JP5454449B2 - Resist removing method, resist removing apparatus, and storage medium - Google Patents

Description

  The present invention relates to a resist removal method, a resist removal apparatus, and a storage medium for removing a resist film formed on a substrate.

  The semiconductor device manufacturing process includes a process of exposing a semiconductor wafer on which a resist film is formed according to a predetermined circuit pattern. In this exposure, a photomask opened according to the circuit pattern is used.

  In order to manufacture the photomask, a resist is supplied to the center of rotation of a square substrate that is supported horizontally and rotates around a vertical axis, and the resist is spread on the peripheral edge of the substrate by centrifugal force, so-called spin coating. Is performed to form a resist film. Then, after exposing the resist so as to correspond to the pattern using a technique such as electron beam drawing or laser drawing, the resist is developed using a developer, and the base film of the resist film is etched according to the formed resist pattern. . Thereafter, the resist film is removed. For example, as described in Patent Document 1, this removal treatment is performed by oxidizing the resist film by water-treating the substrate by supplying a treatment gas containing water vapor and hydrogen peroxide to the substrate, and then applying water to the substrate. A processing solution is supplied to remove the resist film.

  By the way, when a resist film is formed on a square substrate by spin coating as described above, the resist pushed from the central portion to the peripheral portion of the substrate flows toward the corner portion along the side of the substrate. The film thickness at the periphery of the formed resist film is larger than the film thickness at the center. Therefore, there is a possibility that the resist film remains on the peripheral portion of the substrate after the resist film removing process. In order to prevent this, for example, it is conceivable to use a resist having high solubility as a processing solution, to increase the supply time of the processing solution, or to increase the temperature of the processing solution. The underlying film is damaged, and as a result, a normal photomask may not be manufactured.

  Patent Document 1 does not discuss such a problem, and therefore cannot solve the problem. In addition, in Patent Document 2, an acidic or alkaline aqueous solution is preferentially brought into contact with an outer peripheral portion of a region where the resist film is thick at the outer peripheral portion of the substrate, thereby reducing the thickness of the entire substrate. However, it does not describe how to supply the aqueous solution specifically, and is insufficient to solve the above problem. Under such circumstances, there is a demand for a technique that can remove the resist film without damaging the substrate.

JP 2004-31750 (FIG. 1 etc.) PCT / JP2007 / 000573 (paragraph 0053 to paragraph 0056)

  The present invention has been made under such circumstances, and an object of the present invention is to remove the resist film without damaging the substrate in which the film thickness of the resist film at the peripheral portion is thicker than the central region. It is to provide technology that can.

The resist removal method of the present invention has a mask made of a resist film formed on the surface thereof, and an oxidizing property for oxidizing the resist film over the entire surface of the substrate where the film thickness of the peripheral resist film is thicker than the central region. A first step of supplying the processing fluid and removing the resist film;
A second step of removing the resist at the edge of the substrate by discharging an alkaline processing liquid from the nozzle along the edge of the substrate to the peripheral edge of the substrate;
Equipped with a,
The second step is performed after the first step .

Specific examples of the resist removal method of the present invention are as follows, for example.
(1) The first step is a step of supplying a processing gas for making the resist water-soluble, which is an oxidizing processing fluid, to the substrate, and then supplying a cleaning liquid to the entire surface of the substrate to remove the resist. And a step of performing.
(2) The first step includes a step of supplying a processing solution for oxidizing the resist, which is an oxidizing processing fluid, to the entire substrate and removing the resist.
(3) The first step includes a step of supplying a cleaning liquid to the entire substrate after removing the supply of the processing liquid to the substrate and removing the first processing liquid from the substrate .
(4 ) The substrate is rectangular.

The resist removal apparatus of the present invention is an apparatus for removing a resist film on a substrate having a mask made of a resist film formed on the surface thereof, and having a film thickness of the resist film at the peripheral portion thicker than the central region.
A first processing unit configured to supply a processing fluid for oxidizing the resist film to the entire surface of the substrate and remove the resist film;
A second processing unit that includes a nozzle that discharges an alkaline processing liquid, and is configured to discharge the processing liquid from the nozzle along the side of the substrate to the periphery of the substrate;
And a controller that outputs a control signal so that the substrate is processed by the first processor and then processed by the second processor .

Specific embodiments of the resist removing apparatus of the present invention are as follows, for example.
( 5 ) The first processing section is an oxidizing processing fluid, a gas supply section for supplying a processing gas for water-solubilizing the resist to the substrate, and a cleaning liquid is supplied to the entire surface of the substrate for water-solubilization. ( 6 ) The first processing unit supplies an entire surface of the substrate with a processing solution for making the resist water-soluble, which is an oxidizing processing fluid, and removes the resist. A liquid processing unit to be removed is provided.
( 7 ) The liquid processing unit includes a processing liquid removing unit that supplies a cleaning liquid to the entire substrate and removes the first processing liquid from the substrate after the supply of the processing liquid to the substrate is stopped .
( 8 ) The substrate is a square substrate.

The storage medium of the present invention is a storage medium storing a computer program used in an apparatus for removing a mask made of a resist film formed on a surface of a substrate,
The computer program is for carrying out the resist removal method described above.

