WO2014069079A1 - Substrate processing device - Google Patents

Substrate processing device Download PDF

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Publication number
WO2014069079A1
WO2014069079A1 PCT/JP2013/072438 JP2013072438W WO2014069079A1 WO 2014069079 A1 WO2014069079 A1 WO 2014069079A1 JP 2013072438 W JP2013072438 W JP 2013072438W WO 2014069079 A1 WO2014069079 A1 WO 2014069079A1
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WO
WIPO (PCT)
Prior art keywords
phosphoric acid
substrate
wafer
aqueous solution
storage tank
Prior art date
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PCT/JP2013/072438
Other languages
French (fr)
Japanese (ja)
Inventor
喬 太田
橋詰　彰夫
大輝 日野出
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大日本スクリーン製造株式会社
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Publication of WO2014069079A1 publication Critical patent/WO2014069079A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
    • H01L21/3105—After-treatment
    • H01L21/311—Etching the insulating layers by chemical or physical means
    • H01L21/31105—Etching inorganic layers
    • H01L21/31111—Etching inorganic layers by chemical means
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67011—Apparatus for manufacture or treatment
    • H01L21/67017—Apparatus for fluid treatment
    • H01L21/67028—Apparatus for fluid treatment for cleaning followed by drying, rinsing, stripping, blasting or the like
    • H01L21/6704—Apparatus for fluid treatment for cleaning followed by drying, rinsing, stripping, blasting or the like for wet cleaning or washing
    • H01L21/67051—Apparatus for fluid treatment for cleaning followed by drying, rinsing, stripping, blasting or the like for wet cleaning or washing using mainly spraying means, e.g. nozzles
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67011—Apparatus for manufacture or treatment
    • H01L21/67017—Apparatus for fluid treatment
    • H01L21/67063—Apparatus for fluid treatment for etching
    • H01L21/67075—Apparatus for fluid treatment for etching for wet etching
    • H01L21/6708—Apparatus for fluid treatment for etching for wet etching using mainly spraying means, e.g. nozzles
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67011—Apparatus for manufacture or treatment
    • H01L21/67017—Apparatus for fluid treatment
    • H01L21/67063—Apparatus for fluid treatment for etching
    • H01L21/67075—Apparatus for fluid treatment for etching for wet etching
    • H01L21/67086—Apparatus for fluid treatment for etching for wet etching with the semiconductor substrates being dipped in baths or vessels
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67011—Apparatus for manufacture or treatment
    • H01L21/67098—Apparatus for thermal treatment
    • H01L21/67109—Apparatus for thermal treatment mainly by convection

Definitions

  • This invention relates to a substrate processing apparatus.
  • substrates to be processed include semiconductor wafers, liquid crystal display substrates, plasma display substrates, FED (Field (Emission Display) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, and photomasks.
  • substrate semiconductor wafers, liquid crystal display substrates, plasma display substrates, FED (Field (Emission Display) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, and photomasks.
  • substrate substrate, ceramic substrate, solar cell substrate and the like.
  • the silicon nitride film is selectively removed by supplying a high-temperature phosphoric acid aqueous solution as an etchant to the surface of the substrate on which the silicon nitride film and the silicon oxide film are formed.
  • a phosphoric acid etching process is performed as necessary.
  • a plurality of substrates are immersed in a processing tank in which a high-temperature phosphoric acid aqueous solution is stored for a certain period of time.
  • a batch type substrate processing apparatus in order to perform a uniform etching process, it is necessary to immerse the substrate in a phosphoric acid aqueous solution stored in a processing tank for a certain period or more. Therefore, the same processing time is required regardless of whether a plurality of substrates are processed at once or when a single substrate is processed.
  • a single wafer type substrate processing apparatus can uniformly process a single substrate in a short time.
  • the etching rate (removal amount per unit time) of the silicon nitride film is highest when the temperature of the phosphoric acid aqueous solution supplied to the substrate is near the boiling point.
  • the temperature of the phosphoric acid aqueous solution is lowered before being supplied to the substrate.
  • the etching rate decreases. For this reason, the time required for etching becomes long and the throughput may be lowered, and an improvement in the etching rate is demanded.
  • the phosphoric acid etching it is required not only to increase the etching rate of the silicon nitride film, but also to increase the selectivity of the silicon nitride film (the removal amount of the silicon nitride film / the removal amount of the silicon oxide film).
  • an object of the present invention is to provide a substrate processing apparatus capable of increasing the nitride film etching rate and at the same time keeping the nitride film selectivity high.
  • the present invention provides a storage tank for storing a phosphoric acid aqueous solution, a substrate holding means for holding the substrate in a horizontal posture in a state in which the substrate is immersed in the phosphoric acid aqueous solution in the storage tank, and the substrate holding means
  • a substrate processing apparatus including a heating unit facing a substrate that is formed, and heating means for heating the substrate by heat radiation or heat transfer from the heating unit.
  • the substrate is immersed in the phosphoric acid aqueous solution in the storage tank.
  • the substrate in the immersion state is given heat from the heat generating part by heat conduction, and at the same time, heat is given by heat radiation (heat radiation).
  • heat radiation heat radiation
  • the phosphoric acid aqueous solution in which the substrate is immersed is maintained at the boiling point by the heat from the heat generating part.
  • the boundary where the substrate surface and the phosphoric acid aqueous solution are in contact with each other is extremely hot locally and the phosphoric acid concentration is kept low as a whole.
  • the phosphoric acid aqueous solution in this state can be applied to the nitride film on the surface of the substrate. Thereby, the etching rate can be greatly increased, and at the same time, the selectivity of the nitride film can be kept high.
  • the substrate can be immersed with a small amount of phosphoric acid aqueous solution. Further, since the substrate is in a horizontal posture, generation of convection in the phosphoric acid aqueous solution can be suppressed, and thereby the temperature and phosphoric acid concentration of the phosphoric acid aqueous solution can be kept uniform.
  • the substrate processing apparatus stores water in the storage tank by controlling water supply means for supplying water to the phosphoric acid aqueous solution stored in the storage tank and supply / stop of water supply from the water supply means. It is preferable to include concentration control means for controlling the concentration of the phosphoric acid aqueous solution.
  • the phosphoric acid aqueous solution is maintained in a boiling state by heating of the heat generating portion with respect to the phosphoric acid aqueous solution.
  • the phosphoric acid concentration of the phosphoric acid aqueous solution gradually increases due to evaporation of water contained in the phosphoric acid aqueous solution.
  • the rise in the boiling point of the phosphoric acid aqueous solution further increases the temperature of the phosphoric acid aqueous solution, which may further increase the phosphoric acid concentration of the phosphoric acid aqueous solution.
  • an increase in the phosphoric acid concentration of the phosphoric acid aqueous solution is suppressed by supplying water to the phosphoric acid aqueous solution maintained in a boiling state. That is, the concentration of the phosphoric acid aqueous solution can be controlled by controlling the supply / stop of water supply to the phosphoric acid aqueous solution. As a result, a phosphoric acid aqueous solution whose concentration is appropriately controlled can be supplied to the substrate, and therefore the selectivity of the nitride film can be maintained even higher.
  • the water supply means may include a porous nozzle having a large number of discharge ports for discharging water droplets. Since water droplets are discharged from each of a large number of discharge ports, water can be supplied almost uniformly to the phosphoric acid aqueous solution stored in the storage tank. As a result, the phosphoric acid concentration of the phosphoric acid aqueous solution can be kept uniform. Thereby, the selectivity of the nitride film can be kept uniform over the entire area of the substrate.
  • the water supply means may include a spray nozzle that injects spray-like water into the reservoir.
  • a spray nozzle that injects spray-like water into the reservoir.
  • finer water droplets are supplied to the phosphoric acid aqueous solution stored in the storage tank.
  • Water and phosphoric acid aqueous solution tend to be relatively difficult to mix due to differences in specific gravity, viscosity, and the like.
  • the smaller the droplet size the easier it is to mix, the water and the phosphoric acid aqueous solution can be smoothly mixed by supplying water in a fine droplet state to the phosphoric acid aqueous solution.
  • the heating means heats the substrate held by the substrate holding means from below.
  • the storage tank may have a bottom surface, and the bottom surface of the storage tank may constitute the heat generating portion. Since the bottom surface of the storage tank is a heat generating part, heat can be applied to the substrate immersed in the phosphoric acid aqueous solution in the storage tank by heat radiation or heat conduction from the heat generating part with a simple configuration.
  • the heating means heats the substrate held by the substrate holding means from above.
  • the heating unit may include an infrared lamp, and the infrared lamp may be disposed to face the surface of the substrate held by the substrate holding unit and irradiate infrared rays toward the surface.
  • the substrate holding means has a substrate support portion that supports a substrate in a non-contact state with respect to the storage tank, and the substrate processing apparatus includes a substrate rotation means that rotates the substrate supported by the substrate support portion. Further, it may be included.
  • the substrate can be rotated (for example, spin dry).
  • FIG. 4 is a schematic diagram for explaining the processing example of FIG. 3.
  • FIG. 4B is a schematic diagram for explaining a process following FIG. 4A. It is a schematic diagram for demonstrating the process following FIG. 4B.
  • FIG. 4D is a schematic diagram for explaining a process following FIG. 4C.
  • FIG. 4D is a schematic diagram for explaining a process following FIG. 4D. It is a schematic diagram for demonstrating the process following FIG. 4E.
  • FIG. 1 is a cross-sectional view schematically showing a configuration of a substrate processing apparatus 1 according to a first embodiment of the present invention.
  • the substrate processing apparatus 1 has a silicon oxide film (oxide film) and a silicon nitride film (on the surface on the device forming region side of a circular semiconductor wafer W (hereinafter simply referred to as “wafer W”) as an example of a substrate (
  • This is a single wafer type apparatus for performing an etching process on the nitride film.
  • This etching process is a process for selectively etching the nitride film from the surface of the wafer W, and an aqueous phosphoric acid solution is used as an etchant.
  • a substrate processing apparatus 1 includes a storage tank (heating means) 4 for storing a phosphoric acid aqueous solution in a processing chamber 2 partitioned by a partition wall (not shown), and a storage tank 4.
  • a spin chuck 3 that rotates while holding the wafer W horizontally while immersed in an aqueous phosphoric acid solution.
  • a heater 28 is embedded in the storage tank 4, and the bottom surface 29 of the storage tank 4 functions as a heat generating unit for heating the wafer W.
  • the substrate processing apparatus 1 includes a phosphoric acid aqueous solution nozzle 5 for discharging a phosphoric acid aqueous solution onto the surface (upper surface) of the wafer W held on the spin chuck 3, and the wafer W held on the spin chuck 3.
  • the spin chuck 3 includes a cylindrical rotating shaft 11 that extends vertically, a disk-shaped spin base 12 that is attached to the upper end of the rotating shaft 11 in a horizontal posture, and a plurality of spin chucks 3 that are arranged on the spin base 12 at regular intervals, for example. (At least three, for example, six) clamping members (substrate support portions) 13 and a spin motor (substrate rotation means) 14 connected to the rotation shaft 11 are provided.
  • Each clamping member 13 is configured by arranging downwardly a clamping pin 34 for clamping the peripheral edge of the wafer W at the tip of an L-shaped support arm 42 in a side view.
  • the clamping pin drive mechanism 43 is coupled to the plurality of clamping pins 34.
  • the clamping pin drive mechanism 43 has a clamping position where the plurality of clamping pins 34 can be brought into contact with the end surface of the wafer W to clamp the wafer W, and an open position radially outward of the wafer W from the clamping position. Can be led to.
  • the wafer W is firmly held by the spin chuck 3 by holding the holding pins 34 in contact with the peripheral end surface of the wafer W.
  • the rotational driving force of the spin motor 14 is input to the rotation shaft 11, so that the wafer W is rotated around the vertical rotation axis A 1 passing through the center of the wafer W. Rotate.
  • the spin chuck 3 can rotate the wafer W at a maximum rotation speed of 2500 rpm.
  • the phosphoric acid aqueous solution nozzle 5 is, for example, a straight nozzle that discharges a phosphoric acid aqueous solution in a continuous flow state, and is fixedly disposed above the spin chuck 3 with its discharge port directed near the rotation center of the wafer W. ing.
  • the phosphoric acid aqueous solution nozzle 5 is connected to a phosphoric acid supply pipe 16 to which a phosphoric acid aqueous solution having a boiling point (for example, about 140 ° C.) from a phosphoric acid aqueous solution supply source is supplied.
  • a phosphate valve 17 for opening and closing the phosphate supply pipe 16 is interposed in the phosphate supply pipe 16.
  • the phosphoric acid aqueous solution is supplied from the phosphoric acid supply pipe 16 to the phosphoric acid aqueous solution nozzle 5, and when the phosphoric acid valve 17 is closed, the phosphoric acid aqueous solution nozzle 5 is supplied from the phosphoric acid supply pipe 16. The supply of the phosphoric acid aqueous solution to is stopped.
  • the bar nozzle 50 is a nozzle that extends linearly and is held in a horizontal position above the spin chuck 3.
  • the bar nozzle 50 extends along the radial direction of the wafer W held by the spin chuck 3 and passes on the rotation axis A1 of the wafer W.
  • the bar nozzle 50 has a cylindrical nozzle pipe 51 whose tip is closed. The tip of the bar nozzle 50 is closed.
  • Each discharge port 52 includes a small hole that opens in the tube wall of the nozzle pipe 51, and each discharge port 52 communicates with the internal space of the nozzle pipe 51.
  • the plurality of discharge ports 52 have substantially the same size and are arranged with substantially equal density.
  • a first water supply pipe 53 to which water from a water supply source is supplied is connected to the proximal end of the nozzle pipe 51.
  • the inside of the nozzle pipe 51 communicates with the inside of the first water supply pipe 53.
  • the first water supply pipe 53 is provided with a first water valve 54 for opening and closing the first water supply pipe 53.
  • first water valve 54 When the first water valve 54 is opened, water is supplied from the first water supply pipe 53 to the bar nozzle 50, and water is discharged downward from each discharge port 52. Since each discharge port is formed from a small hole, each discharge port 52 drops as a droplet. At this time, the discharge flow rate of water from each discharge port 52 is uniform.
  • the water dripped from each discharge port 52 is poured into the storage tank 4 of the spin chuck 3.
  • the water nozzle 30 is, for example, a straight nozzle that discharges DIW for rinsing in a continuous flow state.
  • the water nozzle 30 is fixedly disposed above the spin chuck 3 with its discharge port directed near the rotation center of the wafer W. Yes.
  • a second water supply pipe 31 to which water from a water supply source is supplied is connected to the water nozzle 30.
  • a second water valve 32 for switching supply / stop of water supply from the water nozzle 30 is interposed in the middle of the second water supply pipe 31.
  • the cup 8 is for processing a phosphoric acid aqueous solution and water after being used for processing the wafer W, and is formed in a bottomed cylindrical container shape.
  • the storage tank 4 has, for example, a substantially cylindrical bottomed container shape, and is formed using ceramic or silicon carbide (SiC).
  • the storage tank 4 is disposed in a horizontal posture between the upper surface of the spin base 12 and the lower surface of the wafer W held by the spin chuck 3.
  • the storage tank 4 includes a horizontally flat circular bottom surface (heat generating portion) 29 and an outer peripheral wall 38 that rises vertically upward from the peripheral edge of the bottom surface 29.
  • the bottom surface 29 of the storage tank 4 and the inner peripheral surface of the outer peripheral wall 38 define a shallow groove storage groove 41 for storing a liquid above the bottom surface 29, and the liquid can be stored above the bottom surface 29. It is like that.
  • the groove depth of the storage groove 41 (the thickness of the liquid stored in the storage groove 41) is set to, for example, about 7 mm within a range of 2 mm to 11 mm.
  • a resistance heater 28 is embedded in the bottom surface 29 of the storage tank 4.
  • Power is supplied to the heater 28 through a power supply line (not shown) that passes through the through hole 24 and the like described below.
  • the storage tank 4 is not configured to be rotatable, and therefore a rotating electrical contact is not required for supplying power to the heater 28. Therefore, compared with the case where the storage tank 4 is rotated, the power supply amount to the storage tank 4 is not limited. Thereby, the wafer W can be heated to a desired high temperature.
  • the heater 28 In the ON state of the heater 28, the heater 28 generates heat by supplying power to the heater 28, the entire storage tank 4 enters a heat generation state, and the entire bottom surface 29 generates heat.
  • the amount of heat generated per unit area of the bottom surface 29 when the heater 28 is on is set uniformly over the entire bottom surface 29.
  • the support rod 25 is inserted in the vertical direction (thickness direction of the spin base 12) along the rotation axis A1 through the through hole 24 penetrating the spin base 12 and the rotation shaft 11 in the vertical direction. It is fixed.
  • the support rod 25 is not in contact with the spin base 12 or the rotating shaft 11 in the through hole 24.
  • the lower end (the other end) of the support rod 25 is fixed to a peripheral member below the spin chuck 3, whereby the support rod 25 is held in a posture.
  • the storage tank 4 is not supported by the spin chuck 3, the storage tank 4 is stationary (non-rotating state) without rotating even when the wafer W is rotating.
  • the support rod 25 is a hollow shaft, and a water supply path 61 for flowing water such as DIW (deionized water) is formed therein.
  • the water supply path 61 communicates with a lower discharge port 62 that opens at the bottom surface 29 of the storage tank 4.
  • the lower discharge port 62 faces the center of the lower surface of the wafer W held by the spin chuck 3.
  • a water supply pipe 63 to which water is supplied from a water supply source is connected to the water supply path 61.
  • the water supply pipe 63 is provided with a water valve 64 for opening and closing the water supply pipe 63.
  • the water valve 64 When the water valve 64 is opened, water is supplied from the water supply pipe 63 to the lower discharge port 62 through the water supply path 61. Thereby, water is discharged from the lower discharge port 62.
  • An elevating mechanism 27 for elevating the storage tank 4 is coupled to the support rod 25.
  • the storage tank 4 is lifted and lowered by the lifting mechanism 27 while maintaining a horizontal posture.
  • the elevating mechanism 27 is constituted by, for example, a ball screw or a motor.
  • the storage tank 4 has a lower position where the lower surface is close to the upper surface of the spin base 12 (a separation position where the lower surface is separated from the wafer W; see FIG. 4A and the like), and an upper surface of the storage tank 4 is the wafer W Are moved up and down with respect to an upper position (a proximity position close to the wafer W; see FIG. 4D and the like) opposed to the lower surface of the wafer W with a small interval W1.
  • interval of the storage tank 4 and the wafer W can be changed.
  • annular groove 37 is formed on the peripheral edge of the bottom surface 29 of the storage tank 4 to accommodate the pin 34 of the clamping member 13 when the storage tank 4 is in the upper position described below.
  • the annular groove 37 has an annular shape with the rotation axis A1 as the center so that the pin 34 of the clamping member 13 can be accommodated during rotation of the spin chuck 3 (spin base 12).
  • the groove depth of the annular groove 37 is set to such a depth that the holding pin 34 and the bottom wall of the annular groove 37 do not interfere when the storage tank 4 is in the upper position described below.
  • the groove width of the annular groove 37 is set wider than the outer diameter of the holding pin 34.
  • the annular groove 37 and the outer peripheral wall 38 are provided adjacent to the inside and outside. That is, the outer peripheral surface of the annular groove 37 and the inner peripheral surface of the outer peripheral wall 38 are continuous to form a vertical surface.
  • the wafer W held by the holding member 13 with the surface facing upward is immersed by the liquid stored in the storage groove 41. Is done. That is, the liquid level of the liquid stored in the storage groove 41 is located above the surface of the wafer W, and as a result, the entire surface of the wafer W is covered with the liquid stored in the storage groove 41.
  • FIG. 2 is a block diagram showing an electrical configuration of the substrate processing apparatus 1.
  • the substrate processing apparatus 1 includes a control unit (temperature control means) 40 including a microcomputer.
  • the controller 40 controls on / off of the heater 28 by switching between energization / disconnection of the heater 28.
