JP4002470B2 - Substrate drying method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate drying method and apparatus for drying a substrate surface without being exposed to oxygen when a substrate immersed in pure water is taken out from the pure water.
[0002]
[Prior art]
Conventionally, in a drying apparatus as disclosed in Japanese Patent Publication No. 6-103686, a substrate that has been cleaned with pure water after being treated with an etching solution using nitrogen gas as a carrier and IPA (isopropyl alcohol) as a vapor. As an example, the wafer is supplied into an upper space in a wafer processing tank. And by draining the pure water of the processing tank from the bottom of the processing tank, the wafer is exposed in the processing tank, and the IPA vapor supplied to the upper space of the processing tank is replaced with water droplets attached to the exposed wafer surface. Thus, the wafer surface is allowed to dry without being oxidized by contact with oxygen.
[0003]
Also, instead of exposing the wafer in the processing tank by draining the pure water of the processing tank from the bottom of the processing tank, the wafer is exposed in the processing tank by lifting the wafer from the processing tank. There is also a drying apparatus in which the IPA vapor supplied to the upper space of the tank is replaced with water droplets adhering to the exposed wafer surface for drying.
[0004]
[Problems to be solved by the invention]
However, in the above structure, the foreign matter generated when cleaning the wafer with pure water floats in the vicinity of the pure water surface of the processing tank, but the pure water in the processing tank is drained from the bottom of the processing tank. In order to expose the wafer in the processing tank, the drainage is performed sequentially from the pure water near the bottom in the processing tank, and the drainage of the pure water near the liquid surface where the foreign matter is floating is performed last. Therefore, there is a problem that the floating foreign matter adheres to the surface of the wafer when the wafer is exposed from the liquid level.
[0005]
Further, in the above structure, since the wafer is exposed by draining pure water from the bottom of the processing tank, the pure water on the liquid surface of the processing tank is not drained to the end, and the IPA on the liquid surface. As the amount of the solubilization increases, the concentration of IPA in the pure water on the liquid surface and the thickness of the layer in which the IPA has melted increase, and the substitution efficiency decreases, so that the drying efficiency decreases. There is a problem that uneven drying occurs on the wafer surface.
[0006]
Further, even when the wafer is exposed by pulling up from the pure water level in the processing tank, there is a problem that foreign matter adheres to the surface of the wafer. In this case, there is a problem that unevenness of drying occurs on the wafer surface due to the fluctuation of the pure water surface.
[0007]
Accordingly, an object of the present invention is to solve the above-mentioned problem, and can reduce the amount of foreign matter adhering to the surface of the substrate when the substrate is exposed from pure water. It is possible to prevent an increase in the concentration of IPA dissolved in pure water on the surface and an increase in the thickness of the pure water layer in which IPA is dissolved, and further, drying efficiency can be improved and drying unevenness can be eliminated. It is to provide a substrate drying method and apparatus.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is configured as follows.
[0009]
According to the first aspect of the present invention, a plurality of substrates that are immersed in the pure water and arranged so that their surfaces are substantially parallel to each other and substantially perpendicular to the surface of the pure water in the drying chamber are disposed on the pure water. In the substrate drying method in which the substrate is exposed from the water and dried.
Supply nitrogen gas and mist or gaseous isopropyl alcohol into the space above the pure water level in the drying chamber,
In the liquid surface of the pure water, the pure water is supplied from the vicinity of one of the side surfaces facing each other in the drying chamber while the pure water is discharged from the vicinity of the other side surface along the liquid surface and the above Forms a unidirectional surface flow along the surface of the substrate, and drains pure water in the drying chamber while draining liquid surface-side pure water from the liquid surface or near the liquid surface with the surface flow. The liquid level is lowered, the substrate is exposed from the pure water in the drying chamber above the liquid level, and the pure water adhering to the exposed surface of the substrate is mist-like. Or substituted with the gaseous isopropyl alcohol,
Then, the substrate drying method is provided, wherein the substrate is dried by evaporating the isopropyl alcohol from the surface of the substrate.
[0010]
According to a second aspect of the present invention, there is provided the substrate drying method according to the first aspect, wherein the pure water is drained from the vicinity of the bottom surface of the drying chamber to lower the liquid level of the pure water. .
[0011]
According to a third aspect of the present invention, there is provided the substrate drying method according to the first aspect or the second aspect, wherein the surface flow is formed at least in a portion where the substrate is exposed on the liquid level.
[0012]
According to the fourth aspect of the present invention, the drainage amount of the pure water from the vicinity of the other side surface is substantially the same as the supply amount of the pure water from the vicinity of the one side surface. A substrate drying method according to any one of the aspects is provided.
[0013]
According to the fifth aspect of the present invention, in any one of the first to fourth aspects, the substrate is fixed in the drying chamber until the substrate is completely exposed from the liquid surface from the pure water. The substrate drying method as described in 1. is provided.
[0014]
According to a sixth aspect of the present invention, there is provided the substrate drying method according to any one of the first to fifth aspects, wherein the substrate is a wafer or a liquid crystal glass substrate.
