JP2007048983A - Substrate treatment method and substrate treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate treatment method and a substrate treatment device capable of satisfactorily removing an organic material such as a resist used as a mask at the time of ion implantation without giving damage to a substrate. <P>SOLUTION: A hydrogen peroxide solution stored in a heating tank 26 is heated to be highly concentrated in a hydrogen peroxide gas supplying part 3, and the highly concentrated hydrogen peroxide solution is further heated in an evaporating unit 32 to produce the hydrogen peroxide gas including no moisture. The hydrogen peroxide gas is supplied to a two-fluid nozzle 6 and a sulfuric acid is concurrently supplied from a sulfuric acid supplier 2, and then a droplet jet flow of the mixed fluid of the hydrogen peroxide gas and the sulfuric acid is supplied from the two-fluid nozzle 6 to the surface of a wafer W held by a spin chuck 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for processing various substrates such as a semiconductor wafer.

  The manufacturing process of a semiconductor device includes, for example, a step of locally implanting impurities (ions) such as phosphorus, arsenic, and boron into the surface of a semiconductor wafer (hereinafter simply referred to as “wafer”). In this step, in order to prevent ion implantation into an undesired portion, a resist made of a photosensitive resin is patterned on the surface of the wafer, and a portion where ion implantation is not desired is masked by the resist. Since the resist patterned on the surface of the wafer becomes unnecessary after ion implantation, after ion implantation, a resist removal process is performed to remove and remove the unnecessary resist on the surface of the wafer. Done.

  In the resist removal process, for example, the resist film is removed by ashing (ashing) with an ashing device, and then the wafer is carried into a cleaning device, and the resist residue (polymer) after ashing is removed from the surface of the wafer. Can be achieved. In the ashing apparatus, for example, a processing chamber containing a wafer is made an oxygen gas atmosphere, and microwaves are radiated into the oxygen gas atmosphere. As a result, oxygen gas plasma (oxygen plasma) is generated in the processing chamber, and this oxygen plasma is irradiated onto the surface of the wafer, whereby the resist film on the surface of the wafer is decomposed and removed. On the other hand, in the cleaning apparatus, for example, a chemical solution such as APM (ammonia-hydrogen peroxide mixture) is supplied to the wafer surface, and the wafer surface is cleaned with the chemical solution (resist residue removal process). As a result, the resist residue adhering to the surface of the wafer is removed.

However, ashing by plasma has a problem that a portion (eg, exposed oxide film) that is not covered with a resist film on the surface of the wafer is damaged.
Therefore, SPM (sulfuric acid / hydrogen peroxide mixture) is a mixed solution of sulfuric acid and hydrogen peroxide solution on the surface of the wafer instead of plasma ashing and cleaning treatment using chemicals such as APM. It is proposed that the resist formed on the surface of the wafer is stripped and removed by the strong oxidizing power of peroxomonosulfuric acid (H ₂ SO ₅ ) contained in the SPM.
JP 2004-288858 A

However, in a wafer that has been subjected to ion implantation (particularly, high-dose ion implantation), the resist surface has been altered (cured), so that the resist cannot be removed satisfactorily, or the time for removing the resist is long. It takes.
Accordingly, an object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of satisfactorily removing organic substances such as a resist used as a mask at the time of ion implantation without damaging the substrate.

  In order to achieve the above object, according to a first aspect of the present invention, in the substrate processing method, the substrate holding step of holding the substrate (W) by the substrate holding means (5), and the hydrogen peroxide in the heating tank (26) A concentration step for heating water to increase its concentration, and a delivery step for sending the hydrogen peroxide solution whose concentration has been increased in the concentration step from the heating tank to the mixing supply means (6); A mixing step of mixing a fluid containing hydrogen peroxide with a fluid containing at least one of sulfuric acid and sulfur trioxide in the mixing and supplying means; and the fluid mixed in the mixing step from the mixing and supplying means. And a fluid supply step for supplying the substrate to the substrate held by the substrate holding means.

In addition, the alphanumeric characters in parentheses represent corresponding components in the embodiments described later. The same applies hereinafter.
According to this method, after the concentration of the hydrogen peroxide solution is increased, a fluid (hydrogen peroxide gas, high concentration hydrogen peroxide solution) containing the hydrogen peroxide and at least one of sulfuric acid and sulfur trioxide are removed. The fluid (sulfuric acid, sulfur trioxide (SO ₃ ), fuming sulfuric acid (H ₂ SO ₄ .nSO ₃ )) is mixed and the mixed fluid is supplied to the substrate.

The mixed fluid of the fluid containing hydrogen peroxide and the fluid containing at least one of sulfuric acid and sulfur trioxide contains peroxomonosulfuric acid (H ₂ SO ₅ ), which is a reaction product of hydrogen peroxide and sulfuric acid. Yes. Therefore, by supplying the mixed fluid to the substrate, unnecessary resist formed on the substrate can be peeled and removed. Moreover, the fluid containing hydrogen peroxide is a highly concentrated hydrogen peroxide solution (for example, a hydrogen peroxide solution having a concentration of 50 to 90%, preferably 70%) or a hydrogen peroxide gas from which moisture has been completely removed. Therefore, when the fluid containing hydrogen peroxide and the fluid containing at least one of sulfuric acid and sulfur trioxide are mixed, a large amount of peroxomonosulfuric acid is generated. Therefore, the resist on the substrate can be efficiently decomposed by the oxidizing power of peroxomonosulfuric acid, and unnecessary resist can be peeled off and removed from the substrate. Moreover, unlike plasma ashing, the substrate surface is not damaged.

