JP2016051715A - Substrate processing apparatus, substrate processing method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a substrate processing apparatus capable of highly precisely removing a coating film on a peripheral edge side of a substrate while avoiding the contamination of the substrate; and the like.SOLUTION: A substrate holding part 11 of a substrate processing apparatus rotates a substrate W having a surface, on which a coating film is formed, around a vertical axis while horizontally holding the substrate, and a solvent steam supply nozzle 31 supplies solvent steam to remove a part of the coating film, to the rotated substrate W. Nozzle moving mechanisms 33, 34 move the solvent steam supply nozzle 31 between a processing position on a peripheral edge side of the substrate W and a retracted position retracted from the processing position, and an exhaust part 32 exhausts solvent steam supplied from the solvent steam supply nozzle 31.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for removing a part of a coating film formed on a surface of a substrate.

  In the process of manufacturing a chip of a semiconductor device, a process of forming a coating film such as a resist film on the surface of a wafer that is a circular substrate is performed. For example, in a resist film forming process, a wafer is carried into a plurality of resist film forming apparatuses, which are substrate processing apparatuses, using a transport mechanism, and a resist solution is applied to the wafer by spin coating to form a resist film. The

  When the spin coating method is used, the resist film is formed on the entire surface of the wafer. The resist film on the peripheral edge side of the resist film is formed by, for example, contacting a member that transports the wafer when the transport mechanism transports the wafer. May be a source. Therefore, in the resist film forming apparatus described above, a process of removing the resist film formed on the peripheral portion of the wafer in a ring shape may be performed.

  For example, in Patent Document 1, a wafer is horizontally held on a spin chuck used for spin coating, rotated around a vertical axis, and a solvent is supplied to the peripheral edge of the rotating wafer, whereby the peripheral edge A technique for dissolving and removing a resist film is described.

JP 2006-93409 A: paragraphs 0003-0004, 0048, FIG.

  Here, in the manufacture of semiconductor devices, there is a demand for providing a semiconductor device formation region as close as possible to the peripheral portion of the wafer in order to increase the number of chips produced from a single wafer. However, when the semiconductor device is formed in the vicinity of the region where the resist film is removed, if the accuracy of adjusting the position where the resist film is removed is low, the resist film in the region where the semiconductor device is formed is also removed. , Leading to a decrease in product yield.

  In order to control the removal position of the resist film with high accuracy, it is preferable to supply a solvent to the wafer rotated at a higher speed in order to suppress wafer shake. However, the higher the rotation speed of the wafer, the greater the risk that the solvent supplied to the wafer will scatter and cause liquid splashing, and this will cause contamination of the semiconductor device formation region.

  The present invention has been made under such circumstances, and an object of the present invention is to perform substrate processing capable of adjusting the removal position of the coating film on the peripheral edge side of the substrate with high accuracy while avoiding contamination of the substrate. An apparatus, a substrate processing method, and a storage medium storing the method are provided.

The substrate processing apparatus of the present invention includes a substrate holding unit that horizontally holds a circular substrate having a coating film formed on a surface thereof and rotates the substrate about a vertical axis;
A solvent vapor supply nozzle for supplying a solvent vapor for removing a part of the coating film to the substrate held and rotated by the substrate holder;
A nozzle moving mechanism for moving the solvent vapor supply nozzle between a processing position on the peripheral edge side of the substrate, which is a region where the coating film is removed by the solvent vapor, and a retreat position retracted from the processing position; and the solvent vapor And an exhaust section for exhausting the solvent vapor supplied from the supply nozzle.

The substrate processing apparatus may have the following configuration.
(A) The solvent vapor supply nozzle has a dew condensation prevention mechanism for preventing dew condensation of the solvent vapor in the nozzle. The dew condensation prevention mechanism includes a heating unit that heats the solvent vapor supply nozzle or a heat insulating unit that insulates the inside of the solvent vapor supply nozzle from the external atmosphere of the solvent vapor supply nozzle.
(B) The exhaust unit includes an exhaust nozzle that is disposed alongside a solvent vapor supply nozzle that supplies solvent vapor at the processing position, and is provided with an exhaust port for exhausting the solvent vapor supplied to the substrate. Was it. Here, the exhaust nozzle is disposed at a position outside the solvent vapor supply nozzle in the radial direction of the substrate when viewed from the central portion side of the substrate held by the substrate holding portion. At this time, the solvent vapor supply nozzle is disposed so as to discharge the solvent vapor obliquely downward in the direction in which the exhaust nozzles are arranged.
(C) The solvent vapor supply nozzle is constituted by an opening end portion of an inner tube of a double tube including an outer tube and an inner tube inserted into the outer tube, and the exhaust portion is an opening end of the outer tube. Exhaust nozzle composed of parts. The opening end portion of the inner pipe constituting the solvent vapor supply nozzle protrudes in the solvent vapor discharge direction from the opening end portion of the outer pipe constituting the exhaust nozzle.
(D) The exhaust nozzle has an exhaust-side dew condensation prevention mechanism for preventing condensation of solvent vapor in the nozzle.
(E) In order to spread the solvent vapor to the area where the coating film is removed, the nozzle moving mechanism moves the solvent vapor supply nozzle that discharges the solvent vapor at the processing position in the radial direction of the substrate. about.
(F) a solvent vapor generation unit that is connected to the solvent vapor supply nozzle and generates solvent vapor from the liquid solvent, and in the solvent vapor supply path from the solvent vapor generation unit to the solvent vapor supply nozzle, condensation of solvent vapor A droplet collecting part for collecting the droplets generated by the above is provided.