  • the control unit 40 controls operations of the spin motor 14, the pinching pin drive mechanism 43, the lifting mechanism 27, and the like.
  • the control unit 40 also controls the opening / closing operations of the phosphoric acid valve 17, the first water valve 54, the second water valve 32, and the like.
  • FIG. 3 is a process diagram for explaining a processing example of the phosphoric acid etching process executed by the substrate processing apparatus 1.
  • 4A to 4F are schematic views for explaining this processing example.
  • the controller 40 turns on the heater 28 (driving state).
  • the bottom surface 29 is in a heat generating state.
  • the control unit 40 opens the phosphoric acid valve 17 and discharges a phosphoric acid aqueous solution having a high boiling point close to the boiling point from the phosphoric acid aqueous solution nozzle 5, and the phosphoric acid aqueous solution is stored in the storage groove 41 of the storage tank 4 in the lower position. Accumulate on.
  • the control unit 40 closes the phosphoric acid valve 17.
  • the phosphoric acid aqueous solution is heated by the bottom surface 29 in an exothermic state, and the phosphoric acid aqueous solution is heated to a boiling point (for example, about 140 ° C.) and then maintained in a boiling state.
  • a boiling point for example, about 140 ° C.
  • water contained in the phosphoric acid aqueous solution evaporates, and the phosphoric acid concentration of the phosphoric acid aqueous solution gradually increases.
  • the control unit 40 opens the first water valve 54 and drops water droplets from the discharge ports 52 of the bar nozzle 50.
  • the liquid droplets dropped from each discharge port 52 are supplied to the phosphoric acid aqueous solution in the storage tank 4. Since water droplets are discharged from each of the large number of discharge ports 52, water is supplied almost uniformly to the phosphoric acid aqueous solution stored in the storage tank 4.
  • By supplying water to the phosphoric acid aqueous solution in the boiling state an increase in the phosphoric acid concentration of the phosphoric acid aqueous solution in the storage tank 4 is suppressed.
  • the supply of water to the phosphoric acid aqueous solution is performed prior to the loading of the wafer W.
  • the controller 40 adjusts the amount of water supplied to the phosphoric acid aqueous solution in the storage tank 4 by opening and closing the first water valve 54 and switching supply / stop of supply from the bar nozzle 50. Since the water is supplied for adjusting the phosphoric acid concentration of the phosphoric acid aqueous solution, the flow rate of the phosphoric acid aqueous solution supplied from the bar nozzle 50 is sufficient. By supplying such water, the phosphoric acid concentration and temperature of the phosphoric acid aqueous solution in the storage tank 4 are controlled to be constant at a predetermined phosphoric acid concentration (81% as an example) and temperature (about 140 ° C. as an example), respectively.
  • the phosphoric acid concentration and temperature of the phosphoric acid aqueous solution in the storage tank 4 are controlled to be constant at a predetermined phosphoric acid concentration (81% as an example) and temperature (about 140 ° C. as an example), respectively.
  • a transfer robot (not shown) is controlled in a state where the temperature of the phosphoric acid aqueous solution and the phosphoric acid concentration in the storage tank 4 are controlled to the intended temperature and concentration, respectively, and an unprocessed wafer W is placed in the processing chamber 2. Is brought in. A silicon nitride film and a silicon oxide film are formed on the surface of the unprocessed wafer W.
  • the loaded wafer W is arranged at a predetermined delivery position facing the bottom surface 29 of the storage tank 4, and the control unit 40 drives the clamping pin drive mechanism 43 to move the plurality of clamping pins 34 from the open position to the clamping position. Lead.
  • the loaded wafer W is held by the spin chuck 3 with its surface facing upward. In the state where the wafer W is at the delivery position, the distance between the lower surface and the bottom surface 29 of the wafer W is, for example, about 50 mm.
  • the control unit 40 controls the elevating mechanism 27 to raise the storage tank 4 to the upper position.
  • the wafer W is immersed in the phosphoric acid aqueous solution in the storage tank 4.
  • the liquid level of the phosphoric acid aqueous solution in the storage tank 4 is located above the surface of the wafer W, and as a result, the entire surface of the wafer W is covered with the phosphoric acid aqueous solution.
  • a phosphoric acid etching process is performed on the surface of the wafer W (step S1). The phosphoric acid etching process is performed until a predetermined etching time elapses.
  • the interval W1 between the lower surface of the wafer W and the bottom surface 29 of the storage tank 4 is set to about 3 mm, for example.
  • the liquid level of the phosphoric acid aqueous solution is located approximately 3 mm above the wafer W.
  • the thickness of the wafer W is, for example, 0.775 mm.
  • the interval W1 can be set as appropriate within a range of 0.3 to 3 mm.
  • the wafer W held by the spin chuck 3 is heated from the bottom surface 29 of the storage tank 4 by thermal radiation. Since the bottom surface 29 and the lower surface of the wafer W are parallel with the storage tank 4 in the upper position, the amount of heat per unit area given to the wafer W from the storage tank 4 is substantially uniform over the entire area of the wafer W. It is.
  • water is appropriately supplied to the phosphoric acid aqueous solution in the storage tank 4 during the phosphoric acid etching step.
  • the controller 40 opens the first water valve 54 and drops water droplets from the discharge ports 52 of the bar nozzle 50. Since water droplets are discharged from each of the large number of discharge ports 52, water is supplied almost uniformly to the phosphoric acid aqueous solution stored in the storage tank 4. Thereby, the phosphoric acid concentration and temperature of the phosphoric acid aqueous solution in the storage tank 4 are controlled to a predetermined phosphoric acid concentration (81% as an example) and temperature (about 140 ° C. as an example), respectively.
  • the control unit 40 controls the spin motor 14 to rotate the wafer W at a predetermined low speed (for example, in the range of 10 to 300 rpm). As the wafer W rotates, the phosphoric acid aqueous solution stored in the storage groove 41 is agitated. Thereby, the phosphoric acid concentration and temperature of the phosphoric acid aqueous solution are uniformly distributed.
  • FIG. 5 is a diagram showing heating of the wafer W by the bottom surface 29 of the storage tank 4.
  • the bottom surface 29 of the storage tank 4 and the lower surface of the wafer W are almost opposed to each other. Further, the interval W1 between the bottom surface 29 of the storage tank 4 and the lower surface of the wafer W is set to, for example, about 3 mm within a range of 0.3 to 3 mm, for example. Therefore, the wafer W is given heat from the bottom surface 29 of the storage tank 4 by heat conduction and heat by radiation. Thereby, it is considered that the temperature of the wafer W is raised to about 160 ° C.
  • FIG. 6 is a graph showing the relationship between the phosphoric acid concentration (H 3 PO 4 concentration) in the phosphoric acid aqueous solution and the boiling point (boiling point) of the phosphoric acid aqueous solution.
  • the curve in FIG. 6 shows a saturation concentration curve, and the region below the curve is a region where a phosphoric acid aqueous solution can exist (H 3 PO 4 existence region).
  • an aqueous phosphoric acid solution having a concentration of 81% has a boiling point of about 140 ° C.
  • an aqueous phosphoric acid solution having a concentration of 81% does not rise to 140 ° C. or higher in the liquid phase.
  • the maximum concentration of the phosphoric acid aqueous solution having a temperature of 160 ° C. is about 86%. Therefore, in a phosphoric acid aqueous solution having a temperature of 160 ° C., the concentration does not decrease below about 86% in a normal state.
  • FIG. 7 is a graph showing the relationship between the phosphoric acid concentration in the phosphoric acid aqueous solution, the temperature of the phosphoric acid aqueous solution, and the etching rate of the silicon nitride film.
  • the solid line indicates the etching rate when the silicon nitride film is etched using an aqueous phosphoric acid solution having temperatures of 150 ° C., 160 ° C., and 170 ° C.
  • the boiling point of phosphoric acid aqueous solution is shown with the broken line.
  • the etching rate is highest when the temperature of the phosphoric acid aqueous solution is 170 ° C., and the etching rate when the temperature of the phosphoric acid aqueous solution is 160 ° C. is second. high. Therefore, if the phosphoric acid concentration is constant, the higher the temperature of the phosphoric acid aqueous solution, the higher the etching rate.
  • the etching rate decreases as the phosphoric acid concentration increases.
  • the temperature of the phosphoric acid aqueous solution is 160 ° C and 170 ° C. Therefore, if the temperature of the phosphoric acid aqueous solution is constant, the lower the phosphoric acid concentration, the higher the etching rate.
  • the temperature of the phosphoric acid aqueous solution is 140 ° C.
  • the state of the phosphoric acid aqueous solution in the storage tank 4 in the phosphoric acid etching process will be described with reference to FIGS.
  • a phosphoric acid aqueous solution whose concentration is adjusted to 81% is stored.
  • the boiling point of this phosphoric acid aqueous solution is about 140 ° C.
  • the phosphoric acid aqueous solution stored in the storage tank 4 is heated by the bottom surface 29 of the storage tank 4 and maintains the boiling point of about 140 ° C.
  • the wafer W is heated to about 160 ° C. by heating from the bottom surface 29 of the storage tank 4.
  • a temperature gradient is formed in the phosphoric acid aqueous solution at the boundary with the surface of the wafer W, which becomes higher as the surface of the wafer W is approached.
  • a high temperature state of about 160 ° C. is realized at the boundary where the surface of the wafer W and the phosphoric acid aqueous solution are in contact with each other.
  • the etching rate of the silicon nitride film can be greatly increased, and at the same time, the selectivity of the silicon nitride film can be kept high.
  • control unit 40 controls the lifting mechanism 27 to lower the storage tank 4 as shown in FIG. 4F. Lower to position. Thereby, the heating of the wafer W by the bottom surface 29 of the storage tank 4 is completed.
  • control unit 40 controls the spin motor 14 to increase the rotation speed of the wafer W to a predetermined rinse processing speed (in the range of 300 to 1500 rpm, for example, 1000 rpm), and opens the second water valve 32, DIW is supplied from the discharge port of the water nozzle 30 toward the vicinity of the rotation center of the wafer W (step S2: rinsing step).
  • the DIW supplied to the surface of the wafer W receives centrifugal force due to the rotation of the wafer W and flows on the surface of the wafer W toward the periphery of the wafer W. Thereby, the phosphoric acid aqueous solution adhering to the surface of the wafer W is washed away by DIW.
  • storage tank cleaning is performed to clean the inner wall surface of the storage tank 4 (the bottom surface 29, the wall surface of the annular groove 37, and the inner peripheral surface of the outer peripheral wall 38) with water.
  • the control unit 40 opens the water valve 64 and discharges water from the lower discharge port 62.
  • the water discharged from the lower discharge port 62 is stored in the storage groove 41 of the storage tank 4.
  • the discharge of water from the lower discharge port 62 is continued even after the storage groove 41 overflows. Thereby, the phosphoric acid aqueous solution adhering to the inner wall surface of the storage tank 4 is washed away with water.
  • the second water valve 32 is closed and the supply of DIW to the surface of the wafer W is stopped.
  • the water supply valve 64 is closed together with the DIW supply stop, and the supply of water to the storage tank 41 is stopped.
  • control unit 40 drives the spin motor 14 to increase the rotation speed of the wafer W to a predetermined high rotation speed (for example, 1500 to 2500 rpm), and shakes off the DIW adhering to the wafer W to be dried.
  • Spin drying is performed (step S3).
  • the DIW adhering to the wafer W is removed by spin drying in step S3.
  • the control unit 40 drives the spin motor 14 to stop the rotation of the spin chuck 3.
  • the control unit 40 drives the holding pin driving mechanism 43 to guide the plurality of holding pins 34 from the holding position to the open position, and the processed wafer W is delivered to the transfer robot.
  • the wafer W is unloaded from the processing chamber 2 by the transfer robot.
  • the wafer W is heated to about 160 ° C. by heating the wafer W by the bottom surface 29 of the storage tank 4.
  • a temperature gradient is formed in the phosphoric acid aqueous solution at the boundary with the surface of the wafer W, which becomes higher as the surface of the wafer W is approached.
  • the phosphoric acid aqueous solution at the boundary with the surface of the wafer W is in a state where the phosphoric acid concentration is maintained at a very high temperature and a low phosphoric acid concentration (the temperature is about 160 ° C. and the concentration is about 81%, A state in which the acid concentration is kept low).
  • the etching rate of the silicon nitride film can be greatly increased, and at the same time, the selectivity of the silicon nitride film can be kept high.
  • FIG. 8 is a diagram schematically showing the configuration of the substrate processing apparatus 101 according to the second embodiment of the present invention.
  • parts corresponding to those shown in the first embodiment are denoted by the same reference numerals as those in FIGS. 1 to 7, and description thereof is omitted.
  • the substrate processing apparatus 101 is different from the substrate processing apparatus 1 according to the first embodiment in that, as a water supply unit for supplying water, instead of the bar nozzle 50, water droplets are ejected in a spray form (spraying).
  • the spray nozzle 102 is employed.
  • a third water supply pipe 103 to which water from a water supply source is supplied is connected to the spray nozzle 102.
  • a third water valve 104 for opening and closing the third water supply pipe 103 is interposed in the third water supply pipe 103. When the third water valve 104 is opened, water is supplied from the third water supply pipe 103 to the spray nozzle 102, and water droplets are ejected (sprayed) from the spray nozzle 102 downward.
  • the water droplets discharged from the spray nozzle 102 are finer (smaller) than the water droplets discharged from the bar nozzle of the first embodiment described above.
  • water droplets are ejected in a spray form from the spray nozzle 102, so that water can be supplied almost uniformly to the phosphoric acid aqueous solution stored in the storage tank 4, As a result, the phosphoric acid concentration of the phosphoric acid aqueous solution can be kept uniform.
  • finer water droplets are supplied from the spray nozzle 102 to the phosphoric acid aqueous solution.
  • Water and phosphoric acid aqueous solution tend to be relatively difficult to mix due to differences in specific gravity, viscosity, and the like.
  • the smaller the droplet size the easier it is to mix, the water and the phosphoric acid aqueous solution can be smoothly mixed by supplying water in a fine droplet state to the phosphoric acid aqueous solution.
  • FIG. 8 shows a case where only one spray nozzle 102 is provided, water can also be discharged from a plurality of spray nozzles at different positions in the left-right direction.
  • FIG. 9 is a diagram schematically showing the configuration of the substrate processing apparatus 201 according to the third embodiment of the present invention.
  • parts corresponding to those shown in the first embodiment are denoted by the same reference numerals as those in FIGS. 1 to 7, and description thereof is omitted.
  • the difference between the substrate processing apparatus 201 and the substrate processing apparatus 1 according to the first embodiment is that a non-heating type storage tank 204 is adopted as the storage tank.
  • the substrate processing apparatus 1 is also different from the substrate processing apparatus 1 in that a heater head 203 for heating the surface of the wafer W is provided above the spin chuck 3.
  • the storage tank 204 is formed using, for example, ceramic, SiC, or heat resistant resin.
  • the configuration of the storage tank 204 is the same as that of the storage tank 4 shown in FIG. 1 except that the heater 28 (see FIG. 1) is not embedded and does not function as a heating means. That is, the storage tank 204 is arranged in a horizontal posture and is moved up and down while maintaining the horizontal posture.
  • the elevating mechanism (see FIG. 1) 27 By driving the elevating mechanism (see FIG. 1) 27, the storage tank 204 has a lower position where the lower surface thereof is close to the upper surface of the spin base 12, and the bottom surface 29 of the storage tank 204 has a minute interval W 1 on the lower surface of the wafer W. It is moved up and down between the upper positions arranged opposite to each other. Thereby, the interval between the storage tank 204 and the wafer W can be changed.
  • a storage groove 41 for storing liquid is defined above the bottom surface 29 by the bottom surface 29 of the storage tank 204 and the inner peripheral surface of the outer peripheral wall 38.
  • the wafer W facing upward is immersed by the liquid stored in the storage groove 41. That is, the entire surface of the wafer W is covered with the liquid stored in the storage groove 41. Even when the wafer W is rotating, the storage groove 41 is not rotated but is stationary (non-rotating state).
  • the heater head 203 has a disk shape having a diameter equivalent to that of the wafer W, and is formed using, for example, ceramic.
  • the heater head 203 is held in a horizontal posture from above by a holder 205.
  • a resistance heater 208 is embedded in the heater head 203.
  • the heater head 203 has a lower surface (heat generating portion) 209 made of a horizontal flat surface.
  • the lower surface 209 of the heater head 203 is disposed to face the entire surface of the wafer W held by the spin chuck 3.
  • the heater 208 generates heat by supplying power to the heater 208, and the entire lower surface 209 generates heat.
  • the heat generation amount per unit area of the lower surface 209 when the heater 28 is on is set to be uniform.
  • the heater 205 is coupled to the holder 205 for raising and lowering the heater head 203.
  • the heater lifting mechanism 206 is electrically connected to the control unit 40 (see FIG. 2).
  • the phosphoric acid aqueous solution is stored in the storage groove 41 of the storage tank 204, as in the first embodiment (see FIG. 4A). Thereafter, an unprocessed wafer W is loaded into the processing chamber 2, and the wafer W is held on the spin chuck 3 (the holding member 13) with the surface thereof facing upward.
  • the control unit 40 controls the elevating mechanism 27 (see FIG. 1) to raise the storage tank 204 to the upper position.
  • the wafer W is immersed in the phosphoric acid aqueous solution in the storage tank 204.
  • the liquid level of the phosphoric acid aqueous solution in the storage tank 204 is located above the surface of the wafer W, and as a result, the entire surface of the wafer W is covered with the phosphoric acid aqueous solution.
  • the surface of the wafer W is subjected to phosphoric acid etching (corresponding to step S1 in FIG. 3).
  • control unit 40 controls the heater lifting mechanism 206 to lower the heater head 203 to a close position where the lower surface 209 of the heater head 203 is close to the surface (upper surface) of the wafer W.
  • the distance between the surface (upper surface) of the wafer W and the lower surface 209 of the heater head 203 is set to about 2 mm, for example.
  • the wafer W held by the spin chuck 3 is heated from the lower surface 209 of the heater head 203 by heat radiation. Since the lower surface 209 of the heater head 203 and the surface of the wafer W are parallel to each other, the amount of heat per unit area given from the heater head 203 to the wafer W is substantially uniform over the entire area of the wafer W. Due to the heating by the heater head 203, the temperature of the wafer W is raised to a temperature slightly higher than the liquid temperature of the phosphoric acid aqueous solution (expected to be about 160 ° C.) and maintained at that temperature.
  • the wafer W immersed in the phosphoric acid aqueous solution in the storage tank 204 is heated using the heater head 203 disposed close to the wafer W. Therefore, the wafer W can be heated satisfactorily without adopting a complicated configuration such as incorporating a heater in the storage tank 204.
  • FIG. 10 is a diagram schematically showing the configuration of a substrate processing apparatus 301 according to the fourth embodiment of the present invention.
  • parts corresponding to the parts shown in the third embodiment are denoted by the same reference numerals as in FIGS. 1 to 7 and FIG. 9, and description thereof is omitted.
  • the substrate processing apparatus 301 is different from the substrate processing apparatus 201 according to the third embodiment in that an infrared heater (heating) is used instead of the heater head 203 as a heater for heating the surface of the wafer W. Means) 303 is provided.
  • the infrared heater 303 has a circular shape in a plan view having a smaller diameter than the wafer W (for example, about 1/5 to 1/10 of the diameter of the wafer W), and the surface of the wafer W held by the spin chuck 3 is Oppositely arranged above.
  • the infrared heater 303 incorporates an infrared lamp 304 having an infrared irradiation surface (heat generating portion) 304A on the lower surface.
  • the infrared irradiation surface 304 ⁇ / b> A faces the surface of the wafer W over substantially the entire area, and the infrared irradiation surface 304 ⁇ / b> A faces the surface of the wafer W.
  • the infrared lamp 38 is configured by accommodating a filament in a quartz pipe. As the infrared lamp 38, a short, medium and long wavelength infrared heater represented by a halogen lamp and a carbon heater can be adopted.