  According to the present invention, a first step of supplying an oxidizing processing fluid for oxidizing a resist film and removing the resist film, and an alkaline processing liquid along the side of the substrate at the peripheral portion of the substrate. And a second step of removing the resist at the edge of the substrate by discharging the nozzle from the nozzle. Therefore, the resist film remains at the periphery of the substrate. Further, as the processing liquid for removing the resist, a processing liquid that does not damage the substrate can be selected, and the supply time of the processing liquid can be shortened, so that the substrate can be prevented from being damaged.

It is a top view of the resist removal apparatus which concerns on embodiment of this invention. It is a vertical side view of the said resist removal apparatus. It is a vertical side view of the said resist removal apparatus. It is a vertical side view of the resist oxidation unit provided in the resist removal apparatus. It is a vertical side view of the said resist oxidation unit. It is a schematic plan view of the resist oxidation unit. It is a top view of the board | substrate edge part processing unit provided in the said resist removal apparatus. It is a perspective view of the substrate edge processing unit. It is a vertical side view of the U-shaped base | substrate provided in the said board | substrate edge part processing unit. FIG. 4 is a vertical side view of the cleaning processing unit 6. 4 is a perspective view of a substrate holding part 61 provided in the cleaning processing unit 6. FIG. It is explanatory drawing which shows a mode that a board | substrate receives processing and changes with a resist removal apparatus. It is explanatory drawing which shows a mode that a board | substrate receives processing and changes with a resist removal apparatus. It is explanatory drawing which shows a mode that a board | substrate receives processing and changes with a resist removal apparatus. It is explanatory drawing which shows a mode that a board | substrate receives processing and changes with a resist removal apparatus. It is explanatory drawing which shows a mode that a board | substrate receives processing and changes with a resist removal apparatus. It is explanatory drawing which shows a mode that a board | substrate receives processing and changes with a resist removal apparatus. It is explanatory drawing which shows a mode that a board | substrate receives processing and changes with a resist removal apparatus. It is explanatory drawing which shows a mode that a board | substrate receives processing and changes with a resist removal apparatus. It is the schematic of the edge part of the board | substrate before receiving a resist removal process. It is the schematic of the corner | angular part of a board | substrate before receiving a resist removal process. It is the schematic of the edge part of the board | substrate after a peripheral part removal process. It is the schematic of the corner | angular part of the board | substrate after a peripheral part removal process. It is the schematic of the edge part of the board | substrate after a resist removal process. It is the schematic of the corner | angular part of the board | substrate after a resist removal process. It is the schematic of the edge part of the board | substrate before receiving a resist removal process. It is the schematic of the corner | angular part of a board | substrate before receiving a resist removal process. It is the schematic of the edge part of the board | substrate after a peripheral part removal process. It is the schematic of the corner | angular part of the board | substrate after a peripheral part removal process. It is the schematic of the edge part of the board | substrate after a resist removal process. It is the schematic of the corner | angular part of the board | substrate after a resist removal process.

  A resist removal apparatus 1 according to the present invention will be described. The resist removing apparatus 1 is an apparatus for removing a resist film formed on the surface of a square substrate B. This substrate B is a mask substrate used for manufacturing a photomask, and the film under the resist film is etched using the resist film as a mask. The resist film is formed by so-called spin coating in which the substrate B is rotated around its central axis, the resist is supplied to the rotation center, and is spread to the peripheral edge of the substrate B by centrifugal force. The film thickness of the part is larger than the film thickness of the central part.

  The resist removing apparatus 1 includes a processing unit for performing each processing on the substrate B. The processing unit includes a resist modification processing unit 2 constituting a first processing unit and a substrate end serving as a second processing unit. A partial processing unit 4 and a cleaning processing unit 6 that constitutes a first processing unit together with the resist modification processing unit 2 are included. The resist modification processing unit 2 is a gas supply unit that oxidizes the resist film with a processing gas containing water vapor and ozone gas to make it water-soluble. The oxidized resist film is particularly highly soluble in an alkaline processing solution. The substrate edge processing unit 4 performs a resist removal process on the peripheral edge of the substrate B. The cleaning processing unit 6 is a cleaning liquid supply unit, and performs resist removal processing on the entire surface of the substrate B. Each unit will be described in detail later.

  FIG. 1 is a schematic plan view of the resist removing apparatus 1, and FIGS. 2 and 3 are side views thereof. The resist removing apparatus 1 includes a carrier station C1 that carries in and out a carrier C in which a substrate B is accommodated, a processing station C2 having the above-described units, a processing station C2, and chemicals and gases used in the processing station C2. And a chemical station C3 for storing and generating the carrier station C1, the processing station C2, and the chemical station C3 are arranged in this order on a straight line.

  As shown in FIG. 1, the carrier station C <b> 1 has a mounting table 11 on which a plurality of carriers C can be mounted, and faces the lid 10 that forms the side wall of the carrier C mounted on the mounting table 11. A window portion 13 that can be opened and closed by a shutter 12 is provided. The shutter 12 has a gripping means (not shown) for gripping the lid 10 that forms the side wall of the carrier C, and grips the lid 10 as shown by a dotted line in FIG. The lid 10 can be retracted.

  The carrier station C1 has a substrate transport mechanism 14 that transfers the substrate B between the carrier C and the processing station C2. The substrate transport mechanism 14 includes a transport arm 15 that is movable in the arrangement direction of the carrier C mounted on the mounting table 11, can be moved back and forth, can be moved up and down, and can be rotated about a vertical axis. Support the back edge of B.