  In the present invention, solvent vapor is supplied to the peripheral edge side of the rotating circular substrate to remove the coating film formed in the peripheral edge region, so that even if the substrate is rotated at high speed, liquid splashing occurs. Therefore, the removal position of the coating film can be adjusted with high accuracy.

It is a vertical side view of the resist film forming apparatus which concerns on embodiment of this invention. It is a top view of the said resist film forming apparatus. It is a block diagram of the solvent vapor | steam supply mechanism which supplies solvent vapor | steam to the said resist film forming apparatus. It is a block diagram of the solvent vapor | steam supply mechanism by the side of the said resist film forming apparatus. It is a schematic diagram which shows the 1st structural example of a dew condensation prevention nozzle. It is a schematic diagram which shows the 2nd structural example of a dew condensation prevention nozzle. It is a schematic diagram which shows the 3rd structural example of a dew condensation prevention nozzle. It is explanatory drawing of the process which removes the resist film of the peripheral part of a wafer using the said solvent vapor supply nozzle. It is a schematic diagram which shows the arrangement position of the said solvent vapor | steam supply nozzle and an exhaust nozzle. It is the schematic diagram of a wafer after removing the resist film of a peripheral part. It is explanatory drawing of the removal process of the resist film which concerns on a modification. It is a schematic diagram which shows the arrangement position of the solvent vapor | steam supply nozzle and exhaust nozzle which concern on the said modification. It is a schematic diagram which shows the 1st structural example of a double tube nozzle. It is a schematic diagram which shows the 2nd structural example of a double tube nozzle. It is a schematic diagram which shows the 3rd structural example of a double tube nozzle. It is explanatory drawing of the removal process of the resist film using the said double tube nozzle. It is a schematic diagram which shows the arrangement position of the said double tube nozzle.

Hereinafter, an embodiment in which a substrate processing apparatus of the present invention is applied to a resist film forming apparatus that applies a resist film to a wafer W will be described with reference to FIGS.
A longitudinal side view of FIG. 1 and a plan view of FIG. 2 show a processing section 1 of the resist film forming apparatus according to the embodiment. The processing unit 1 includes a spin chuck 11 that is a substrate holding unit that holds the back surface of the wafer W by suction, and a cup 12 that surrounds the spin chuck 11 and has an open upper side. The cup 12 is provided with an exhaust port 13 for exhausting the inside thereof and a drain port 14 for discharging the processing liquid received by the cup 12. On the lower side of the wafer W held on the spin chuck 11, for example, three elevating pins 15 connected to an elevating mechanism (not shown) are arranged. These lift pins 15 transfer the wafer W between the external transfer mechanism and the spin chuck 11.

  Further, the processing unit 1 includes a plurality of resist supply nozzles 21 for properly using a plurality of types of resist solutions, and a solvent supply nozzle 22 for supplying a prewetting solvent supplied to the wafer W prior to the supply of the resist solution. I have. The resist supply nozzle 21 and the solvent supply nozzle 22 are provided at the tip of a common arm 23. The base end portion of the arm 23 is connected to a moving portion 24 that supports the arm 23 so that it can move up and down and move along the guide rail 25.

  The moving unit 24 is supplied with processing liquids (various resists and solvents) from the nozzles 21 and 22, and is a processing position above the center of the wafer W, and a retreat position where the nozzles 21 and 22 are retracted when not in use. These nozzles 21 and 22 can be moved between them. At the retreat position of the nozzles 21 and 22, a nozzle bath 26 having a resist solution or solvent drain port (not shown) is provided.

  Further, the processing unit 1 is provided with a mechanism for performing processing for removing the resist film on the peripheral portion of the wafer W. The resist film removal mechanism is configured to remove the resist film using solvent vapor in order to cope with the problem of liquid splash when the peripheral resist film is removed using a liquid solvent.

  Regarding the mechanism for removing the resist film at the peripheral edge of the wafer W, the processing unit 1 is supplied from the solvent vapor supply nozzle 31 for supplying the vapor of the solvent for dissolving the resist film to the region and the solvent vapor supply nozzle 31. And an exhaust nozzle 32 having an exhaust port for exhausting the solvent vapor.

  The solvent vapor supply nozzle 31 and the exhaust nozzle 32 are provided at the distal end portion of the common arm 33 so that the solvent vapor discharge port and the exhaust port are opened downward in the vertical direction. When the solvent vapor supply nozzle 31 and the exhaust nozzle 32 are moved to the processing position where the solvent vapor is supplied, the solvent vapor supply nozzle 31 is positioned inward in the radial direction when viewed from the central portion side of the wafer W. The exhaust nozzles 32 are arranged adjacent to each other so that they are located outside the solvent vapor supply nozzle 31. For example, as shown in FIG. 8, at the processing position, the solvent vapor supply nozzle 31 is positioned so that the opening of the solvent vapor supply nozzle 31 is positioned above the inner peripheral edge of the region where the resist film 101 is removed in a ring shape. Be placed.