  • the holder 205 is coupled with a heater swing mechanism 306 for swinging the infrared heater 303 about a predetermined vertical swing axis provided outside the surface of the wafer W.
  • the infrared heater 303 has an arc-shaped trajectory that intersects the rotation direction of the wafer W between the rotation center (on the rotation axis A ⁇ b> 1) and the peripheral edge of the surface of the wafer W. It is provided to be movable so as to draw.
  • the heater elevating mechanism 206 is controlled, and the infrared heater 303 is lowered to a close position where the infrared irradiation surface 304A is close to the surface (upper surface) of the wafer W. It is done.
  • the distance between the surface (upper surface) of the wafer W and the infrared irradiation surface 304A of the infrared heater 303 is set to about 10 mm, for example.
  • the infrared irradiation surface 304 ⁇ / b> A of the infrared heater 303 in the close position does not come into contact with the phosphoric acid aqueous solution in the storage tank 204.
  • the wafer W held by the spin chuck 3 is heated by thermal radiation from the infrared irradiation surface 304A of the infrared heater 303. Due to the heating by the infrared heater 303, the temperature of the wafer W is raised to a slightly higher temperature than the liquid temperature of the phosphoric acid aqueous solution (expected to be about 160 ° C.) and maintained at this temperature. In this state, a temperature gradient is formed in the phosphoric acid aqueous solution at the boundary with the surface of the wafer W, which becomes higher as the surface of the wafer W is approached.
  • the heater elevating mechanism 206 is controlled so that the infrared heater 303 is largely retracted upward from the proximity position, whereby the heating of the wafer W by the infrared heater 303 is stopped.
  • the infrared heater 303 When the infrared heater 303 irradiates infrared rays, the infrared heater 303 is scanned between the rotation center of the wafer W and the periphery of the wafer W, or the infrared heater 303 is moved to the rotation center of the wafer W. It is placed stationary above the position excluding. Since the wafer W rotates about the rotation axis A ⁇ b> 1, almost the entire area of the wafer W can be heated by irradiation with infrared rays from the infrared heater 303.
  • the wafer W immersed in the phosphoric acid aqueous solution in the storage tank 204 is heated using the infrared heater 303 disposed close to the wafer W. Therefore, the wafer W can be heated satisfactorily without adopting a complicated configuration such as incorporating a heater in the storage tank 204.
  • the infrared heater 303 capable of giving a large amount of heat is provided as a heating means, the wafer W can be heated while adopting a simple configuration as the heating means.
  • the diameter of the infrared heater 303 can be formed to the same diameter as the wafer W.
  • the infrared heater 303 is provided so that the lower surface of the infrared heater 303 faces the entire surface of the wafer W.
  • FIG. 11 is a diagram schematically showing a configuration of a substrate processing apparatus 401 according to the fifth embodiment of the present invention.
  • parts corresponding to those shown in the first embodiment are denoted by the same reference numerals as those in FIGS. 1 to 7, and description thereof is omitted.
  • the substrate processing apparatus 401 includes a substrate holding table 402 as substrate holding means for holding the wafer W.
  • the substrate holder 402 is used in place of the spin chuck 3 of the first embodiment.
  • the substrate holder 402 includes a storage tank 404 (heating means) for storing a phosphoric acid aqueous solution.
  • the storage tank 404 has, for example, a substantially cylindrical bottomed container shape, and is formed using ceramic or silicon carbide (SiC).
  • the storage tank 404 includes a bottom surface portion 409A having a horizontally flat circular bottom surface 409, and an outer peripheral wall 408 that rises vertically upward from the peripheral edge of the bottom surface 409.
  • a storage groove 405 for storing liquid is defined above the bottom surface 29 by the bottom surface 409 of the storage tank 404 and the inner peripheral surface of the outer peripheral wall 408, so that the liquid can be stored above the bottom surface 409.
  • the groove depth of the storage groove 405 (the thickness of the liquid stored in the storage groove 41) is set to, for example, about 7 mm within the range of 2 mm to 11 mm.
  • a resistance heater 406 is embedded in the bottom surface portion 409 ⁇ / b> A of the storage tank 404.
  • the heater 406 In the ON state of the heater 406, the heater 406 generates heat by supplying power to the heater 406, and the entire storage tank 404 is heated. As a result, the entire bottom surface 409 generates heat. In the entire area of the bottom surface 409, the heat generation amount per unit area of the bottom surface 409 when the heater 406 is on is set to be uniform.
  • a plurality of (for example, three) lift pins 403 that move the wafer W up and down relative to the storage tank 404 are provided in association with the storage tank 404.
  • the plurality of lift pins 403 are inserted through a through hole 412 formed vertically through the bottom surface portion 409A of the storage tank 404, and are provided so as to be movable up and down with respect to the bottom surface 409 of the storage tank 404.
  • Each lift pin 403 is supported by a common support member 410.
  • a lift pin elevating mechanism 411 including a cylinder is coupled to the support member 410.
  • the lift pin lifting mechanism 411 includes a plurality of lift pins 403 between a position where the tips of the plurality of lift pins 403 protrude above the substrate holding table 402 and a position where the tips of the plurality of lift pins 403 retract below the substrate holding table 402.
  • the book lift pins 403 are moved up and down integrally.
  • the lift pin lifting mechanism 411 is controlled so that the tips of the plurality of lift pins 403 protrude above the substrate holding table 402. Then, an unprocessed wafer W is loaded, and this wafer W is placed on the tips of a plurality of lift pins 403. At this time, the lift pin raising / lowering mechanism 411 is controlled, the plurality of lift pins 403 are lowered, and the wafer W is transferred from the plurality of lift pins 403 to the substrate holding table 402. As a result, the wafer W is placed on the bottom surface 409 of the storage tank 404 with the surface thereof facing upward. In this state, the lower surface of the wafer W is in contact with the bottom surface 409 of the storage tank 404. Further, in this state, each through hole 412 is closed by the wafer W.
  • the phosphoric acid aqueous solution is stored in the storage groove 405 of the storage tank 404. Since the through hole 412 is blocked by the wafer W, the phosphoric acid aqueous solution does not leak from the storage groove 405. Then, the wafer W is immersed in the phosphoric acid aqueous solution in the storage tank 404. At this time, the liquid level of the phosphoric acid aqueous solution in the storage tank 404 is located above the surface of the wafer W, and as a result, the entire surface of the wafer W is covered with the phosphoric acid aqueous solution. By immersing the wafer W in the phosphoric acid aqueous solution, the surface of the wafer W is subjected to phosphoric acid etching (corresponding to step S1 in FIG. 3).
  • the wafer W held on the substrate holding table 402 is heated by heat conduction from the storage tank 404. Due to heating by the storage tank 404, the temperature of the wafer W is raised to about 200 ° C. and maintained. In this state, a temperature gradient is formed in the phosphoric acid aqueous solution at the boundary with the surface of the wafer W, which becomes higher as the surface of the wafer W is approached.
  • the temperature of the wafer W is raised to about 200 ° C. by heating the wafer W by heat conduction in the bottom surface 409 of the storage tank 404.
  • a temperature gradient is formed in the phosphoric acid aqueous solution at the boundary with the surface of the wafer W, which becomes higher as the surface of the wafer W is approached.
  • the etching rate of the silicon nitride film can be greatly increased, and at the same time, the selectivity of the silicon nitride film can be kept high.
  • a lift pin 403A having a seal portion 420 for sealing the through hole 412 may be employed instead of each lift pin 403 as indicated by a broken line in FIG.
  • the seal portion 420 is provided at the tip (upper end) of the lift pin 403A and has a truncated cone shape whose diameter increases toward the upper side.
  • the opening end of the through hole 412 has a tapered surface 421 formed of a conical surface whose diameter increases toward the upper side.
  • the seal part 420 of the lift pin 403A is accommodated in the opening end of the through hole 412 in a state where the lift pin 403A is in the retreat position where it is retracted below the wafer W. In this state, the outer peripheral surface of the seal portion 420 contacts the tapered surface 421, and the seal portion 420 seals (closes) the through hole 412. Since the through hole 412 is sealed by the seal portion 420 of the lift pin 403A, leakage of the phosphoric acid aqueous solution from the storage groove 405 can be prevented more reliably.
  • the second embodiment and the fifth embodiment can be combined. That is, in the second embodiment, instead of the bar nozzle 50 (see FIG. 1), a spray nozzle 102 that discharges (sprays) water droplets in a spray form may be employed.
  • FIG. 8 shows a case where only one spray nozzle 102 is provided, but water can also be discharged from a plurality of spray nozzles at different positions in the left-right direction. .
  • DIW has been described as an example of water supplied to the phosphoric acid aqueous solution in the storage tank 4, 404, but carbonated water is used as the water supplied to the phosphoric acid aqueous solution.
  • Electrolytic ion water, ozone water, reduced water (hydrogen water), magnetic water, etc. may be employed.
  • the case where the storage tanks 4, 404 are provided with the heater function has been described.
  • the storage tanks 4, 404 and the heaters may be separated.
  • a configuration in which the heater is heated from below the storage tanks 4, 404 may be used.
  • the heater head 203 is formed to have a diameter sufficiently smaller than the diameter of the wafer W, and the heater head 203 is placed on the surface of the wafer W while the heater head 203 in the on state is opposed to the surface of the wafer W. You may make it move along a surface.
  • the infrared heater 303 is formed to have a diameter sufficiently smaller than the diameter of the wafer W, and the infrared heater 303 is placed on the surface of the wafer W while the infrared heater 303 in the on state is opposed to the surface of the wafer W. You may make it move along a surface.

Abstract

A substrate processing device comprises: a storage tank for storing a phosphoric acid aqueous solution; a substrate support means for supporting a substrate immersed in the phosphoric acid aqueous solution horizontally in the storage tank; and a heating means, having a heater arranged opposite the substrate which is supported by the substrate support means, for heating the substrate with radiant heat or transmitted heat from the heater.

Description

基板処理装置Substrate processing equipment
　この発明は、基板処理装置に関する。処理対象となる基板には、たとえば、半導体ウエハ、液晶表示装置用基板、プラズマディスプレイ用基板、ＦＥＤ（Field Emission Display）用基板、光ディスク用基板、磁気ディスク用基板、光磁気ディスク用基板、フォトマスク用基板、セラミック基板、太陽電池用基板などが含まれる。 This invention relates to a substrate processing apparatus. Examples of substrates to be processed include semiconductor wafers, liquid crystal display substrates, plasma display substrates, FED (Field （Emission Display) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, and photomasks. Substrate, ceramic substrate, solar cell substrate and the like.
　半導体装置や液晶表示装置などの製造工程では、シリコン窒化膜とシリコン酸化膜とが形成された基板の表面にエッチング液としての高温のリン酸水溶液を供給して、シリコン窒化膜を選択的に除去するリン酸エッチング処理が必要に応じて行われる。 In the manufacturing process of semiconductor devices and liquid crystal display devices, the silicon nitride film is selectively removed by supplying a high-temperature phosphoric acid aqueous solution as an etchant to the surface of the substrate on which the silicon nitride film and the silicon oxide film are formed. A phosphoric acid etching process is performed as necessary.
　複数枚の基板を一括して処理するバッチ式の基板処理装置では、高温のリン酸水溶液が貯留された処理槽に複数枚の基板が一定時間浸漬される。 In a batch-type substrate processing apparatus that processes a plurality of substrates at once, a plurality of substrates are immersed in a processing tank in which a high-temperature phosphoric acid aqueous solution is stored for a certain period of time.
特開２００７－２５８４０５号公報JP 2007-258405 A
　バッチ式の基板処理装置では、均一なエッチング処理を行うために、処理槽に貯留されたリン酸水溶液に基板を一定間以上浸漬させる必要がある。したがって、複数枚の基板を一括して処理する場合でも、一枚の基板を処理する場合でも同じ処理時間が必要である。 In a batch type substrate processing apparatus, in order to perform a uniform etching process, it is necessary to immerse the substrate in a phosphoric acid aqueous solution stored in a processing tank for a certain period or more. Therefore, the same processing time is required regardless of whether a plurality of substrates are processed at once or when a single substrate is processed.
　一方、枚葉式の基板処理装置では、一枚の基板を短時間で均一に処理することができる。 On the other hand, a single wafer type substrate processing apparatus can uniformly process a single substrate in a short time.
　シリコン窒化膜のエッチングレート（単位時間当たりの除去量）は、基板に供給されたリン酸水溶液の温度が沸点付近のときに最も高い。しかしながら、枚葉式の基板処理装置では、リン酸水溶液の温度をタンク内で沸点付近に調節したとしても、基板に供給されるまでの間にリン酸水溶液の温度が低下するから、シリコン窒化膜のエッチングレートが低下する。このため、エッチングに要する時間が長くなり、スループットが低下するおそれがあり、エッチングレートの向上が求められている。 The etching rate (removal amount per unit time) of the silicon nitride film is highest when the temperature of the phosphoric acid aqueous solution supplied to the substrate is near the boiling point. However, in the single wafer processing apparatus, even if the temperature of the phosphoric acid aqueous solution is adjusted to the vicinity of the boiling point in the tank, the temperature of the phosphoric acid aqueous solution is lowered before being supplied to the substrate. The etching rate decreases. For this reason, the time required for etching becomes long and the throughput may be lowered, and an improvement in the etching rate is demanded.
　また、リン酸エッチングでは、シリコン窒化膜のエッチングレートを高めることだけでなく、シリコン窒化膜の選択比（シリコン窒化膜の除去量／シリコン酸化膜の除去量）を高めることも求められている。 In addition, in the phosphoric acid etching, it is required not only to increase the etching rate of the silicon nitride film, but also to increase the selectivity of the silicon nitride film (the removal amount of the silicon nitride film / the removal amount of the silicon oxide film).
　そこで、この発明の目的は、窒化膜のエッチングレートを高めつつ、同時に窒化膜の選択比を高く保つことができる基板処理装置を提供することである。 Therefore, an object of the present invention is to provide a substrate processing apparatus capable of increasing the nitride film etching rate and at the same time keeping the nitride film selectivity high.
　この発明は、リン酸水溶液を貯留する貯留槽と、前記貯留槽内のリン酸水溶液に基板を浸漬させた状態で、当該基板を水平姿勢に保持する基板保持手段と、前記基板保持手段に保持されている基板と対向する発熱部を有し、当該基板を、前記発熱部からの熱輻射または熱伝達により加熱する加熱手段とを含む、基板処理装置を提供する。 The present invention provides a storage tank for storing a phosphoric acid aqueous solution, a substrate holding means for holding the substrate in a horizontal posture in a state in which the substrate is immersed in the phosphoric acid aqueous solution in the storage tank, and the substrate holding means There is provided a substrate processing apparatus including a heating unit facing a substrate that is formed, and heating means for heating the substrate by heat radiation or heat transfer from the heating unit.
　この構成によれば、貯留槽内のリン酸水溶液に基板が浸漬される。浸漬状態にある基板に、熱伝導によって発熱部からの熱が与えられると同時に、熱輻射（熱ふく射）によって熱が与えられる。一方、基板を浸漬しているリン酸水溶液は、発熱部からの熱により沸点に維持されている。 According to this configuration, the substrate is immersed in the phosphoric acid aqueous solution in the storage tank. The substrate in the immersion state is given heat from the heat generating part by heat conduction, and at the same time, heat is given by heat radiation (heat radiation). On the other hand, the phosphoric acid aqueous solution in which the substrate is immersed is maintained at the boiling point by the heat from the heat generating part.
　ここで、基板がリン酸水溶液の沸点以上に加熱されている場合、基板表面とリン酸水溶液とが接する境界では、局所的には極めて高温で、かつ全体としてリン酸濃度が低く維持された状態を実現することができ、その状態のリン酸水溶液を、基板の表面の窒化膜に作用させることができる。これにより、エッチングレートを非常に高めることができ、同時に窒化膜の選択比を高く維持することができる。 Here, when the substrate is heated to the boiling point or higher of the phosphoric acid aqueous solution, the boundary where the substrate surface and the phosphoric acid aqueous solution are in contact with each other is extremely hot locally and the phosphoric acid concentration is kept low as a whole. The phosphoric acid aqueous solution in this state can be applied to the nitride film on the surface of the substrate. Thereby, the etching rate can be greatly increased, and at the same time, the selectivity of the nitride film can be kept high.
　また、基板を水平姿勢に保持させつつ、その基板を、貯留槽内のリン酸水溶液に浸漬させることにより、少ない液量のリン酸水溶液で基板の浸漬を実現することができる。また、基板が水平姿勢であるために、リン酸水溶液での対流の発生等を抑制することができ、これにより、リン酸水溶液の温度やリン酸濃度を均一に保つことができる。 Also, by immersing the substrate in the phosphoric acid aqueous solution in the storage tank while holding the substrate in a horizontal position, the substrate can be immersed with a small amount of phosphoric acid aqueous solution. Further, since the substrate is in a horizontal posture, generation of convection in the phosphoric acid aqueous solution can be suppressed, and thereby the temperature and phosphoric acid concentration of the phosphoric acid aqueous solution can be kept uniform.
　前記基板処理装置は、前記貯留槽に貯留されているリン酸水溶液に水を供給する水供給手段と、前記水供給手段からの水の供給／供給停止を制御することにより、前記貯留槽に貯留されているリン酸水溶液の濃度を制御する濃度制御手段とを含むことが好ましい。 The substrate processing apparatus stores water in the storage tank by controlling water supply means for supplying water to the phosphoric acid aqueous solution stored in the storage tank and supply / stop of water supply from the water supply means. It is preferable to include concentration control means for controlling the concentration of the phosphoric acid aqueous solution.
　リン酸水溶液に対する発熱部の加熱により、リン酸水溶液は沸騰状態に維持されている。リン酸水溶液が沸騰状態にあると、リン酸水溶液に含まれる水の蒸発により、リン酸水溶液のリン酸濃度が徐々に濃くなる。その結果、リン酸水溶液の沸点の上昇により、リン酸水溶液の液温がさらに上昇し、リン酸水溶液のリン酸濃度がさらに高くなってしまうおそれがある。 The phosphoric acid aqueous solution is maintained in a boiling state by heating of the heat generating portion with respect to the phosphoric acid aqueous solution. When the phosphoric acid aqueous solution is in a boiling state, the phosphoric acid concentration of the phosphoric acid aqueous solution gradually increases due to evaporation of water contained in the phosphoric acid aqueous solution. As a result, the rise in the boiling point of the phosphoric acid aqueous solution further increases the temperature of the phosphoric acid aqueous solution, which may further increase the phosphoric acid concentration of the phosphoric acid aqueous solution.
　前記の構成によれば、沸騰状態に維持されているリン酸水溶液に対する水の供給により、リン酸水溶液のリン酸濃度の上昇が抑制される。すなわち、リン酸水溶液に対する水の供給／供給停止を制御することにより、リン酸水溶液の濃度を制御することができる。これにより、適度に濃度制御されたリン酸水溶液を基板に供給することができ、ゆえに、窒化膜の選択比をより一層高く維持することができる。 According to the above configuration, an increase in the phosphoric acid concentration of the phosphoric acid aqueous solution is suppressed by supplying water to the phosphoric acid aqueous solution maintained in a boiling state. That is, the concentration of the phosphoric acid aqueous solution can be controlled by controlling the supply / stop of water supply to the phosphoric acid aqueous solution. As a result, a phosphoric acid aqueous solution whose concentration is appropriately controlled can be supplied to the substrate, and therefore the selectivity of the nitride film can be maintained even higher.
　前記水供給手段は、水の液滴を吐出する多数の吐出口を有する多孔ノズルを含んでいてもよい。多数の吐出口のそれぞれから水の液滴が吐出されるので、貯留槽に貯留されているリン酸水溶液に、ほぼ均一に水を供給することができる。その結果、リン酸水溶液のリン酸濃度を均一に保つことができる。これにより、窒化膜の選択比を、基板の全域で一様に保つことができる。 The water supply means may include a porous nozzle having a large number of discharge ports for discharging water droplets. Since water droplets are discharged from each of a large number of discharge ports, water can be supplied almost uniformly to the phosphoric acid aqueous solution stored in the storage tank. As a result, the phosphoric acid concentration of the phosphoric acid aqueous solution can be kept uniform. Thereby, the selectivity of the nitride film can be kept uniform over the entire area of the substrate.