  The processing station C2 includes a shelf unit U1 on the carrier station C1 side, and the shelf unit U1 includes transfer stages TRS1 and TRS2 on which the substrate B is placed, and a stage that cools the placed substrate B. The cooling units CPL1 and CPL2 are stacked on each other. The substrate B loaded from the carrier station C1 is delivered to the delivery stage TRS1, and the substrate B returned to the carrier station C1 is delivered to the delivery stage TRS2. In FIG. 2, 16a and 16b are transfer ports provided in the boundary wall that divides the carrier station C1 and the processing station C2, and the transfer arm 16 is connected to the transfer stages TRS1 and TRS2 through the transfer ports 16a and 16b. to access.

  When viewing the processing station C2 from the carrier station C1, for example, eight resist modification processing units (VOS) 2 are arranged in two rows and four stages on the left side, and the resist modification processing unit 2 is opposed to the right side. Two substrate edge processing units 4 and two cleaning processing units 6 are provided. In this example, the substrate end processing unit 4 is stacked on the carrier station C1 side, and the cleaning processing unit 6 is stacked on the chemical station C3 side.

  A main substrate transport mechanism 17 is provided so as to be surrounded by the shelf unit U1, the resist modification processing unit (VOS) 2, the substrate edge processing unit 4, and the cleaning processing unit 6. A shelf unit U2 is provided so as to face the shelf unit U1 with the main substrate transport mechanism 17 interposed therebetween. The shelf unit U2 is configured by stacking heating units (HP) 19 for heating the substrate B in four stages.

  The main substrate transport mechanism 17 has a transport arm 18 that supports and transports the rear edge of the substrate B. The transfer arm 18 is configured to be rotatable about a vertical axis, movable back and forth in the front-rear direction, and movable up and down, and transfers the substrate B between units provided in the processing station C2.

  The chemical station C3 is provided with a processing gas supply unit 10A and a processing liquid supply unit 10B. The processing gas supply unit 10A includes an ozone gas generation unit (not shown) that generates ozone gas by discharging in a gas containing oxygen, and a water vapor generation unit (not shown) that generates water vapor. A gas obtained by mixing N2 gas as a dilution gas with water vapor is supplied to the resist modification processing unit 2 as a processing gas. The processing liquid supply unit 10B stores each processing liquid supplied to the substrate B by the substrate edge processing unit 4 and the cleaning processing unit 6, and supplies these processing liquids to each processing unit.

  The resist removing apparatus 1 is provided with a control unit 100 including a computer. The control unit 100 includes a data processing unit including a program, a memory, and a CPU. The control unit 100 sends a control signal to each part of the resist removing apparatus 1 from the control unit 100 to transport the substrate B as described later. A group of steps is assembled so that the substrate B can be processed. This program (including programs related to processing parameter input operations and display) is stored in a computer storage medium such as a flexible disk, compact disk, hard disk, or MO (magneto-optical disk) memory card and installed in the control unit 100. Is done.

  Hereinafter, the configuration of each unit provided in the processing station C2 will be described. First, the resist modification unit 2 will be described with reference to FIGS. 4 and 5 which are longitudinal side views. The resist modification processing unit 2 includes a hermetically sealed chamber 21 that accommodates the substrate B. The chamber 21 includes a fixed lower container 21a and a lid 21b that covers the upper surface of the lower container 21a. Can be moved up and down by a cylinder 22. 4 shows a state in which the lid 21b is closed in order to process the substrate B, and FIG. 5 shows a state in which the lid 21b is opened in order to carry the substrate B into the chamber 21. In the figure, reference numeral 21 c denotes an O-ring for making the inside of the chamber 21 airtight.

  The lower container 21a is provided with a stage 23 on which the substrate B is placed, and the stage 23 is provided with support pins 23a for supporting the edge of the back surface of the substrate. The peripheral edge of the stage 23 rises to form an upright wall 24, and suppresses the processing gas supplied into the chamber 21 from flowing into the back surface of the substrate B. A heater 25 is embedded in the stage 23.

  A gas inlet 26 for introducing the processing gas into the chamber 21 and a gas outlet 27 for exhausting the processing gas to the outside are opened in the side wall of the lower container 21 a, and the processing supplied from the gas inlet 26. The gas flows in the horizontal direction in the chamber 21 toward the gas discharge port 27. This processing gas is a mixed gas of water vapor and N2 gas obtained by vaporizing ozone gas and pure water, and is supplied from the processing gas supply unit 10A of the chemical station C3. An exhaust mechanism 28 constituted by a vacuum pump or the like is connected to the gas outlet 27.

  On the back surface of the lid 21b, claw members 31 that hold the back surface edge of the substrate B are provided at, for example, three locations (one location in FIG. 4 and only two locations in FIG. 5). The substrate transport mechanism 17 delivers the substrate B to the claw member 31. When the lid 21 b is lowered while the claw member 31 holds the substrate B, the substrate B is transferred to the stage 23. A heater 32 is embedded in the lid 21b and adjusts the temperature of the substrate B together with the heater 25 of the lower container 21a.