According to a second aspect of the present invention, in the substrate processing method according to the first aspect, in the mixing step, at least one of hydrogen peroxide solution, sulfuric acid, and sulfur trioxide fed from the heating tank in the feeding step. It is the process of mixing with the fluid containing.
In the case of this method, a large amount of peroxomonosulfuric acid can be produced by mixing a high-concentration hydrogen peroxide solution delivered from a heating tank with a fluid containing at least one of sulfuric acid and sulfur trioxide. it can.

The invention according to claim 3 further includes a superwater vaporization step of heating and vaporizing the hydrogen peroxide solution delivered from the heating tank in the delivery step in the substrate processing method according to claim 1, wherein the mixing step Is a step of mixing the hydrogen peroxide gas generated in the pervaporation step with a fluid containing at least one of sulfuric acid and sulfur trioxide.
In the case of this method, a large amount of peroxomonosulfuric acid can be generated by mixing hydrogen peroxide gas with a fluid containing at least one of sulfuric acid and sulfur trioxide.

  The invention described in claim 4 further includes a sulfuric acid vaporization step for vaporizing a fluid containing at least one of sulfuric acid and sulfur trioxide in the substrate processing method according to any one of claims 1 to 3, wherein the mixing step Is a step of mixing a fluid containing hydrogen peroxide and a gas containing at least one of sulfuric acid and sulfur trioxide generated in the sulfuric acid vaporization step.

  According to this method, since the gas containing at least one of sulfuric acid and sulfur trioxide does not have moisture, the gas and the fluid containing hydrogen peroxide are mixed with each other, so that a larger amount of peroxo monooxide can be obtained. Sulfuric acid can be produced. Therefore, the resist on the substrate can be decomposed more efficiently, and the unnecessary resist can be peeled off and removed from the substrate better.

A fifth aspect of the present invention is the substrate processing method according to any one of the first to fourth aspects, wherein the oxidant supplies the oxidant to the substrate held by the substrate holding means prior to the fluid supply step. The method further includes a supplying step.
According to this method, by supplying the oxidizing agent to the substrate before the mixed fluid of the fluid containing hydrogen peroxide and the fluid containing at least one of sulfuric acid and sulfur trioxide is supplied to the substrate, Unnecessary resist on the substrate can be oxidized in advance so that the resist can be easily peeled off from the substrate. Therefore, when the mixed fluid is supplied to the substrate, unnecessary resist can be peeled off and removed from the substrate more satisfactorily.

According to a sixth aspect of the present invention, in the substrate processing method according to the fifth aspect, the oxidizing agent supplying step and the fluid supplying step are repeatedly performed a plurality of times.
According to this method, unnecessary resist can be reliably peeled off and removed from the substrate.
In addition, as described in Claim 7, it is preferable that the oxidizing agent includes at least one of water vapor, ozone water, ozone gas, hydrogen peroxide water, and hydrogen peroxide gas.

  According to an eighth aspect of the present invention, in the substrate processing apparatus, the substrate holding means (5) for holding the substrate (W), a fluid containing hydrogen peroxide, and a fluid containing at least one of sulfuric acid and sulfur trioxide. Mixing supply means (6) for mixing and supplying the mixed fluid to the substrate held by the substrate holding means, and high concentration means for heating the hydrogen peroxide solution to increase its concentration (26, 27) and delivery means (29, 30, 33) for delivering the hydrogen peroxide solution whose concentration has been increased by the concentration-enhancing means to the mixing means.

According to this configuration, the substrate processing method according to claim 1 can be realized, and an effect similar to the effect described in relation to claim 1 can be achieved.
The invention according to claim 9 is the substrate processing apparatus according to claim 8, further comprising a superwater vaporization unit (32) for heating and vaporizing the hydrogen peroxide solution delivered by the delivery means, The supply means mixes the hydrogen peroxide gas generated by the perhydrovaporization unit with a fluid containing at least one of sulfuric acid and sulfur trioxide.

According to this configuration, the substrate processing method according to claim 3 can be realized, and the same effect as the effect described in relation to claim 3 can be achieved.
The concentration-improving means includes a heating tank (26) for storing the hydrogen peroxide solution, and a heating means (27) for heating the hydrogen peroxide solution in the heating tank. The hydrogen peroxide solution in the heating tank may be sent out.

According to an eleventh aspect of the present invention, in the substrate processing apparatus according to any one of the eighth to tenth aspects, a sulfuric acid vaporization unit (67) for heating and vaporizing a fluid containing at least one of sulfuric acid and sulfur trioxide. ), And the mixing and supplying means mixes the fluid containing hydrogen peroxide and the gas generated by the sulfuric acid vaporization unit.
According to this configuration, the substrate processing method according to claim 4 can be realized, and the same effect as the effect described in relation to claim 4 can be achieved.

A twelfth aspect of the present invention is the substrate processing apparatus according to any one of the eighth to eleventh aspects, further comprising an oxidant supply means (3, 6) for supplying an oxidant to the substrate held by the substrate holding means. It is further characterized by including.
According to this configuration, the substrate processing method according to claim 5 can be realized, and the same effect as the effect described in relation to claim 5 can be achieved.

In addition, as described in Claim 13, it is preferable that the oxidizing agent includes at least one of water vapor, ozone water, ozone gas, hydrogen peroxide water, and hydrogen peroxide gas.
A fourteenth aspect of the present invention is the substrate processing apparatus according to any one of the eighth to thirteenth aspects, wherein the mixed supply means is a casing (39) and a fluid formed at one end of the casing and containing hydrogen peroxide. And a sulfuric acid discharge port (41) that is formed at the one end of the casing and discharges a fluid containing at least one of sulfuric acid and sulfur trioxide. It includes an external mixing type two-fluid nozzle that mixes the fluid discharged from the discharge port and the fluid discharged from the sulfuric acid discharge port outside the casing.