　また、前記水供給手段は、前記貯留部にスプレー状の水を噴射するスプレーノズルを含んでいてもよい。スプレー状の水を噴射することにより、貯留槽に貯留されているリン酸水溶液に、より細かい水の液滴が供給される。水とリン酸水溶液とは、それらの比重や粘度等の相違のために、比較的混ざりにくい傾向にある。しかしながら、液滴の大きさが細かければ細かいほど混ざり易いので、細かい液滴の状態の水をリン酸水溶液に供給することにより、水とリン酸水溶液とをスムーズに混合させることができる。 Further, the water supply means may include a spray nozzle that injects spray-like water into the reservoir. By spraying spray-like water, finer water droplets are supplied to the phosphoric acid aqueous solution stored in the storage tank. Water and phosphoric acid aqueous solution tend to be relatively difficult to mix due to differences in specific gravity, viscosity, and the like. However, since the smaller the droplet size, the easier it is to mix, the water and the phosphoric acid aqueous solution can be smoothly mixed by supplying water in a fine droplet state to the phosphoric acid aqueous solution.
　この発明の一実施形態では、前記加熱手段は、前記基板保持手段に保持されている基板を、下方側から加熱する。 In one embodiment of the present invention, the heating means heats the substrate held by the substrate holding means from below.
　この場合、前記貯留槽は底面を有し、前記貯留槽の前記底面が前記発熱部を構成していてもよい。貯留槽の底面が発熱部であるので、貯留槽内のリン酸水溶液に浸漬されている基板に対し、簡単な構成で、発熱部から熱輻射または熱伝導により熱を与えることができる。 In this case, the storage tank may have a bottom surface, and the bottom surface of the storage tank may constitute the heat generating portion. Since the bottom surface of the storage tank is a heat generating part, heat can be applied to the substrate immersed in the phosphoric acid aqueous solution in the storage tank by heat radiation or heat conduction from the heat generating part with a simple configuration.
　この発明の他の実施形態では、前記加熱手段は、前記基板保持手段に保持されている基板を、上方側から加熱する。前記加熱手段は赤外線ランプを有し、前記赤外線ランプは、前記基板保持手段に保持されている基板の表面に対向配置されて、当該表面に向けて赤外線を照射してもよい。 In another embodiment of the present invention, the heating means heats the substrate held by the substrate holding means from above. The heating unit may include an infrared lamp, and the infrared lamp may be disposed to face the surface of the substrate held by the substrate holding unit and irradiate infrared rays toward the surface.
　前記基板保持手段は、前記貯留槽に対して非接触状態で、基板を支持する基板支持部を有し、前記基板処理装置は、前記基板支持部に支持された基板を回転させる基板回転手段をさらに含んでいてもよい。 The substrate holding means has a substrate support portion that supports a substrate in a non-contact state with respect to the storage tank, and the substrate processing apparatus includes a substrate rotation means that rotates the substrate supported by the substrate support portion. Further, it may be included.
　この構成によれば、基板に対して回転処理（たとえばスピンドライ）を施すことができる。 According to this configuration, the substrate can be rotated (for example, spin dry).
　本発明における前述の、またはさらに他の目的、特徴および効果は、添付図面を参照して次に述べる実施形態の説明により明らかにされる。 The above-described or other objects, features, and effects of the present invention will be clarified by the following description of embodiments with reference to the accompanying drawings.
本発明の第１実施形態に係る基板処理装置の構成を模式的に示す断面図である。It is sectional drawing which shows typically the structure of the substrate processing apparatus which concerns on 1st Embodiment of this invention. 図１に示す基板処理装置の電気的構成を示すブロック図である。It is a block diagram which shows the electric constitution of the substrate processing apparatus shown in FIG. 図１に示す基板処理装置によって実行されるリン酸エッチング処理の処理例について説明するための工程図である。It is process drawing for demonstrating the process example of the phosphoric acid etching process performed by the substrate processing apparatus shown in FIG. 図３の処理例を説明するための模式的な図である。FIG. 4 is a schematic diagram for explaining the processing example of FIG. 3. 図４Ａに続く工程を説明するための模式的な図である。FIG. 4B is a schematic diagram for explaining a process following FIG. 4A. 図４Ｂに続く工程を説明するための模式的な図である。It is a schematic diagram for demonstrating the process following FIG. 4B. 図４Ｃに続く工程を説明するための模式的な図である。FIG. 4D is a schematic diagram for explaining a process following FIG. 4C. 図４Ｄに続く工程を説明するための模式的な図である。FIG. 4D is a schematic diagram for explaining a process following FIG. 4D. 図４Ｅに続く工程を説明するための模式的な図である。It is a schematic diagram for demonstrating the process following FIG. 4E. 貯留槽の底面によるウエハの加熱を示す図である。It is a figure which shows the heating of the wafer by the bottom face of a storage tank. リン酸水溶液におけるリン酸濃度と、リン酸水溶液の沸点との関係を示すグラフである。It is a graph which shows the relationship between the phosphoric acid concentration in phosphoric acid aqueous solution, and the boiling point of phosphoric acid aqueous solution. リン酸水溶液におけるリン酸濃度およびリン酸水溶液の温度と、シリコン窒化膜のエッチングレートとの関係を示すグラフである。It is a graph which shows the relationship between the phosphoric acid concentration in phosphoric acid aqueous solution, the temperature of phosphoric acid aqueous solution, and the etching rate of a silicon nitride film. 本発明の第２実施形態に係る基板処理装置の構成を模式的に示す図である。It is a figure which shows typically the structure of the substrate processing apparatus which concerns on 2nd Embodiment of this invention. 本発明の第３実施形態に係る基板処理装置の構成を模式的に示す図である。It is a figure which shows typically the structure of the substrate processing apparatus which concerns on 3rd Embodiment of this invention. 本発明の第４実施形態に係る基板処理装置の構成を模式的に示す図である。It is a figure which shows typically the structure of the substrate processing apparatus which concerns on 4th Embodiment of this invention. 本発明の第５実施形態に係る基板処理装置の構成を模式的に示す図である。It is a figure which shows typically the structure of the substrate processing apparatus which concerns on 5th Embodiment of this invention.
　図１は、本発明の第１実施形態に係る基板処理装置１の構成を模式的に示す断面図である。 FIG. 1 is a cross-sectional view schematically showing a configuration of a substrate processing apparatus 1 according to a first embodiment of the present invention.
　この基板処理装置１は、基板の一例としての円形の半導体ウエハＷ（以下、単に「ウエハＷ」という）におけるデバイス形成領域側の表面に対して、シリコン酸化膜（酸化膜）およびシリコン窒化膜（窒化膜）のエッチング処理を施すための枚葉型の装置である。このエッチング処理は、ウエハＷの表面から、窒化膜を選択的にエッチングするための処理であり、エッチング液としてリン酸水溶液が用いられる。 The substrate processing apparatus 1 has a silicon oxide film (oxide film) and a silicon nitride film (on the surface on the device forming region side of a circular semiconductor wafer W (hereinafter simply referred to as “wafer W”) as an example of a substrate ( This is a single wafer type apparatus for performing an etching process on the nitride film. This etching process is a process for selectively etching the nitride film from the surface of the wafer W, and an aqueous phosphoric acid solution is used as an etchant.
　図１に示すように、基板処理装置１は、隔壁（図示しない）により区画された処理室２内に、リン酸水溶液を貯留するための貯留槽（加熱手段）４と、貯留槽４内にリン酸水溶液に浸漬させた状態で、ウエハＷを水平に保持して回転させるスピンチャック３とを備えている。貯留槽４はヒータ２８が埋設されており、貯留槽４の底面２９がウエハＷを加熱するための発熱部として機能する。また、基板処理装置１は、スピンチャック３に保持されているウエハＷの表面（上面）にリン酸水溶液を吐出するためのリン酸水溶液ノズル５と、スピンチャック３に保持されているウエハＷの表面に水の液滴を滴下させるためのバーノズル（多孔ノズル）５０と、スピンチャック３に保持されているウエハＷの表面に水を吐出するための水ノズル３０と、スピンチャック３を収容するカップ８とを備えている。 As shown in FIG. 1, a substrate processing apparatus 1 includes a storage tank (heating means) 4 for storing a phosphoric acid aqueous solution in a processing chamber 2 partitioned by a partition wall (not shown), and a storage tank 4. A spin chuck 3 that rotates while holding the wafer W horizontally while immersed in an aqueous phosphoric acid solution. A heater 28 is embedded in the storage tank 4, and the bottom surface 29 of the storage tank 4 functions as a heat generating unit for heating the wafer W. Further, the substrate processing apparatus 1 includes a phosphoric acid aqueous solution nozzle 5 for discharging a phosphoric acid aqueous solution onto the surface (upper surface) of the wafer W held on the spin chuck 3, and the wafer W held on the spin chuck 3. A bar nozzle (perforated nozzle) 50 for dropping water droplets on the surface, a water nozzle 30 for discharging water onto the surface of the wafer W held on the spin chuck 3, and a cup containing the spin chuck 3 8 and.
　スピンチャック３として、たとえば挟持式のものが採用されている。スピンチャック３は、鉛直に延びる筒状の回転軸１１と、回転軸１１の上端に水平姿勢に取り付けられた円板状のスピンベース１２と、スピンベース１２にたとえば等間隔で配置された複数個（少なくとも３個。たとえば６個）の挟持部材（基板支持部）１３と、回転軸１１に連結されたスピンモータ（基板回転手段）１４とを備えている。 For example, a pinch type is used as the spin chuck 3. The spin chuck 3 includes a cylindrical rotating shaft 11 that extends vertically, a disk-shaped spin base 12 that is attached to the upper end of the rotating shaft 11 in a horizontal posture, and a plurality of spin chucks 3 that are arranged on the spin base 12 at regular intervals, for example. (At least three, for example, six) clamping members (substrate support portions) 13 and a spin motor (substrate rotation means) 14 connected to the rotation shaft 11 are provided.
　各挟持部材１３は、側面視Ｌ形の支持アーム４２の先端に、ウエハＷの周縁部を挟持するための挟持ピン３４を下向きに配設して構成されている。 Each clamping member 13 is configured by arranging downwardly a clamping pin 34 for clamping the peripheral edge of the wafer W at the tip of an L-shaped support arm 42 in a side view.
　複数の挟持ピン３４には、挟持ピン駆動機構４３が結合されている。挟持ピン駆動機構４３は、複数の挟持ピン３４を、ウエハＷの端面と当接してウエハＷを挟持することができる挟持位置と、この挟持位置よりもウエハＷの径方向外方の開放位置とに導くことができるようになっている。スピンチャック３は、各挟持ピン３４をウエハＷの周端面に接触させて挟持することにより、ウエハＷがスピンチャック３に強固に保持される。ウエハＷが複数個の挟持部材１３に保持された状態で、スピンモータ１４の回転駆動力が回転軸１１に入力されることにより、ウエハＷの中心を通る鉛直な回転軸線Ａ１まわりにウエハＷが回転する。スピンチャック３はウエハＷを、最大２５００ｒｐｍの回転速度で回転させることができる。 The clamping pin drive mechanism 43 is coupled to the plurality of clamping pins 34. The clamping pin drive mechanism 43 has a clamping position where the plurality of clamping pins 34 can be brought into contact with the end surface of the wafer W to clamp the wafer W, and an open position radially outward of the wafer W from the clamping position. Can be led to. In the spin chuck 3, the wafer W is firmly held by the spin chuck 3 by holding the holding pins 34 in contact with the peripheral end surface of the wafer W. In a state where the wafer W is held by the plurality of clamping members 13, the rotational driving force of the spin motor 14 is input to the rotation shaft 11, so that the wafer W is rotated around the vertical rotation axis A 1 passing through the center of the wafer W. Rotate. The spin chuck 3 can rotate the wafer W at a maximum rotation speed of 2500 rpm.
　リン酸水溶液ノズル５は、たとえば、連続流の状態でリン酸水溶液を吐出するストレートノズルであり、スピンチャック３の上方で、その吐出口をウエハＷの回転中心付近に向けて固定的に配置されている。リン酸水溶液ノズル５には、リン酸水溶液供給源からの沸点（たとえば約１４０℃）近くのリン酸水溶液が供給されるリン酸供給管１６が接続されている。リン酸供給管１６には、リン酸供給管１６を開閉するためのリン酸バルブ１７が介装されている。リン酸バルブ１７が開かれると、リン酸供給管１６からリン酸水溶液ノズル５にリン酸水溶液が供給され、また、リン酸バルブ１７が閉じられると、リン酸供給管１６からリン酸水溶液ノズル５へのリン酸水溶液の供給が停止される。 The phosphoric acid aqueous solution nozzle 5 is, for example, a straight nozzle that discharges a phosphoric acid aqueous solution in a continuous flow state, and is fixedly disposed above the spin chuck 3 with its discharge port directed near the rotation center of the wafer W. ing. The phosphoric acid aqueous solution nozzle 5 is connected to a phosphoric acid supply pipe 16 to which a phosphoric acid aqueous solution having a boiling point (for example, about 140 ° C.) from a phosphoric acid aqueous solution supply source is supplied. A phosphate valve 17 for opening and closing the phosphate supply pipe 16 is interposed in the phosphate supply pipe 16. When the phosphoric acid valve 17 is opened, the phosphoric acid aqueous solution is supplied from the phosphoric acid supply pipe 16 to the phosphoric acid aqueous solution nozzle 5, and when the phosphoric acid valve 17 is closed, the phosphoric acid aqueous solution nozzle 5 is supplied from the phosphoric acid supply pipe 16. The supply of the phosphoric acid aqueous solution to is stopped.
　バーノズル５０は直線状に延びるノズルであって、スピンチャック３の上方で水平姿勢に保持されている。バーノズル５０は、スピンチャック３に保持されたウエハＷの半径方向に沿って延び、かつ当該ウエハＷの回転軸線Ａ１上を通っている。バーノズル５０は、先端が閉塞された円筒状のノズル配管５１を有している。バーノズル５０の先端は、閉塞されている。 The bar nozzle 50 is a nozzle that extends linearly and is held in a horizontal position above the spin chuck 3. The bar nozzle 50 extends along the radial direction of the wafer W held by the spin chuck 3 and passes on the rotation axis A1 of the wafer W. The bar nozzle 50 has a cylindrical nozzle pipe 51 whose tip is closed. The tip of the bar nozzle 50 is closed.
　ノズル配管５１の周面の下端縁には、水の液滴を滴下するための多数の吐出口５２が、一列または複数列に並んで形成されている。各吐出口５２はノズル配管５１の管壁に開口する小孔からなり、各吐出口５２はノズル配管５１の内部空間と連通している。これら複数の吐出口５２はほぼ同じ大きさを有し、ほぼ等密度で配置されている。 At the lower end edge of the peripheral surface of the nozzle pipe 51, a large number of discharge ports 52 for dropping water droplets are formed in a line or a plurality of lines. Each discharge port 52 includes a small hole that opens in the tube wall of the nozzle pipe 51, and each discharge port 52 communicates with the internal space of the nozzle pipe 51. The plurality of discharge ports 52 have substantially the same size and are arranged with substantially equal density.
　ノズル配管５１の基端には、水供給源からの水が供給される第１水供給管５３が接続されている。ノズル配管５１の内部が第１水供給管５３の内部と連通している。第１水供給管５３には、第１水供給管５３を開閉するための第１水バルブ５４が介装されている。第１水バルブ５４が開かれると、第１水供給管５３からバーノズル５０に水が供給され、各吐出口５２から水が下方に向けて吐出される。各吐出口が小孔より形成されているので、各吐出口５２は液滴となって滴下する。このとき、各吐出口５２からの水の吐出流量は均一である。各吐出口５２から滴下された水は、スピンチャック３の貯留槽４に降り注がれる。 A first water supply pipe 53 to which water from a water supply source is supplied is connected to the proximal end of the nozzle pipe 51. The inside of the nozzle pipe 51 communicates with the inside of the first water supply pipe 53. The first water supply pipe 53 is provided with a first water valve 54 for opening and closing the first water supply pipe 53. When the first water valve 54 is opened, water is supplied from the first water supply pipe 53 to the bar nozzle 50, and water is discharged downward from each discharge port 52. Since each discharge port is formed from a small hole, each discharge port 52 drops as a droplet. At this time, the discharge flow rate of water from each discharge port 52 is uniform. The water dripped from each discharge port 52 is poured into the storage tank 4 of the spin chuck 3.
　水ノズル３０は、たとえば、連続流の状態でリンス用のＤＩＷを吐出するストレートノズルであり、スピンチャック３の上方で、その吐出口をウエハＷの回転中心付近に向けて固定的に配置されている。水ノズル３０には、水供給源からの水が供給される第２水供給管３１が接続されている。第２水供給管３１の途中部には、水ノズル３０からの水の供給／供給停止を切り換えるための第２水バルブ３２が介装されている。 The water nozzle 30 is, for example, a straight nozzle that discharges DIW for rinsing in a continuous flow state. The water nozzle 30 is fixedly disposed above the spin chuck 3 with its discharge port directed near the rotation center of the wafer W. Yes. A second water supply pipe 31 to which water from a water supply source is supplied is connected to the water nozzle 30. A second water valve 32 for switching supply / stop of water supply from the water nozzle 30 is interposed in the middle of the second water supply pipe 31.
　カップ８は、ウエハＷの処理に用いられた後のリン酸水溶液や水を処理するためのものであり、有底円筒容器状に形成されている。 The cup 8 is for processing a phosphoric acid aqueous solution and water after being used for processing the wafer W, and is formed in a bottomed cylindrical container shape.
　貯留槽４は、たとえば略円筒の有底容器状をなし、セラミックや炭化ケイ素（ＳｉＣ）を用いて形成されている。貯留槽４は、スピンベース１２の上面と、スピンチャック３に保持されるウエハＷの下面との間に水平姿勢で配置されている。貯留槽４は、水平平坦な円形の底面（発熱部）２９と、底面２９の周縁部から鉛直上方に立ち上がる外周壁３８とを備えている。貯留槽４の底面２９と外周壁３８の内周面とによって、底面２９の上方に液を溜めるための浅溝の貯留溝４１が区画されており、底面２９の上方に液を溜めることができるようになっている。貯留溝４１の溝深さ（貯留溝４１に溜められる液の厚み）は、２ｍｍ～１１ｍｍの範囲内でたとえば約７ｍｍに設定されている。貯留槽４の底面２９の内部には、抵抗式のヒータ２８が埋設されている。 The storage tank 4 has, for example, a substantially cylindrical bottomed container shape, and is formed using ceramic or silicon carbide (SiC). The storage tank 4 is disposed in a horizontal posture between the upper surface of the spin base 12 and the lower surface of the wafer W held by the spin chuck 3. The storage tank 4 includes a horizontally flat circular bottom surface (heat generating portion) 29 and an outer peripheral wall 38 that rises vertically upward from the peripheral edge of the bottom surface 29. The bottom surface 29 of the storage tank 4 and the inner peripheral surface of the outer peripheral wall 38 define a shallow groove storage groove 41 for storing a liquid above the bottom surface 29, and the liquid can be stored above the bottom surface 29. It is like that. The groove depth of the storage groove 41 (the thickness of the liquid stored in the storage groove 41) is set to, for example, about 7 mm within a range of 2 mm to 11 mm. A resistance heater 28 is embedded in the bottom surface 29 of the storage tank 4.
　次に述べる貫通穴２４等を挿通する給電線（図示しない）を介してヒータ２８に対する給電が行われている。貯留槽４は回転可能な構成ではなく、したがって、ヒータ２８への給電のために回転電気接点が不要である。そのため、貯留槽４を回転させる場合と比較して、貯留槽４への給電量が制限されない。これにより、ウエハＷを所望の高温まで加熱することが可能である。 Power is supplied to the heater 28 through a power supply line (not shown) that passes through the through hole 24 and the like described below. The storage tank 4 is not configured to be rotatable, and therefore a rotating electrical contact is not required for supplying power to the heater 28. Therefore, compared with the case where the storage tank 4 is rotated, the power supply amount to the storage tank 4 is not limited. Thereby, the wafer W can be heated to a desired high temperature.
