process for applying a resist solution on a substrate to form a resist, an exposure process for exposing a predetermined pattern on the resist, and a developing process for developing the exposed resist are sequentially performed. A photolithography process is performed. As a result, a predetermined resist pattern is formed on the substrate. Then, using this resist pattern as a mask, the film to be processed on the substrate is etched. Thereafter, the resist is removed to form a predetermined pattern on the surface of the substrate.

  Patent Document 1 below discloses a method for removing a resist formed on the surface of a substrate by the action of ultraviolet rays and ozone. Specifically, in this method, an ozone atmosphere is provided in the chamber by supplying an ozone-containing gas (a mixed gas of ozone and oxygen) into the chamber that houses the substrate. And ozone is decomposed | disassembled by irradiating a board | substrate with an ultraviolet-ray in ozone atmosphere. As a result, hydroxy radicals (OH radicals), which are active oxygen having relatively high oxidizing power, are generated. The removal of the resist by ozone is promoted by this hydroxy radical.

JP 2000-286251 A Special table 2013-510332 gazette

Hydroxy radicals are likely to be generated by the reaction between ozone and hydrogen radicals. However, the method described in Patent Document 1 cannot supply sufficient hydrogen radicals in the chamber. For this reason, hydroxy radicals cannot be sufficiently generated, and thus there is a possibility that resist peeling cannot be promoted sufficiently.
On the other hand, Patent Document 2 discloses a method of irradiating the surface of a substrate with ultraviolet rays in a state where a liquid film (liquid film) such as ozone water is formed on the surface of the substrate. In this method, hydrogen radicals can be generated from water by ultraviolet rays. However, since ultraviolet rays are absorbed by the liquid film, they cannot reach the vicinity of the surface of the substrate sufficiently, and there is a possibility that sufficient hydrogen radicals cannot be generated near the surface of the substrate. This makes it impossible to generate sufficient hydroxy radicals near the surface of the substrate. Therefore, there is a possibility that peeling of the resist cannot be promoted sufficiently.

Therefore, it is demanded to solve these problems and favorably promote the peeling of the resist formed on the surface of the substrate.
One object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of satisfactorily removing a resist formed on the surface of a substrate.

The present invention is a substrate processing method for removing a resist from the surface of a substrate, wherein the substrate is supported on a support member horizontally, and a mixed gas of water vapor and ozone gas is supplied near the surface of the substrate. There is provided a substrate processing method comprising: a mixed gas supply step for performing an ultraviolet ray irradiation step for irradiating the mixed gas supplied near the surface of the substrate with ultraviolet rays.
According to this method, a mixed gas in which water vapor and ozone gas are mixed is supplied in the vicinity of the surface of the horizontally supported substrate. By irradiating the mixed gas with ultraviolet rays, water vapor in the mixed gas is decomposed. Thereby, hydrogen radicals are generated. Therefore, a sufficient amount of hydroxy radicals can be generated by reacting hydrogen radicals with ozone.

Further, since water vapor, that is, gaseous water is supplied to the surface of the substrate, it is possible to prevent liquid water from adhering to the surface of the substrate. Therefore, ozone can be decomposed in the vicinity of the surface of the substrate without being inhibited by absorption of ultraviolet rays by liquid water.
As a result, the resist formed on the surface of the substrate can be removed (peeled) satisfactorily.
In one embodiment of the present invention, the ultraviolet irradiation step includes a step of generating hydroxy radicals in the vicinity of the surface of the substrate by ultraviolet irradiation and a step of decomposing the resist by the hydroxy radicals. Therefore, the resist can be reliably decomposed by hydroxy radicals generated by the irradiation of ultraviolet rays.

In one embodiment of the present invention, the substrate processing method is further performed in parallel with the mixed gas supply step, and further includes a first heating step of heating the substrate. Thereby, the mixed gas near the surface of the substrate can be heated. Therefore, liquefaction of water vapor near the surface of the substrate can be suppressed.
In one embodiment of the present invention, the substrate processing method further includes a second heating step that is performed in parallel with the ultraviolet irradiation step and heats the substrate. Thereby, the decomposition product of the resist generated near the surface of the substrate is heated. Therefore, the decomposed product of the resist can be sublimated into a gaseous state. Therefore, it can suppress that the decomposition product of a resist solidifies on the surface of a board | substrate. Therefore, the resist formed on the surface of the substrate can be removed satisfactorily.

  In one embodiment of the present invention, the mixed gas supply step includes a mixed gas discharge step of discharging the mixed gas from a discharge port toward the surface of the substrate. According to this method, the ratio (ratio) of water vapor and ozone gas in the vicinity of the surface of the substrate is compared with the structure in which water vapor and ozone gas are discharged toward the surface of the substrate from separate discharge ports. Can be kept even in the whole area.

In one embodiment of the present invention, the substrate processing method includes a space forming step for accommodating the substrate and forming a space blocked from the outside at least before the start of the ultraviolet irradiation step, and execution of the ultraviolet irradiation step. And an exhaust process for exhausting the space.
Thus, the substrate is accommodated in a space blocked from the outside before the mixed gas near the surface of the substrate is irradiated with ultraviolet rays. Therefore, it is possible to irradiate ultraviolet rays in a state where the mixed gas is filled in the space (the space near the surface of the substrate). Therefore, a sufficient amount of hydroxy radicals can be generated. On the other hand, the space for accommodating the substrate is exhausted during irradiation with ultraviolet rays. Thereby, before solidifying on the surface of a board | substrate, the decomposition product of a resist can be discharged | emitted outside the space.

  In one embodiment of the present invention, the substrate processing method further includes a mixed gas forming step of forming the mixed gas by supplying the ozone gas to liquid water stored in a tank. Therefore, when preparing the mixed gas, it is not necessary to prepare the water vapor separately from the ozone gas and then mix the ozone gas and the water vapor. That is, the mixed gas can be easily prepared.