According to this configuration, the fluid containing hydrogen peroxide and the fluid containing at least one of sulfuric acid and sulfur trioxide can be mixed well, and the mixed fluid can be supplied to the substrate.
A fifteenth aspect of the present invention is the substrate processing apparatus according to any one of the eighth to thirteenth aspects, wherein the mixing supply means is formed facing the mixing tube (54) and the mixing tube, A super-water discharge port (58) for discharging a fluid containing the mixture into the mixing tube; and a sulfuric acid discharge port for discharging a fluid containing at least one of sulfuric acid and sulfur trioxide formed into the mixing tube. (66), and an internal mixed two-fluid that provides a mixing chamber (64) in the mixing tube for mixing the fluid discharged from the excess water discharge port and the fluid discharged from the sulfuric acid discharge port A nozzle is included.

  According to this configuration, the fluid containing hydrogen peroxide and the fluid containing at least one of sulfuric acid and sulfur trioxide can be mixed well, and the mixed fluid can be supplied to the substrate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram conceptually showing the structure of a substrate processing apparatus according to an embodiment of the present invention. This substrate processing apparatus performs a single-wafer type resist removal process. For example, ion implantation for locally implanting impurities (ions) such as phosphorus, arsenic and boron into the surface of a wafer W as an example of a substrate. After the processing, it is used to peel off and remove the resist that is no longer needed from the surface of the wafer W.

The substrate processing apparatus includes a processing unit 1 that performs processing (resist removal processing) on a wafer W, a sulfuric acid supply unit 2 that supplies sulfuric acid used for processing the wafer W to the processing unit 1, and a processing A hydrogen peroxide gas supply unit 3 for supplying hydrogen peroxide gas used for processing the wafer W to the unit 1 is provided.
The processing unit 1 includes a processing chamber 4 partitioned by a partition wall. In the processing chamber 4, a spin chuck 5 for holding and rotating the wafer W substantially horizontally, hydrogen peroxide gas is supplied to the surface of the wafer W held on the spin chuck 5, and sulfuric acid and excess A two-fluid nozzle 6 for supplying a mixed fluid with hydrogen oxide gas and a blocking plate 7 for controlling the atmosphere near the surface of the wafer W held by the spin chuck 5 are arranged.

  The spin chuck 5 is provided at substantially equiangular intervals at a plurality of locations around the motor 8, a disk-shaped spin base 9 that is rotated around the vertical axis by the rotational driving force of the motor 8, and the periphery of the spin base 9. And a plurality of clamping members 10 for clamping the wafer W in a substantially horizontal posture. When a rotational driving force is generated from the motor 8 in a state where the wafer W is sandwiched by the plurality of clamping members 10, the spin base 9 is rotated around the vertical axis by the rotational driving force, and together with the spin base 9, the wafer W is rotated around the vertical axis while maintaining a substantially horizontal posture.

The spin chuck 5 is not limited to such a configuration. For example, the back surface (non-device surface) of the wafer W is vacuum-sucked to hold the wafer W in a horizontal posture, and in that state A vacuum chuck of a vacuum suction type that can rotate the wafer W held by rotating around a vertical axis may be employed.
The two-fluid nozzle 6 is provided above the spin chuck 5. The two-fluid nozzle 6 is supplied with sulfuric acid from the sulfuric acid supply unit 2 and hydrogen peroxide gas from the hydrogen peroxide gas supply unit 3. When only the hydrogen peroxide gas is supplied to the two-fluid nozzle 6, the hydrogen peroxide gas is supplied to the surface of the wafer W held by the spin chuck 5. Further, when sulfuric acid and hydrogen peroxide gas are simultaneously supplied to the two-fluid nozzle 6, sulfuric acid and hydrogen peroxide gas are mixed to form fine droplets of the mixed fluid. Is jetted and supplied to the surface of the wafer W.

  The two-fluid nozzle 6 is in the form of a scan nozzle that can change the supply position of the hydrogen peroxide gas and the mixed fluid on the surface of the wafer W. That is, an arm (not shown) that can swing in a substantially horizontal plane is provided above the spin chuck 5, and the two-fluid nozzle 6 is attached to the arm. When supplying the hydrogen peroxide gas and the mixed fluid from the two-fluid nozzle 6 to the surface of the wafer W, the arm is swung within a predetermined angle range, whereby the hydrogen peroxide gas and the mixture on the surface of the wafer W are mixed. The fluid supply position is scanned (moved).

  The blocking plate 7 is formed in a disk shape having a diameter substantially the same as or larger than that of the wafer W. The blocking plate 7 is disposed substantially horizontally above the spin chuck 5, at a position where it is largely retracted above the spin chuck 5, and at a position facing the surface of the wafer W held by the spin chuck 5. It can be moved up and down. Further, the blocking plate 7 is provided to be rotatable about the same rotation axis as the rotation axis of the wafer W (spin base 9).

Further, the blocking plate 7 supplies DIW (deionized water) supplied from the DIW supply source via the valve 11 to the surface of the wafer W held by the spin chuck 5 from the center of the lower surface thereof. Be able to. Furthermore, nitrogen gas (N ₂ ) supplied from the nitrogen gas supply source through the valve 12 is supplied to a space between the wafer W and the wafer W held by the spin chuck 5. Can be done.

  Further, a splash guard 13 for capturing a mixed fluid of sulfuric acid and hydrogen peroxide gas scattered from the wafer W and DIW is provided so as to surround the periphery of the spin chuck 5. The splash guard 13 can be moved up and down between a position facing the peripheral end surface of the wafer W held by the spin chuck 5 and a position below the wafer W held by the spin chuck 5. It is possible to capture the mixed fluid of sulfuric acid and hydrogen peroxide gas and DIW scattered from the wafer W at a position facing the peripheral end surface. The mixed fluid of sulfuric acid and hydrogen peroxide gas and DIW captured by the splash guard 13 flow down along the inner surface of the splash guard 13 and are collected in a container-like cup 14 that accommodates the spin chuck 5. It is discharged through a drain line 15 connected to 14.

