JP3954464B2 - Substrate processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, vapor of an organic solvent such as isopropyl alcohol (IPA) is applied to a substrate such as a semiconductor wafer, a glass substrate for a liquid crystal display device, a glass substrate for a plasma display panel (PDP), a glass substrate for a photomask, or an optical disk substrate. The present invention relates to a substrate processing apparatus for supplying and drying a substrate.
[0002]
[Prior art]
In a semiconductor device manufacturing process, after a semiconductor wafer is cleaned using a rinsing liquid, for example, pure water, it is necessary to dry the wafer and remove moisture from the wafer surface. With the recent miniaturization of patterns, it has become difficult to completely remove moisture from the wafer surface. However, if moisture remains on the wafer surface, substances in the air, thin film components, etc. and pure water Reaction may generate pollutants, and for this reason, a drying process after wafer cleaning is becoming more and more important. Conventionally, as a wafer drying apparatus, as shown in FIG. 4, a batch-type drying apparatus is used in which an organic solvent vapor, for example, IPA vapor is supplied to the wafer to dry the wafer.
[0003]
The drying apparatus shown in FIG. 4 includes a processing chamber 1 that can be hermetically sealed. An air supply port 2 is formed in the ceiling portion of the processing chamber 1, and a gas supply pipe 3 is connected to the air supply port 2 in communication. The gas supply pipe 3 is connected to the IPA vapor supply source and the nitrogen gas supply source. An exhaust port 4 is formed at the bottom of the processing chamber 1, and an exhaust pipe 5 is connected to the exhaust port 4. The exhaust pipe 5 is connected to a flow path by a vacuum pump (not shown). After cleaning with pure water, a plurality of wafers W are carried into the processing chamber 1 while being held in parallel in a vertical posture on the wafer holder 7 fixed to the wafer holding arm 6, and the plurality of wafers are transferred. W is accommodated in the processing chamber 1 at a time.
[0004]
When a plurality of wafers W are accommodated in the processing chamber 1, first, the inside of the processing chamber 1 is evacuated and the inside of the processing chamber 1 is decompressed. Next, after the exhaust operation is stopped, as shown in FIG. 4A, IPA vapor is supplied into the processing chamber 1 together with nitrogen gas (carrier gas) to condense the IPA vapor on the surface of the wafer W. Then, the pure water adhering to the surface of the wafer W is replaced with IPA. Subsequently, after the supply operation of the IPA vapor is stopped, the inside of the processing chamber 1 is again evacuated, and the inside of the processing chamber 1 is decompressed. Then, as shown in FIG. The heated nitrogen gas is supplied to evaporate IPA on the surface of the wafer W, thereby drying the wafer W.
[0005]
[Problems to be solved by the invention]
However, the conventional batch-type drying apparatus has the following problems. That is, in the drying apparatus having the structure as shown in FIG. 4, when the diameter of the wafer is increased, it is difficult to uniformly condense the vapor of IPA over the entire surface of all the wafers, and the IPA per wafer. The amount of use increases. In addition, it takes much processing time to uniformly dry all the wafers. Furthermore, the apparatus becomes large, and particle management becomes difficult due to the increase in the size of the apparatus. In addition, it cannot meet the demand for small lot production.
[0006]
The present invention has been made in view of the above circumstances, and it is easy to uniformly condense the vapor of the organic solvent over the entire surface of the substrate even when the substrate has a large diameter, thereby reducing the amount of the organic solvent used. An object of the present invention is to provide a substrate processing apparatus that can reduce the processing time, can reduce the size of the apparatus, can easily manage particles, and can meet demands for small-lot production. And
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a substrate processing apparatus for drying a substrate by supplying a vapor of an organic solvent to the substrate, a processing chamber that can be hermetically sealed and each substrate is accommodated one by one and dried. Vapor supply means for supplying vapor of the organic solvent into the chamber and pressure reducing means for reducing the pressure inside the processing chamber are provided.
[0008]
The invention according to claim 2 is the substrate processing apparatus according to claim 1, wherein the processing chamber includes a heater for heating the substrate.
[0009]
According to a third aspect of the present invention, in the substrate processing apparatus according to the first or second aspect, the vapor supply means supplies vapor of an organic solvent together with a carrier gas.