  In one embodiment of the present invention, there is provided a substrate processing apparatus for removing a resist from a surface of a substrate, a supporting member that horizontally supports the substrate, and a mixed gas that supplies a mixed gas toward the surface of the substrate. A supply unit; an ultraviolet irradiation unit for irradiating ultraviolet rays toward the surface of the substrate; a mixed gas supply step for supplying the mixed gas from the mixed gas supply unit to the vicinity of the surface of the substrate; and a vicinity of the surface of the substrate. There is provided a substrate processing apparatus including a control device that executes an ultraviolet irradiation step of irradiating the ultraviolet irradiation unit with ultraviolet rays in a state where the mixed gas is supplied.

  According to this configuration, a mixed gas in which water vapor and ozone gas are mixed is supplied near the surface of the substrate that is horizontally supported by the support member. By irradiating the mixed gas with ultraviolet rays from the ultraviolet irradiation unit, water vapor in the mixed gas is decomposed. Thereby, hydrogen radicals are generated. Therefore, a sufficient amount of hydroxy radicals can be generated by reacting hydrogen radicals with ozone.

Further, since water vapor, that is, gaseous water is supplied to the surface of the substrate, it is possible to prevent liquid water from adhering to the surface of the substrate. Therefore, ozone can be decomposed in the vicinity of the surface of the substrate without being inhibited by absorption of ultraviolet rays by liquid water.
As a result, the resist formed on the surface of the substrate can be satisfactorily removed.
In one embodiment of the present invention, in the ultraviolet irradiation step, the control device executes a step of generating a hydroxy radical near the surface of the substrate by ultraviolet irradiation and a step of decomposing a resist by the hydroxy radical. . Therefore, the resist can be reliably decomposed by hydroxy radicals generated by the irradiation of ultraviolet rays.

  In one embodiment of the present invention, the substrate processing apparatus further includes a first substrate heating unit that heats the substrate. And the said control apparatus performs the 1st heating process which heats the said board | substrate to the said 1st board | substrate heating unit in parallel with the said mixed gas supply process. Therefore, the mixed gas near the surface of the substrate can be heated using the first substrate heating unit. Therefore, liquefaction of water vapor near the surface of the substrate can be suppressed.

  In one embodiment of the present invention, the substrate processing apparatus further includes a second substrate heating unit that heats the substrate. And the said control apparatus performs the 2nd heating process which heats the said board | substrate to the said 2nd board | substrate heating unit in parallel with the said ultraviolet irradiation process. Therefore, the resist decomposition product generated near the surface of the substrate can be heated using the second substrate heating unit. Thereby, the decomposition product of the resist can be sublimated to be in a gaseous state. Therefore, it can suppress that the decomposition product of a resist solidifies on the surface of a board | substrate. Therefore, the resist formed on the surface of the substrate can be removed satisfactorily.

  In one embodiment of the present invention, the substrate processing apparatus further includes a space forming unit that accommodates the substrate and forms a space blocked from the outside, and an exhaust unit that exhausts the space. The control device controls the space forming unit to form a space at least before the start of the ultraviolet irradiation process, and controls the exhaust unit during the execution of the ultraviolet irradiation process. And an exhaust process for exhausting the space.

  Thereby, before the mixed gas near the surface of the substrate is irradiated with ultraviolet rays by the space forming unit, a space blocked from the outside is formed, and the substrate is accommodated in the space. Therefore, ultraviolet rays can be irradiated from the ultraviolet irradiation unit in a state where the mixed gas is filled in the space (a space near the surface of the substrate). Therefore, a sufficient amount of hydroxy radicals can be generated. On the other hand, during irradiation with ultraviolet light, the space for housing the substrate is exhausted by the exhaust unit. Thereby, before solidifying on the surface of a board | substrate, the decomposition product of a resist can be discharged | emitted outside the space.

  In one embodiment of the present invention, the substrate processing apparatus further includes a tank that stores liquid water and an ozone gas supply unit that supplies ozone gas to the liquid water stored in the tank. And the said control apparatus performs the mixed gas formation process which forms the said mixed gas by supplying the said ozone gas to the liquid water stored in the said tank from the said ozone gas supply unit. According to this configuration, the mixed gas is formed by supplying ozone gas from the ozone gas supply unit to the liquid water stored in the tank. Therefore, when preparing the mixed gas, it is not necessary to prepare the water vapor separately from the ozone gas and then mix the ozone gas and the water vapor. That is, the mixed gas can be easily prepared.

FIG. 1 is a schematic plan view for explaining the internal layout of the substrate processing apparatus according to the first embodiment of the present invention. FIG. 2 is a schematic view of a gas processing unit provided in the substrate processing apparatus. FIG. 3 is a schematic view of a cross section taken along line III-III in FIG. FIG. 4 is a schematic diagram for explaining the configuration of the mixed gas supply unit and the discharge unit provided in the gas processing unit. FIG. 5 is a block diagram for explaining an electrical configuration of a main part of the substrate processing apparatus. FIG. 6 is a flowchart for explaining an example of substrate processing by the substrate processing apparatus. FIG. 7 is a schematic diagram illustrating a cross-sectional state of the substrate before and after the substrate processing illustrated in FIG. 6 is performed. FIG. 8 is a flowchart showing an example of the dry processing step shown in FIG. 6 (step S2 in FIG. 6). FIG. 9A is a schematic diagram for explaining the dry treatment process. FIG. 9B is a schematic diagram for explaining the dry treatment process. FIG. 9C is a schematic diagram for explaining the dry treatment process. FIG. 9D is a schematic diagram for explaining the dry treatment process. FIG. 10 is a graph for comparing the oxidation potential of an oxidant and the binding energy of a covalent bond. FIG. 11 is a schematic diagram of a gas processing unit according to a first modification of the present embodiment. FIG. 12 is a schematic diagram of a gas processing unit according to a second modification of the present embodiment. FIG. 13 is a schematic view of the hood of the gas processing unit according to the third modification of the present embodiment as viewed from below.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an illustrative plan view for explaining an internal layout of a substrate processing apparatus 1 according to an embodiment of the present invention.
The substrate processing apparatus 1 is a single wafer processing apparatus that processes substrates W such as silicon wafers one by one. The substrate processing apparatus 1 includes a load port LP that holds a plurality of carriers C that accommodate a substrate W, and a plurality of processing units 2 that process the substrate W transferred from the plurality of load ports LP with a processing fluid. The processing fluid includes a processing gas that is a gas for processing the substrate W and a processing liquid that is a liquid for processing the substrate W.