The sulfuric acid supply unit 2 includes a sulfuric acid tank 16 that stores sulfuric acid having a high concentration (for example, a concentration of 98%), and a sulfuric acid supply passage 17 that supplies the sulfuric acid stored in the sulfuric acid tank 16 to the two-fluid nozzle 6. The temperature control circuit 18 is provided for circulating the sulfuric acid stored in the sulfuric acid tank 16 and adjusting the liquid temperature of the sulfuric acid to a constant high temperature (for example, 80 to 120 ° C.).
One end of the sulfuric acid supply path 17 is disposed in the sulfuric acid solution stored in the sulfuric acid tank 16, and the other end is connected to the two-fluid nozzle 6. In this sulfuric acid supply path 17, in order from the sulfuric acid tank 16 side, a filter 19 for removing foreign matters in the sulfuric acid flowing through the sulfuric acid supply path 17, and sulfuric acid is pumped out from the sulfuric acid tank 16, and the sulfuric acid is discharged into a two-fluid nozzle. 6 and a valve 21 for opening and closing the sulfuric acid supply path 17 are interposed. When the pump 20 is driven with the valve 21 opened, the sulfuric acid stored in the sulfuric acid tank 16 is supplied to the two-fluid nozzle 6 through the sulfuric acid supply path 17.

  One end of the temperature control circuit 18 is disposed in the sulfuric acid solution stored in the sulfuric acid tank 16, and is once drawn out from the sulfuric acid tank 16, and the other end is disposed in the upper part of the sulfuric acid tank 16. Yes. In order to this temperature control circuit 18 from one end side, a filter 22 for removing foreign matters in the sulfuric acid flowing through the temperature control circuit 18, and sulfuric acid is pumped out from the sulfuric acid tank 16, and the sulfuric acid is supplied to the sulfuric acid tank. The pump 23 for returning to 16, the heater 24 for heating the sulfuric acid which distribute | circulates the temperature control circuit 18 to a fixed temperature, and the valve 25 for opening and closing the temperature control circuit 18 are interposed. During operation of the substrate processing apparatus, the valve 25 is always opened and the pump 23 and the heater 24 are driven. The sulfuric acid stored in the sulfuric acid tank 16 circulates through the temperature control circuit 18, The heater 24 is heated to a certain temperature on the way and returned to the sulfuric acid tank 16. Thereby, the liquid temperature of the sulfuric acid stored in the sulfuric acid tank 16 is adjusted and held at a constant temperature.

  The hydrogen peroxide gas supply unit 3 heats the hydrogen peroxide solution stored in the heating tank 26 and stores the hydrogen peroxide solution in a closed type to increase the concentration (for example, the concentration 50 to 50). 90%, preferably 70%), a hydrogen peroxide solution supply path 28 for supplying hydrogen peroxide solution to the heating vessel 26, and a nitrogen gas supply to the heating vessel 26. Nitrogen gas supply passage 29, hydrogen peroxide solution outlet passage 30 for extracting the hydrogen peroxide solution stored in the heating tank 26, and carrier gas for feeding nitrogen gas into the hydrogen peroxide solution outlet passage 30 A vaporization unit 32 for heating and vaporizing the hydrogen peroxide solution flowing through the supply channel 31, the hydrogen peroxide solution outlet channel 30, and the hydrogen peroxide gas generated by the vaporization unit 32 to the two-fluid nozzle 6. Peroxidized water to supply And a gas supply passage 33.

The heating member 27 includes, for example, a heater and is provided so as to cover the bottom surface and the side surface of the heating tank 26. By the heating member 27, the hydrogen peroxide solution stored in the heating tank 26 is heated to a constant temperature (for example, 100 ° C.).
The hydrogen peroxide solution supply path 28 is provided with a valve 34 for opening and closing the hydrogen peroxide solution supply path 28. When the amount of the hydrogen peroxide solution stored in the heating tank 26 is smaller than a predetermined amount, the valve 34 is opened, and the hydrogen peroxide solution is supplied from the hydrogen peroxide solution supply path 28 to the heating tank 26.

The nitrogen gas supply path 29 is provided with a valve 35 for opening and closing the nitrogen gas supply path 29.
One end of the hydrogen peroxide solution lead-out path 30 is disposed in the hydrogen peroxide solution stored in the heating tank 26, and the other end is connected to the vaporization unit 32. A valve 36 for opening and closing the hydrogen peroxide solution outlet passage 30 is interposed in the hydrogen peroxide solution outlet passage 30. When the valve 35 interposed in the nitrogen gas supply path 29 is opened in a state where the valve 36 is opened, nitrogen gas is supplied from the nitrogen gas supply path 29 to the heating tank 26, and the inside of the heating tank 26 By increasing the pressure, the hydrogen peroxide solution stored in the heating tank 26 is sent out to the hydrogen peroxide solution outlet passage 30.

  The carrier gas supply path 31 is in the middle of the hydrogen peroxide solution outlet path 30 and is branched and connected between the vaporization unit 32 and the valve 36. The carrier gas supply path 31 is provided with a valve 37 for opening and closing the carrier gas supply path 31. When this valve 37 is opened, nitrogen gas is sent from the carrier gas supply path 31 to the hydrogen peroxide solution lead-out path 30, and this nitrogen gas becomes the carrier gas, and is supplied from the heating tank 26 to the hydrogen peroxide solution lead-out path 30. The delivered hydrogen peroxide solution is carried to the vaporization unit 32.