[0010]
According to a fourth aspect of the present invention, in the substrate processing apparatus according to the third aspect, the vapor supply means is connected to a flow path connected to a carrier gas supply source and a gas supply pipe connected to a carrier gas supply source, and to an organic solvent supply source. The liquid supply pipe, the gas supply pipe and the mixing section in which the liquid supply pipe are connected to each other, the heating means for heating and vaporizing the organic solvent mixed with the carrier gas in the mixing section, and the generated organic And a vapor feed pipe for feeding the solvent vapor together with the carrier gas into the processing chamber.
[0011]
According to a fifth aspect of the present invention, in the substrate processing apparatus of the third or fourth aspect, the carrier gas is nitrogen gas, and the organic solvent is isopropyl alcohol.
[0012]
According to a sixth aspect of the present invention, in the substrate processing apparatus according to any one of the first to fifth aspects, the inside of the processing chamber in which the substrate is accommodated and hermetically sealed is stepwise reduced by the pressure reducing means. It is made to be made to be done.
[0013]
In the substrate processing apparatus according to the first aspect of the present invention, the cleaned substrates are stored one by one in a processing chamber that can be hermetically sealed, and the organic solvent is introduced into the processing chamber in which the substrate is stored by the vapor supply means. Of steam is supplied. The vapor of the organic solvent supplied into the processing chamber is condensed on the surface of the substrate and replaced with pure water or the like attached to the surface of the substrate. Then, the inside of the processing chamber is decompressed by the decompression means, whereby the organic solvent on the surface of the substrate is quickly evaporated and the substrate is dried.
[0014]
In the substrate processing apparatus according to the second aspect, the substrate accommodated in the processing chamber is heated by the heater, and the drying of the substrate is further promoted.
[0015]
In the substrate processing apparatus according to the third aspect of the present invention, the vapor of the organic solvent is supplied together with the carrier gas and supplied into the processing chamber.
[0016]
In the substrate processing apparatus of the invention according to claim 4, the carrier gas fed from the carrier gas supply source through the gas supply pipe and the organic solvent fed from the organic solvent supply source through the liquid supply pipe The organic solvent mixed in the mixing section and mixed with the carrier gas in the mixing section is heated and vaporized by the heating means, and the vapor of the generated organic solvent is fed together with the carrier gas through the vapor feed pipe. To be supplied into the processing chamber.
[0017]
In the substrate processing apparatus according to the fifth aspect of the present invention, vapor of isopropyl alcohol is supplied together with nitrogen gas and supplied into the processing chamber.
[0018]
In the substrate processing apparatus according to the sixth aspect of the present invention, the internal pressure of the processing chamber is reduced stepwise by the pressure reducing means, thereby reducing damage to the substrate accommodated in the hermetically sealed processing chamber.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention will be described below with reference to FIGS.
[0020]
1 and 2 show an example of an embodiment of the present invention, FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a main part of a substrate processing apparatus, and FIG. 2 shows the apparatus shown in FIG. It is a schematic channel system diagram. The apparatus includes a processing chamber 10 that accommodates substrates, for example, semiconductor wafers W one by one. The processing chamber 10 includes a base 12 and a hood 14. The hood unit 14 is supported by a support / movement mechanism (not shown) so as to be movable in the vertical direction. The base 12 is brought into tight contact with the base 12.
[0021]
A heater 16 is disposed at the bottom of the processing chamber 10, and the wafer W is supported on the heater 16. An air supply port 18 is formed in the ceiling portion of the processing chamber 10, and a steam supply pipe 20 is connected to the air supply port 18 in communication. An exhaust port 22 is formed at the bottom of the processing chamber 10, and an exhaust pipe 24 is connected to the exhaust port 22. A pressure gauge 26 for confirming the pressure inside the processing chamber 10 is inserted in the exhaust pipe 24. A diffusion plate 28 is disposed in the processing chamber 10 near the ceiling. The diffusion plate 28 is formed with a large number of through holes dispersed over the entire surface, and the gas introduced into the processing chamber 10 from the vapor supply pipe 20 through the air supply port 18 by the diffusion plate 28. The light is diffused and supplied uniformly to the entire surface of the wafer W.