  A ring member 33a is provided outside the lower container 21a, and a ring member 33b is provided outside the lid 21b. The ring member 33a and the ring member 33b are provided with a notch 33c from the outer periphery toward the inside. A plurality of the notches 33c are formed in the circumferential direction of the ring members 33a and 33b, and are arranged so as to overlap each other. A rotation drive mechanism 34 is provided below the chamber 21, and a plurality of connection portions 35 extend outward from the chamber 21 from the rotation drive mechanism 34, and the connection portions 35 are vertically driven by the rotation drive mechanism 34. Rotate around an axis. A support portion 36 that extends upward on the outer periphery of the ring members 33a and 33b is provided at the distal end of the connection portion 35. Press rollers 37a and 37b that rotate about a horizontal axis are supported on the support portion 36 in the vertical direction. .

  As indicated by the chain line in the plan view of the chamber 21 in FIG. 6, when the substrate B is processed, the pressing rollers 37a and 37b ride on the ring members 33a and 33b and press the ring members 33a and 33b together to process the chamber 21. Keep the space airtight. When the substrate B is delivered, the pressing rollers 37a and 37b are moved to a position overlapping the notch 33c so that they do not interfere with the elevation of the lid 21b.

  Next, the substrate edge processing unit 4 will be described based on the plan view of FIG. 5 and the perspective view of FIG. The substrate end processing unit 4 includes a transfer chuck 41 that transfers the substrate B to and from the main substrate transfer mechanism 17, four mounting tables 45 on which the substrate B is mounted by the transfer chuck 41, and two nozzles Part 50.

  The delivery chuck 41 is formed in a horizontal square ring shape, and a plurality of support pins 42 for supporting the back surface edge of the substrate B are arranged on the front surface thereof. The delivery chuck 41 is connected to a drive mechanism 44 provided on the lower side of the delivery chuck 41 via a support member 43, and is configured to be movable up and down and rotatable about a vertical axis by the drive mechanism 44. Thereby, the delivery chuck 41 can change the orientation of the substrate B placed on the placement table 45.

  Two of the four mounting tables 45 are opposed to each other with an interval in the front-rear direction (Y-axis direction in FIG. 7), and the opposed groups are respectively along the left-right direction (X-axis direction in FIG. 7). It is provided at intervals. Support pins 46 are provided on the upper surface of each mounting table 45, and an edge portion of the substrate B is mounted on each support pin 46 so that the substrate B is supported horizontally. In the figure, reference numeral 47 denotes a support member for the mounting table 45 provided at the lower part of each mounting table 45.

  Further, on the mounting table 45 arranged in the left-right direction (X direction), run-up stages 48, 48 are arranged. The run-up stage 48 is a horizontal plate-like member extending in the left-right direction, and both left and right ends thereof are widened in the front-rear direction, and are configured as a widened portion 49 having a rectangular shape in plan view. The widened portion 49 serves to regulate the position of the substrate B in the lateral direction, and the air flow around the nozzle portion 50 is less affected when the corners of the substrate B are processed than when the sides of the substrate B are processed. And the role of preventing change.

  Next, the two nozzle parts 50 will be described. Each nozzle unit 50 includes a base 51 formed in a U shape in a side view and a support member 52 that supports the base 51, and the bases 51 are provided to face each other in the left-right direction. . The support member 52 is configured to be movable in the front-rear direction along a guide 53 extending in the front-rear direction.

  Referring also to FIG. 9, the base 51 is composed of an upper piece 51 a, a lower piece 51 b, and a wall 51 c, and the upper piece 51 a and the lower piece 51 b are substrates placed on the placing table 45. It is provided at a height position that sandwiches the ends of B. The upper piece portion 51a is provided with a processing liquid discharge port 54a that opens to the surface of the end portion of the substrate B, and the lower piece portion 51b is provided with a processing liquid discharge port 54b that opens to the back surface of the end portion of the substrate B. Yes. Two of these treatment liquid discharge ports 54a and 54b are provided at intervals in the moving direction of the base 51 (the front and back direction of the paper surface of FIG. 9). A processing liquid supply mechanism 55 and a cleaning liquid supply mechanism 5A are connected to the processing liquid discharge ports 54a and 54b. The processing liquid supply mechanism 55 supplies TMAH (tetramethylammonium hydroxide), which is an alkaline chemical, as the processing liquid to the processing liquid discharge ports 54a and 54b, and the cleaning liquid supply mechanism 5A uses pure water as the cleaning liquid. 54a and 54b. These TMAH and pure water are switched to each other and supplied to the substrate B from the processing liquid discharge ports 54a and 54b.

  Further, a gas discharge port 56 is provided on the lower surface of the upper piece 51a closer to the center of the substrate B than the processing liquid discharge port 54a, and discharges N2 gas supplied from an N2 gas supply mechanism 57. . The gas discharge ports 56 are opened obliquely toward the wall 51c, and a large number are provided in the moving direction of the base 51. The wall 51c has an exhaust port 58 connected to the exhaust mechanism 5A. When the processing liquid is discharged to the edge of the substrate B from the processing liquid discharge ports 54a and 54b, exhaust from the exhaust port 58 and discharge of N2 gas from the gas discharge port 56 are performed, and the excess processing liquid is dissolved. The resist does not scatter to the center side of the substrate B and is removed from the exhaust port 58. The arrows in FIG. 9 indicate the flow of discharged liquid and exhaust gas by the discharged processing liquid and N2 gas. The upper piece portions 51a and 51b are provided with light projecting portions 59a and 59b. When the substrate B and the run-up stage 48 block light projection from the light projecting portion 59a to the light receiving portion 59b, the above-described substrate B The processing liquid is discharged, N2 gas is discharged, and the exhaust port 58 is evacuated.