  The vaporization unit 32 has a built-in heater 38, and the heater 38 instantaneously heats the hydrogen peroxide solution flowing in along with the nitrogen gas from the hydrogen peroxide solution outlet passage 30 to vaporize the hydrogen peroxide solution. Hydrogen peroxide gas is generated by evaporating water contained in the hydrogen peroxide solution. As such a vaporization unit 32, for example, a commercially available vaporizer having chemical resistance against hydrogen peroxide can be used.

FIG. 2 is a schematic cross-sectional view showing a configuration example of the two-fluid nozzle 6. FIG. 2A shows the configuration of a so-called external mixing type two-fluid nozzle, and FIG. 2B shows the configuration of a so-called internal mixing type two-fluid nozzle.
The external mixed two-fluid nozzle shown in FIG. 2 (a) includes a casing 39, and a first fluid discharge port 41 for discharging a first fluid toward the external space 40 at the tip of the casing 39; It has an annular shape surrounding the first fluid discharge port 42, and has a second fluid discharge port 42 for discharging the second fluid toward the external space 40.

More specifically, the casing 39 includes an inner flow pipe 43 and an outer holding body 44 that surrounds the inner flow pipe 43 and holds the inner flow pipe 43 coaxially in an inserted state. .
The inner flow pipe 43 has a first fluid channel 45 inside thereof. The front end (lower end) of the first fluid channel 45 opens as the first fluid discharge port 41, and the upper end on the opposite side forms a first fluid introduction port 46 for introducing fluid. Further, the inner flow pipe 43 is formed in a bowl shape in which a tip end (lower end) 47 and an upper end 48 on the opposite side protrude outwardly, and the tip end 47 and the upper end 48 of these bowls are formed. Is in contact with the inner surface of the outer holding body 44, and a space 49 is formed between the outer surface of the inner flow pipe 43 and the inner surface of the outer holding body 44 between the tip portion 47 and the other end portion 48. A second fluid flow path 50 that connects the space 49 and the external space 40 is formed at the distal end portion 47 of the inner flow pipe 43, and the distal end of the second fluid flow path 50 serves as the second fluid discharge port 42. It is open. The second fluid flow path 50 has a cross-sectional shape that is inclined so as to approach the central axis of the inner flow pipe 43 toward the distal end side.

The outer holding body 44 has a second fluid introduction port 51 on its side surface. The second fluid introduction port 51 communicates with a space 49 formed between the outer surface of the inner flow pipe 43 and the inner surface of the outer holding body 44.
When this external mixing type two-fluid nozzle is employed as the two-fluid nozzle 6, the sulfuric acid supply path 17 is connected to the first fluid introduction port 46, and the hydrogen peroxide gas supply path 33 is connected to the second fluid introduction port 51. The Then, when sulfuric acid is supplied from the sulfuric acid supply path 17 to the first fluid flow path 45 and hydrogen peroxide gas is supplied from the hydrogen peroxide gas supply path 33 to the space 49, the first fluid discharge port 41 passes through the outside. Sulfuric acid is discharged into the space 40 and hydrogen peroxide gas is discharged from the second fluid discharge port 42 into the external space 40. Then, in the external space 40, sulfuric acid and hydrogen peroxide gas collide and mix, and a jet of fine droplets of the mixed fluid is formed.

On the other hand, the internal mixed two-fluid nozzle shown in FIG. 2B has a first fluid introduction part 52, a second fluid introduction part 53, and a droplet formation and discharge part 54. The first fluid introduction part 52, the second fluid introduction part 53, and the droplet formation discharge part 54 all have a tube shape, and are connected in series in that order.
The first fluid introduction part 52 integrally has a large diameter part 55 fitted into the upper end part of the second fluid introduction part 53 and a small diameter part 56 continuous below the large diameter part 55. In addition, a first fluid channel 57 is formed through the first fluid introduction part 52. And the front-end | tip (lower end) of the 1st fluid flow path 57 opens as the 1st fluid discharge outlet 58, and the upper end of the opposite side forms the 1st fluid introduction port 59 for introducing a fluid. .

A second fluid introduction port 60 for introducing a fluid is formed on the side surface of the second fluid introduction portion 53. The second fluid introduction port 60 communicates with a space 61 formed between the outer surface of the small diameter portion 56 of the first fluid introduction portion 52 and the inner surface of the second fluid introduction portion 53.
The upper end of the droplet forming / discharging unit 54 is fitted into the lower end of the second fluid introducing unit 53. The droplet forming / discharging portion 54 integrally has a tapered portion 62 whose inner diameter decreases as it goes downward, and a straight pipe-shaped straight portion 63 that is continuous with the lower end of the tapered portion 62 and has a uniform inner diameter. ing. The lower end of the first fluid introduction part 52 enters the taper part 62, and the space 61 and the internal space 64 of the taper part 62 are between the outer surface of the first fluid introduction part 52 and the inner surface of the taper part 62. A communication path 65 communicating with the (mixing chamber) is formed.

  When this internal mixed two-fluid nozzle is employed as the two-fluid nozzle 6, the hydrogen peroxide gas supply path 33 is connected to the first fluid introduction port 59, and the sulfuric acid supply path 17 is connected to the second fluid introduction port 60. The Then, hydrogen peroxide gas is supplied from the hydrogen peroxide gas supply path 33 to the first fluid flow path 57. The hydrogen peroxide gas supplied to the first fluid flow channel 57 flows into the internal space 64 of the tapered portion 62 from the first fluid discharge port 58. On the other hand, sulfuric acid is supplied from the sulfuric acid supply path 17 to the space 61 between the outer surface of the first fluid introduction portion 52 and the inner surface of the tapered portion 62. The sulfuric acid supplied to the space 61 flows into the internal space 64 of the tapered portion 62 from the lower end opening 66 of the communication path 65 through the communication path 65. Thereby, in the internal space 64, hydrogen peroxide gas and sulfuric acid are mixed, and fine droplets of the mixed fluid are formed. The droplets are accelerated by the taper portion 62 and ejected vigorously from the tip of the straight portion 63.