[0015]
According to the seventh aspect of the present invention, there are provided a plurality of substrates having side surfaces facing each other and arranged in the pure water so that the surfaces thereof are substantially parallel to each other and substantially perpendicular to the liquid surface of the pure water. A drying chamber that can be immersed in the pure water;
A replacement medium supply device for supplying nitrogen gas and mist-like or gaseous isopropyl alcohol into the space above the surface of the pure water in the drying chamber;
In the liquid surface of the pure water, the pure water is drained from the vicinity of the other side surface while supplying pure water from the vicinity of one of the mutually facing side surfaces of the drying chamber, and along the liquid surface. And a liquid surface side pure water drainage device that forms a surface flow in one direction along the surface of the substrate and drains the liquid surface side pure water from the liquid surface of the pure water or near the liquid surface by the surface flow. When,
A drying chamber drainage device for draining the pure water in the drying chamber,
While the surface flow formed by the liquid surface side pure water drainage device drains the liquid surface side pure water from the liquid surface of the pure water or near the liquid surface, the pure water by the drying chamber drainage device is discharged. The level of the pure water is lowered by draining the water, the substrate is exposed from the pure water above the liquid level, and the pure water attached to the exposed surface of the substrate is The mist alcohol or the gaseous isopropyl alcohol supplied by a replacement medium supply device is substituted, and then the substrate is dried by evaporating the isopropyl alcohol from the surface of the substrate. A substrate drying apparatus is provided.
[0016]
According to the eighth aspect of the present invention, the liquid surface side pure water drainage device comprises:
A liquid surface pure water supply mechanism having a liquid surface pure water supply unit provided near the one side surface in the drying chamber and supplying pure water to the liquid surface of the pure water through the liquid surface pure water supply unit When,
Liquid level pure water drainage having a liquid level pure water drainage part provided near the other side surface in the drying chamber and draining the liquid side pure water through the liquid level pure water drainage part. Liquid mechanism;
An elevating mechanism for elevating and lowering the liquid surface pure water supply unit and the liquid surface pure water drainage unit in the drying chamber;
The liquid level pure water supply unit and the liquid level pure water drainage unit are lowered by the lifting mechanism in accordance with the descent of the liquid level in the drying chamber, while the liquid level passes through the liquid level pure water supply unit. The pure water is supplied by the liquid surface pure water supply mechanism, and the liquid surface side pure water is discharged by the liquid surface pure water drain mechanism through the liquid surface pure water drainage section to form the surface flow. A substrate drying apparatus according to an aspect is provided.
[0017]
According to the ninth aspect of the present invention, the liquid surface pure water supply unit and the liquid surface pure water drainage unit are provided in the drying chamber so as to face each other.
The liquid surface pure water supply unit includes a plurality of holes for supplying the pure water formed at the opposing positions,
The liquid surface pure water drainage section provides the substrate drying apparatus according to the eighth aspect, which includes a plurality of holes for draining the liquid surface side pure water formed at the facing positions.
[0018]
According to a tenth aspect of the present invention, in the substrate drying apparatus according to any one of the seventh to ninth aspects, the surface flow is formed at least at a portion of the liquid surface where the substrate is exposed. I will provide a.
[0019]
According to an eleventh aspect of the present invention, the drying chamber draining apparatus is the substrate drying apparatus according to any one of the seventh to tenth aspects, which drains the pure water from the vicinity of the bottom surface of the drying chamber. I will provide a.
[0020]
According to a twelfth aspect of the present invention, in the substrate drying apparatus according to any one of the seventh to eleventh aspects,
A substrate support mechanism for supporting the substrate;
The substrate supporting position by the substrate support mechanism is fixed in the drying chamber until the substrate is completely exposed from the liquid surface by the drainage of the pure water by the drying chamber drainage device. A substrate drying apparatus is provided.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below in detail with reference to the drawings.
[0022]
A substrate drying apparatus according to an embodiment of the present invention is a wafer drying apparatus 501 that dries a wafer as an example of a substrate. FIG. 1 is a longitudinal sectional view of the wafer drying apparatus 501, and FIG. 2 is a cross-sectional view taken along the line BB in FIG. FIG. 4 is a flowchart showing a schematic configuration of the wafer drying apparatus 501. The substrate used in the present invention includes a liquid crystal panel substrate (liquid crystal glass substrate) in addition to the wafer.
[0023]
As shown in FIGS. 1, 2, 3, and 4, the wafer drying apparatus 501 has a substantially rectangular parallelepiped box shape with the entire upper surface open and four side surfaces and a bottom surface, and the inside thereof. And a drying chamber 201 that can be dried after being washed by immersing a plurality of disc-shaped wafers 2 in the stored pure water 40, and a substantially rectangular parallelepiped box shape. And a processing chamber 212 which has a space 4 which can be sealed and has a drying chamber 201 fixed therein.