[0022]
As shown in FIG. 2, the steam supply pipe 20 is connected to a mixing unit 30, and the mixing unit 30 is connected to a gas supply pipe 32 that is connected to a carrier gas, for example, a nitrogen gas supply source. , And an IPA supply pipe 34 connected to a supply source of an organic solvent, for example, IPA, is connected in communication. Opening and closing control valves 36 and 38 are inserted in the gas supply pipe 32 and the IPA supply pipe 34, respectively. In addition, although devices and members such as a mass flow controller and a filter are inserted in the gas supply pipe 32 and the IPA supply pipe 34, illustration thereof is omitted. The mixing unit 30 is provided with a heater (not shown) for heating and vaporizing the IPA supplied through the IPA supply pipe 34. Furthermore, the steam supply pipe 20 is also provided with a heater 40 for preventing the IPA vapor flowing through the pipe from condensing. Each of these heaters is adjusted to a constant temperature by a temperature controller (not shown). And the thermocouples 42 and 44 for monitoring the temperature of a heater are attached to the mixing part 30 and the steam feed pipe 20, respectively.
[0023]
The exhaust pipe 24 is connected to a vacuum pump 46 that depressurizes the inside of the processing chamber 10, and an open / close control valve 48 is interposed in the middle of the pipe. The exhaust pipe 24 is provided with a bypass pipe 50 that branches upstream of the opening / closing control valve 48 and joins downstream of the opening / closing control valve 48, and an opening / closing control valve 52 is interposed in the bypass pipe 50. In addition, a needle valve 54 for adjusting a pressure reduction speed inside the processing chamber 10 by the vacuum pump 46 is inserted in the bypass pipe 50.
[0024]
In addition, a resistance temperature detector 56 for detecting the temperature of the heater 16 is attached to the processing chamber 10. A temperature controller 58 for adjusting the temperature of the heater 16 to a constant temperature is provided.
[0025]
Next, an operation of drying the semiconductor wafer W after being cleaned using a rinse liquid, for example, pure water, using the apparatus having the above-described configuration will be described with reference to FIG. FIG. 3 is a diagram showing a pressure sequence inside the processing chamber 10.
[0026]
When the pure water cleaned wafer W is loaded into the processing chamber 10 and held on the heater 16 and the processing chamber 10 is sealed (time t ₀ ; the internal pressure of the processing chamber 10 at this time is the atmospheric pressure P ₀ ), the vacuum pump 46 is driven, the open / close control valve 52 is opened (at this time, the open / close control valves 36, 38, and 48 are closed), and the inside of the processing chamber 10 is decompressed. In this case, temporarily closes the opening and closing control valve 52 at time t _1, open again at time t _2, closed once again at time t _3, and controlled to open again at time t _4, the internal pressure P ₃ to the target The pressure is reduced stepwise in the order of P ₀ → P ₁ → P ₂ → P ₃ until it reaches. By doing so, damage to the wafer W (device) can be reduced. At this time, by adjusting the orifice of the needle valve 54 in advance, the pressure inside the processing chamber 10 can be reduced at an appropriate pressure reduction rate.
[0027]
When the internal pressure of the processing chamber 10 reaches P ₃ (time t ₅ ), the open / close control valve 52 is closed and the open / close control valves 36 and 38 are opened. Thereafter, supply of IPA vapor and nitrogen gas into the processing chamber 10 is performed. Is started (time t ₆ ). As the IPA vapor and nitrogen gas are supplied, the internal pressure of the processing chamber 10 increases (the degree of decompression decreases), and when the internal pressure reaches P ₁ (time t ₇ ), the open / close control valves 36 and 38 are closed. Then, the supply of IPA vapor and nitrogen gas into the processing chamber 10 is stopped, and this state is maintained. During this time, the IPA vapor supplied into the processing chamber 10 is condensed on the surface of the wafer W, and the pure water adhering to the surface of the wafer W is replaced with IPA.