The substrate processing apparatus 1 includes an indexer robot IR, a shuttle SH, and a main transfer robot CR arranged on a transfer path extending from a plurality of load ports LP to a plurality of processing units 2, and a control device 3 that controls the substrate processing apparatus 1. including.
The indexer robot IR transports the substrate W between the plurality of load ports LP and the shuttle SH. The shuttle SH transports the substrate W between the indexer robot IR and the main transport robot CR. The main transfer robot CR transfers the substrate W between the shuttle SH and the plurality of processing units 2. 1 indicate the moving direction of the indexer robot IR and the moving direction of the shuttle SH.

  The plurality of processing units 2 form four towers respectively arranged at four positions separated horizontally. Each tower includes a plurality of processing units 2 stacked in the vertical direction. Two towers are arranged on both sides of the conveyance path. The plurality of processing units 2 include a plurality of dry processing units 2D that process the substrate W while the substrates W are dried, and a plurality of wet processing units 2W that process the substrate W with the processing liquid. Two towers on the load port LP side are constituted by a plurality of dry processing units 2D. The remaining two towers are constituted by a plurality of wet processing units 2W.

  The wet processing unit 2W includes a wet chamber 9 provided with a loading / unloading port through which the substrate W passes, a shutter 10 for opening / closing the loading / unloading port of the wet chamber 9, and a substrate W held horizontally in the wet chamber 9. A spin chuck 11 that rotates the substrate W around a rotation axis A <b> 1 that passes through the center of the substrate W, and a plurality of nozzles 12 and 13 that discharge a processing liquid toward the substrate W held by the spin chuck 11 are included. The plurality of nozzles 12 and 13 include a chemical liquid nozzle 12 that discharges a chemical liquid and a rinse liquid nozzle 13 that discharges a rinse liquid.

The dry processing unit 2D includes a dry chamber 4 provided with a carry-in / out port through which the substrate W passes, a shutter 5 that opens and closes the carry-in / out port of the dry chamber 4, and a mixed gas of water vapor and ozone gas (O ₃ gas). And a gas processing unit 8 for processing the substrate W.
FIG. 2 is a schematic diagram for explaining a configuration example of the gas processing unit 8.
The gas processing unit 8 includes a support member 23 that supports the substrate W from below so that the substrate W is in a horizontal posture, and a heater 22 that heats the support member 23 to heat the substrate W supported by the support member 23. And a hood 30 that faces the support member 23 from above, and a hood lifting unit 29 that lifts and lowers the hood 30 relative to the support member 23 and the base ring 27. The gas processing unit 8 horizontally places the substrate W between the base ring 27 that supports the hood 30 from below, the O-ring 28 that seals between the hood 30 and the base ring 27, and the support member 23 and the hood 30. It further includes a plurality of lift pins 24 to be supported and a lift lifting / lowering unit 26 that lifts and lowers the plurality of lift pins 24.

The heater 22 is connected to a heater energization unit 31 that supplies power to the heater 22. In the present embodiment, the heater 22 is adjacent to the support member 23 from below. However, unlike the present embodiment, the heater 22 may be disposed inside the support member 23.
The support member 23 includes a disc-shaped base portion 23b disposed below the substrate W, a plurality of hemispherical protrusion portions 23a protruding upward from the upper surface of the base portion 23b, and an outer peripheral surface of the base portion 23b. And an annular flange portion 23c protruding in the direction. The upper surface of the base portion 23 b is parallel to the lower surface of the substrate W and has an outer diameter equal to or greater than the outer diameter of the substrate W. The plurality of projecting portions 23a are in contact with the lower surface of the substrate W at positions away from the upper surface of the base portion 23b. The plurality of protruding portions 23a are arranged at a plurality of positions in the upper surface of the base portion 23b so that the substrate W is horizontally supported. The substrate W is supported horizontally with the lower surface of the substrate W separated upward from the upper surface of the base portion 23b. A base ring 27 is connected to the flange portion 23c.

The dry processing unit 2D includes a cooling unit 7 (see FIG. 1) for cooling the substrate W heated by the heater 22 in the dry chamber 4, and a substrate W heated by the gas processing unit 8 in the dry chamber 4. And an indoor transport mechanism 6 (see FIG. 1).
The plurality of lift pins 24 are respectively inserted into a plurality of through holes that penetrate the support member 23. Intrusion of fluid from the outside of the gas processing unit 8 into the through hole is prevented by a bellows 25 surrounding the lift pin 24. The gas processing unit 8 may include an O-ring that seals a gap between the outer peripheral surface of the lift pin 24 and the inner peripheral surface of the through hole in place of or in addition to the bellows 25. The lift pin 24 includes a hemispherical upper end portion that contacts the lower surface of the substrate W. The upper ends of the lift pins 24 are arranged at the same height.

  The lift elevating unit 26 includes an upper position where the upper ends of the plurality of lift pins 24 are positioned above the support member 23 (the position shown in FIGS. 9A and 9B), and upper ends of the plurality of lift pins 24 are located inside the support member 23. The plurality of lift pins 24 are moved in the vertical direction between the lower position (the position shown in FIG. 2) retracted. The lift lifting unit 26 may be an electric motor or an air cylinder, or may be an actuator other than these.