　ヒータ２８のオン状態では、ヒータ２８への給電により当該ヒータ２８が発熱し、貯留槽４全体が発熱状態になり、底面２９全域が発熱する。ヒータ２８のオン状態における底面２９の単位面積当たりの発熱量は、底面２９の全域で均一に設定されている。 In the ON state of the heater 28, the heater 28 generates heat by supplying power to the heater 28, the entire storage tank 4 enters a heat generation state, and the entire bottom surface 29 generates heat. The amount of heat generated per unit area of the bottom surface 29 when the heater 28 is on is set uniformly over the entire bottom surface 29.
　支持ロッド２５は、スピンベース１２および回転軸１１を上下方向に貫通する貫通穴２４を回転軸線Ａ１に沿って鉛直方向（スピンベース１２の厚み方向）に挿通し、その上端が、貯留槽４に固定されている。支持ロッド２５は貫通穴２４においてスピンベース１２または回転軸１１と接触していない。支持ロッド２５の下端（他端）は、スピンチャック３の下方の周辺部材に固定され、これにより、支持ロッド２５が姿勢保持されている。このように、貯留槽４がスピンチャック３に支持されていないので、ウエハＷの回転中であっても、貯留槽４は回転せずに静止（非回転状態）している。 The support rod 25 is inserted in the vertical direction (thickness direction of the spin base 12) along the rotation axis A1 through the through hole 24 penetrating the spin base 12 and the rotation shaft 11 in the vertical direction. It is fixed. The support rod 25 is not in contact with the spin base 12 or the rotating shaft 11 in the through hole 24. The lower end (the other end) of the support rod 25 is fixed to a peripheral member below the spin chuck 3, whereby the support rod 25 is held in a posture. As described above, since the storage tank 4 is not supported by the spin chuck 3, the storage tank 4 is stationary (non-rotating state) without rotating even when the wafer W is rotating.
　支持ロッド２５は中空軸であり、その内部には、ＤＩＷ（脱イオン水）等の水が流通するための水供給路６１が形成されている。水供給路６１は、貯留槽４の底面２９で開口する下吐出口６２に連通している。下吐出口６２は、スピンチャック３に保持されるウエハＷの下面中心に対向している。 The support rod 25 is a hollow shaft, and a water supply path 61 for flowing water such as DIW (deionized water) is formed therein. The water supply path 61 communicates with a lower discharge port 62 that opens at the bottom surface 29 of the storage tank 4. The lower discharge port 62 faces the center of the lower surface of the wafer W held by the spin chuck 3.
　水供給路６１には、水供給源から水が供給される水下供給管６３が接続されている。水下供給管６３には、この水下供給管６３を開閉するための水下バルブ６４が介装されている。水下バルブ６４が開かれると、水下供給管６３から水供給路６１を介して下吐出口６２に水が供給される。これにより、下吐出口６２から水が吐出される。 A water supply pipe 63 to which water is supplied from a water supply source is connected to the water supply path 61. The water supply pipe 63 is provided with a water valve 64 for opening and closing the water supply pipe 63. When the water valve 64 is opened, water is supplied from the water supply pipe 63 to the lower discharge port 62 through the water supply path 61. Thereby, water is discharged from the lower discharge port 62.
　支持ロッド２５には、貯留槽４を昇降させるための昇降機構２７が結合されている。貯留槽４は、昇降機構２７により水平姿勢を維持したまま昇降される。昇降機構２７は、たとえばボールねじやモータによって構成されている。昇降機構２７の駆動により、貯留槽４は、その下面がスピンベース１２の上面に近接する下位置（ウエハＷから離反する離反位置。図４Ａ等参照）と、貯留槽４の上面が、ウエハＷの下面に微小な間隔Ｗ１を隔てて対向配置される上位置（ウエハＷに近接する近接位置。図４Ｄ等参照）との間で昇降させられる。これにより、貯留槽４とウエハＷとの間隔を変更させることが可能である。 An elevating mechanism 27 for elevating the storage tank 4 is coupled to the support rod 25. The storage tank 4 is lifted and lowered by the lifting mechanism 27 while maintaining a horizontal posture. The elevating mechanism 27 is constituted by, for example, a ball screw or a motor. By driving the elevating mechanism 27, the storage tank 4 has a lower position where the lower surface is close to the upper surface of the spin base 12 (a separation position where the lower surface is separated from the wafer W; see FIG. 4A and the like), and an upper surface of the storage tank 4 is the wafer W Are moved up and down with respect to an upper position (a proximity position close to the wafer W; see FIG. 4D and the like) opposed to the lower surface of the wafer W with a small interval W1. Thereby, the space | interval of the storage tank 4 and the wafer W can be changed.
　貯留槽４の底面２９の周縁部には、貯留槽４が次に述べる上位置にあるときに、挟持部材１３の挟持ピン３４を収容するための環状溝３７が形成されている。環状溝３７は、スピンチャック３（スピンベース１２）の回転中に挟持部材１３の挟持ピン３４を収容できるように、回転軸線Ａ１を中心とする円環状をなしている。環状溝３７の溝深さは、貯留槽４が次に述べる上位置にあるときに、挟持ピン３４と環状溝３７の底壁とが干渉しない程度の深さに設定されている。また、環状溝３７の溝幅は、挟持ピン３４の外径よりも広く設定されている。また、図１では、環状溝３７と外周壁３８とが内外に隣接して設けられている。すなわち、環状溝３７の外周面と外周壁３８の内周面とが連続し、鉛直面をなしている。 An annular groove 37 is formed on the peripheral edge of the bottom surface 29 of the storage tank 4 to accommodate the pin 34 of the clamping member 13 when the storage tank 4 is in the upper position described below. The annular groove 37 has an annular shape with the rotation axis A1 as the center so that the pin 34 of the clamping member 13 can be accommodated during rotation of the spin chuck 3 (spin base 12). The groove depth of the annular groove 37 is set to such a depth that the holding pin 34 and the bottom wall of the annular groove 37 do not interfere when the storage tank 4 is in the upper position described below. Further, the groove width of the annular groove 37 is set wider than the outer diameter of the holding pin 34. Moreover, in FIG. 1, the annular groove 37 and the outer peripheral wall 38 are provided adjacent to the inside and outside. That is, the outer peripheral surface of the annular groove 37 and the inner peripheral surface of the outer peripheral wall 38 are continuous to form a vertical surface.
　貯留槽４が上位置にあり、かつ貯留溝４１に液が満たされた状態では、貯留溝４１に溜められている液によって、表面を上向きの状態で挟持部材１３に挟持されたウエハＷが浸漬される。つまり、貯留溝４１に溜められている液の液面がウエハＷの表面よりも上方に位置し、その結果、貯留溝４１に溜められている液によってウエハＷの表面の全域が覆われる。 When the storage tank 4 is in the upper position and the storage groove 41 is filled with the liquid, the wafer W held by the holding member 13 with the surface facing upward is immersed by the liquid stored in the storage groove 41. Is done. That is, the liquid level of the liquid stored in the storage groove 41 is located above the surface of the wafer W, and as a result, the entire surface of the wafer W is covered with the liquid stored in the storage groove 41.
　図２は、基板処理装置１の電気的構成を示すブロック図である。 FIG. 2 is a block diagram showing an electrical configuration of the substrate processing apparatus 1.
　基板処理装置１は、マイクロコンピュータを含む構成の制御部（温度制御手段）４０を備えている。制御部４０は、ヒータ２８への通電／切断の切換えにより、ヒータ２８のオン／オフを制御する。また、制御部４０は、スピンモータ１４、挟持ピン駆動機構４３、昇降機構２７等の動作を制御する。また、制御部４０は、リン酸バルブ１７、第１水バルブ５４、第２水バルブ３２等の開閉動作を制御する。 The substrate processing apparatus 1 includes a control unit (temperature control means) 40 including a microcomputer. The controller 40 controls on / off of the heater 28 by switching between energization / disconnection of the heater 28. The control unit 40 controls operations of the spin motor 14, the pinching pin drive mechanism 43, the lifting mechanism 27, and the like. The control unit 40 also controls the opening / closing operations of the phosphoric acid valve 17, the first water valve 54, the second water valve 32, and the like.
　図３は、基板処理装置１によって実行されるリン酸エッチング処理の処理例について説明するための工程図である。図４Ａ～図４Ｆは、この処理例について説明するための模式的な図である。 FIG. 3 is a process diagram for explaining a processing example of the phosphoric acid etching process executed by the substrate processing apparatus 1. 4A to 4F are schematic views for explaining this processing example.
　以下では、図１～図４Ｆを参照して、リン酸エッチング処理の処理例について説明する。 Hereinafter, an example of the phosphoric acid etching process will be described with reference to FIGS. 1 to 4F.
　図４Ａに示すように、ウエハＷの搬入に先立って、制御部４０はヒータ２８をオン（駆動状態）にしておく。ヒータ２８のオン状態では底面２９が発熱状態にある。また、制御部４０は、リン酸バルブ１７を開いて、リン酸水溶液ノズル５から沸点に近い高温のリン酸水溶液を吐出し、そのリン酸水溶液を、下位置にある貯留槽４の貯留溝４１に溜める。リン酸水溶液が貯留溝４１に満たされると、制御部４０はリン酸バルブ１７を閉じる。発熱状態にある底面２９によってリン酸水溶液が加熱され、リン酸水溶液は沸点（たとえば約１４０℃）まで昇温させられ、その後沸騰状態に維持される。加熱状態の維持により、リン酸水溶液に含まれる水が蒸発して、リン酸水溶液のリン酸濃度が徐々に濃くなる。 As shown in FIG. 4A, prior to the loading of the wafer W, the controller 40 turns on the heater 28 (driving state). When the heater 28 is on, the bottom surface 29 is in a heat generating state. The control unit 40 opens the phosphoric acid valve 17 and discharges a phosphoric acid aqueous solution having a high boiling point close to the boiling point from the phosphoric acid aqueous solution nozzle 5, and the phosphoric acid aqueous solution is stored in the storage groove 41 of the storage tank 4 in the lower position. Accumulate on. When the phosphoric acid aqueous solution is filled in the storage groove 41, the control unit 40 closes the phosphoric acid valve 17. The phosphoric acid aqueous solution is heated by the bottom surface 29 in an exothermic state, and the phosphoric acid aqueous solution is heated to a boiling point (for example, about 140 ° C.) and then maintained in a boiling state. By maintaining the heating state, water contained in the phosphoric acid aqueous solution evaporates, and the phosphoric acid concentration of the phosphoric acid aqueous solution gradually increases.
　次いで、図４Ｂに示すように、制御部４０は、第１水バルブ５４を開いて、バーノズル５０の各吐出口５２から水の液滴を滴下する。各吐出口５２から滴下される液滴は、貯留槽４内のリン酸水溶液に供給される。多数の吐出口５２のそれぞれから水の液滴が吐出されるので、貯留槽４に貯留されているリン酸水溶液に、ほぼ均一に水が供給される。沸騰状態にあるリン酸水溶液に水を供給することにより、貯留槽４内のリン酸水溶液のリン酸濃度の上昇が抑制される。リン酸水溶液への水の供給は、ウエハＷの搬入に先立って行われる。 Next, as shown in FIG. 4B, the control unit 40 opens the first water valve 54 and drops water droplets from the discharge ports 52 of the bar nozzle 50. The liquid droplets dropped from each discharge port 52 are supplied to the phosphoric acid aqueous solution in the storage tank 4. Since water droplets are discharged from each of the large number of discharge ports 52, water is supplied almost uniformly to the phosphoric acid aqueous solution stored in the storage tank 4. By supplying water to the phosphoric acid aqueous solution in the boiling state, an increase in the phosphoric acid concentration of the phosphoric acid aqueous solution in the storage tank 4 is suppressed. The supply of water to the phosphoric acid aqueous solution is performed prior to the loading of the wafer W.
　制御部４０は第１水バルブ５４を開閉して、バーノズル５０からの供給／供給停止を切り換えることにより、貯留槽４内のリン酸水溶液に供給する水の量を調節する。リン酸水溶液のリン酸濃度の調整のための水供給であるので、バーノズル５０から供給されるリン酸水溶液の流量は小流量で足りる。このような水の供給により、貯留槽４内のリン酸水溶液のリン酸濃度および温度が、それぞれ予め定めるリン酸濃度（一例として８１％）および温度（一例として約１４０℃）に一定に制御される。 The controller 40 adjusts the amount of water supplied to the phosphoric acid aqueous solution in the storage tank 4 by opening and closing the first water valve 54 and switching supply / stop of supply from the bar nozzle 50. Since the water is supplied for adjusting the phosphoric acid concentration of the phosphoric acid aqueous solution, the flow rate of the phosphoric acid aqueous solution supplied from the bar nozzle 50 is sufficient. By supplying such water, the phosphoric acid concentration and temperature of the phosphoric acid aqueous solution in the storage tank 4 are controlled to be constant at a predetermined phosphoric acid concentration (81% as an example) and temperature (about 140 ° C. as an example), respectively. The
　貯留槽４内のリン酸水溶液の温度およびリン酸濃度がそれぞれ所期の温度および濃度に制御された状態で、搬送ロボット（図示しない）が制御されて、処理室２内に未処理のウエハＷが搬入される。未処理のウエハＷの表面にはシリコン窒化膜およびシリコン酸化膜が形成されている。搬入されたウエハＷは、貯留槽４の底面２９に対向する所定の受渡位置に配置され、制御部４０は挟持ピン駆動機構４３を駆動して、複数の挟持ピン３４を開放位置から挟持位置に導く。これにより、図４Ｃに示すように、搬入されたウエハＷは、その表面を上方に向けた状態でスピンチャック３に保持される。なお、ウエハＷが受渡位置にある状態で、ウエハＷの下面と底面２９との間隔がたとえば５０ｍｍ程度とされている。 A transfer robot (not shown) is controlled in a state where the temperature of the phosphoric acid aqueous solution and the phosphoric acid concentration in the storage tank 4 are controlled to the intended temperature and concentration, respectively, and an unprocessed wafer W is placed in the processing chamber 2. Is brought in. A silicon nitride film and a silicon oxide film are formed on the surface of the unprocessed wafer W. The loaded wafer W is arranged at a predetermined delivery position facing the bottom surface 29 of the storage tank 4, and the control unit 40 drives the clamping pin drive mechanism 43 to move the plurality of clamping pins 34 from the open position to the clamping position. Lead. As a result, as shown in FIG. 4C, the loaded wafer W is held by the spin chuck 3 with its surface facing upward. In the state where the wafer W is at the delivery position, the distance between the lower surface and the bottom surface 29 of the wafer W is, for example, about 50 mm.
　スピンチャック３にウエハＷが保持されると、図４Ｄに示すように、制御部４０は昇降機構２７を制御して、貯留槽４を上位置まで上昇させる。貯留槽４が上位置にある状態では、貯留槽４のリン酸水溶液中にウエハＷが浸漬される。このとき、貯留槽４のリン酸水溶液の液面がウエハＷの表面よりも上方に位置し、その結果、リン酸水溶液によってウエハＷの表面の全域が覆われる。リン酸水溶液へのウエハＷの浸漬によって、ウエハＷの表面にリン酸エッチング処理が施される（ステップＳ１）。リン酸エッチング処理は、予め定めるエッチング時間が経過するまで実行される。 When the wafer W is held on the spin chuck 3, as shown in FIG. 4D, the control unit 40 controls the elevating mechanism 27 to raise the storage tank 4 to the upper position. In a state where the storage tank 4 is in the upper position, the wafer W is immersed in the phosphoric acid aqueous solution in the storage tank 4. At this time, the liquid level of the phosphoric acid aqueous solution in the storage tank 4 is located above the surface of the wafer W, and as a result, the entire surface of the wafer W is covered with the phosphoric acid aqueous solution. By immersing the wafer W in the phosphoric acid aqueous solution, a phosphoric acid etching process is performed on the surface of the wafer W (step S1). The phosphoric acid etching process is performed until a predetermined etching time elapses.
　貯留槽４が上位置にある状態で、ウエハＷの下面と貯留槽４の底面２９との間隔Ｗ１は、たとえば３ｍｍ程度に設定されている。この状態で、ウエハＷの約３ｍｍ上方に、リン酸水溶液の液面が位置している。なお、ウエハＷの厚みは、たとえば０．７７５ｍｍである。なお、間隔Ｗ１は０．３～３ｍｍの範囲内で適宜設定できる。 With the storage tank 4 in the upper position, the interval W1 between the lower surface of the wafer W and the bottom surface 29 of the storage tank 4 is set to about 3 mm, for example. In this state, the liquid level of the phosphoric acid aqueous solution is located approximately 3 mm above the wafer W. Note that the thickness of the wafer W is, for example, 0.775 mm. The interval W1 can be set as appropriate within a range of 0.3 to 3 mm.
　ウエハＷの下面と貯留槽４の底面２９とが接近しているので、スピンチャック３に保持されているウエハＷは、貯留槽４の底面２９から熱輻射により加熱される。貯留槽４が上位置にある状態で、底面２９とウエハＷの下面とが平行をなしているので、ウエハＷに貯留槽４から与えられる単位面積当たりの熱量は、ウエハＷの全域においてほぼ均一である。 Since the lower surface of the wafer W and the bottom surface 29 of the storage tank 4 are close to each other, the wafer W held by the spin chuck 3 is heated from the bottom surface 29 of the storage tank 4 by thermal radiation. Since the bottom surface 29 and the lower surface of the wafer W are parallel with the storage tank 4 in the upper position, the amount of heat per unit area given to the wafer W from the storage tank 4 is substantially uniform over the entire area of the wafer W. It is.
　また、図４Ｅに示すように、リン酸エッチング工程中には、適宜、貯留槽４のリン酸水溶液に水が供給される。制御部４０は、第１水バルブ５４を開いて、バーノズル５０の各吐出口５２から水の液滴を滴下する。多数の吐出口５２のそれぞれから水の液滴が吐出されるので、貯留槽４に貯留されているリン酸水溶液に、ほぼ均一に水が供給される。これにより、貯留槽４内のリン酸水溶液のリン酸濃度および温度が、それぞれ予め定めるリン酸濃度（一例として８１％）および温度（一例として約１４０℃）に一定に制御される。 Further, as shown in FIG. 4E, water is appropriately supplied to the phosphoric acid aqueous solution in the storage tank 4 during the phosphoric acid etching step. The controller 40 opens the first water valve 54 and drops water droplets from the discharge ports 52 of the bar nozzle 50. Since water droplets are discharged from each of the large number of discharge ports 52, water is supplied almost uniformly to the phosphoric acid aqueous solution stored in the storage tank 4. Thereby, the phosphoric acid concentration and temperature of the phosphoric acid aqueous solution in the storage tank 4 are controlled to a predetermined phosphoric acid concentration (81% as an example) and temperature (about 140 ° C. as an example), respectively.
　さらに、リン酸エッチング工程では、制御部４０はスピンモータ１４を制御して、ウエハＷを予め定める低速度（たとえば１０～３００rpmの範囲）で回転させる。ウエハＷの回転により、貯留溝４１に溜められたリン酸水溶液が撹拌される。これにより、リン酸水溶液のリン酸濃度および温度が均一に分布するようになる。 Further, in the phosphoric acid etching step, the control unit 40 controls the spin motor 14 to rotate the wafer W at a predetermined low speed (for example, in the range of 10 to 300 rpm). As the wafer W rotates, the phosphoric acid aqueous solution stored in the storage groove 41 is agitated. Thereby, the phosphoric acid concentration and temperature of the phosphoric acid aqueous solution are uniformly distributed.
　図５は、貯留槽４の底面２９によるウエハＷの加熱を示す図である。 FIG. 5 is a diagram showing heating of the wafer W by the bottom surface 29 of the storage tank 4.