As the two-fluid nozzle 6, either an external mixing type two-fluid nozzle shown in FIG. 2 (a) or an internal mixing type two-fluid nozzle shown in FIG. 2 (b) may be adopted. Even if it exists, hydrogen peroxide gas and sulfuric acid can be mixed well and the mixed fluid can be supplied to the surface of the wafer W.
FIG. 3 is a view for explaining a resist removal process in the substrate processing apparatus shown in FIG. In the resist removal process, a wafer W having unnecessary resist after the ion implantation process is carried into the process chamber 4 by a transfer robot (not shown). At this time, the two-fluid nozzle 6 and the blocking plate 7 are arranged at positions retracted from the vicinity of the spin chuck 5 so as not to hinder the loading of the wafer W.

  When the wafer W is transferred from the transfer robot to the spin chuck 5 and is held on the spin chuck 5, first, the motor 8 is driven to move the wafer W together with the spin base 9 to a predetermined rotational speed (for example, 500 rpm). After the two-fluid nozzle 6 is disposed above the wafer W, hydrogen peroxide gas is supplied from the hydrogen peroxide gas supply unit 3 to the two-fluid nozzle 6, and the hydrogen peroxide gas is supplied from the two-fluid nozzle 6. It is supplied to the surface of the rotating wafer W. Thereby, the resist on the surface of the wafer W reacts with the hydrogen peroxide gas, and the resist is oxidized. That is, hydrogen peroxide gas is supplied from the two-fluid nozzle 6 to the surface of the wafer W as an oxidant for oxidizing the resist.

  When a predetermined time (for example, 60 sec) elapses from the start of supply of the hydrogen peroxide water gas, the sulfuric acid supply unit continues to supply the hydrogen peroxide gas from the hydrogen peroxide gas supply unit 3 to the two-fluid nozzle 6. The supply of sulfuric acid from 2 to the two-fluid nozzle 6 is started. As a result, a jet of droplets of a mixed fluid of hydrogen peroxide gas and sulfuric acid is supplied from the two-fluid nozzle 6 to the surface of the rotating wafer W.

The mixed fluid of hydrogen peroxide gas and sulfuric acid contains peroxomonosulfuric acid (H ₂ SO ₅ ), which is a reaction product of hydrogen peroxide (H ₂ O ₂ ) and sulfuric acid (H ₂ SO ₄ ). Therefore, when a jet of droplets of a mixed fluid of hydrogen peroxide gas and sulfuric acid is supplied to the surface of the wafer W, the resist is peeled off and removed from the surface of the wafer W by the strong oxidizing power of peroxomonosulfuric acid. . Moreover, since the hydrogen peroxide gas supplied to the two-fluid nozzle 6 is a gas not containing water having a hydrogen peroxide concentration of almost 100%, when this hydrogen peroxide gas and sulfuric acid are mixed, a large amount of hydrogen peroxide gas is supplied. Peroxomonosulfuric acid is produced. Therefore, the decomposition reaction (oxidation) of the resist with peroxomonosulfuric acid proceeds efficiently, and the resist is peeled off from the surface of the wafer W and removed. Furthermore, the hydrogen peroxide gas is a high-temperature gas generated by further heating the hydrogen peroxide solution heated to a constant temperature by the vaporization unit 32. The fluid mixed with sulfuric acid whose temperature is adjusted to the temperature is heated to a high temperature at which the oxidizing power of beloxomonosulfuric acid can be fully exerted by the heat of reaction (heat of reaction when peroxomonosulfuric acid is produced) during mixing. The Therefore, the resist on the surface of the wafer W is more effectively stripped and removed.

  While the mixed fluid of hydrogen peroxide gas and sulfuric acid is being supplied to the surface of the wafer W, the hydrogen peroxide gas supply unit 3 heats the hydrogen peroxide solution in the heating tank 26 to heat the hydrogen peroxide solution. The hydrogen peroxide solution is sent out from the heating tank 26, the hydrogen peroxide solution is sent out from the sulfuric acid tank 16, and the hydrogen peroxide solution is vaporized by the vaporizing unit 32. And a mixing step in which hydrogen peroxide gas and sulfuric acid are mixed by the two-fluid nozzle 6.

  When a predetermined time (for example, 60 sec) elapses from the start of supply of the mixed fluid of sulfuric acid and hydrogen peroxide gas, the supply of hydrogen peroxide gas from the hydrogen peroxide gas supply unit 3 to the two-fluid nozzle 6 is stopped. Then, the supply of sulfuric acid from the sulfuric acid supply unit 2 to the two-fluid nozzle 6 is stopped. Subsequently, the two-fluid nozzle 6 is retracted from above the wafer W, and then the blocking plate 7 is brought close to the surface of the wafer W. Then, DIW is supplied from the blocking plate 7 to the surface of the rotating wafer W while the rotation of the wafer W is continued. The DIW supplied onto the surface of the wafer W receives a centrifugal force due to the rotation of the wafer W and flows on the surface of the wafer W from the central portion toward the periphery. As a result, the DIW spreads over the entire surface of the wafer W, and the surface of the wafer W is washed away by the DIW. The supply of DIW to the surface of the wafer W is continued for a predetermined time (for example, 120 sec).

  When a predetermined time elapses after the DIW supply to the surface of the wafer W is started, the DIW supply is stopped. Thereafter, the rotation speed of the wafer W is increased to 2500 rpm, and nitrogen gas is supplied from the blocking plate 7 toward the surface of the wafer W. As a result, the space between the surface of the wafer W and the blocking plate 7 becomes a nitrogen gas atmosphere. In the nitrogen gas atmosphere, DIW attached to the surface of the wafer W is shaken off by centrifugal force, and the wafer W is It will be dried. When a predetermined time (for example, 30 seconds) elapses from the start of the supply of nitrogen gas, the rotation of the wafer W by the spin chuck 5 is stopped, and after the shielding plate 7 is retracted upward, the processed wafer W is moved by the transfer robot. It is carried out.