  The hood lifting / lowering unit 29 vertically moves the hood 30 between an upper position (position shown in FIG. 9A) and a lower position (position shown in FIG. 2). The upper position is a position where the lower surface of the hood 30 is separated from the upper surface of the base ring 27 so that the substrate W can pass between the lower surface of the hood 30 and the upper surface of the base ring 27. The lower position is a position where a gap between the lower surface of the hood 30 and the upper surface of the base ring 27 is sealed, and a space S for accommodating the substrate W supported by the support member 23 is formed. The hood lifting / lowering unit 29 may be an electric motor or an air cylinder, or may be an actuator other than these.

The gas processing unit 8 includes a mixed gas supply unit 14 that supplies a mixed gas toward the upper surface of the substrate W, an exhaust unit 15 that exhausts the space S, and an ultraviolet irradiation unit 16 that irradiates ultraviolet rays toward the upper surface of the substrate W. And further including.
The mixed gas supply unit 14 includes a plurality of mixed gas nozzles 40 that discharge the mixed gas toward the upper surface of the substrate W, and a mixed gas supply pipe 42 that supplies the mixed gas from the mixed gas supply source 41 to the plurality of mixed gas nozzles 40. And a mixed gas valve 43 interposed in the mixed gas supply pipe 42. The plurality of mixed gas nozzles 40 have discharge ports 40 a that open at positions facing the substrate W on the lower surface of the hood 30. The mixed gas valve 43 switches presence / absence of supply of mixed gas to the plurality of mixed gas nozzles 40.

The exhaust unit 15 has a plurality of exhaust ports 50a that open on the upper surface of the support member 23, and an exhaust pipe 52 that guides the gas in the space S to the outside of the space S, and the exhaust pipe 52 that opens and closes the flow path. And an exhaust valve 53.
The ultraviolet irradiation unit 16 includes a plurality of ultraviolet lamps 60 and a lamp energization unit 61 connected to the plurality of ultraviolet lamps 60. The ultraviolet lamp 60 emits ultraviolet rays when supplied with power from the lamp energization unit 61. In the present embodiment, one lamp energization unit 61 is provided for each ultraviolet lamp 60, but a common lamp energization unit may be provided for a plurality of ultraviolet lamps 60. The plurality of ultraviolet lamps 60 are attached to the lower surface of the hood 30, and at least some of them face the substrate W. The ultraviolet lamp 60 is composed of, for example, a low-pressure mercury lamp that irradiates ultraviolet rays of 185 nm.

FIG. 3 is a schematic view of a cross section taken along line III-III in FIG.
The plurality of mixed gas nozzles 40 includes a central nozzle 40A having a discharge port 40a that opens at a position facing the center of the substrate W, and a plurality of outer peripheries having a discharge port 40a that opens at a position facing the outer periphery of the substrate W. Nozzle 40B. The central portion of the substrate W is a portion located at the center of the substrate W in plan view. The outer peripheral portion of the substrate W is a portion between the central portion of the substrate W and the peripheral portion of the substrate W in plan view. The plurality of outer peripheral nozzles 40B are arranged at equal intervals around a vertical line A2 passing through the center of the substrate W. For example, a total of four outer peripheral nozzles 40B are provided at 90 ° intervals.

  The ultraviolet lamp 60 includes a center lamp 60A that faces the vicinity of the center of the substrate W, and a plurality of outer peripheral lamps 60B that face the outer periphery of the substrate W. The center lamp 60A surrounds the center nozzle 40A in a plan view and is located on the vertical line A2 side with respect to the plurality of outer peripheral nozzles 40B. The plurality of outer peripheral lamps 60B are arranged at equal intervals around the vertical line A2. For example, a total of four outer peripheral lamps 60B are provided at intervals of 90 °. The plurality of outer peripheral lamps 60B are located on the side opposite to the vertical line A2 side from the plurality of outer peripheral nozzles 40B. The plurality of outer peripheral lamps 60B are also opposed to the peripheral edge of the substrate W.

FIG. 4 is a schematic diagram for explaining the configuration of the mixed gas supply unit 14 and the exhaust unit 15 provided in the gas processing unit 8.
The mixed gas supply source 41 includes a tank 41A in which liquid water is stored, and an ozone gas supply unit 41B that supplies ozone gas to the liquid water stored in the tank 41A. The ozone gas supply unit 41B includes an ozone gas nozzle 44 that supplies ozone gas to water in the tank 41A, an ozone supply pipe 45 that supplies ozone gas from an ozone gas supply source to the ozone gas nozzle 44, and an ozone gas that is interposed in the ozone supply pipe 45. And a valve 46. The ozone gas nozzle 44 has a discharge port 44a disposed in the water in the tank 41A. The ozone gas valve 46 switches whether or not ozone gas is supplied to the ozone gas nozzle 44.

  The mixed gas supply pipe 42 of the mixed gas supply unit 14 includes a main pipe 42A in which a mixed gas valve 43 is interposed, and a plurality of branch pipes 42B branched from the other end of the main pipe 42A. The main pipe 42A has an intake port 42a provided at a position above the water surface in the tank 41A. The same number of branch pipes 42B as the mixed gas nozzles 40 are provided, and each branch pipe 42B is connected to the corresponding mixed gas nozzle 40 one by one.

The exhaust pipe 52 of the exhaust unit 15 is branched from the main pipe 52A in which an exhaust valve 53 and a filter 54 are interposed, and the main pipe 52A, and each branch pipe has one outlet 50a (see also FIG. 2). 52B. The filter 54 is for filtering the gas discharged from the space S.
The mixed gas valve 43, the ozone gas valve 46, the tank 41 </ b> A, the exhaust valve 53 and the filter 54 are disposed in the fluid box 17 adjacent to the dry chamber 4.