  Next, the cleaning unit 6 will be described with reference to FIGS. 10 and 11. The cleaning processing unit 6 includes a substrate holding unit 61 that holds the substrate B. The substrate holding unit 61 includes a horizontal ring member 62 and a plurality of support pins 63 arranged in the circumferential direction of the ring member 62. It is configured. The lower side of the support pin 63 has an enlarged diameter. The lower side of the enlarged diameter holds the edge of the back surface of the substrate B and regulates the position of the side of the substrate B on the upper side. A support member 64 extends from the inner periphery of the ring member 62 toward the center of the ring member, and the support member 64 is connected to a shaft portion 65 extending in the vertical direction. A plurality of support members 64 are provided in the circumferential direction of the ring member 62, and the support members 64 are opened so that the cleaning liquid can be supplied to the back surface of the substrate B from below the support members 64. The shaft portion 65 is connected to the drive mechanism 66, and the substrate B held by the ring member 62 via the shaft portion 65 is rotated by the drive mechanism 66 around its central axis. Further, the ring member 62 is moved up and down by the drive mechanism 66, and the substrate B is transferred to and from the main substrate transport mechanism 17.

  A support plate 67 is provided so as to surround the shaft portion 65, and two back surface cleaning nozzles 68 are provided on the support plate 67. The back surface cleaning nozzle 68 is disposed below the end of the substrate B. The back surface cleaning nozzle 68 supplies, for example, pure water, which is a cleaning liquid, and SC1 (a mixed solution of ammonia water, hydrogen peroxide water, and water) to the center portion of the substrate B while switching to each other. Further, a guide member 69 having an inclined surface that descends outward from the back surface cleaning nozzle 68 is provided, and a liquid receiving portion 72 having a recess 71 is provided below the guide member 69. The liquid flowing on the inclined surface is guided by the recess 71. A drainage port 73 is opened on the bottom surface of the recess 71. In addition, an exhaust pipe 74 standing on the bottom surface of the recess 71 is provided to exhaust the periphery of the substrate B.

  A cylindrical intermediate cup 75 surrounding the side of the substrate holding part 61 is provided between the liquid receiving part 72 and the guide member 69, and the upper part of the intermediate cup 75 bends inward. ing. The intermediate cup 75 receives the cleaning liquid scattered from the substrate B on its inner peripheral surface and guides it to the recess 71. An outer cup 76 is provided outside the intermediate cup 75 so as to surround the intermediate cup 75 and prevents the cleaning liquid from splashing. The upper end of the outer cup 76 is bent inward and extends obliquely. The outer cup 76 is configured to be movable up and down via an elevating mechanism 78 so as not to hinder the movement of a surface cleaning nozzle 77 described later. The surface cleaning nozzle 77 is configured to be movable between the center of the substrate B and a standby area (not shown) provided outside the outer cup 76. For example, the surface cleaning nozzle 77 switches between pure water and SC1 as a cleaning liquid to the substrate B. Supply.

  Next, a processing procedure in the resist removal apparatus 1 will be described with reference to FIGS. In this example, a resist film 81 made of a negative resist is formed on the surface of the substrate B carried into the resist removing apparatus 1. As shown in FIG. 12, the peripheral portion of the resist film 81 is raised by the centrifugal force acting when the resist film 81 is formed by spin coating.

  The substrate B transferred to the mounting table 11 of the carrier station C1 while being stored in the carrier C is transferred in the order of the substrate transfer mechanism 14 → the transfer stage TRS1 of the processing station C2 → the main substrate transfer mechanism 17. The substrate is transferred to the lid 21b of the resist modification processing unit 2 by the substrate transport mechanism 17. When the lid 21b is lowered and the substrate B is delivered to the stage 23 and the inside of the chamber 21 becomes airtight, the gas is discharged from the gas outlet 27 and the ozone, water vapor, and N2 gas described above are discharged from the gas inlet 26. The process gas containing is supplied, and forms the airflow which goes to a horizontal direction as shown by the arrow in FIG.

  The resist film 81 is oxidized by being exposed to the processing gas, and is denatured so as to have high solubility in alkali. After the supply of the processing gas is stopped, N 2 gas is supplied into the chamber 21, the processing gas in the chamber 21 is purged, the lid 21 b is opened, and the substrate B is transferred to the chamber by the main substrate transfer mechanism 17. 21. The main substrate transport mechanism 17 transports the substrate B to the cleaning processing unit 6, and the substrate holder 61 moves upward to receive the substrate B, and then descends to the processing position of the substrate B.

  After the surface cleaning nozzle 77 moves from the outside of the outer cup 76 to the center of the substrate B, the outer cup 76 moves up. As the substrate holding portion 61 rotates, pure water W is discharged from the front surface cleaning nozzle 77 and the back surface cleaning nozzle 68 to the front and back center portions of the substrate B, respectively. The discharged pure water W spreads to the peripheral edge of the substrate B by centrifugal force (FIG. 14). As a result, the resist film 81 on the surface of the substrate B is dissolved in the pure water W and removed. When the discharge of the pure water W from the front surface cleaning nozzle 77 and the back surface cleaning nozzle 68 is stopped, the rotational speed of the substrate holder 61 is increased, the pure water W is shaken off, and the substrate B is dried (FIG. 15). Thereafter, the rotation of the substrate holder 61 is stopped, the outer cup 76 is lowered, the surface cleaning nozzle 77 is retracted to the outside of the outer cup 76, the substrate holder 61 is raised, and the substrate is transferred to the main substrate transfer mechanism 17. B is delivered.