  Here, a part of the solvent vapor supplied from the solvent vapor supply nozzle 31 may reach a region radially inward of the wafer W with respect to the position below the opening due to diffusion or the like to dissolve the resist film 101. is there. Therefore, for example, it is preferable to accurately grasp the correspondence relationship between the position of the solvent vapor supply nozzle 31 and the position of the inner peripheral edge of the resist film removal region in advance by a preliminary experiment. The arrangement position of the solvent vapor supply nozzle 31 is set based on the correspondence relationship previously grasped so that the resist film 101 in a desired removal region can be removed.

  Further, the height of the solvent vapor supply nozzle 31 at the processing position is such that the height distance H from the upper surface of the resist film 101 formed on the wafer W to the lower end of the solvent vapor supply nozzle 31 is as shown in FIG. For example, it is set to a value within the range of 0.5 to 3 mm.

  The exhaust nozzle 32 arranged adjacent to the solvent vapor supply nozzle 31 has a distance D (see FIG. 8) between the central axes of the solvent vapor supply nozzle 31 and the exhaust nozzle 32 set to, for example, 1 to 20 mm. The arrangement height of the exhaust nozzle 32 is set such that, for example, the lower end of the exhaust nozzle 32 is at the same height as the lower end of the solvent vapor supply nozzle 31 or a position higher than this (see FIG. 32 and an example in which the heights of the lower ends of the solvent vapor supply nozzle 31 are aligned.

  Here, FIGS. 8 and 9 show a state in which the exhaust nozzle 32 is disposed above the bevel, which is an inclined surface formed on the peripheral portion of the wafer W. The arrangement is not limited to the case of being arranged on the upper side, and it may be arranged on the outer side of the periphery of the wafer W. In FIG. 9, the inner edge of the bevel formation region is indicated by a broken line (the same in FIG. 12).

  The base end portion of the arm 33 is connected to a moving portion 34 that supports the arm 33 so that it can move up and down and move along the guide rail 35. The moving unit 34 is provided with a nozzle bath 36 having a processing position set above the peripheral edge of the wafer W held by the spin chuck 11 and a drain port (not shown) for condensed solvent. This corresponds to a nozzle moving mechanism that moves the nozzles 31 and 32 between the retreat positions where the nozzles 31 and 32 are sometimes retreated.

  3 and 4 show the configuration of the solvent vapor supply mechanism that supplies the solvent vapor to the arm 33. As shown in FIG. 3, the solvent vapor supply mechanism of this example is generated by a solvent vapor generation unit 42 that heats the liquid solvent L supplied from the solvent container 41 to generate solvent vapor, and the solvent vapor generation unit 42 generates the solvent vapor. And a mixing valve 443 which is a carrier gas mixing section for mixing the carrier gas with the solvent vapor.

  The solvent container 41 contains the liquid solvent L which is a raw material for the solvent vapor, and is replaced with a new one when the liquid solvent L becomes empty. The liquid solvent L is not particularly limited as long as it has the ability to dissolve the resist film formed on the wafer W, but cyclohexane (boiling point 156 ° C.) or PGMEA (propylene glycol-1-methyl). Ether acetate, boiling point 146 ° C.).

  A nitrogen gas supply path 401 connected to the nitrogen gas supply source 40 is inserted on the vapor phase side of the solvent container 41. On the other hand, a solvent transfer path 402 connected to the solvent vapor generating part 42 is inserted on the liquid phase part side (liquid solvent L). As a result, the liquid solvent L in the solvent container 41 can be pushed out by the nitrogen gas received from the nitrogen gas supply source 40 and transferred to the solvent vapor generation unit 42. A liquid filter 412 for removing bubbles and particles contained in the liquid solvent L is interposed in the solvent transfer path 402.

  The solvent vapor generation unit 42 includes a solvent tank 421 that stores the liquid solvent L received from the solvent container 41, and a heater 422 that heats the liquid solvent L in the solvent tank 421 to generate solvent vapor. The solvent transfer path 402 is inserted on the liquid phase side (liquid solvent L) of the solvent tank 421, while the solvent vapor generated in the solvent tank 421 is extracted on the gas phase side of the solvent tank 421. A solvent vapor extraction path 403 is inserted.

The heater 422 includes a jacket heater that accommodates the solvent tank 421, a tape heater wound around the outer wall surface of the solvent tank 421, and the like, and heats the inside of the solvent tank 421. The heater 422 can raise and lower the heating temperature by increasing or decreasing the power supplied from the power supply unit 423.
The solvent tank 421 is provided with a liquid level gauge (not shown). When the liquid level of the liquid solvent L in the solvent tank 421 falls below a preset height position, the liquid solvent from the solvent container 41 to the solvent tank 421 is displayed. L is transferred.

  In the solvent vapor extraction path 403 on the outlet side of the solvent tank 421, a regulator 441 with a pressure gauge 442 for keeping the pressure in the solvent tank 421 constant is provided. The regulator 441 is configured as a pressure reducing valve that adjusts the secondary pressure so as to be a predetermined target value.