  FIG. 5 is a block diagram for explaining an electrical configuration of a main part of the substrate processing apparatus 1. The control device 3 includes a microcomputer, and controls a control target provided in the substrate processing apparatus 1 according to a predetermined program. More specifically, the control device 3 includes a processor (CPU) 3A and a memory 3B in which a program is stored, and the processor 3A executes various programs to execute various controls for substrate processing. It is configured as follows. In particular, the control device 3 controls the operations of the indexer robot IR, the main transfer robot CR, the shuttle SH, the elevating units 26 and 29, the energizing units 31 and 61, the valves 43, 46, and 53, the wet processing unit 2W, and the like.

FIG. 6 is a process diagram showing an example of the processing of the substrate W executed by the substrate processing apparatus 1, and mainly shows processing realized by the control device 3 executing a program. FIG. 7 is a schematic diagram illustrating a cross section of the substrate W before and after the example of the processing of the substrate W illustrated in FIG. 6 is performed.
As shown on the left side of FIG. 7, the substrate W to be processed by the substrate processing apparatus 1 is subjected to an etching process for etching a thin film covered with a resist pattern PR to form a thin film pattern PF. It is. That is, the carrier C in which such a substrate W is accommodated is placed on the load port LP. As described below, in the substrate processing by the substrate processing apparatus 1, the resist pattern PR located on the thin film pattern PF is removed (resist removing step). The right side of FIG. 7 shows a cross section of the substrate W on which the resist removing process has been performed.

  When the substrate W is processed by the substrate processing apparatus 1, the indexer robot IR, the shuttle SH, and the main transfer robot CR transfer the substrate W in the carrier C placed on the load port LP to the dry processing unit 2D (see FIG. 6 step S1). In the dry processing unit 2D, a dry processing step of processing the substrate W with the mixed gas is performed (step S2 in FIG. 6). Thereafter, the main transfer robot CR carries the substrate W in the dry processing unit 2D into the wet processing unit 2W (step S3 in FIG. 6).

  In the wet processing unit 2W, a wet processing step of supplying a processing liquid to the upper surface of the substrate W is performed while rotating the substrate W (step S4 in FIG. 6). Specifically, a chemical solution supply step is performed in which the chemical solution is discharged to the chemical solution nozzle 12 toward the upper surface of the substrate W while rotating the substrate W. Thereafter, a rinsing liquid supply step is performed in which the rinsing liquid is discharged to the rinsing liquid nozzle 13 toward the upper surface of the substrate W while rotating the substrate W. Then, the drying process which dries the board | substrate W by rotating the board | substrate W at high speed is performed. Subsequently, the indexer robot IR, the shuttle SH, and the main transfer robot CR transfer the substrate W in the wet processing unit 2W to the carrier C placed on the load port LP (step S5 in FIG. 6).

FIG. 8 is a flowchart showing an example of the dry processing step (step S2 in FIG. 6). 9A to 9D are schematic views for explaining the dry treatment process (step S2 in FIG. 6).
As shown in FIG. 9A, when the substrate W is loaded into the dry processing unit 2D, the hood lift unit 29 positions the hood in the upper position, and the lift lift unit 26 positions the plurality of lift pins 24 in the upper position. In this state, the main transfer robot CR moves the hand H into the dry chamber 4 while supporting the substrate W with the hand H. Thereafter, the substrate W having the device forming surface facing upward is placed on the plurality of lift pins 24. The main transport robot CR moves the hand H out of the dry chamber 4 after passing the substrate W on the hand H to the dry processing unit 2D. Thereafter, the carry-in / out port of the dry chamber 4 is closed. In this way, the loading of the substrate W into the dry chamber 4 is completed (step T1). The substrate W may be placed on the plurality of lift pins 24 by the hand H of the main transport robot CR, or may be placed on the plurality of lift pins 24 by the indoor transport mechanism 6 (see FIG. 1).

  As shown in FIG. 9B, the hood lifting / lowering unit 29 moves the hood 30 to the lower position (step T2). Thereby, a space S for accommodating the substrate W is formed between the hood 30 and the support member 23 (space forming step). The hood 30 and the support member 23 function as a space forming unit that accommodates the substrate W. At the same time, the lift lifting unit 26 moves the plurality of lift pins 24 to the lower position. Thereby, the board | substrate W is supported by the support member 23 (support process).

  The heater energization unit 31 energizes the heater 22 before the substrate W is supported by the support member 23. Therefore, the support member 23 is heated by the heater 22 before the substrate W is supported by the support member 23. The support member 23 is maintained at a temperature higher than room temperature (for example, 100 ° C. or higher). When the substrate W is supported by the support member 23, heating of the substrate W is started (step T3).

  Next, as shown in FIG. 9C, the ozone gas valve 46 is opened, and ozone gas is sent into the water in the tank 41A. Specifically, the water in the tank 41A is passed through the bubbles of ozone gas by bubbling. Thereby, water vapor | steam generate | occur | produces in a bubble, this water vapor | steam mixes with ozone gas, and mixed gas is formed (mixed gas formation process). Then, the mixed gas valve 43 is opened, and the mixed gas is discharged from the discharge ports 40a of the plurality of mixed gas nozzles 40 via the tank 41A and the mixed gas supply pipe 42 (step T4). That is, the mixed gas discharge process is performed. Thereby, the mixed gas is supplied into the space S.

Then, the exhaust valve 53 is opened (step T5). Thereby, the air in the space S is pushed out of the space S by the mixed gas. By continuing to supply the mixed gas to the space S, the mixed gas is filled in the space S. When the mixed gas is filled in the space S, the mixed gas is sufficiently supplied also near the upper surface of the substrate W (mixed gas supply step).
Further, the substrate W is heated by the heater 22 while being supplied to the mixed gas in the vicinity of the upper surface of the substrate W (first heating step). That is, the first heating process is performed in parallel with the mixed gas supply process. The heater 22 functions as a first heating unit that heats the substrate W.