  Subsequently, the main substrate holding unit 17 transports the substrate B to the substrate edge processing unit 4, and the substrate B is transferred to the mounting table 45 via the chuck 41. Thereafter, when the base body 51 of each nozzle portion 50 moves from one end side of the guide 53 toward the other end side of the guide 53 and reaches the run-up stage 48 on one end side of the guide 53, exhaust from the exhaust port 58, The N2 gas is discharged from the gas discharge port 56 and the TMAH, which is the processing liquid, is discharged from the processing liquid discharge ports 54a and 54b.

  The processing liquid is supplied to the resist 82 remaining at the end of the substrate B along the two opposing sides of the substrate B. The resist 82 is dissolved, and the dissolved resist 82 and excess processing liquid are discharged from the exhaust port 58. To be removed. In FIG. 16, the flow of the processing liquid discharged from the substrate 51 is indicated by arrows. When the base 51 passes over the run-up stage 48 on the other end side of the guide 53, the exhaust, the discharge of N2 gas and the discharge of the processing liquid are temporarily stopped and the base 51 returns to the one end side of the guide 53.

  Then, the chuck 41 lifts the substrate B, rotates 90 °, and descends to transfer the substrate B to the mounting table 45 again. Then, the base 51 moves again toward the other end of the guide 53, and exhaust, N2 gas and processing liquid are discharged as in the previous processing, and along the two opposite sides of the substrate B. The resist 82 is dissolved. In this way, the processing liquid is supplied to the entire circumference of the substrate B, the resist 82 on the peripheral edge of the substrate B is removed (FIG. 17), and the base 51 passes over the run-up stage 48 on the other end side of the guide 53. The exhaust, the discharge of N2 gas, and the discharge of the processing liquid are stopped again, and the base 51 returns to one end side of the guide 53.

  Thereafter, the base body 51 moves from one end side of the guide 53 toward the other end side of the guide 53, and when reaching the run-up stage 48 on one end side of the guide 53, exhaust from the exhaust port 58, and from the gas discharge port 56. N2 gas is discharged and pure water is discharged from the treatment liquid discharge ports 54a and 54b. As in the case of supplying TMAH, the substrate 51 continues to move while the substrate 51 moves, and the pure water is washed away from the TMAH adhering to the substrate B and removed from the exhaust port 58 together with the TMAH. When the supply of pure water to the two sides of the substrate B is finished, the orientation of the substrate B of the mounting table 45 is changed by 90 ° as in the case of supplying TMAH, and pure water is supplied to the remaining two sides. . When pure water is supplied to the entire peripheral edge of the substrate B, the chuck 41 lifts the substrate B and transfers it to the main substrate transport mechanism 17.

  The main substrate transport mechanism 17 transports the substrate B to the cleaning processing unit 6. Then, as described above, when the substrate holding unit 61 receives the substrate B and rotates, the processing liquid L, for example, SC1 is transferred from the front surface cleaning nozzle 77 and the back surface cleaning nozzle 68 moved to the center of the substrate B to the surface of the substrate B. Resist residues and particles discharged to the center of the back surface and adhering to the substrate B are removed by squeezing out of the substrate B by centrifugal force (FIG. 18). Thereafter, pure water W is discharged from the front surface cleaning nozzle 77 and the rear surface cleaning nozzle 68 instead of SC1, and the processing liquid L is removed. Thereafter, when the discharge of the pure water W from the front surface cleaning nozzle 77 and the back surface cleaning nozzle 68 is stopped, the rotation speed of the substrate holder 61 is increased, the pure water W is shaken off, and the substrate B is dried (FIG. 19). ).

  Thereafter, the rotation of the substrate holder 61 is stopped, the outer cup 76 is lowered, the surface cleaning nozzle 77 is retracted to the outside of the outer cup 76, the substrate holder 61 is raised, and the substrate is transferred to the main substrate transfer mechanism 17. B is delivered. The main substrate holding part 17 delivers the substrate B to the heating unit 19, and the substrate B is heated and dried. Thereafter, the main substrate holding unit 17 transports the substrate B to the cooling unit CPL, and after the substrate B is cooled, it is transported to the delivery stage TRS2 and returned to the carrier C by the substrate transport mechanism 14.

  According to this resist removing apparatus 1, after the resist film of the substrate B is altered and water-solubilized by the resist modification processing unit 2, the resist at the center of the substrate B is removed by the cleaning processing unit 6, and then the substrate edge processing unit 4, TMAH which is an alkaline processing liquid is supplied to the peripheral portion of the substrate B, and the resist remaining on the peripheral portion is removed. Therefore, it is possible to suppress the resist from remaining on the peripheral edge of the substrate B, and to use a treatment liquid (cleaning liquid) that has a small influence on the substrate as the treatment liquid (cleaning liquid) used in the washing treatment unit 6, Since the temperature of the processing liquid can be suppressed, the central portion of the substrate B can be prevented from being damaged by the processing liquid.