　前述のように、貯留槽４の底面２９とウエハＷの下面のほぼ全面に対向している。また、貯留槽４の底面２９と、ウエハＷの下面との間隔Ｗ１は、たとえば０．３～３ｍｍの範囲でたとえば３ｍｍ程度に設定されている。したがって、ウエハＷは、貯留槽４の底面２９からの熱が熱伝導によって与えられるとともに、熱輻射によって熱が与えられる。これにより、ウエハＷが１６０℃程度まで昇温していると考えられる。 As described above, the bottom surface 29 of the storage tank 4 and the lower surface of the wafer W are almost opposed to each other. Further, the interval W1 between the bottom surface 29 of the storage tank 4 and the lower surface of the wafer W is set to, for example, about 3 mm within a range of 0.3 to 3 mm, for example. Therefore, the wafer W is given heat from the bottom surface 29 of the storage tank 4 by heat conduction and heat by radiation. Thereby, it is considered that the temperature of the wafer W is raised to about 160 ° C.
　図６は、リン酸水溶液におけるリン酸濃度（Ｈ３ＰＯ４　concentration）と、リン酸水溶液の沸点（沸騰点；Boiling Point）との関係を示すグラフである。図６中の曲線は飽和濃度曲線を示し、当該曲線よりも下方の領域は、リン酸水溶液が存在可能な領域（Ｈ３ＰＯ４　existence region）である。 FIG. 6 is a graph showing the relationship between the phosphoric acid concentration (H 3 PO 4 concentration) in the phosphoric acid aqueous solution and the boiling point (boiling point) of the phosphoric acid aqueous solution. The curve in FIG. 6 shows a saturation concentration curve, and the region below the curve is a region where a phosphoric acid aqueous solution can exist (H 3 PO 4 existence region).
　図６に示すように、リン酸水溶液におけるリン酸濃度が高くなるにつれて、リン酸水溶液の沸点が高くなっている。たとえば８１％の濃度を有するリン酸水溶液では、その沸点が約１４０℃である。通常、８１％の濃度のリン酸水溶液は、液相において、１４０℃以上に昇温しない。 As shown in FIG. 6, as the phosphoric acid concentration in the phosphoric acid aqueous solution increases, the boiling point of the phosphoric acid aqueous solution increases. For example, an aqueous phosphoric acid solution having a concentration of 81% has a boiling point of about 140 ° C. Usually, an aqueous phosphoric acid solution having a concentration of 81% does not rise to 140 ° C. or higher in the liquid phase.
　一方、１６０℃の温度を有するリン酸水溶液の最大濃度は約８６％である。したがって、１６０℃の温度を有するリン酸水溶液において、その濃度が約８６％未満になることは通常の状態では発生しない。 On the other hand, the maximum concentration of the phosphoric acid aqueous solution having a temperature of 160 ° C. is about 86%. Therefore, in a phosphoric acid aqueous solution having a temperature of 160 ° C., the concentration does not decrease below about 86% in a normal state.
　図７は、リン酸水溶液におけるリン酸濃度およびリン酸水溶液の温度とシリコン窒化膜のエッチングレートとの関係を示すグラフである。図７では、１５０℃、１６０℃および１７０℃の温度を有するリン酸水溶液を用いてシリコン窒化膜をエッチングしたときのエッチングレートを実線で示している。また、図７では、リン酸水溶液の沸点を破線で示している。 FIG. 7 is a graph showing the relationship between the phosphoric acid concentration in the phosphoric acid aqueous solution, the temperature of the phosphoric acid aqueous solution, and the etching rate of the silicon nitride film. In FIG. 7, the solid line indicates the etching rate when the silicon nitride film is etched using an aqueous phosphoric acid solution having temperatures of 150 ° C., 160 ° C., and 170 ° C. Moreover, in FIG. 7, the boiling point of phosphoric acid aqueous solution is shown with the broken line.
　図７に示すように、リン酸濃度が一定であれば、リン酸水溶液の温度が１７０℃のときのエッチングレートが最も高く、リン酸水溶液の温度が１６０℃のときのエッチングレートが二番目に高い。したがって、リン酸濃度が一定であれば、リン酸水溶液の温度が高いほどエッチングレートが高い。 As shown in FIG. 7, when the phosphoric acid concentration is constant, the etching rate is highest when the temperature of the phosphoric acid aqueous solution is 170 ° C., and the etching rate when the temperature of the phosphoric acid aqueous solution is 160 ° C. is second. high. Therefore, if the phosphoric acid concentration is constant, the higher the temperature of the phosphoric acid aqueous solution, the higher the etching rate.
　一方、リン酸水溶液の温度が１５０℃のとき、エッチングレートは、リン酸濃度の増加に伴って減少する。リン酸水溶液の温度が１６０℃および１７０℃のときについても同様である。したがって、リン酸水溶液の温度が一定であれば、リン酸濃度が低いほどエッチングレートが高い。また、図示はしていないが、リン酸水溶液の温度が１４０℃のときについても同様である。 On the other hand, when the temperature of the phosphoric acid aqueous solution is 150 ° C., the etching rate decreases as the phosphoric acid concentration increases. The same applies when the temperature of the phosphoric acid aqueous solution is 160 ° C and 170 ° C. Therefore, if the temperature of the phosphoric acid aqueous solution is constant, the lower the phosphoric acid concentration, the higher the etching rate. Although not shown, the same is true when the temperature of the phosphoric acid aqueous solution is 140 ° C.
　図５～図７を併せて参照して、リン酸エッチング工程における貯留槽４内のリン酸水溶液の状態について説明する。貯留槽４には、８１％に濃度調節されたリン酸水溶液が貯留されている。このリン酸水溶液の沸点は約１４０℃である。貯留槽４に貯留されたリン酸水溶液は、貯留槽４の底面２９によって加熱され、沸点である約１４０℃の状態を維持している。 The state of the phosphoric acid aqueous solution in the storage tank 4 in the phosphoric acid etching process will be described with reference to FIGS. In the storage tank 4, a phosphoric acid aqueous solution whose concentration is adjusted to 81% is stored. The boiling point of this phosphoric acid aqueous solution is about 140 ° C. The phosphoric acid aqueous solution stored in the storage tank 4 is heated by the bottom surface 29 of the storage tank 4 and maintains the boiling point of about 140 ° C.
　貯留槽４の底面２９による加熱により、ウエハＷは約１６０℃に昇温される。この状態で、ウエハＷ表面との境界部分のリン酸水溶液に、ウエハＷの表面に近づくほど高くなる温度勾配が形成される。その結果、ウエハＷ表面とリン酸水溶液とが接する境界では、たとえば約１６０℃の高温状態が実現される。 The wafer W is heated to about 160 ° C. by heating from the bottom surface 29 of the storage tank 4. In this state, a temperature gradient is formed in the phosphoric acid aqueous solution at the boundary with the surface of the wafer W, which becomes higher as the surface of the wafer W is approached. As a result, a high temperature state of about 160 ° C. is realized at the boundary where the surface of the wafer W and the phosphoric acid aqueous solution are in contact with each other.
　換言すると、ウエハＷ表面とリン酸水溶液とが接する境界では、局所的には極めて高温で、かつリン酸濃度が低く維持された状態を実現することができる。具体的には、当該境界において、温度が約１６０℃で濃度が約８１％という、通常では存在しない高温低濃度の状態を実現することができる（この状態におけるシリコン窒化膜のエッチングレートおよびシリコン窒化膜の選択比の一例を「実施例」として図７中に示す）。この状態のリン酸水溶液が、ウエハＷの表面のシリコン窒化膜に作用するから、シリコン窒化膜のエッチングレートを非常に高めることができ、同時にシリコン窒化膜の選択比を高く維持することができる。 In other words, at the boundary where the surface of the wafer W and the phosphoric acid aqueous solution are in contact with each other, it is possible to realize a state where the temperature is locally extremely high and the phosphoric acid concentration is kept low. Specifically, a high temperature and low concentration state that does not normally exist can be realized at a temperature of about 160 ° C. and a concentration of about 81% at the boundary (the silicon nitride film etching rate and silicon nitridation in this state). An example of the selectivity of the membrane is shown in FIG. Since the phosphoric acid aqueous solution in this state acts on the silicon nitride film on the surface of the wafer W, the etching rate of the silicon nitride film can be greatly increased, and at the same time, the selectivity of the silicon nitride film can be kept high.
　ところで、ウエハＷのリン酸水溶液に対する浸漬開始から、予め定めるエッチング時間が経過すると、図４Ｆに示すように、制御部４０は、制御部４０は昇降機構２７を制御して、貯留槽４を下位置まで下降させる。これにより、貯留槽４の底面２９によるウエハＷの加熱は終了する。 By the way, when a predetermined etching time has elapsed from the start of immersion of the wafer W in the phosphoric acid aqueous solution, the control unit 40 controls the lifting mechanism 27 to lower the storage tank 4 as shown in FIG. 4F. Lower to position. Thereby, the heating of the wafer W by the bottom surface 29 of the storage tank 4 is completed.
　次いで、制御部４０は、スピンモータ１４を制御して、ウエハＷの回転速度を所定のリンス処理速度（３００～１５００rpmの範囲で、たとえば１０００rpm）に上げるとともに、第２水バルブ３２を開いて、水ノズル３０の吐出口からウエハＷの回転中心付近に向けてＤＩＷを供給する（ステップＳ２：リンス工程）。ウエハＷの表面に供給されたＤＩＷは、ウエハＷの回転による遠心力を受けて、ウエハＷの表面上をウエハＷの周縁に向けて流れる。これにより、ウエハＷの表面に付着しているリン酸水溶液がＤＩＷによって洗い流される。 Next, the control unit 40 controls the spin motor 14 to increase the rotation speed of the wafer W to a predetermined rinse processing speed (in the range of 300 to 1500 rpm, for example, 1000 rpm), and opens the second water valve 32, DIW is supplied from the discharge port of the water nozzle 30 toward the vicinity of the rotation center of the wafer W (step S2: rinsing step). The DIW supplied to the surface of the wafer W receives centrifugal force due to the rotation of the wafer W and flows on the surface of the wafer W toward the periphery of the wafer W. Thereby, the phosphoric acid aqueous solution adhering to the surface of the wafer W is washed away by DIW.
　また、このリンス工程と並行して、貯留槽４の内壁面（底面２９、環状溝３７の壁面および外周壁３８の内周面）を水で洗浄する貯留槽洗浄が実行される。この貯留槽洗浄では、制御部４０は、水下バルブ６４を開いて、下吐出口６２から水を吐出する。下吐出口６２から吐出される水は、貯留槽４の貯留溝４１に溜められる。下吐出口６２からの水の吐出は、貯留溝４１が溢れた後も続行される。これにより、貯留槽４の内壁面に付着していたリン酸水溶液が水で洗い流される。 In parallel with this rinsing step, storage tank cleaning is performed to clean the inner wall surface of the storage tank 4 (the bottom surface 29, the wall surface of the annular groove 37, and the inner peripheral surface of the outer peripheral wall 38) with water. In this storage tank cleaning, the control unit 40 opens the water valve 64 and discharges water from the lower discharge port 62. The water discharged from the lower discharge port 62 is stored in the storage groove 41 of the storage tank 4. The discharge of water from the lower discharge port 62 is continued even after the storage groove 41 overflows. Thereby, the phosphoric acid aqueous solution adhering to the inner wall surface of the storage tank 4 is washed away with water.
　ＤＩＷの供給が所定のリンス時間にわたって続けられると、第２水バルブ３２が閉じられて、ウエハＷの表面へのＤＩＷの供給が停止される。また、ＤＩＷの供給停止に併せて、水下バルブ６４が閉じられて、貯留槽４１への水の供給が停止される。 When the DIW supply is continued for a predetermined rinse time, the second water valve 32 is closed and the supply of DIW to the surface of the wafer W is stopped. In addition, the water supply valve 64 is closed together with the DIW supply stop, and the supply of water to the storage tank 41 is stopped.
　その後、制御部４０は、スピンモータ１４を駆動して、ウエハＷの回転速度を所定の高回転速度（たとえば１５００～２５００rpm）に上げて、ウエハＷに付着しているＤＩＷを振り切って乾燥されるスピンドライが行われる（ステップＳ３）。ステップＳ３のスピンドライによって、ウエハＷに付着しているＤＩＷが除去される。 Thereafter, the control unit 40 drives the spin motor 14 to increase the rotation speed of the wafer W to a predetermined high rotation speed (for example, 1500 to 2500 rpm), and shakes off the DIW adhering to the wafer W to be dried. Spin drying is performed (step S3). The DIW adhering to the wafer W is removed by spin drying in step S3.
　スピンドライが予め定めるスピンドライ時間にわたって行われると、制御部４０は、スピンモータ１４を駆動して、スピンチャック３の回転を停止させる。これにより、１枚のウエハＷに対するレジスト除去処理が終了する。その後、制御部４０は挟持ピン駆動機構４３を駆動して、複数の挟持ピン３４を挟持位置から開放位置に導き、処理済みのウエハＷが搬送ロボットに受け渡される。搬送ロボットによってウエハＷが処理室２から搬出される。 When the spin dry is performed for a predetermined spin dry time, the control unit 40 drives the spin motor 14 to stop the rotation of the spin chuck 3. Thus, the resist removal process for one wafer W is completed. Thereafter, the control unit 40 drives the holding pin driving mechanism 43 to guide the plurality of holding pins 34 from the holding position to the open position, and the processed wafer W is delivered to the transfer robot. The wafer W is unloaded from the processing chamber 2 by the transfer robot.
　以上によりこの実施形態によれば、貯留槽４の底面２９によるウエハＷへの加熱により、ウエハＷが約１６０℃に昇温される。この状態で、ウエハＷ表面との境界部分のリン酸水溶液に、ウエハＷの表面に近づくほど高くなる温度勾配が形成される。その結果、ウエハＷの表面との境界部分におけるリン酸水溶液において、極めて高温で、かつリン酸濃度が低く維持された状態（温度が約１６０℃で濃度が約８１％という、高温で、かつリン酸濃度が低く維持された状態）を実現することができる。この状態のリン酸水溶液が、ウエハＷの表面のシリコン窒化膜に作用するから、シリコン窒化膜のエッチングレートを非常に高めることができ、同時にシリコン窒化膜の選択比を高く維持することができる。 As described above, according to this embodiment, the wafer W is heated to about 160 ° C. by heating the wafer W by the bottom surface 29 of the storage tank 4. In this state, a temperature gradient is formed in the phosphoric acid aqueous solution at the boundary with the surface of the wafer W, which becomes higher as the surface of the wafer W is approached. As a result, the phosphoric acid aqueous solution at the boundary with the surface of the wafer W is in a state where the phosphoric acid concentration is maintained at a very high temperature and a low phosphoric acid concentration (the temperature is about 160 ° C. and the concentration is about 81%, A state in which the acid concentration is kept low). Since the phosphoric acid aqueous solution in this state acts on the silicon nitride film on the surface of the wafer W, the etching rate of the silicon nitride film can be greatly increased, and at the same time, the selectivity of the silicon nitride film can be kept high.
　図８は、本発明の第２実施形態に係る基板処理装置１０１の構成を模式的に示す図である。図８において、第１実施形態に示された各部に対応する部分には、図１～図７の場合と同一の参照符号を付して示し、説明を省略する。 FIG. 8 is a diagram schematically showing the configuration of the substrate processing apparatus 101 according to the second embodiment of the present invention. In FIG. 8, parts corresponding to those shown in the first embodiment are denoted by the same reference numerals as those in FIGS. 1 to 7, and description thereof is omitted.
　基板処理装置１０１が、第１実施形態に係る基板処理装置１と相違する点は、水を供給するための水供給手段として、バーノズル５０に代えて、水の液滴をスプレー状に吐出（噴霧）するスプレーノズル１０２を採用した点である。スプレーノズル１０２には、水供給源からの水が供給される第３水供給管１０３が接続されている。第３水供給管１０３には、第３水供給管１０３を開閉するための第３水バルブ１０４が介装されている。第３水バルブ１０４が開かれると、第３水供給管１０３からスプレーノズル１０２に水が供給され、スプレーノズル１０２から下方に向けて水の液滴がスプレー状に吐出（噴霧）される。スプレーノズル１０２から吐出される水の液滴は、前述の第１実施形態のバーノズルから吐出される水の液滴よりも細かい（小さい）。 The substrate processing apparatus 101 is different from the substrate processing apparatus 1 according to the first embodiment in that, as a water supply unit for supplying water, instead of the bar nozzle 50, water droplets are ejected in a spray form (spraying). The spray nozzle 102 is employed. A third water supply pipe 103 to which water from a water supply source is supplied is connected to the spray nozzle 102. A third water valve 104 for opening and closing the third water supply pipe 103 is interposed in the third water supply pipe 103. When the third water valve 104 is opened, water is supplied from the third water supply pipe 103 to the spray nozzle 102, and water droplets are ejected (sprayed) from the spray nozzle 102 downward. The water droplets discharged from the spray nozzle 102 are finer (smaller) than the water droplets discharged from the bar nozzle of the first embodiment described above.
　第２実施形態によれば、スプレーノズル１０２からスプレー状に水の液滴が吐出されるので、貯留槽４に貯留されているリン酸水溶液に、ほぼ均一に水を供給することができ、その結果、リン酸水溶液のリン酸濃度を均一に保つことができる。 According to the second embodiment, water droplets are ejected in a spray form from the spray nozzle 102, so that water can be supplied almost uniformly to the phosphoric acid aqueous solution stored in the storage tank 4, As a result, the phosphoric acid concentration of the phosphoric acid aqueous solution can be kept uniform.
　また、スプレーノズル１０２からリン酸水溶液に対し、より細かい水の液滴が供給される。水とリン酸水溶液とは、それらの比重や粘度等の相違のために、比較的混ざりにくい傾向にある。しかしながら、液滴の大きさが細かければ細かいほど混ざり易いので、細かい液滴の状態の水をリン酸水溶液に供給することにより、水とリン酸水溶液とをスムーズに混合させることができる。 Further, finer water droplets are supplied from the spray nozzle 102 to the phosphoric acid aqueous solution. Water and phosphoric acid aqueous solution tend to be relatively difficult to mix due to differences in specific gravity, viscosity, and the like. However, since the smaller the droplet size, the easier it is to mix, the water and the phosphoric acid aqueous solution can be smoothly mixed by supplying water in a fine droplet state to the phosphoric acid aqueous solution.
　なお、図８では、スプレーノズル１０２を１つだけ設ける場合を示しているが、左右方向に関しそれぞれ異なる位置にある複数のスプレーノズルから、水をスプレー状に吐出することもできる。 Although FIG. 8 shows a case where only one spray nozzle 102 is provided, water can also be discharged from a plurality of spray nozzles at different positions in the left-right direction.
　図９は、本発明の第３実施形態に係る基板処理装置２０１の構成を模式的に示す図である。図９において、第１実施形態に示された各部に対応する部分には、図１～図７の場合と同一の参照符号を付して示し、説明を省略する。 FIG. 9 is a diagram schematically showing the configuration of the substrate processing apparatus 201 according to the third embodiment of the present invention. In FIG. 9, parts corresponding to those shown in the first embodiment are denoted by the same reference numerals as those in FIGS. 1 to 7, and description thereof is omitted.
　基板処理装置２０１が、第１実施形態に係る基板処理装置１と相違する点は、貯留槽として、非加熱型の貯留槽２０４を採用した点である。また、スピンチャック３の上方に、ウエハＷの表面を加熱するためのヒータヘッド２０３を設けた点も、基板処理装置１と相違している。 The difference between the substrate processing apparatus 201 and the substrate processing apparatus 1 according to the first embodiment is that a non-heating type storage tank 204 is adopted as the storage tank. The substrate processing apparatus 1 is also different from the substrate processing apparatus 1 in that a heater head 203 for heating the surface of the wafer W is provided above the spin chuck 3.