  For example, when cyclohexane is used as the liquid solvent L, the target value of the pressure on the secondary side of the regulator 441 (detected value of the pressure gauge 442) is set to 110 kPa which is the saturated vapor pressure at the boiling point of cyclohexane. The detection result of the pressure on the secondary side of the regulator 441 detected by the pressure gauge 442 is fed back to the power supply unit 423. When the pressure decreases, the heating temperature of the heater 422 is increased to increase the amount of solvent vapor generated, and the pressure When the temperature rises, control is performed to lower the heating temperature and reduce the amount of solvent vapor generated. The heater 422 can raise the temperature of the contact surface with the solvent tank 421 up to 200 ° C., for example, higher than the boiling point of cyclohexane.

  On the downstream side of the regulator 441, a mixing valve 443 that mixes nitrogen gas as a carrier gas with the solvent vapor extracted from the solvent tank 421 by the solvent vapor extraction path 403 is provided. A carrier gas supply path 404 that supplies nitrogen gas joins the mixing valve 443, and a mixed gas of solvent vapor and nitrogen gas supplied from the solvent vapor extraction path 403 is supplied to the solvent vapor supply path 405. .

  The carrier gas supply path 404 is connected to a carrier gas supply unit 43 including a nitrogen gas storage unit and a flow rate adjustment unit (not shown). Between the carrier gas supply unit 43 and the mixing valve 443, a heater 431 for heating the temperature of the nitrogen gas supplied to the mixing valve 443 to a temperature equal to or higher than the dew point (boiling point) of the liquid solvent L, and a mixing valve 443 A regulator (pressure reducing valve) 432 with a pressure gauge 433 for adjusting the pressure of the supplied nitrogen gas to a predetermined target value and a gas filter 434 for removing particles in the nitrogen gas are provided on the carrier gas supply path 404. Is interposed. In this example, the heater 431 heats the nitrogen gas to a temperature at which the temperature of the mixed gas after mixing the solvent vapor and the nitrogen gas at the mixing valve 443 is equal to or higher than the dew point of cyclohexane, for example, 165 ° C.

  With respect to the solvent vapor extracted from the solvent tank 421 through the solvent vapor extraction path 403, nitrogen gas adjusted to a predetermined temperature and pressure is supplied at a predetermined flow rate (for example, 200 ml / min (0 ° C., 1 atm reference, below). The same)), the mixed gas containing the solvent vapor can be supplied to the solvent vapor supply nozzle 31 at a stable flow rate.

In addition, the solvent vapor extracted from the solvent tank 421 is mixed with nitrogen gas having a temperature equal to or higher than the dew point temperature of the solvent, thereby diluting the solvent vapor without lowering the temperature of the mixed gas below the dew point of the solvent. Can do. As a result, the partial pressure of the solvent vapor in the mixed gas is reduced. For example, when the liquid solvent L is boiled in the solvent tank 421, mist is accompanied with the solvent vapor extracted from the solvent tank 421. Moreover, the said mist can be evaporated and the solvent vapor | steam in mixed gas can be made into a superheated state.
In the description of the gas flowing downstream of the mixing valve 443, the above-described mixed gas may be referred to as “solvent vapor”.

  The solvent vapor supply path 405 on the downstream side of the mixing valve 443 is provided with an opening / closing valve 444 for performing supply / blocking of the solvent vapor to the solvent vapor supply nozzle 31 (FIG. 3). Further, as shown in FIG. 4, on the downstream side of the opening / closing valve 444, there is provided a drain case 45 which is a droplet collecting part for collecting the solvent condensed in the pipe of the solvent vapor supply path 405 and separating it from the solvent vapor. It has been. The solvent vapor supply path 405 connected to the outlet side of the drain case 45 is introduced into the housing 10 that accommodates the processing unit 1, and the end thereof is connected to the solvent vapor supply nozzle 31. The solvent collected in the drain case 45 is discharged to the outside through the drain discharge path 406 in which the opening / closing valve 451 is opened.

Next, the exhaust nozzle 32 is connected to an external exhaust mechanism 51 formed of a vacuum pump or the like via an exhaust path 501, and the solvent is processed by an abatement equipment (not shown) provided on the downstream side of the exhaust mechanism 51. The exhaust flow rate of the gas exhausted through the exhaust nozzle 32 is adjusted to, for example, 200 ml / min, which is the same flow rate as the supply flow rate of the nitrogen gas that is the carrier gas.
The exhaust nozzle 32 constitutes the exhaust part of the present embodiment.

  As described above, in the solvent vapor supply mechanism and the exhaust section described with reference to FIGS. 3 and 4, the pipes constituting the flow paths 403, 404, 405, and 501 through which the gas flows are insulated from the outside air. Each valve 441, 432, 443, 444, 451 is constituted by an air operation valve, for example, and operates by adjusting the pressure of the working air.

  The solvent vapor supply nozzle 31 and the exhaust nozzle 32 provided at the ends of the insulated carrier gas supply path 404 and the exhaust path 501 and opened at the ends of the carrier gas supply path 404 and the exhaust path 501 Compared to the inside of piping, it is more susceptible to outside air, and there is a risk of condensation.