As described above, according to this embodiment, after the concentration of the hydrogen peroxide solution is increased, the hydrogen peroxide gas generated by further heating the hydrogen peroxide and sulfuric acid are mixed, The mixed fluid is supplied to the surface of the wafer W.
Since the mixed fluid of hydrogen peroxide gas and sulfuric acid contains peroxomonosulfuric acid, which is a reaction product of hydrogen peroxide and sulfuric acid, by supplying this mixed fluid to the surface of the wafer W, the wafer W Unnecessary resist formed on the surface can be removed by stripping. In addition, since the hydrogen peroxide gas does not contain moisture, a large amount of peroxomonosulfuric acid is produced when the hydrogen peroxide gas and sulfuric acid are mixed. Therefore, the resist on the surface of the wafer W can be efficiently decomposed by the oxidizing power of peroxomonosulfuric acid, and unnecessary resist can be peeled off from the surface of the wafer W and removed. In addition, unlike plasma ashing, the surface of the wafer W is not damaged.

  Further, before the mixed fluid of hydrogen peroxide gas and sulfuric acid is supplied to the surface of the wafer W, hydrogen peroxide gas as an oxidizing agent is supplied to the surface of the wafer W, so that Unnecessary resist is oxidized in advance so that the resist is easily peeled off from the surface of the wafer W. Therefore, when supplying the mixed fluid of hydrogen peroxide gas and sulfuric acid to the surface of the wafer W, unnecessary resist can be peeled off and removed from the surface of the wafer W even better.

  In this embodiment, the step of supplying an oxidant to the surface of the wafer W (oxidant supply step), and the hydrogen peroxide gas and sulfuric acid are supplied to the surface of the wafer W after the oxidant supply step. Although the case where the process of supplying the mixed fluid (fluid supply process) is performed once is taken as an example, the oxidant supply process and the fluid supply process may be alternately repeated a plurality of times. By so doing, unnecessary resist can be reliably peeled off and removed from the surface of the wafer W.

  Further, the oxidizing agent is not limited to hydrogen peroxide gas, but may be hydrogen peroxide solution delivered from the heating tank 26 in a state where the driving of the vaporizing unit 32 is stopped. Further, a nozzle different from the two-fluid nozzle 6 may be provided, and an oxidizing agent may be supplied from the nozzle to the surface of the wafer W. In this case, the oxidizing agent is water vapor, ozone water, ozone gas, peroxidation, or the like. It is preferable to include at least one of hydrogen water and hydrogen peroxide gas.

  Furthermore, in this embodiment, the case where the mixed fluid of hydrogen peroxide gas and sulfuric acid is supplied to the surface of the wafer W is taken as an example. However, the vaporization unit 32 is omitted or the vaporization unit 32 is driven. Is stopped, high concentration hydrogen peroxide solution is supplied from the hydrogen peroxide gas supply unit 3 to the two-fluid nozzle 6, and sulfuric acid is supplied from the sulfuric acid supply unit 2 to the two-fluid nozzle 6. Thus, a mixed liquid of high-concentration hydrogen peroxide and sulfuric acid may be supplied to the surface of the wafer W.

  Further, as shown in FIG. 4, sulfuric acid flowing in the sulfuric acid supply path 17 in the middle of the sulfuric acid supply path 17 between the valve 21 and the two-fluid nozzle 6 is instantaneously heated by the heater 68, A vaporization unit 67 that generates sulfuric acid gas by vaporizing the sulfuric acid is interposed, and hydrogen peroxide gas or high-concentration hydrogen peroxide water is supplied from the hydrogen peroxide gas supply unit 3 to the two-fluid nozzle 6. At the same time, even if sulfuric acid gas is supplied from the sulfuric acid supply unit 2 to the two-fluid nozzle 6, hydrogen peroxide gas or a mixed fluid of high-concentration hydrogen peroxide water and sulfuric acid gas is supplied to the surface of the wafer W. Good. Preferably, a mixed fluid of hydrogen peroxide gas and sulfuric acid gas is supplied to the surface of the wafer W. In this case, since hydrogen peroxide gas and sulfuric acid gas do not have moisture, By mixing with sulfuric acid gas, a larger amount of peroxomonosulfuric acid can be produced. For this reason, the resist on the surface of the wafer W can be decomposed more efficiently, and unnecessary resist can be peeled off and removed from the surface of the wafer W better.

Furthermore, the case where sulfuric acid is supplied from the sulfuric acid supply unit 2 to the two-fluid nozzle 6 is taken as an example, but it is preferable that a fluid containing at least one of sulfuric acid and sulfur trioxide is supplied to the two-fluid nozzle 6. For example, sulfur trioxide (SO ₃ ) or fuming sulfuric acid (H ₂ SO ₄ .nSO ₃ ) may be supplied to the two-fluid nozzle 6.
Moreover, although the process which peels and removes an unnecessary resist from the surface of the wafer W was taken as an example, it is not restricted to a resist, This invention can also be applied to the process which removes organic substance from the surface of the wafer W.

Further, the substrate to be processed is not limited to the wafer W, but a glass substrate for a liquid crystal display device, a glass substrate for a plasma display, a glass substrate for an FED, an optical disk substrate, a magnetic disk substrate, a magneto-optical disk substrate, or a photomask substrate It may be a substrate.
In addition, various design changes can be made within the scope of matters described in the claims.