[0028]
Thereafter, the open / close control valve 48 is opened, and the vacuum pump 46 starts evacuating the processing chamber 10 (time t ₈ ). By this evacuation operation, the IPA on the surface of the wafer W is quickly evaporated and discharged from the processing chamber 10, and the wafer W is dried. Subsequently, the opening / closing control valve 36 is opened, and supply of only nitrogen gas into the processing chamber 10 is started (time t ₉ ). Then, the opening / closing control valve 48 is opened to stop the exhaust from the inside of the processing chamber 10 (time t ₁₀ ), and when the internal pressure of the processing chamber 10 reaches the atmospheric pressure P ₀ (time t ₁₁ ), the opening / closing control valve. 36 is closed and the supply of nitrogen gas into the processing chamber 10 is stopped. If necessary, when supply of nitrogen gas into the processing chamber 10 is started (time t ₉ ), or when supply of nitrogen gas into the processing chamber 10 is stopped (time t ₁₁ ). The heater 16 is energized to heat the wafer W by the heater 16. When the drying process is completed (time t ₁₂ ), the processing chamber 10 is opened and the wafer W is taken out from the processing chamber 10.
[0029]
The means for generating IPA vapor and supplying it to the processing chamber is not limited to that of the above-described embodiment. For example, IPA is stored in a sealed tank, the IPA in the tank is heated by a heater, nitrogen gas is supplied into the tank and nitrogen gas is bubbled in the IPA to generate IPA vapor, An IPA vapor supply system that feeds the generated IPA vapor into the processing chamber together with nitrogen gas may be used.
[0030]
【The invention's effect】
When the substrate processing apparatus according to each of the inventions according to claims 1 to 5 is used, the vapor of the organic solvent can always be uniformly condensed over the entire surface of the substrate even when the substrate has a large diameter. The difference in quality can be eliminated. In addition, the amount of organic solvent used can be reduced, the processing time can be shortened, the apparatus can be miniaturized, and particle management is facilitated. Furthermore, it can meet the demand for small lot production.
[0031]
In the substrate processing apparatus according to the sixth aspect of the present invention, damage to the substrate can be reduced during the substrate drying process.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a main part of a substrate processing apparatus according to an embodiment of the present invention. It is a schematic flow-path system diagram of the apparatus shown in FIG.
FIG. 2 is a schematic flow system diagram of the apparatus shown in FIG.
FIG. 3 is a diagram showing an example of a pressure sequence inside a processing chamber when a semiconductor wafer is dried using the substrate processing apparatus shown in FIG. 1;
FIG. 4 is a schematic view showing an example of the configuration of a conventional substrate drying apparatus.
[Explanation of symbols]
W Semiconductor wafer 10 Processing chamber 16, 40 Heater 18 Processing chamber air supply port 20 Steam supply tube 22 Processing chamber exhaust port 24 Exhaust tube 26 Pressure gauge 28 Diffusion plate 30 Mixing unit 32 Gas supply tube 34 IPA supply tube 36 38, 48, 52 Open / close control valves 42, 44 Thermocouple 46 Vacuum pump 50 Bypass pipe 54 Needle valve 56 Resistance temperature detector 58 Temperature controller

Claims (6)

In a substrate processing apparatus for drying a substrate by supplying vapor of an organic solvent to the substrate,
A processing chamber capable of being hermetically sealed and containing substrates one by one and drying;
Vapor supply means for supplying organic solvent vapor into the processing chamber;
Decompression means for decompressing the inside of the processing chamber;
A substrate processing apparatus comprising: The processing apparatus according to claim 1, wherein the processing chamber includes a heater for heating the substrate. The substrate processing apparatus according to claim 1, wherein the vapor supply unit supplies vapor of an organic solvent together with a carrier gas. The steam supply means;
A gas supply pipe connected to the carrier gas supply channel, and
A liquid supply pipe connected to the organic solvent supply path,
A mixing section in which the gas supply pipe and the liquid supply pipe are respectively connected in communication;
A heating means for heating and vaporizing the organic solvent mixed with the carrier gas in the mixing section;
A vapor feed pipe for feeding the vapor of the generated organic solvent into the processing chamber together with a carrier gas;
The substrate processing apparatus according to claim 3, comprising: 5. The substrate processing apparatus according to claim 3, wherein the carrier gas is nitrogen gas and the organic solvent is isopropyl alcohol. The substrate processing apparatus according to claim 1, wherein the inside of the processing chamber in which the substrate is accommodated and hermetically sealed is decompressed stepwise by the decompression unit.

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