Therefore, a dew condensation prevention mechanism is provided in the solvent vapor supply nozzle 31 and the exhaust nozzle 32 shown in FIGS. For example, as shown in FIG. 5, a dew condensation prevention nozzle 7a in which a resistance heating element is embedded in a pipe or wound with a tape heater to use the heater 71 as a dew condensation prevention mechanism may be used. Further, as shown in FIG. 6, a dew condensation prevention nozzle 7b using a vacuum heat insulation tube portion 72 whose tube wall is vacuum insulated as a dew condensation prevention mechanism may be employed. Furthermore, as shown in FIG. 7, it is possible to prevent the occurrence of condensation in the region by using a condensation prevention nozzle 7 c in which a vacuum heat insulating pipe portion 72 is further provided on the outer peripheral side of the heater 71.
The condensation prevention nozzles 7a to 7c are formed to have a length of about 5 to 10 mm and an inner diameter (opening diameter) of the tube of about 1 to 5 mm.

  The resist film forming apparatus having the configuration described above is provided with a control unit 6 including a computer. The control unit 6 has a program storage unit (not shown), and steps are set in the program storage unit so as to execute processing for removing the resist film on the peripheral portion of the wafer W, which will be described later. The program is stored. Based on this program, the control unit 6 outputs a control signal to each part of the resist film forming apparatus, and the moving unit 34 moves the solvent vapor supply nozzle 31 and the exhaust nozzle 32 between the processing position and the retreat position, and the heater. Operations such as heating in the solvent tank 421 by 422, supply of nitrogen gas by the carrier gas supply unit 43, and supply of solvent vapor to the solvent vapor supply nozzle 31 by the opening / closing valve 444 are controlled. The program storage unit is configured as a storage medium such as a hard disk, a compact disk, a magnetic optical disk, or a memory card.

Hereinafter, an operation of removing the resist film on the peripheral edge of the wafer W by the resist film forming apparatus of the present embodiment will be described with reference to FIGS.
First, the wafer W held by the wafer holding unit of the external transfer mechanism is carried into the housing 10 of the resist film forming apparatus and transferred to the spin chuck 11 via the lift pins 15.

  Next, the resist supply nozzle 21 and the solvent supply nozzle 22 are moved from the retracted position to the processing position, and the wafer W is rotated at a predetermined rotational speed by the spin chuck 11 so that the liquid is supplied from the solvent supply nozzle 22 to the center of the wafer W. A pre-wet process is performed in which the solvent is discharged to spread the solvent over the entire surface of the wafer W. Thereafter, the resist is supplied from one of the resist supply nozzles 21 to the center of the wafer W, and the resist solution is spread over the entire surface of the wafer W. As a result, a resist film 101 is formed on the entire surface of the wafer W by spin coating.

  When the resist film 101 is formed, the resist supply nozzle 21 and the solvent supply nozzle 22 are retracted to the retracted position, while the solvent vapor supply nozzle 31 and the exhaust nozzle 32 are moved to the processing position. Further, the rotation speed of the wafer W is adjusted to 2000 rpm within the range of 2000 to 4000 rpm.

  On the other hand, on the solvent vapor supply mechanism side, when the solvent vapor is not supplied from the solvent vapor supply nozzle 31, the on-off valve 444 shown in FIG. Nitrogen gas is not supplied. The heater 422 of the solvent vapor generating unit 42 adjusts the heating temperature in the solvent tank 421 so that the secondary pressure of the regulator 441 detected by the pressure gauge 442 becomes a target value.

  When the solvent vapor supply mechanism stands by in this state, when the solvent vapor supply nozzle 31 and the exhaust nozzle 32 move to the processing position and the rotation speed of the wafer W reaches the target rotation speed, the solvent vapor supply path 405 The opening / closing valve 444 is opened, and nitrogen gas is supplied from the carrier gas supply unit 43 at a flow rate of, for example, 200 ml / min. The nitrogen gas is heated by the heater 431, the pressure is adjusted by the regulator 432, and then supplied to the mixing valve 443.

  The nitrogen gas flowing into the mixing valve 443 draws in the solvent vapor on the solvent vapor extraction path 403 side by, for example, the Bernoulli effect, and the nitrogen gas and the solvent vapor are mixed in the mixing valve 443. The solvent vapor mixed with the nitrogen gas flows toward the downstream side of the opening / closing valve 444, and after the drainage generated by the condensation is removed by the drain case 45, the solvent vapor is supplied to the solvent vapor supply nozzle 31.

  The solvent vapor supplied to the solvent vapor supply nozzle 31 is discharged from the opening at the end thereof, and is supplied to the surface of the wafer W rotating on the lower side of the opening. The solvent vapor discharged from the solvent vapor supply nozzle 31 rapidly decreases in temperature and is condensed on the surface of the resist film 101. The solvent condensed on the surface of the wafer W spreads from the lower position of the solvent vapor supply nozzle 31 toward the outer region by the action of the centrifugal force acting on the wafer W. As a result, a solvent liquid film F is formed in a ring shape in a region on the peripheral edge side of the wafer W to cover the resist film 101 formed in the region.

  Here, in the region where the liquid film F is formed, the solvent is volatilized from the surface of the liquid film F and the heat of vaporization is taken away, or the surface of the rotating wafer W is cooled by air, thereby suppressing the temperature rise. Yes. For this reason, the surface of the wafer W to which the solvent vapor is supplied is maintained at a temperature at which the solvent can be condensed on the surface when the solvent vapor contacts.