It is a figure which shows notionally the structure of the substrate processing apparatus which concerns on one Embodiment of this invention. FIG. 2 is a schematic cross-sectional view illustrating a configuration example of a two-fluid nozzle provided in the substrate processing apparatus illustrated in FIG. 1, and FIG. 2A illustrates a configuration of a so-called external mixing type two-fluid nozzle, and FIG. Shows a configuration of a so-called internal mixing type two-fluid nozzle. It is a figure for demonstrating the resist removal process in the substrate processing apparatus shown in FIG. It is a figure which shows notionally the structure (The structure provided with the vaporization unit for vaporizing a sulfuric acid) of the substrate processing apparatus which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Hydrogen peroxide gas supply part 5 Spin chuck 6 Two-fluid nozzle 26 Heating tank 27 Heating member 29 Nitrogen gas supply path 30 Hydrogen peroxide solution extraction path 32 Evaporation unit 33 Hydrogen peroxide gas supply path 39 Casing 40 External space 41 1st Fluid discharge port 42 Second fluid discharge port 54 Droplet forming discharge unit 58 First fluid discharge port 64 Internal space 66 Lower end opening 67 Vaporization unit

Claims (15)

A substrate holding step of holding the substrate by the substrate holding means;
A high concentration step of heating the hydrogen peroxide solution in the heating tank to increase its concentration;
A delivery step of delivering the hydrogen peroxide solution whose concentration has been increased in the high concentration step from the heating tank to the mixing supply means;
In the mixing and supplying means, a mixing step of mixing a fluid containing hydrogen peroxide and a fluid containing at least one of sulfuric acid and sulfur trioxide;
And a fluid supply step of supplying the fluid mixed in the mixing step to the substrate held by the substrate holding unit from the mixing supply unit.   The mixing step is a step of mixing a hydrogen peroxide solution sent from the heating tank in the sending step with a fluid containing at least one of sulfuric acid and sulfur trioxide. The substrate processing method as described. Further comprising a superhydrovaporization step of heating and evaporating the hydrogen peroxide solution delivered from the heating tank in the delivery step;
2. The mixing step according to claim 1, wherein the mixing step is a step of mixing a hydrogen peroxide gas generated in the perhydrovaporization step with a fluid containing at least one of sulfuric acid and sulfur trioxide. Substrate processing method. A sulfuric acid vaporization step of vaporizing a fluid containing at least one of sulfuric acid and sulfur trioxide;
The mixing step is a step of mixing a fluid containing hydrogen peroxide with a gas containing at least one of sulfuric acid and sulfur trioxide generated in the sulfuric acid vaporization step. 4. The substrate processing method according to any one of 3 above.   5. The substrate processing according to claim 1, further comprising an oxidant supply step of supplying an oxidant to the substrate held by the substrate holding means prior to the fluid supply step. Method.   6. The substrate processing method according to claim 5, wherein the oxidant supply step and the fluid supply step are repeatedly executed a plurality of times.   7. The substrate processing method according to claim 5, wherein the oxidizing agent includes at least one of water vapor, ozone water, ozone gas, hydrogen peroxide solution, and hydrogen peroxide gas. Substrate holding means for holding the substrate;
Mixing supply means for mixing a fluid containing hydrogen peroxide with a fluid containing at least one of sulfuric acid and sulfur trioxide, and supplying the mixed fluid to the substrate held by the substrate holding means;
High concentration means for heating the hydrogen peroxide solution to increase its concentration,
A substrate processing apparatus, comprising: a sending means for sending the hydrogen peroxide solution whose concentration has been increased by the high concentration means toward the mixing means. Further comprising a perwater vaporization unit for heating and vaporizing the hydrogen peroxide solution delivered by the delivery means;
9. The substrate processing according to claim 8, wherein the mixing and supplying means mixes the hydrogen peroxide gas generated in the perhydrovaporization unit with a fluid containing at least one of sulfuric acid and sulfur trioxide. apparatus. The high concentration means comprises a heating tank for storing hydrogen peroxide solution, and a heating means for heating the hydrogen peroxide solution in the heating tank,
The substrate processing apparatus according to claim 8, wherein the delivery unit delivers the hydrogen peroxide solution in the heating tank. A sulfuric acid vaporization unit for heating and vaporizing a fluid containing at least one of sulfuric acid and sulfur trioxide;
11. The substrate processing apparatus according to claim 8, wherein the mixing and supplying unit mixes a fluid containing hydrogen peroxide and a gas generated by the sulfuric acid vaporization unit.   The substrate processing apparatus according to claim 8, further comprising an oxidant supply unit that supplies an oxidant to the substrate held by the substrate holding unit.   The substrate processing method according to claim 12, wherein the oxidizing agent includes at least one of water vapor, ozone water, ozone gas, hydrogen peroxide solution, and hydrogen peroxide gas.   The mixing and supplying means includes a casing, a super-water discharge port that is formed at one end of the casing and discharges a fluid containing hydrogen peroxide, is formed at the one end of the casing, and is at least one of sulfuric acid and sulfur trioxide. An external mixing type two-fluid nozzle that mixes the fluid discharged from the excess water discharge port and the fluid discharged from the sulfuric acid discharge port outside the casing. 14. The substrate processing apparatus according to claim 8, wherein the substrate processing apparatus is characterized in that:   The mixing supply means is formed facing the mixing tube, the mixing tube, a superwater discharge port for discharging a fluid containing hydrogen peroxide into the mixing tube, and formed facing the mixing tube. A sulfuric acid discharge port for discharging a fluid containing at least one of sulfur oxides into the mixing tube, and for mixing the fluid discharged from the excess water discharge port and the fluid discharged from the sulfuric acid discharge port 14. The substrate processing apparatus according to claim 8, further comprising an internal mixing type two-fluid nozzle that provides a mixing chamber in the mixing tube.

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