　貯留槽２０４は、たとえば、セラミックやＳｉＣ、耐熱樹脂を用いて形成されている。貯留槽２０４の構成は、ヒータ２８（図１参照）が埋設されておらず加熱手段として機能しない点を除いて、図１に示す貯留槽４と共通の構成である。つまり、貯留槽２０４は水平姿勢で配置され、その水平姿勢を維持したまま昇降される。昇降機構（図１参照）２７の駆動により、貯留槽２０４は、その下面がスピンベース１２の上面に近接する下位置と、貯留槽２０４の底面２９が、ウエハＷの下面に微小な間隔Ｗ１を隔てて対向配置される上位置との間で昇降させられる。これにより、貯留槽２０４とウエハＷとの間隔を変更することが可能である。 The storage tank 204 is formed using, for example, ceramic, SiC, or heat resistant resin. The configuration of the storage tank 204 is the same as that of the storage tank 4 shown in FIG. 1 except that the heater 28 (see FIG. 1) is not embedded and does not function as a heating means. That is, the storage tank 204 is arranged in a horizontal posture and is moved up and down while maintaining the horizontal posture. By driving the elevating mechanism (see FIG. 1) 27, the storage tank 204 has a lower position where the lower surface thereof is close to the upper surface of the spin base 12, and the bottom surface 29 of the storage tank 204 has a minute interval W 1 on the lower surface of the wafer W. It is moved up and down between the upper positions arranged opposite to each other. Thereby, the interval between the storage tank 204 and the wafer W can be changed.
　貯留槽２０４の底面２９と外周壁３８の内周面とによって、底面２９の上方に液を溜めるための貯留溝４１が区画されている。貯留槽２０４が上位置にある状態で、かつ貯留溝４１に液が満たされた状態では、貯留溝４１に溜められている液によって、表面上向きのウエハＷが浸漬される。つまり、貯留溝４１に溜められている液によってウエハＷの表面の全域が覆われる。また、ウエハＷの回転中であっても、貯留溝４１は回転せずに静止（非回転状態）している。 A storage groove 41 for storing liquid is defined above the bottom surface 29 by the bottom surface 29 of the storage tank 204 and the inner peripheral surface of the outer peripheral wall 38. In a state where the storage tank 204 is in the upper position and the storage groove 41 is filled with the liquid, the wafer W facing upward is immersed by the liquid stored in the storage groove 41. That is, the entire surface of the wafer W is covered with the liquid stored in the storage groove 41. Even when the wafer W is rotating, the storage groove 41 is not rotated but is stationary (non-rotating state).
　ヒータヘッド２０３は、ウエハＷと同等の径を有する円板状をなし、たとえばセラミック等を用いて形成されている。ヒータヘッド２０３は、ホルダ２０５によって上方から、水平姿勢で保持されている。ヒータヘッド２０３の内部には、抵抗式のヒータ２０８が埋設されている。ヒータヘッド２０３は、水平平坦面からなる下面（発熱部）２０９を有している。ヒータヘッド２０３の下面２０９は、スピンチャック３に保持されているウエハＷの表面の全域に対向配置されている。ヒータ２０８のオン状態では、ヒータ２０８への給電により当該ヒータ２０８が発熱し、下面２０９全域が発熱する。下面２０９の全域において、ヒータ２８のオン状態における下面２０９の単位面積当たりの発熱量は均一に設定されている。 The heater head 203 has a disk shape having a diameter equivalent to that of the wafer W, and is formed using, for example, ceramic. The heater head 203 is held in a horizontal posture from above by a holder 205. A resistance heater 208 is embedded in the heater head 203. The heater head 203 has a lower surface (heat generating portion) 209 made of a horizontal flat surface. The lower surface 209 of the heater head 203 is disposed to face the entire surface of the wafer W held by the spin chuck 3. In the ON state of the heater 208, the heater 208 generates heat by supplying power to the heater 208, and the entire lower surface 209 generates heat. In the entire area of the lower surface 209, the heat generation amount per unit area of the lower surface 209 when the heater 28 is on is set to be uniform.
　ホルダ２０５には、ヒータヘッド２０３を昇降させるためのヒータ昇降機構２０６が結合されている。ヒータ昇降機構２０６は制御部４０（図２参照）に電気的に接続されている。 The heater 205 is coupled to the holder 205 for raising and lowering the heater head 203. The heater lifting mechanism 206 is electrically connected to the control unit 40 (see FIG. 2).
　このような基板処理装置２０１で実行されるリン酸エッチング処理では、第１実施形態と同様に（図４Ａ参照）、貯留槽２０４の貯留溝４１にリン酸水溶液が溜められる。その後、処理室２内に未処理のウエハＷが搬入され、スピンチャック３（の挟持部材１３）にウエハＷが、その表面を上方に向けた状態に保持される。 In the phosphoric acid etching process executed by the substrate processing apparatus 201, the phosphoric acid aqueous solution is stored in the storage groove 41 of the storage tank 204, as in the first embodiment (see FIG. 4A). Thereafter, an unprocessed wafer W is loaded into the processing chamber 2, and the wafer W is held on the spin chuck 3 (the holding member 13) with the surface thereof facing upward.
　スピンチャック３にウエハＷが保持されると、制御部４０は昇降機構２７（図１参照）を制御して、貯留槽２０４を上位置まで上昇させる。貯留槽２０４が上位置にある状態では、貯留槽２０４のリン酸水溶液中にウエハＷが浸漬される。このとき、貯留槽２０４のリン酸水溶液の液面がウエハＷの表面よりも上方に位置し、その結果、リン酸水溶液によってウエハＷの表面の全域が覆われる。リン酸水溶液へのウエハＷの浸漬によって、ウエハＷの表面にリン酸エッチング処理が施される（図３のステップＳ１に相当）。 When the wafer W is held on the spin chuck 3, the control unit 40 controls the elevating mechanism 27 (see FIG. 1) to raise the storage tank 204 to the upper position. In a state where the storage tank 204 is in the upper position, the wafer W is immersed in the phosphoric acid aqueous solution in the storage tank 204. At this time, the liquid level of the phosphoric acid aqueous solution in the storage tank 204 is located above the surface of the wafer W, and as a result, the entire surface of the wafer W is covered with the phosphoric acid aqueous solution. By immersing the wafer W in the phosphoric acid aqueous solution, the surface of the wafer W is subjected to phosphoric acid etching (corresponding to step S1 in FIG. 3).
　また、制御部４０はヒータ昇降機構２０６を制御して、ヒータヘッド２０３を、ヒータヘッド２０３の下面２０９がウエハＷの表面（上面）に近接する近接位置まで下降させる。ヒータヘッド２０３が近接位置にある状態で、ウエハＷの表面（上面）とヒータヘッド２０３の下面２０９との間隔は、たとえば約２ｍｍ程度に設定されている。ヒータヘッド２０３がリン酸水溶液に対する耐薬性を有する材質を用いて形成されている場合には、ヒータヘッド２０３の下部を、貯留槽２０４のリン酸水溶液に漬けることができ、この状態でウエハＷを加熱することができる。 Further, the control unit 40 controls the heater lifting mechanism 206 to lower the heater head 203 to a close position where the lower surface 209 of the heater head 203 is close to the surface (upper surface) of the wafer W. In a state where the heater head 203 is in the proximity position, the distance between the surface (upper surface) of the wafer W and the lower surface 209 of the heater head 203 is set to about 2 mm, for example. When the heater head 203 is formed using a material having chemical resistance to the phosphoric acid aqueous solution, the lower part of the heater head 203 can be dipped in the phosphoric acid aqueous solution in the storage tank 204, and the wafer W is placed in this state. Can be heated.
　ウエハＷの表面（上面）とヒータヘッド２０３の下面２０９との間隔が２ｍｍ程度であるので、スピンチャック３に保持されているウエハＷは、ヒータヘッド２０３の下面２０９から熱輻射により加熱される。ヒータヘッド２０３の下面２０９とウエハＷの表面とが平行をなしているので、ヒータヘッド２０３からウエハＷに与えられる単位面積当たりの熱量は、ウエハＷの全域においてほぼ均一である。ヒータヘッド２０３による加熱により、ウエハＷの温度は、リン酸水溶液の液温よりもやや高温（約１６０℃であると予想される）まで昇温されて、その温度のまま維持される。この状態で、ウエハＷ表面との境界部分のリン酸水溶液に、ウエハＷの表面に近づくほど高くなる温度勾配が形成される。その後、予め定めるエッチング時間が経過すると、ヒータ昇降機構２０６が制御されてヒータヘッド２０３が近接位置から上方に大きく退避させられ、これにより、ヒータヘッド２０３によるウエハＷの加熱は停止される。 Since the distance between the surface (upper surface) of the wafer W and the lower surface 209 of the heater head 203 is about 2 mm, the wafer W held by the spin chuck 3 is heated from the lower surface 209 of the heater head 203 by heat radiation. Since the lower surface 209 of the heater head 203 and the surface of the wafer W are parallel to each other, the amount of heat per unit area given from the heater head 203 to the wafer W is substantially uniform over the entire area of the wafer W. Due to the heating by the heater head 203, the temperature of the wafer W is raised to a temperature slightly higher than the liquid temperature of the phosphoric acid aqueous solution (expected to be about 160 ° C.) and maintained at that temperature. In this state, a temperature gradient is formed in the phosphoric acid aqueous solution at the boundary with the surface of the wafer W, which becomes higher as the surface of the wafer W is approached. Thereafter, when a predetermined etching time elapses, the heater elevating mechanism 206 is controlled and the heater head 203 is largely retracted upward from the proximity position, whereby the heating of the wafer W by the heater head 203 is stopped.
　その後、第１実施形態の場合と同様、リンス処理（図３のステップＳ２に相当）およびスピンドライ（図３のステップＳ３に相当）が実行される。 Thereafter, as in the case of the first embodiment, rinsing processing (corresponding to step S2 in FIG. 3) and spin drying (corresponding to step S3 in FIG. 3) are executed.
　第３実施形態によれば、貯留槽２０４のリン酸水溶液に浸漬されているウエハＷを、その上方に近接配置されたヒータヘッド２０３を用いて加熱する。そのため、貯留槽２０４にヒータを内蔵する等の複雑な構成を採用することなく、ウエハＷを良好に加熱することができる。 According to the third embodiment, the wafer W immersed in the phosphoric acid aqueous solution in the storage tank 204 is heated using the heater head 203 disposed close to the wafer W. Therefore, the wafer W can be heated satisfactorily without adopting a complicated configuration such as incorporating a heater in the storage tank 204.
　図１０は、本発明の第４実施形態に係る基板処理装置３０１の構成を模式的に示す図である。図１０において、第３実施形態に示された各部に対応する部分には、図１～図７および図９の場合と同一の参照符号を付して示し、説明を省略する。 FIG. 10 is a diagram schematically showing the configuration of a substrate processing apparatus 301 according to the fourth embodiment of the present invention. In FIG. 10, parts corresponding to the parts shown in the third embodiment are denoted by the same reference numerals as in FIGS. 1 to 7 and FIG. 9, and description thereof is omitted.
　基板処理装置３０１が、基板処理装置３０１が、第３実施形態に係る基板処理装置２０１と相違する点は、ウエハＷの表面を加熱するためのヒータとして、ヒータヘッド２０３に代えて赤外線ヒータ（加熱手段）３０３を設けた点にある。 The substrate processing apparatus 301 is different from the substrate processing apparatus 201 according to the third embodiment in that an infrared heater (heating) is used instead of the heater head 203 as a heater for heating the surface of the wafer W. Means) 303 is provided.
　赤外線ヒータ３０３は、ウエハＷよりも小径（たとえば、ウエハＷの径の１/５～１/１０程度）を有する平面視円形状をなし、スピンチャック３に保持されたウエハＷの表面に対し、上方に対向配置されている。赤外線ヒータ３０３は、赤外線照射面（発熱部）３０４Ａを下面に有する赤外線ランプ３０４を内蔵している。赤外線照射面３０４Ａは、ウエハＷの表面に略全域に対向している赤外線照射面３０４Ａは、ウエハＷの表面に対向している。赤外線ランプ３８は、フィラメントを石英配管内に収容して構成されている。赤外線ランプ３８として、ハロゲンランプやカーボンヒータに代表される短・中・長波長の赤外線ヒータを採用することができる。 The infrared heater 303 has a circular shape in a plan view having a smaller diameter than the wafer W (for example, about 1/5 to 1/10 of the diameter of the wafer W), and the surface of the wafer W held by the spin chuck 3 is Oppositely arranged above. The infrared heater 303 incorporates an infrared lamp 304 having an infrared irradiation surface (heat generating portion) 304A on the lower surface. The infrared irradiation surface 304 </ b> A faces the surface of the wafer W over substantially the entire area, and the infrared irradiation surface 304 </ b> A faces the surface of the wafer W. The infrared lamp 38 is configured by accommodating a filament in a quartz pipe. As the infrared lamp 38, a short, medium and long wavelength infrared heater represented by a halogen lamp and a carbon heater can be adopted.
　ホルダ２０５には、赤外線ヒータ３０３を、ウエハＷの面外に設けられた所定の鉛直の揺動軸線まわりに揺動させるためのヒータ揺動機構３０６が結合されている。ヒータ揺動機構３０６が制御されることにより、赤外線ヒータ３０３が、ウエハＷの表面の回転中心（回転軸線Ａ１上）と周縁部との間を、ウエハＷの回転方向と交差する円弧状の軌跡を描くように移動可能に設けられている。 The holder 205 is coupled with a heater swing mechanism 306 for swinging the infrared heater 303 about a predetermined vertical swing axis provided outside the surface of the wafer W. By controlling the heater swing mechanism 306, the infrared heater 303 has an arc-shaped trajectory that intersects the rotation direction of the wafer W between the rotation center (on the rotation axis A <b> 1) and the peripheral edge of the surface of the wafer W. It is provided to be movable so as to draw.
　リン酸エッチング処理（図３のステップＳ１に相当）では、ヒータ昇降機構２０６が制御されて、赤外線ヒータ３０３が、その赤外線照射面３０４ＡがウエハＷの表面（上面）に近接する近接位置まで下降させられる。赤外線ヒータ３０３が近接位置にある状態で、ウエハＷの表面（上面）と赤外線ヒータ３０３の赤外線照射面３０４Ａとの間隔は、たとえば１０ｍｍ程度に設定されている。この実施形態では、近接位置にある赤外線ヒータ３０３の赤外線照射面３０４Ａが、貯留槽２０４のリン酸水溶液に接液することはない。 In the phosphoric acid etching process (corresponding to step S1 in FIG. 3), the heater elevating mechanism 206 is controlled, and the infrared heater 303 is lowered to a close position where the infrared irradiation surface 304A is close to the surface (upper surface) of the wafer W. It is done. In a state where the infrared heater 303 is in the proximity position, the distance between the surface (upper surface) of the wafer W and the infrared irradiation surface 304A of the infrared heater 303 is set to about 10 mm, for example. In this embodiment, the infrared irradiation surface 304 </ b> A of the infrared heater 303 in the close position does not come into contact with the phosphoric acid aqueous solution in the storage tank 204.
　ウエハＷの表面と赤外線照射面３０４Ａとが近接されるので、スピンチャック３に保持されているウエハＷは、赤外線ヒータ３０３の赤外線照射面３０４Ａから熱輻射により加熱される。赤外線ヒータ３０３による加熱により、ウエハＷの温度は、リン酸水溶液の液温よりもやや高温（約１６０℃であると予想される）まで昇温されて、この温度のまま維持される。この状態で、ウエハＷ表面との境界部分のリン酸水溶液に、ウエハＷの表面に近づくほど高くなる温度勾配が形成される。その後、予めエッチング時間が経過すると、ヒータ昇降機構２０６が制御されて赤外線ヒータ３０３が近接位置から上方に大きく退避させられ、これにより、赤外線ヒータ３０３によるウエハＷの加熱は停止される。 Since the surface of the wafer W and the infrared irradiation surface 304A are close to each other, the wafer W held by the spin chuck 3 is heated by thermal radiation from the infrared irradiation surface 304A of the infrared heater 303. Due to the heating by the infrared heater 303, the temperature of the wafer W is raised to a slightly higher temperature than the liquid temperature of the phosphoric acid aqueous solution (expected to be about 160 ° C.) and maintained at this temperature. In this state, a temperature gradient is formed in the phosphoric acid aqueous solution at the boundary with the surface of the wafer W, which becomes higher as the surface of the wafer W is approached. Thereafter, when the etching time elapses in advance, the heater elevating mechanism 206 is controlled so that the infrared heater 303 is largely retracted upward from the proximity position, whereby the heating of the wafer W by the infrared heater 303 is stopped.
　なお、赤外線ヒータ３０３による赤外線照射時には、赤外線ヒータ３０３を、ウエハＷの回転中心の上方とウエハＷの周縁部の上方との間でスキャンさせるか、あるいは、赤外線ヒータ３０３を、ウエハＷの回転中心を除く位置の上方に静止配置させる。ウエハＷが回転軸線Ａ１まわりに回転するので、赤外線ヒータ３０３からの赤外線の照射によりウエハＷの略全域を加熱することができる。 When the infrared heater 303 irradiates infrared rays, the infrared heater 303 is scanned between the rotation center of the wafer W and the periphery of the wafer W, or the infrared heater 303 is moved to the rotation center of the wafer W. It is placed stationary above the position excluding. Since the wafer W rotates about the rotation axis A <b> 1, almost the entire area of the wafer W can be heated by irradiation with infrared rays from the infrared heater 303.
　第４実施形態によれば、貯留槽２０４のリン酸水溶液に浸漬されているウエハＷを、その上方に近接配置された赤外線ヒータ３０３を用いて加熱する。そのため、貯留槽２０４にヒータを内蔵する等の複雑な構成を採用することなく、ウエハＷを良好に加熱することができる。 According to the fourth embodiment, the wafer W immersed in the phosphoric acid aqueous solution in the storage tank 204 is heated using the infrared heater 303 disposed close to the wafer W. Therefore, the wafer W can be heated satisfactorily without adopting a complicated configuration such as incorporating a heater in the storage tank 204.
　また、大きな熱量を与えることが可能な赤外線ヒータ３０３を加熱手段として設けるので、加熱手段として簡便な構成を採用しつつ、ウエハＷを加熱することができる。 Further, since the infrared heater 303 capable of giving a large amount of heat is provided as a heating means, the wafer W can be heated while adopting a simple configuration as the heating means.
　なお、第４実施形態において、赤外線ヒータ３０３の径を、ウエハＷと同等の径に形成することもできる。この場合、赤外線ヒータ３０３の下面が、ウエハＷの表面の全域に対向するように、赤外線ヒータ３０３が設けられている。 In the fourth embodiment, the diameter of the infrared heater 303 can be formed to the same diameter as the wafer W. In this case, the infrared heater 303 is provided so that the lower surface of the infrared heater 303 faces the entire surface of the wafer W.
　図１１は、本発明の第５実施形態に係る基板処理装置４０１の構成を模式的に示す図である。図１１において、第１実施形態に示された各部に対応する部分には、図１～図７の場合と同一の参照符号を付して示し、説明を省略する。 FIG. 11 is a diagram schematically showing a configuration of a substrate processing apparatus 401 according to the fifth embodiment of the present invention. In FIG. 11, parts corresponding to those shown in the first embodiment are denoted by the same reference numerals as those in FIGS. 1 to 7, and description thereof is omitted.
　基板処理装置４０１は、ウエハＷを保持するための基板保持手段として、基板保持台４０２を備えている。基板保持台４０２は、第１実施形態のスピンチャック３に代えて用いられる。 The substrate processing apparatus 401 includes a substrate holding table 402 as substrate holding means for holding the wafer W. The substrate holder 402 is used in place of the spin chuck 3 of the first embodiment.