  In the region where the liquid film F is formed, the resist film 101 is dissolved in the liquid film F, and the resist film 101 in the region is removed from the surface of the wafer W. The liquid solvent containing the dissolved resist film 101 is shaken off from the rotating wafer W, received by the surrounding cup 12, collected at the bottom of the cup 12, and discharged from the drain port 14.

  At this time, by removing the resist film 101 with the liquid solvent condensed on the surface of the wafer W, the amount of the liquid solvent existing on the surface of the wafer W is reduced, and the droplets from the wafer W are scattered or scattered. The amount of mist generated due to the collision of the droplets with the cup 12 can be suppressed. As a result, it is possible to suppress the floating mist from flowing into the device formation region of the wafer W and damaging the resist film in the region.

  Further, as shown by broken arrows in FIGS. 8 and 9, excessive solvent vapor that has not condensed on the surface of the wafer W, nitrogen gas mixed in the solvent vapor, and part of the solvent vapor volatilized from the liquid film F Flows toward the exhaust nozzle 32 disposed adjacent to the solvent vapor supply nozzle 31. These gases are exhausted to the outside of the resist film forming apparatus using an opening formed at the lower end of the exhaust nozzle 32 as an exhaust port. The gas that has not reached the exhaust nozzle 32 flows into the cup 12 and is exhausted to the outside through the exhaust port 13.

  Here, as described above, since the exhaust nozzle 32 is disposed so as to be located on the outer side of the wafer W with respect to the solvent vapor supply nozzle 31, excess solvent vapor or solvent vapor volatilized from the liquid film F is provided. However, a flow that flows from the inner side to the outer side in the radial direction of the wafer W is formed. As a result, it is possible to suppress diffusion toward the inside of the wafer W, which is a semiconductor device formation region, and to suppress damage to the resist film 101 on the device formation region side.

  As described above, it is possible to suppress the occurrence of liquid splash by supplying solvent vapor instead of the conventional liquid solvent. As a result, the wafer W can be rotated at a higher speed (2000 to 4000 rpm) than the conventional rotation speed (about 1000 rpm) to remove the resist film at the peripheral portion, so that the wafer W is prevented from blurring and the resist is accurately resisted. The removal position of the film 101 can be adjusted.

  At this time, in order to spread the solvent vapor to the region where the resist film 101 is removed, the solvent vapor supply nozzle 31 is moved outward in the warp direction of the wafer W by using the moving unit 34. The removal region of the resist film 101 may be scanned with the above.

  Further, as described with reference to FIGS. 5 to 7, the solvent vapor supply nozzle 31 and the exhaust nozzle 32 are configured by dew condensation prevention nozzles 7 a to 7 c that prevent dew condensation of the solvent vapor therein. For this reason, the occurrence of a situation in which droplets generated in the solvent vapor supply nozzle 31 and the exhaust nozzle 32 collide with the rotating wafer W to cause liquid splashing can be suppressed.

  During this process, in the solvent vapor supply mechanism, the solvent vapor in the solvent tank 421 is consumed, and a pressure change occurs in a direction in which the pressure on the secondary side of the regulator 441 decreases. Accordingly, control is performed to increase the output of the heater 422 based on the pressure detection result by the pressure gauge 442 to increase the amount of solvent vapor generated and maintain the supply pressure of the solvent vapor on the secondary side of the regulator 441.

Thus, when the solvent vapor is supplied for a predetermined time, for example, 30 to 60 seconds, the resist film 101 on the peripheral edge side of the wafer W is removed in a ring shape (FIG. 10).
When the process of removing a part of the resist film 101 is completed, the supply of nitrogen gas from the carrier gas supply unit 43 is stopped, the open / close valve 444 is closed, and the discharge of the solvent vapor from the solvent vapor supply nozzle 31 is ended.

  Thereafter, the rotation of the wafer W is stopped at the timing when the solvent condensed on the surface of the wafer W evaporates and the liquid film F disappears. Next, the wafer W is delivered to an external transport mechanism in the reverse order to that at the time of loading, and the wafer W that has been subjected to the resist film formation process and the peripheral edge resist film removal process is unloaded.

  The resist film forming apparatus according to the present embodiment has the following effects. Since solvent vapor is supplied to the peripheral edge side of the rotating wafer W to remove the resist film 101 formed in the peripheral edge area, the occurrence of liquid splashing is suppressed even when the wafer W is rotated at a high speed. The removal position of the resist film 101 can be adjusted with high accuracy.

  11 and 12, the solvent vapor supply nozzle 31 a is inclined and arranged in the direction in which the exhaust nozzles 32 are arranged, so that the solvent vapor is discharged obliquely downward toward the exhaust nozzle 32 to facilitate exhaust. A modified example is shown. In this example, the crossing angle θ with respect to the upper surface of the wafer W is set to, for example, 30 ° in the range of 5 ° to 90 ° as shown in FIG. 11, and the crossing with respect to the tangential direction of the rotating wafer W as shown in FIG. The angle φ is set to, for example, 8.5 ° in the range of 0 ° to 90 °. As a result, the solvent vapor discharged from the solvent vapor supply nozzle 31 can easily flow toward the position where the exhaust nozzle 32 is disposed, and the diffusion of the solvent vapor to the inside of the wafer W, which is a device formation region, can be more efficiently performed. Can be suppressed.