  The resist modification processing unit 2 is not limited to the configuration in which the processing gas containing ozone is supplied to the substrate B as described above, as long as the processing fluid having oxidizing power can be supplied to the substrate B. For example, the resist modification processing unit 2 is configured in the same manner as the cleaning processing unit 6, and SPM (mixed solution of sulfuric acid and hydrogen peroxide solution) is supplied from the nozzle 77 as a processing solution. Then, similarly to the cleaning processing unit 6, the SPM may be supplied to the center of the rotating substrate B, and the resist film may be oxidized by spreading the SPM to the peripheral edge of the substrate B by centrifugal force.

  As described above, when the resist is oxidized by the processing liquid, the resist is oxidized by the processing liquid and the resist is washed away by the pressure received from the processing liquid and removed from the substrate B. After removing the resist, the liquid supplied from the nozzle 77 is switched to, for example, pure water, and the processing liquid is removed from the substrate B. In this case, the nozzle 77 corresponds to a cleaning liquid supply section and a processing liquid removal section referred to in the claims. Since the substrate B processed by the resist modification unit 2 is subjected to the resist oxidation process and the removal process at the same time, for example, after the processing by the resist modification unit 2 is finished, It is transferred to the substrate edge processing unit 4 without being transferred, and then transferred to the cleaning processing unit 6 for the purpose of removing resist residues and particles as described above. In addition to the SPM, the treatment liquid in this case may be a mixed liquid of sulfuric acid and another oxidizing agent such as ozone, or may be a single ozone water. Further, when the resist is oxidized and removed by the processing liquid, the substrate B is not rotated, for example, by discharging the processing liquid from the nozzle 77 for supplying the processing liquid and moving the nozzle 77 in the lateral direction. Oxidation and removal may be performed.

  Further, the substrate end processing unit 4 only needs to be able to supply an alkaline processing liquid to the peripheral portion of the substrate B. For example, in addition to TMAH, a processing liquid containing ammonia may be supplied. In the above example, after the processing liquid is supplied to the end of the substrate B by the substrate end processing unit 4, the processing liquid is transferred to the cleaning processing unit 6 without supplying pure water to the end. The alkaline processing liquid attached to the substrate B may be removed.

  The substrate B is transported in the order of the resist modification processing unit 2 → the cleaning processing unit 6 → the substrate edge processing unit 4 → and the resist film remaining on the peripheral edge after the processing in the cleaning processing unit 6 is transferred to the substrate edge processing unit 4. May be removed. Although the transport path of the substrate B in the case where the resist film is a negative resist has been described, even in the case of a positive resist, processing can be performed by transporting the substrate B along the transport path similar to that of the negative resist. Further, in the case of a positive type resist, the substrate B may be transferred and processed in the order of the substrate edge processing unit 4 → the resist modification processing unit 2 → the cleaning processing unit 6. In the evaluation test described later, it was confirmed that the resist film residue did not remain on the substrate B even if the processing was performed in this order. The reason for this is that the surface of the positive resist is oxidized during the etching process of the previous stage of the resist removal process, that is, the peripheral portion of the resist film 81 is oxidized before being transferred to the resist removal apparatus 1, It is considered that the peripheral edge portion can be effectively removed by the substrate edge processing unit 2 because the solubility in alkalinity is increased. In the case of a negative resist, since surface oxidation is unlikely to occur during the etching process, it is effective to carry the process between units as described in the above-described embodiment.

  The present invention is effective not only when removing a resist film spin-coated on a square substrate, but also when removing a resist film spin-coated on a circular substrate such as a semiconductor wafer.

(Evaluation Test 1)
Next, the evaluation test that has become the basis for the present invention will be described. The sides and corners of the substrate B on which a resist film made of a negative resist was formed by spin coating were photographed. 20 and 21 schematically show a photograph of a side portion and a corner portion taken. In the figure, a hatched area 91 and a number of dotted areas 92 indicate areas where the resist is applied, and the area 92 has a resist film thickness larger than that of the area 91. In addition, the resist is not apply | coated to the white area | region in a figure, but the base film which consists of Cr (chromium) of the lower layer of a resist is the area | region exposed. 20 and 21, the white area is an inclined surface of the substrate B formed so as to descend from the edge of the surface of the substrate B toward the side surface of the substrate B.

Similarly to the above embodiment, the substrate B was conveyed in the order of the resist modification processing unit 2 → the cleaning processing unit 6 → the substrate edge processing unit 4 → the cleaning processing unit 6 to perform the resist removal processing. Then, while transporting from the substrate edge processing unit 4 to the cleaning processing unit 6, photographs of the side and corner portions of the substrate B were taken to examine how the resist was removed. In addition, photographs of the sides and corners of the substrate B were taken after processing by the cleaning processing unit 6 to examine how the resist was removed. The processing conditions of each processing unit will be described. In the resist modification processing unit 2, the processing gas containing ozone and water vapor is supplied for 600 seconds, and the concentration of ozone in the processing gas is 200 g / m ³ . . In the substrate edge processing unit 4, TMAH was used as the processing liquid. As the processing liquid of the cleaning processing unit 6, SC1 was used and this was supplied by two-fluid spray (Atomise Spray).