　基板保持台４０２は、リン酸水溶液を溜めるための貯留槽４０４（加熱手段）を備えている。貯留槽４０４は、たとえば略円筒の有底容器状をなし、セラミックや炭化ケイ素（ＳｉＣ）を用いて形成されている。貯留槽４０４は、水平平坦な円形の底面４０９を有する底面部４０９Ａと、底面４０９の周縁部から鉛直上方に立ち上がる外周壁４０８とを備えている。貯留槽４０４の底面４０９と外周壁４０８の内周面とによって、底面２９の上方に液を溜めるための貯留溝４０５が区画されており、底面４０９の上方に液を溜めることができるようになっており、貯留溝４０５の溝深さ（貯留溝４１に溜められる液の厚み）は、２ｍｍ～１１ｍｍの範囲内でたとえば約７ｍｍに設定されている。貯留槽４０４の底面部４０９Ａには、抵抗式のヒータ４０６が埋設されている。 The substrate holder 402 includes a storage tank 404 (heating means) for storing a phosphoric acid aqueous solution. The storage tank 404 has, for example, a substantially cylindrical bottomed container shape, and is formed using ceramic or silicon carbide (SiC). The storage tank 404 includes a bottom surface portion 409A having a horizontally flat circular bottom surface 409, and an outer peripheral wall 408 that rises vertically upward from the peripheral edge of the bottom surface 409. A storage groove 405 for storing liquid is defined above the bottom surface 29 by the bottom surface 409 of the storage tank 404 and the inner peripheral surface of the outer peripheral wall 408, so that the liquid can be stored above the bottom surface 409. The groove depth of the storage groove 405 (the thickness of the liquid stored in the storage groove 41) is set to, for example, about 7 mm within the range of 2 mm to 11 mm. A resistance heater 406 is embedded in the bottom surface portion 409 </ b> A of the storage tank 404.
　ヒータ４０６のオン状態では、ヒータ４０６への給電により当該ヒータ４０６が発熱し、貯留槽４０４全体が発熱状態になる。これにより、底面４０９全域が発熱する。底面４０９の全域において、ヒータ４０６のオン状態における底面４０９の単位面積当たりの発熱量は均一に設定されている。 In the ON state of the heater 406, the heater 406 generates heat by supplying power to the heater 406, and the entire storage tank 404 is heated. As a result, the entire bottom surface 409 generates heat. In the entire area of the bottom surface 409, the heat generation amount per unit area of the bottom surface 409 when the heater 406 is on is set to be uniform.
　基板処理装置４０１では、貯留槽４０４に関連して、貯留槽４０４に対してウエハＷを昇降させる複数本（たとえば、３本）のリフトピン４０３が設けられている。複数本のリフトピン４０３は、貯留槽４０４の底面部４０９Ａを上下に貫通して形成された貫通孔４１２に挿通されて、その貯留槽４０４の底面４０９に対して昇降可能に設けられている。また、各リフトピン４０３は共通の支持部材４１０に支持されている。支持部材４１０には、シリンダを含むリフトピン昇降機構４１１が結合されている。リフトピン昇降機構４１１は、複数本のリフトピン４０３の先端が基板保持台４０２の上方に突出する位置と、複数本のリフトピン４０３の先端が基板保持台４０２の下方に退避する位置との間で、複数本のリフトピン４０３を一体的に昇降させる。 In the substrate processing apparatus 401, a plurality of (for example, three) lift pins 403 that move the wafer W up and down relative to the storage tank 404 are provided in association with the storage tank 404. The plurality of lift pins 403 are inserted through a through hole 412 formed vertically through the bottom surface portion 409A of the storage tank 404, and are provided so as to be movable up and down with respect to the bottom surface 409 of the storage tank 404. Each lift pin 403 is supported by a common support member 410. A lift pin elevating mechanism 411 including a cylinder is coupled to the support member 410. The lift pin lifting mechanism 411 includes a plurality of lift pins 403 between a position where the tips of the plurality of lift pins 403 protrude above the substrate holding table 402 and a position where the tips of the plurality of lift pins 403 retract below the substrate holding table 402. The book lift pins 403 are moved up and down integrally.
　基板処理装置４０１で実行されるリン酸エッチング処理では、まず、リフトピン昇降機構４１１が制御されて、複数本のリフトピン４０３の先端が基板保持台４０２の上方に突出する。そして、未処理のウエハＷが搬入され、このウエハＷが複数本のリフトピン４０３の先端上に載置される。このとき、リフトピン昇降機構４１１が制御されて、複数本のリフトピン４０３が降下し、ウエハＷが複数本のリフトピン４０３から基板保持台４０２に引き渡される。これにより、貯留槽４０４の底面４０９上に、ウエハＷが、その表面を上方に向けた状態で載置される。この状態で、ウエハＷの下面は、貯留槽４０４の底面４０９に接している。また、この状態で、各貫通孔４１２がウエハＷによって塞がれる。 In the phosphoric acid etching process executed by the substrate processing apparatus 401, first, the lift pin lifting mechanism 411 is controlled so that the tips of the plurality of lift pins 403 protrude above the substrate holding table 402. Then, an unprocessed wafer W is loaded, and this wafer W is placed on the tips of a plurality of lift pins 403. At this time, the lift pin raising / lowering mechanism 411 is controlled, the plurality of lift pins 403 are lowered, and the wafer W is transferred from the plurality of lift pins 403 to the substrate holding table 402. As a result, the wafer W is placed on the bottom surface 409 of the storage tank 404 with the surface thereof facing upward. In this state, the lower surface of the wafer W is in contact with the bottom surface 409 of the storage tank 404. Further, in this state, each through hole 412 is closed by the wafer W.
　次いで、貯留槽４０４の貯留溝４０５にリン酸水溶液が溜められる。貫通孔４１２がウエハＷによって塞がれているので、貯留溝４０５からリン酸水溶液は漏出しない。そして、貯留槽４０４のリン酸水溶液中にウエハＷが浸漬される。このとき、貯留槽４０４のリン酸水溶液の液面がウエハＷの表面よりも上方に位置し、その結果、リン酸水溶液によってウエハＷの表面の全域が覆われる。リン酸水溶液へのウエハＷの浸漬によって、ウエハＷの表面にリン酸エッチング処理が施される（図３のステップＳ１に相当）。 Next, the phosphoric acid aqueous solution is stored in the storage groove 405 of the storage tank 404. Since the through hole 412 is blocked by the wafer W, the phosphoric acid aqueous solution does not leak from the storage groove 405. Then, the wafer W is immersed in the phosphoric acid aqueous solution in the storage tank 404. At this time, the liquid level of the phosphoric acid aqueous solution in the storage tank 404 is located above the surface of the wafer W, and as a result, the entire surface of the wafer W is covered with the phosphoric acid aqueous solution. By immersing the wafer W in the phosphoric acid aqueous solution, the surface of the wafer W is subjected to phosphoric acid etching (corresponding to step S1 in FIG. 3).
　したがって、基板保持台４０２に保持されているウエハＷは、貯留槽４０４からの熱伝導により加熱される。貯留槽４０４による加熱により、ウエハＷの温度は約２００℃まで昇温され、維持される。この状態で、ウエハＷ表面との境界部分のリン酸水溶液に、ウエハＷの表面に近づくほど高くなる温度勾配が形成される。 Therefore, the wafer W held on the substrate holding table 402 is heated by heat conduction from the storage tank 404. Due to heating by the storage tank 404, the temperature of the wafer W is raised to about 200 ° C. and maintained. In this state, a temperature gradient is formed in the phosphoric acid aqueous solution at the boundary with the surface of the wafer W, which becomes higher as the surface of the wafer W is approached.
　第５実施形態によれば、貯留槽４０４の底面４０９の熱伝導によるウエハＷへの加熱により、ウエハＷが約２００℃に昇温される。この状態で、ウエハＷ表面との境界部分のリン酸水溶液に、ウエハＷの表面に近づくほど高くなる温度勾配が形成される。その結果、ウエハＷの表面との境界部分におけるリン酸水溶液において、極めて高温で、かつリン酸濃度が低く維持された状態を実現することができる。この状態のリン酸水溶液が、ウエハＷの表面のシリコン窒化膜に作用するから、シリコン窒化膜のエッチングレートを非常に高めることができ、同時にシリコン窒化膜の選択比を高く維持することができる。 According to the fifth embodiment, the temperature of the wafer W is raised to about 200 ° C. by heating the wafer W by heat conduction in the bottom surface 409 of the storage tank 404. In this state, a temperature gradient is formed in the phosphoric acid aqueous solution at the boundary with the surface of the wafer W, which becomes higher as the surface of the wafer W is approached. As a result, it is possible to realize a state in which the phosphoric acid aqueous solution at the boundary portion with the surface of the wafer W is maintained at a very high temperature and a low phosphoric acid concentration. Since the phosphoric acid aqueous solution in this state acts on the silicon nitride film on the surface of the wafer W, the etching rate of the silicon nitride film can be greatly increased, and at the same time, the selectivity of the silicon nitride film can be kept high.
　なお、第５実施形態において、図１１に破線で示すように各リフトピン４０３に代えて、貫通孔４１２をシールするためのシール部４２０を有するリフトピン４０３Ａを採用してもよい。シール部４２０は、リフトピン４０３Ａの先端部（上端部）に設けられ、上方に向かう程拡径する円錐台状をなしている。この場合、貫通孔４１２の開口端部には、上方に向かう程拡径する円錐面からなるテーパ面４２１を有している。 In the fifth embodiment, a lift pin 403A having a seal portion 420 for sealing the through hole 412 may be employed instead of each lift pin 403 as indicated by a broken line in FIG. The seal portion 420 is provided at the tip (upper end) of the lift pin 403A and has a truncated cone shape whose diameter increases toward the upper side. In this case, the opening end of the through hole 412 has a tapered surface 421 formed of a conical surface whose diameter increases toward the upper side.
　リフトピン４０３ＡがウエハＷの下方に退避する退避位置にある状態で、リフトピン４０３Ａのシール部４２０は貫通孔４１２の開口端部に収容される。この状態で、シール部４２０の外周面がテーパ面４２１と接触し、シール部４２０が貫通孔４１２をシールする（塞ぐ）。リフトピン４０３Ａのシール部４２０によって貫通孔４１２がシールされているので、貯留溝４０５からリン酸水溶液の漏出をより確実に防止することができる。 The seal part 420 of the lift pin 403A is accommodated in the opening end of the through hole 412 in a state where the lift pin 403A is in the retreat position where it is retracted below the wafer W. In this state, the outer peripheral surface of the seal portion 420 contacts the tapered surface 421, and the seal portion 420 seals (closes) the through hole 412. Since the through hole 412 is sealed by the seal portion 420 of the lift pin 403A, leakage of the phosphoric acid aqueous solution from the storage groove 405 can be prevented more reliably.
　以上、本発明の５つの実施形態について説明したが、本発明は他の形態で実施することもできる。 As mentioned above, although 5 embodiment of this invention was described, this invention can also be implemented with another form.
　たとえば、第２実施形態と第５実施形態とを組み合わせることができる。すなわち、第２実施形態において、バーノズル５０（図１参照）に代えて、水の液滴をスプレー状に吐出（噴霧）するスプレーノズル１０２を採用してもよい。 For example, the second embodiment and the fifth embodiment can be combined. That is, in the second embodiment, instead of the bar nozzle 50 (see FIG. 1), a spray nozzle 102 that discharges (sprays) water droplets in a spray form may be employed.
　なお、第２実施形態において、図８では、スプレーノズル１０２を１つだけ設ける場合を示しているが、左右方向に関し異なる位置にある複数のスプレーノズルから、水をスプレー状に吐出することもできる。 In the second embodiment, FIG. 8 shows a case where only one spray nozzle 102 is provided, but water can also be discharged from a plurality of spray nozzles at different positions in the left-right direction. .
　また、第１、第２および第５実施形態において、バーノズル５０またはスプレーノズル１０２を用いて、貯留槽４，４０４のリン酸水溶液に水を供給するものを例に挙げて説明したが、リンス用の水ノズル３０を用いて貯留槽４，４０４内のリン酸水溶液に水（ＤＩＷ）を供給するようにしてもよい。 Moreover, in 1st, 2nd and 5th embodiment, although using as an example what supplies water to the phosphoric acid aqueous solution of the storage tank 4404 using the bar nozzle 50 or the spray nozzle 102, it was for rinse. You may make it supply water (DIW) to the phosphoric acid aqueous solution in the storage tank 4404 using the water nozzle 30 of this.
　また、第１、第２および第５実施形態において、貯留槽４，４０４内のリン酸水溶液に供給する水としてＤＩＷを例に挙げて説明したが、リン酸水溶液に供給する水として、炭酸水、電解イオン水、オゾン水、還元水（水素水）、磁気水などを採用してもよい。 In the first, second and fifth embodiments, DIW has been described as an example of water supplied to the phosphoric acid aqueous solution in the storage tank 4, 404, but carbonated water is used as the water supplied to the phosphoric acid aqueous solution. Electrolytic ion water, ozone water, reduced water (hydrogen water), magnetic water, etc. may be employed.
　また、第１、第２および第５実施形態において、貯留槽４，４０４にヒータの機能を持たせる場合について説明したが、貯留槽４，４０４とヒータとを分離した構成であってもよい。この場合、たとえば、貯留槽４，４０４の下方からヒータにより加熱する構成であってもよい。 In the first, second, and fifth embodiments, the case where the storage tanks 4, 404 are provided with the heater function has been described. However, the storage tanks 4, 404 and the heaters may be separated. In this case, for example, a configuration in which the heater is heated from below the storage tanks 4, 404 may be used.
　また、第３実施形態において、ヒータヘッド２０３をウエハＷの径よりも十分に小径に形成し、オン状態のヒータヘッド２０３をウエハＷの表面に対向配置しつつ、当該ヒータヘッド２０３をウエハＷの表面に沿って移動させるようにしてもよい。 In the third embodiment, the heater head 203 is formed to have a diameter sufficiently smaller than the diameter of the wafer W, and the heater head 203 is placed on the surface of the wafer W while the heater head 203 in the on state is opposed to the surface of the wafer W. You may make it move along a surface.
　また、第４実施形態において、赤外線ヒータ３０３をウエハＷの径よりも十分に小径に形成し、オン状態の赤外線ヒータ３０３をウエハＷの表面に対向配置しつつ、当該赤外線ヒータ３０３をウエハＷの表面に沿って移動させるようにしてもよい。 Further, in the fourth embodiment, the infrared heater 303 is formed to have a diameter sufficiently smaller than the diameter of the wafer W, and the infrared heater 303 is placed on the surface of the wafer W while the infrared heater 303 in the on state is opposed to the surface of the wafer W. You may make it move along a surface.
　本発明の実施形態について詳細に説明してきたが、これらは本発明の技術的内容を明らかにするために用いられた具体例に過ぎず、本発明はこれらの具体例に限定して解釈されるべきではなく、本発明の範囲は添付の請求の範囲によってのみ限定される。 Although the embodiments of the present invention have been described in detail, these are only specific examples used to clarify the technical contents of the present invention, and the present invention is construed to be limited to these specific examples. Rather, the scope of the present invention is limited only by the accompanying claims.
　この出願は、２０１２年１１月５日に日本国特許庁に提出された特願２０１２－２４３５９６号に対応しており、この出願の全開示はここに引用により組み込まれるものとする。 This application corresponds to Japanese Patent Application No. 2012-243596 filed with the Japan Patent Office on November 5, 2012, the entire disclosure of which is incorporated herein by reference.
　　１；１０１；２０１；３０１；４０１　基板処理装置
　　３　スピンチャック
　　４　貯留槽
　１３　挟持部材
　１４　スピンモータ
　２９　底面
　４０　制御部
　５０　バーノズル
１０２　スプレーノズル
２０３　抵抗式ヒータ
２０４　貯留槽
２０９　下面
３０３　赤外線ヒータ
３０４Ａ　赤外線照射面
３０４　赤外線ランプ
４０２　基板保持台
４０４　貯留槽
４０９　底面
　　Ｗ　ウエハ DESCRIPTION OF SYMBOLS 1; 101; 201; 301; 401 Substrate processing apparatus 3 Spin chuck 4 Storage tank 13 Holding member 14 Spin motor 29 Bottom surface 40 Control part 50 Bar nozzle 102 Spray nozzle 203 Resistance type heater 204 Storage tank 209 Lower surface 303 Infrared heater 304A Infrared irradiation surface 304 Infrared lamp 402 Substrate holder 404 Storage tank 409 Bottom surface W Wafer

Claims (9)

  1. 　リン酸水溶液を貯留する貯留槽と、
    　前記貯留槽内のリン酸水溶液に基板を浸漬させた状態で、当該基板を水平姿勢に保持する基板保持手段と、
    　前記基板保持手段に保持されている基板と対向する発熱部を有し、当該基板を、前記発熱部からの熱輻射または熱伝達により加熱する加熱手段とを含む、基板処理装置。     A storage tank for storing a phosphoric acid aqueous solution;
    A substrate holding means for holding the substrate in a horizontal position in a state where the substrate is immersed in the phosphoric acid aqueous solution in the storage tank;
    A substrate processing apparatus, comprising: a heating unit that opposes a substrate held by the substrate holding unit; and heating unit that heats the substrate by heat radiation or heat transfer from the heating unit.
  2. 　前記貯留槽に貯留されているリン酸水溶液に水を供給する水供給手段と、
    　前記水供給手段からの水の供給／供給停止を制御することにより、前記貯留槽に貯留されているリン酸水溶液の濃度を制御する濃度制御手段とを含む、請求項１記載の基板処理装置。     Water supply means for supplying water to the phosphoric acid aqueous solution stored in the storage tank;
    The substrate processing apparatus according to claim 1, further comprising: concentration control means for controlling the concentration of the phosphoric acid aqueous solution stored in the storage tank by controlling supply / stop of water supply from the water supply means.
  3. 　前記水供給手段は、水の液滴を吐出する多数の吐出口を有する多孔ノズルを含む、請求項１または２に記載の基板処理装置。 3. The substrate processing apparatus according to claim 1, wherein the water supply means includes a porous nozzle having a plurality of discharge ports for discharging water droplets.
  4. 　前記水供給手段は、前記貯留部にスプレー状の水を噴射するスプレーノズルを含む、請求項１または２に記載の基板処理装置。 3. The substrate processing apparatus according to claim 1, wherein the water supply means includes a spray nozzle that injects spray-like water into the storage section.
  5. 　前記加熱手段は、前記基板保持手段に保持されている基板を、下方側から加熱する、請求項１～４のいずれか一項に記載の基板処理装置。 5. The substrate processing apparatus according to claim 1, wherein the heating unit heats the substrate held by the substrate holding unit from below.
  6. 　前記貯留槽は底面を有し、
    　前記貯留槽の前記底面が前記発熱部を構成している、請求項５に記載の基板処理装置。     The reservoir has a bottom surface;
    The substrate processing apparatus according to claim 5, wherein the bottom surface of the storage tank constitutes the heat generating portion.
  7. 　前記加熱手段は、前記基板保持手段に保持されている基板を、上方側から加熱する、請求項１～４のいずれか一項に記載の基板処理装置。 5. The substrate processing apparatus according to claim 1, wherein the heating unit heats the substrate held by the substrate holding unit from above.
  8. 　前記加熱手段は赤外線ランプを有し、
    　前記赤外線ランプは、前記基板保持手段に保持されている基板の表面に対向配置されて、当該表面に向けて赤外線を照射する、請求項７に記載の基板処理装置。     The heating means has an infrared lamp,
    The substrate processing apparatus according to claim 7, wherein the infrared lamp is disposed to face the surface of the substrate held by the substrate holding unit and irradiates infrared rays toward the surface.
  9. 　前記基板保持手段は、前記貯留槽に対して非接触状態で、基板を支持する基板支持部を有し、
    　前記基板支持部に支持された基板を回転させる基板回転手段をさらに含む、請求項１～８のいずれか一項に記載の基板処理装置。
          The substrate holding means has a substrate support portion that supports the substrate in a non-contact state with respect to the storage tank,
    The substrate processing apparatus according to any one of claims 1 to 8, further comprising a substrate rotating unit that rotates the substrate supported by the substrate support section.
PCT/JP2013/072438 2012-11-05 2013-08-22 Substrate processing device WO2014069079A1 (en)

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