  In addition, as indicated by a broken line in FIG. 12, the exhaust nozzle 32 may be disposed on the downstream side in the rotation direction of the wafer W with respect to the solvent vapor supply nozzle 31a. Accordingly, the exhaust of the solvent vapor by the exhaust nozzle 32 can be executed at the arrival position of the solvent vapor flowing toward the downstream side in the rotation direction of the wafer W while flowing from the discharge position toward the outer peripheral side of the wafer W.

  Next, in FIGS. 13 to 17, the solvent vapor supply nozzle 31 b and the double pipe nozzle (double pipe) 70 including the outer pipe 702 and the inner pipe 701 inserted inside the outer pipe 702 are used. The example which comprised the exhaust nozzle 32b is shown. In the double pipe nozzle 70, the upstream side of the inner pipe 701 is connected to the solvent vapor supply path 405 of FIG. 4, and the solvent vapor supply nozzle 31 b is configured by the opening end portion on the downstream side of the inner pipe 701. Further, the upstream side of the outer pipe 702 is connected to the exhaust passage 501 in FIG. 4, and the exhaust nozzle 32 b is configured by the opening end portion on the downstream side of the outer pipe 702.

  As shown in FIGS. 13 to 16, the opening end of the inner pipe 701 constituting the solvent vapor supply nozzle 31b is directed in the direction in which the solvent vapor projects more than the opening end of the outer pipe 702 constituting the exhaust nozzle 32b. Thus, a protruding portion 703 is formed. By forming the protruding portion 703, it is possible to prevent a problem that the solvent vapor discharged from the solvent vapor supply nozzle 31b is exhausted from the exhaust nozzle 32b before reaching the surface of the wafer W. .

  As a dew condensation prevention mechanism for preventing the dew condensation of the solvent vapor in the double tube nozzle 70, a double tube nozzle 70a in which a heater 71 is provided on the inner tube 701 or the outer tube 702 as shown in FIG. 13 may be used. . Further, as shown in FIG. 14, a double tube nozzle 70b using a vacuum heat insulating tube portion 72 in which the inner wall of the inner tube 701 and the outer tube 702 is thermally insulated by vacuum may be employed. Further, as shown in FIG. 15, condensation is generated using a double tube nozzle 70 c in which a heater 71 is provided in the inner tube 701 and the outer tube 702, and a vacuum heat insulating tube portion 72 is provided on the outer peripheral side of the outer tube 702. May be prevented.

  The double tube nozzle 70 (70a to 70c) has a length of about 5 to 10 mm, the entire diameter of the double tube nozzle 70 (the outer diameter of the outer tube 702) is about 5 to 15 mm, and the inner diameter (opening diameter) of the inner tube 701. Is approximately 1 to 5 mm, and the width (opening width) of the outer tube 702 that opens in an annular shape is approximately 1 to 5 mm.

  As shown in FIGS. 16 and 17, when the solvent vapor is supplied using the double tube nozzle 70, the solvent vapor supplied from the solvent vapor supply nozzle 31 b reaches the surface of the wafer W, and then the solvent vapor supply is performed. The solvent vapor is exhausted toward the exhaust nozzle 32b disposed around the nozzle 31b. As a result, the region where the supply and exhaust of the solvent vapor is performed can be more locally limited, and the diffusion of the solvent vapor toward the device formation region can be suppressed.

  In each embodiment described above, the exhaust part for exhausting the solvent vapor is not limited to the case where the exhaust part is configured by the exhaust nozzles 32 and 32b arranged adjacent to the solvent vapor supply nozzles 31, 31a and 31b. Instead of providing the exhaust nozzles 32 and 32b, the exhaust port 13 of the cup 12 may be used as an exhaust portion for solvent vapor.

  Further, the solvent vapor supply nozzles 31, 31a, 31b and the exhaust nozzles 32, 32b are not limited to the case where only one set is provided, and a plurality of these may be provided. Further, the configuration of the solvent vapor supply nozzles 31, 31a, 31b and the exhaust nozzles 32, 32b is not limited to the type having one solvent vapor discharge port and one exhaust port. For example, a plurality of discharge ports and exhaust ports may be provided side by side in the circumferential direction of the wafer W, or a slit-like discharge port and exhaust port extending along the circumferential direction of the wafer W may be provided.

  As described with reference to FIGS. 5 to 7 and FIGS. 13 to 15, the solvent vapor supply nozzle 31 and the exhaust nozzle 32 (including the solvent vapor supply nozzle 31 b and the exhaust nozzle 32 b of the double tube nozzle 70) are used. On the other hand, it is not essential to provide the heater 71 and the vacuum heat insulating tube 72 as a dew condensation prevention mechanism. Depending on the ease of condensation in the solvent vapor supply nozzle 31 and the exhaust nozzle 32, the installation of a condensation prevention mechanism may be omitted.

  Furthermore, in order to prevent the generation of mist accompanying the boiling of the liquid solvent L, the liquid vapor is heated to a temperature lower than the boiling point of the solvent in the solvent tank 421 to volatilize the solvent vapor, and then the solvent vapor is heated. Thus, a solvent vapor having a pressure higher than the saturated vapor pressure may be obtained. Further, after the carrier gas such as nitrogen gas is bubbled into the liquid solvent L to obtain a mixed vapor of the solvent vapor and the carrier gas, the mixed vapor may be heated.