Then, as shown in FIG. 9D, the ultraviolet lamp 60 is irradiated with ultraviolet rays by energizing the ultraviolet lamp 60 in a state where the mixed gas is supplied near the upper surface of the substrate W (step T6). Thereby, the mixed gas near the upper surface of the substrate W is irradiated with ultraviolet rays (ultraviolet irradiation step).
The space S is already formed before the mixed gas near the upper surface of the substrate W starts to be irradiated with ultraviolet rays (before the ultraviolet irradiation step). Further, the exhaust valve 53 is kept open while the mixed gas near the upper surface of the substrate W is irradiated with ultraviolet rays. Therefore, the exhaust process for exhausting the space S is performed during the execution of the ultraviolet irradiation process.

  Further, the substrate W is heated by the heater 22 while the mixed gas in the vicinity of the upper surface of the substrate W is irradiated with ultraviolet rays (second heating step). That is, the second heating process is performed in parallel with the ultraviolet irradiation process. The heater 22 functions as a second heating unit that heats the substrate W. In the present embodiment, when the heater 22 heats the substrate W, the first heating process and the second heating process are performed in parallel.

As will be described in detail later, the resist formed on the upper surface of the substrate W is oxidized and decomposed by irradiating the mixed gas near the upper surface of the substrate W with ultraviolet rays. As a result, the resist pattern PR is removed from the upper surface of the substrate W.
Then, after performing ultraviolet irradiation for a predetermined time, the lamp energizing unit 61 stops energizing the ultraviolet lamp 60 from the upper surface of the substrate W (step T7). Then, the mixed gas valve 43 is closed and the supply of the mixed gas to the space S is stopped (step T8). Then, the exhaust valve 53 is closed and the exhaust of the space S is stopped (step T9). Thereafter, the hood elevating unit 29 raises the hood 30 to the upper position (step T10).

Then, the substrate W on the support member 23 is lifted by a plurality of lift pins 24. The main transfer robot CR receives the substrate W with the hand H after the substrate W is cooled by the cooling unit 7 (see FIG. 1). Thereafter, the main transfer robot CR carries the substrate W on the hand H into the wet processing unit 2W.
According to the present embodiment, a mixed gas in which water vapor and ozone gas are mixed is supplied near the upper surface of the substrate W supported horizontally by the support member 23. Then, when the mixed gas is irradiated with ultraviolet rays from the ultraviolet irradiation unit 16, hydroxy radicals (.OH) are generated. Specifically, first, by irradiation with ultraviolet rays, water vapor (H ₂ O) is decomposed to generate hydroxy radicals (.OH) and hydrogen radicals (.H) as shown in the following chemical formula 1.

Then, as shown in the following chemical formula 2, hydrogen radicals (.H) and ozone (O ₃ ) react to generate hydroxy radicals (.OH) and oxygen (O ₂ ).

Therefore, a sufficient amount of hydroxy radicals (.OH) can be generated by decomposition of water vapor (H ₂ O) and reaction of hydrogen radicals (.H) with ozone (O ₃ ).
Furthermore, since water vapor (gaseous water) is supplied to the upper surface of the substrate W, it is possible to suppress water droplets (liquid water) from adhering to the upper surface of the substrate W. Therefore, ozone can be decomposed in the vicinity of the upper surface of the substrate W without being inhibited by absorption of ultraviolet rays by liquid water.

  The phenolic resin constituting the resist is oxidized by the hydroxy radicals and ozone thus generated. As a result, the phenol resin is decomposed into lower carboxylic acids such as acetic acid and oxalic acid. These lower carboxylic acids are further oxidized by hydroxy radicals and ozone and decomposed into carbon dioxide and water. In this way, the resist is decomposed by hydroxy radicals and ozone.

As described above, since the resist formed on the upper surface of the substrate W is decomposed by a sufficient amount of hydroxy radicals, the resist can be favorably removed from the surface of the substrate W.
The lifetime of the hydroxy radical is 1.0 × 10 ⁻⁶ sec. According to the configuration (method) of this embodiment, the hydroxy radical can be generated near the upper surface of the substrate W. Therefore, the amount of hydroxyl radicals that decompose the resist before the hydroxy radicals disappear can be increased.

  In other words, in the present embodiment, the ultraviolet irradiation step includes a step of generating hydroxy radicals near the upper surface of the substrate W by irradiation of ultraviolet rays, and a step of decomposing the resist by hydroxy radicals. Therefore, the resist can be reliably decomposed by the hydroxy radical generated by the irradiation of ultraviolet rays from the ultraviolet irradiation unit 16.

Here, the mechanism of resist decomposition will be described. The molecule constituting the resist formed on the surface of the substrate W contains a carbon-carbon double bond (C = C), and this double bond is broken by oxidation to decompose the resist. Is done.
FIG. 10 is a graph for comparing the oxidation potential of an oxidant and the binding energy of a covalent bond. The right half of the graph shown in FIG. 10 shows the binding energy required to break a typical covalent bond contained in the organic compound. The left half of the graph shown in FIG. 10 shows an oxidation potential as an index of the oxidation ability of a typical oxidant. When the oxidation potential of the oxidant is higher than the bond energy of the covalent bond, the covalent bond is broken by oxidation. As shown in FIG. 10, the bond energy of the carbon-carbon double bond (C = C) is 1.5V. On the other hand, the oxidation potential of ozone (O ₃ ) is 2.07V, and the oxidation potential of hydroxy radical (.OH) is 2.81V. Therefore, the carbon-carbon double bond (C = C) is oxidized by both ozone (O ₃ ) and hydroxy radical (.OH). Since the oxidation potential of hydroxy radicals (.OH) is higher than the oxidation potential of ozone (O ₃ ), the generation of more hydroxyl radicals effectively creates carbon-carbon double bonds (C = C). Can be oxidized. That is, the resist can be efficiently decomposed.