  22 and 23 schematically show photographs of sides and corners of the substrate B taken after processing by the substrate edge processing unit 4, respectively. As shown in FIGS. 22 and 23, after the processing by the substrate edge processing unit 4, the resist film regions 91 and 92 have been removed. In the figure, 93 is a resist residue. 24 and 25 schematically show photographs of sides and corners of the substrate B taken after the processing by the substrate end processing unit 4 and further by the cleaning processing unit 6, respectively. It was confirmed that the resist residue 93 was also removed at the sides and corners of the substrate B after the cleaning processing unit 6 was processed.

(Evaluation test 2)
Although the experiment similar to the evaluation test 1 was conducted, as a difference, the resist film of the substrate B is composed of a positive resist, and the substrate B is transported by the substrate end processing unit 4 → resist modification processing unit 2 → cleaning processing unit. The order was 6. Then, before processing by the substrate edge processing unit 4, after processing by the substrate edge processing unit 4, before processing by the cleaning processing unit 6, and after processing by the cleaning processing unit 6, photographs of sides and corners of the substrate B are taken. Images were taken and the state of the resist film was examined. Further, in this evaluation test 2, the substrate edge processing unit 4 was treated with TMAH and then rinsed with pure water in which CO2 was dissolved. FIGS. 26 and 27 schematically show the sides and corners of the substrate B before processing in the substrate end processing unit 4, respectively, and a region 92 having a larger film thickness than the region 91 is formed.

  28 and 29 show the side and corner of the substrate B processed by the substrate edge processing unit 4, respectively. As shown in FIGS. 28 and 29, it was confirmed that the region 92 disappeared after the processing of the substrate edge processing unit 4 and the film thickness of the peripheral portion of the substrate B was lowered. 30 and 31 schematically show photographs of the sides and corners of the substrate B taken after processing by the cleaning processing unit 6, respectively. As shown in FIGS. 30 and 31, resist residues could not be confirmed at the side and corner portions of the substrate B after the processing by the cleaning unit 6. From the results of Evaluation Test 1 and Evaluation Test 2, it was shown that the resist film can be removed with high certainty by the techniques of these experiments, and the knowledge of the present invention was obtained.

B Substrate C1 Carrier station C2 Processing station C3 Chemical station 1 Resist removing device 17 Main substrate transfer mechanism 2 Resist modification processing unit 21 Chamber 23 Stage 4 Substrate edge processing unit 41 Chuck 45 Mounting table 50 Nozzle unit 6 Cleaning processing unit 61 Substrate holding Unit 77 Surface cleaning nozzle 100 control unit

Claims (11)

A mask made of a resist film is formed on the surface, and an oxidative processing fluid for oxidizing the resist film is supplied to the entire surface of the substrate in which the film thickness of the resist film at the peripheral portion is thicker than that in the central region. A first step of removing the film;
A second step of removing the resist at the edge of the substrate by discharging an alkaline processing liquid from the nozzle along the edge of the substrate to the peripheral edge of the substrate;
Equipped with a,
A resist removing method , wherein the second step is performed after the first step .   The first step includes a step of supplying a processing gas, which is an oxidative processing fluid, for making the resist water-soluble, and a step of supplying a cleaning liquid to the entire surface of the substrate to remove the resist. The resist removal method according to claim 1, further comprising:   2. The resist removal according to claim 1, wherein the first step includes a step of supplying a processing solution for making the resist water-soluble, which is an oxidizing processing fluid, to the entire substrate and removing the resist. Method.   4. The first step includes a step of supplying a cleaning liquid to the entire substrate after removing the supply of the processing liquid to the substrate and removing the first processing liquid from the substrate. The resist removal method as described. The substrate resist removal method according to any one of claims 1 to 4, characterized in that it is rectangular. In an apparatus for removing a resist film from a substrate in which a mask made of a resist film is formed on the surface and the film thickness of the resist film at the peripheral portion is thicker than the central region,
A first processing unit configured to supply a processing fluid for oxidizing the resist film to the entire surface of the substrate and remove the resist film;
A second processing unit that includes a nozzle that discharges an alkaline processing liquid, and is configured to discharge the processing liquid from the nozzle along the side of the substrate to the periphery of the substrate;
And a control unit that outputs a control signal so that the substrate is processed by the first processing unit and then processed by the second processing unit. Removal device. The first processing unit includes a gas supply unit that supplies a processing gas for water-solubilizing the resist, which is an oxidizing processing fluid, to the substrate, and a resist that is water-solubilized by supplying a cleaning liquid to the entire surface of the substrate. A cleaning liquid supply section for removing
The resist removing apparatus according to claim 6 , further comprising: The first processing unit is the oxidation of the treatment fluids, according to claim 6, characterized in that it comprises a liquid processing unit for removing the resist with a treatment liquid for water-solubilizing the resist is supplied to the entire substrate Resist remover. The said liquid processing part is provided with the processing liquid removal part which supplies a washing | cleaning liquid to the whole board | substrate after the supply of the said processing liquid to a board | substrate is stopped, and removes a 1st processing liquid from a board | substrate. 9. The resist removing apparatus according to 8 . The substrate is a resist film removing apparatus according to any one of claims 6 to 9, characterized in that a rectangular substrate. A storage medium storing a computer program used in an apparatus for removing a mask made of a resist film formed on a surface of a substrate,
A storage medium characterized in that the computer program is for carrying out the resist removal method according to any one of claims 1 to 5 .

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