  In addition, in the above-described example, the solvent vapor supply nozzle 31 and the solvent vapor supply mechanism for removing the resist film at the peripheral portion are provided together with the resist film forming apparatus, but the resist film 101 at the peripheral portion of the wafer W is provided. The removal process may be performed by an apparatus having the removal function alone.

  And the kind of coating film removed by supply of solvent vapor | steam is not restricted to a resist film. For example, it may be applied to the removal of the antireflection film formed on the surface of the wafer W before the formation of the resist film. In addition, you may apply to the removal of the adhesive agent used for bonding of the coating film and wafer W of medium viscosity and high viscosity.

  Furthermore, the position where the solvent vapor is supplied by the solvent vapor supply nozzle 31 is not limited to the case where the position is set on the upper surface side of the wafer W. For example, in order to remove the coating film formed so as to wrap around the lower surface side of the wafer W, a solvent vapor may be supplied to the peripheral portion on the lower surface side of the wafer W.

W Wafer 101 Resist film 11 Spin chuck 31 Solvent vapor supply nozzle 32 Exhaust nozzle 405 Solvent vapor supply path 41 Solvent container 42 Solvent vapor generation part 443 Mixing valve 6 Control part 7a-7c Condensation prevention nozzles 70, 70a-70c
Double tube nozzle 701 Inner tube 702 Outer tube 703 Protrusion 71 Heater 72 Vacuum heat insulation tube

Claims (15)

A substrate holding part for horizontally holding a circular substrate having a coating film formed on the surface and rotating the substrate around a vertical axis;
A solvent vapor supply nozzle for supplying a solvent vapor for removing a part of the coating film to the substrate held and rotated by the substrate holder;
A nozzle moving mechanism for moving the solvent vapor supply nozzle between a processing position on the peripheral edge side of the substrate, which is a region where the coating film is removed by the solvent vapor, and a retreat position retracted from the processing position; and the solvent vapor And an exhaust unit for exhausting the solvent vapor supplied from the supply nozzle.   The substrate processing apparatus according to claim 1, wherein the solvent vapor supply nozzle includes a dew condensation prevention mechanism for preventing dew condensation of the solvent vapor in the nozzle.   The substrate processing apparatus according to claim 2, wherein the dew condensation prevention mechanism includes a heating unit that heats the solvent vapor supply nozzle.   4. The substrate processing apparatus according to claim 2, wherein the dew condensation prevention mechanism includes a heat insulating portion that insulates the inside of the solvent vapor supply nozzle from an external atmosphere of the solvent vapor supply nozzle.   The exhaust section includes an exhaust nozzle that is disposed alongside a solvent vapor supply nozzle that supplies solvent vapor at the processing position, and is provided with an exhaust port for exhausting the solvent vapor supplied to the substrate. 5. The substrate processing apparatus according to claim 1, wherein the substrate processing apparatus is characterized in that:   The exhaust nozzle is disposed at a position outside the solvent vapor supply nozzle in a radial direction of the substrate when viewed from a central portion side of the substrate held by the substrate holding unit. 5. The substrate processing apparatus according to 5.   The substrate processing apparatus according to claim 5, wherein the solvent vapor supply nozzle is arranged so as to discharge the solvent vapor obliquely downward toward the direction in which the exhaust nozzles are arranged.   The solvent vapor supply nozzle is configured by an open end portion of an inner tube of a double tube comprising an outer tube and an inner tube inserted into the outer tube, and the exhaust portion is configured by an open end portion of the outer tube. 6. The substrate processing apparatus according to claim 1, wherein the substrate processing apparatus is an exhaust nozzle.   The opening end portion of the inner pipe constituting the solvent vapor supply nozzle protrudes in the solvent vapor discharge direction from the opening end portion of the outer pipe constituting the exhaust nozzle. The substrate processing apparatus as described.   The substrate processing apparatus according to claim 5, wherein the exhaust nozzle includes an exhaust-side dew condensation prevention mechanism for preventing condensation of solvent vapor in the nozzle.   The nozzle moving mechanism moves the solvent vapor supply nozzle that discharges the solvent vapor in the processing position in the radial direction of the substrate in order to spread the solvent vapor to the region where the coating film is removed. The substrate processing apparatus according to claim 1.   The solvent vapor supply section is connected to the solvent vapor supply nozzle and generates a solvent vapor from the liquid solvent, and the solvent vapor supply path from the solvent vapor generation section to the solvent vapor supply nozzle is caused by condensation of the solvent vapor. The substrate processing apparatus according to claim 1, further comprising a droplet collection unit for collecting the droplets. A step in which a coating film is formed on the surface and the substrate held horizontally is rotated about the vertical axis;
Supplying solvent vapor to the coating film in the peripheral edge side region in order to remove the coating film in the peripheral edge side region of the rotating substrate;
And evacuating the solvent vapor supplied to the substrate.   The substrate processing according to claim 13, further comprising a step of moving a position where the solvent vapor is supplied to the substrate in a radial direction of the substrate in order to distribute the solvent vapor to a region where the coating film is removed. Method. A computer-readable storage medium storing a computer program used in a substrate processing apparatus for performing processing for removing a part of a coating film formed on a surface of a substrate,
15. A storage medium characterized in that the computer program is configured to execute a substrate processing method according to claim 13 or 14.

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