Moreover, according to this embodiment, the 1st heating process which heats the board | substrate W is performed in parallel with a mixed gas supply process. Therefore, the mixed gas near the upper surface of the substrate W is heated by the heater 22. Therefore, liquefaction of water vapor in the vicinity of the upper surface of the substrate W can be suppressed.
Moreover, according to this embodiment, the 2nd heating process which heats the board | substrate W is performed in parallel with an ultraviolet irradiation process. Therefore, the decomposition product of the resist generated near the upper surface of the substrate W is heated by the heater 22. Thereby, the decomposition product of the resist can be sublimated to be in a gaseous state. Therefore, it is possible to suppress the decomposition product of the resist from solidifying on the upper surface of the substrate W. Therefore, the resist formed on the surface of the substrate W can be removed satisfactorily. By performing the second heating process for heating the substrate W in parallel with the ultraviolet irradiation process, liquefaction of water vapor in the vicinity of the upper surface of the substrate W can be suppressed even in the ultraviolet irradiation process.

  Further, according to the present embodiment, in the mixed gas supply process, the mixed gas is discharged from the discharge port 40a toward the upper surface of the substrate W (mixed gas discharge process). Thus, the mixed gas is discharged from the discharge port 40a toward the upper surface of the substrate W. Therefore, the ratio (ratio) of water vapor and ozone gas in the vicinity of the upper surface of the substrate W in the entire area of the upper surface of the substrate as compared with the configuration in which the water vapor and ozone gas are discharged toward the upper surface of the substrate W from separate discharge ports. Can be kept even.

Further, according to the present embodiment, the space S is formed before the start of the ultraviolet irradiation process (space forming process), and the space S is exhausted during the execution of the ultraviolet irradiation process (exhaust process).
As a result, the substrate W is accommodated in the space S blocked from the outside before the mixed gas near the upper surface of the substrate W is irradiated with ultraviolet rays. Therefore, it is possible to irradiate ultraviolet rays in a state where the mixed gas is filled in the space S (the space near the upper surface of the substrate W). Therefore, a sufficient amount of hydroxy radicals can be generated. On the other hand, the space S is exhausted during the irradiation of ultraviolet rays. Accordingly, the resist decomposition product can be discharged to the outside of the space S before the resist decomposition product is solidified on the upper surface of the substrate W.

  Moreover, according to this embodiment, mixed gas is formed by supplying ozone gas from the ozone gas supply unit 41B to the liquid water stored in the tank 41A (mixed gas forming step). Therefore, when preparing the mixed gas, it is not necessary to prepare the water vapor separately from the ozone gas and then mix the ozone gas and the water vapor. That is, the mixed gas can be easily prepared as compared with the case of preparing the water vapor separately from the ozone gas.

  FIG. 11 is a schematic diagram of a gas processing unit 8 according to a first modification of the present embodiment. In the gas processing unit 8 according to the first modification, one mixed gas supply pipe 42 is connected to each mixed gas nozzle 40. The mixed gas supply pipe 42 is a merging pipe 42C connected to the mixed gas nozzle 40, a steam pipe 42D for supplying water vapor supplied from a water vapor supply source to the merging pipe 42C, and a ozone pipe supplied from an ozone gas supply source. Ozone gas piping 42E supplied to 42C. The water vapor in the water vapor pipe 42D and the ozone gas in the ozone gas pipe 42E are mixed in the merge pipe 42C. The mixed gas mixed in the joining pipe 42 </ b> C is supplied from the mixed gas nozzle 40. The steam pipe 42D is provided with a steam valve 43D that opens and closes the flow path. An ozone gas valve 43E that opens and closes the flow path is interposed in the ozone gas pipe 42E.

  The substrate processing apparatus 1 according to the first modification can also perform the same substrate processing as that of the substrate processing apparatus 1 according to the present embodiment. In addition, the same effect as that of the present embodiment is obtained in the first modification. In the first modification, the component ratio (ratio) of water vapor and ozone gas in the mixed gas can be adjusted by adjusting the opening of the water vapor valve 43D and the ozone gas valve 43E. For example, if there is too much water vapor in the mixed gas, water droplets are likely to adhere to the upper surface of the substrate W. On the other hand, when there is too little water vapor contained in the mixed gas, hydroxy radicals cannot be generated sufficiently. By adjusting the ratio of water vapor in the mixed gas, it is possible to suppress adhesion of water droplets to the upper surface of the substrate W while sufficiently generating hydroxy radicals.

  FIG. 12 is a schematic diagram of a gas processing unit 8 according to a second modification of the present embodiment. The gas processing unit 8 according to the second modification is configured such that water vapor and ozone gas are discharged from separate discharge ports 80a and 81a. The mixed gas supply unit 14 includes a water vapor nozzle 80 that discharges water vapor and an ozone gas nozzle 81 that discharges ozone gas instead of the mixed gas nozzle 40. The water vapor nozzle 80 has a discharge port 80a. The ozone gas nozzle 81 has a discharge port 81a. The mixed gas supply unit 14 includes a water vapor supply pipe 82 that supplies water vapor from a water vapor supply source to the water vapor nozzle 80, a water vapor valve 83 that is interposed in the water vapor supply pipe 82 and opens and closes the flow path thereof, and an ozone gas supply source. An ozone gas supply pipe 84 that supplies ozone gas to the ozone gas nozzle 81 and an ozone gas valve 85 that is interposed in the ozone gas supply pipe 84 and opens and closes the flow path thereof are included. The water vapor discharged from the water vapor nozzle 80 and the ozone gas discharged from the ozone gas nozzle 81 are mixed in the space S, whereby a mixed gas is formed. By forming the mixed gas in the space S, the mixed gas is supplied near the upper surface of the substrate W.

Also in the substrate processing apparatus 1 according to the second modification, the same substrate processing as that of the substrate processing apparatus 1 according to the present embodiment can be executed. In addition, the second modification also has the same effect as this embodiment.
The present invention is not limited to the embodiments described above, and can be implemented in other forms.

For example, in the above-described embodiment, the mixed gas supply process and the ultraviolet irradiation process are performed in parallel. However, unlike the above-described embodiment, the ultraviolet irradiation may be started after the supply of the mixed gas is stopped. That is, in FIG. 8, the mixed gas supply stop (step T8) may be executed before the start of ultraviolet irradiation (step T6).
In such a case, the second heating step is started after the end of the first heating step. Therefore, it is possible to change the temperature of the heater 22 between the first heating process for heating the substrate W in the mixed gas supply process and the second heating process for heating the substrate W in the ultraviolet irradiation process. For example, when the sublimation temperature of the decomposed product of the resist is different from the temperature necessary for preventing water droplets from adhering to the surface of the substrate W, the temperature of the substrate W in the first heating step and the second temperature are adjusted accordingly. It is possible to change the temperature of the substrate W in the heating process. When the second heating process is started after the first heating process is finished, the first heater that heats the substrate W in the first heating process and the substrate W that heats the substrate W in the second heating process are used instead of the heater 22. Two heaters may be provided.

In the above-described embodiment, the space S is formed by lowering the hood 30 before starting the supply of the mixed gas. However, unlike the above-described embodiment, the space S may be formed after the supply of the mixed gas is started. That is, in FIG. 8, the mixed gas supply start (step T4) may be executed before the hood lowering (step T2).
Unlike the above-described embodiment, the exhaust unit 15 may include an exhaust pump (not shown) such as a vacuum pump that is connected to the exhaust pipe 52 and exhausts the space S through the exhaust port 50a. .

  Unlike the above-described embodiment, as shown in FIG. 13, the ultraviolet lamp 60 may include a rod-shaped lamp 60C extending linearly instead of the center lamp 60A and the outer peripheral lamp 60B (see FIG. 3). Good. The ultraviolet lamp 60 is not limited to these forms, and is preferably provided so as to be evenly opposed to the entire substrate W in order to uniformly generate hydroxy radicals on the entire surface of the substrate W.

Further, as indicated by a two-dot chain line in FIG. 3, the plurality of outer peripheral nozzles 40 </ b> B of the mixed gas nozzle 40 may be arranged side by side in a radial direction orthogonal to the vertical line A <b> 2 passing through the center of the substrate W. Moreover, the some outer periphery nozzle 40B arrange | positioned along with radial direction may be arrange | positioned at equal intervals around the perpendicular line A2.
In addition, various changes can be made within the scope described in the claims.

1: substrate processing device 3: control device 14: mixed gas supply unit 15: exhaust unit 16: ultraviolet irradiation unit 22: heater (first substrate heating unit, second substrate heating unit)
23: Support member (space forming unit)
30: Hood (space forming unit)
40a: discharge port 41A: tank 41B: ozone gas supply unit S: space W: substrate

Claims (13)

A substrate processing method for removing a resist from a surface of a substrate,
A supporting step of horizontally supporting the substrate on a supporting member;
A mixed gas supply step of supplying a mixed gas of water vapor and ozone gas near the surface of the substrate;
And an ultraviolet irradiation step of irradiating the mixed gas supplied near the surface of the substrate with ultraviolet rays.   The substrate processing method according to claim 1, wherein the ultraviolet irradiation step includes a step of generating hydroxy radicals near the surface of the substrate by ultraviolet irradiation, and a step of decomposing the resist by the hydroxy radicals.   The substrate processing method according to claim 1, further comprising a first heating step that is performed in parallel with the mixed gas supply step and heats the substrate.   The substrate processing method according to claim 1, further comprising a second heating step that is performed in parallel with the ultraviolet irradiation step and heats the substrate.   The substrate processing method according to claim 1, wherein the mixed gas supply step includes a mixed gas discharge step of discharging the mixed gas from a discharge port toward the surface of the substrate. At least before the start of the ultraviolet irradiation step, a space forming step for accommodating the substrate and forming a space blocked from the outside;
The substrate processing method according to claim 1, further comprising an exhaust process for exhausting the space during execution of the ultraviolet irradiation process.   The substrate processing method according to claim 1, further comprising a mixed gas forming step of forming the mixed gas by supplying the ozone gas to liquid water stored in a tank. A substrate processing apparatus for removing a resist from a surface of a substrate,
A support member for horizontally supporting the substrate;
A mixed gas supply unit for supplying a mixed gas toward the surface of the substrate;
An ultraviolet irradiation unit for irradiating ultraviolet rays toward the surface of the substrate;
A mixed gas supply step for supplying the mixed gas from the mixed gas supply unit to the vicinity of the surface of the substrate; and ultraviolet irradiation for irradiating the ultraviolet irradiation unit to the ultraviolet irradiation unit in a state where the mixed gas is supplied to the vicinity of the surface of the substrate. A substrate processing apparatus including a control device for performing the process.   9. The substrate according to claim 8, wherein in the ultraviolet irradiation step, the control device executes a step of generating hydroxy radicals near the surface of the substrate by ultraviolet irradiation and a step of decomposing a resist by the hydroxy radicals. Processing equipment. A first substrate heating unit for heating the substrate;
10. The substrate processing apparatus according to claim 8, wherein the control device executes a first heating step in which the first substrate heating unit heats the substrate in parallel with the mixed gas supply step. A second substrate heating unit for heating the substrate;
The said control apparatus performs the 2nd heating process which heats the said board | substrate to the said 2nd substrate heating unit in parallel with the said ultraviolet irradiation process, The substrate processing apparatus as described in any one of Claims 8-10. . A space forming unit that accommodates the substrate and forms a space blocked from outside; and an exhaust unit that exhausts the space;
The control device controls the space forming unit to form a space by controlling the space forming unit at least before the start of the ultraviolet irradiation process, and controls the exhaust unit during execution of the ultraviolet irradiation process. The substrate processing apparatus according to claim 8, further performing an exhaust process of exhausting. A tank for storing liquid water;
An ozone gas supply unit that supplies ozone gas to liquid water stored in the tank;
The said control apparatus performs the mixed gas formation process which forms the said mixed gas by supplying the said ozone gas to the liquid water stored in the said tank from the said ozone gas supply unit, The any one of Claims 8-12 The substrate processing apparatus according to one item.

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