[0024]
The drying chamber 201 can carry in a known wafer carrier 13 that supports a plurality of wafers 2 with their surfaces arranged substantially parallel to each other in a vertical direction at regular intervals and supported in parallel. The wafer carrier 13 is provided with a carrier fixing portion 9 which is an example of a substrate support mechanism for releasably fixing the wafer carrier 13 in the drying chamber 201. The wafer carrier 13 includes, for example, a plurality of fixing pins, and a fixing pin receiving portion that can be fitted to each of the fixing pins is provided in the carrier fixing portion 9, so that each of the fixing pins and the fixing pin receiving portions is provided. The wafer carrier 13 is fixed to the carrier fixing portion 9 by fitting. The fixing mechanism may be another known fixing mechanism. In a state where the wafer carrier 13 is fixed to the carrier fixing part 9, the fixing mechanism 9 is interposed between the wafer carrier 13 and the carrier fixing part 9. As long as no rattling occurs.
[0025]
Further, the carrier fixing unit 9 is attached to the bottom surface of the drying chamber 201, and all the wafers 2 supported by the wafer carrier 13 are in the pure water 40 in a state where the drying chamber 201 is filled with pure water. It is possible to immerse all at once. Instead of carrying a plurality of wafers 2 into the drying chamber 201 using the wafer carrier 13, the wafer 2 is directly carried into the drying chamber 201 without using the wafer carrier 13, and the bottom surface in the drying chamber 201 is used. The support position may be fixed by supporting the wafer 2 by the substrate support mechanism fixed to the substrate.
[0026]
Further, the processing chamber 212 has a lid 211 that can be opened and closed on the upper surface thereof, and by opening the lid 211, supply and removal of the wafer carrier 13 storing a large number of wafers 2 and maintenance inside the processing chamber 212 are possible. The space 4 inside the processing chamber 212 can be sealed by closing the lid 211. Further, the lid 211 is made to inject nitrogen gas into the space 4 on the liquid surface of the pure water 40 accommodated in the drying chamber 201 in the processing chamber 212, and at the same time, as an example of a substitution medium, liquid phase isopropyl alcohol ( Hereinafter, simply referred to as “IPA”), two mist spraying apparatuses 3 that are examples of a replacement medium supply apparatus that sprays mist-like IPA into the space 4 and injects nitrogen gas into the space 4. The drying nozzle 5 is provided. The detailed description of the structure of the mist spraying device 3 will be described later.
[0027]
Further, a pure water supply unit 210 that is an example of a tubular pure water supply mechanism that supplies pure water to the inside of the drying chamber 201 is provided in an inner lower portion of the drying chamber 201, and the pure water is uniformly introduced into the drying chamber 201. In the drying chamber 201, the pure water supply unit 210 has a large number of pure water supply holes on its tubular outer periphery.
[0028]
Further, the bottom surface of the drying chamber 201 is provided with a gradient toward the center thereof, and a drainage port 19 is provided at the center portion thereof. Pure water contained in the drying chamber 201 from the drainage port 19 is provided. Can be smoothly drained out of the drying chamber 201.
[0029]
In addition, it has an elongated rectangular tube shape in the direction along the liquid surface and a blow nozzle 251 which is an example of a liquid surface pure water supply unit capable of supplying pure water, and also has an elongated rectangular tube shape in the direction along the liquid surface. In addition, a suction nozzle 252 which is an example of a liquid surface pure water drainage section capable of draining pure water is provided on side surfaces facing each other inside the drying chamber 201. Referring to FIG. 1, the blow nozzle 251 is located on the inner side of the left side of the drying chamber 201, the suction nozzle 252 is disposed on the right side of the figure, and the side surfaces and the longitudinal surfaces thereof are substantially parallel to each other. It is provided so that it can move up and down along the side. Further, the blowing nozzles 251 are formed in a line at regular intervals so that a plurality of supply holes 251a, which are examples of holes, are substantially parallel to the liquid surface on the surfaces facing the suction nozzle 252. Further, the suction nozzle 252 has a plurality of drainage liquids, which are examples of holes, on a surface facing the blowing nozzle 251, that is, a surface facing the surface where the plurality of supply holes 251 a are formed in the blowing nozzle 251. The holes 252a are formed in a row and at regular intervals so as to be substantially parallel to the liquid surface. Here, a partially enlarged plan view showing a planar relationship of the wafer 2 in a state supported by the supply hole 251a, the drainage hole 252a, and the wafer carrier 13 is shown in FIG. 5 (A), and FIG. 5B is a cross-sectional view taken along the line C-C in FIG. As shown in FIGS. 5 (A) and 5 (B), the fixed interval of the supply holes 251a in the blow nozzle 251 and the fixed interval of the drain holes 252a in the suction nozzle 252 are, for example, the same interval. The interval is the same as the support interval of the wafer 2 instructed by the wafer carrier 13. Further, each supply hole 251a and each drainage hole 252a are formed to face each other on a one-to-one basis, and a virtual straight line connecting the supply hole 251a and the drainage hole 252a facing each other is a wafer. It is located between adjacent wafers 2 supported by the carrier 13. In the drying chamber 201, each supply hole 251 a of the blow nozzle 251 and each drain hole 252 a of the suction nozzle 252 are formed at the same height.
[0030]
In addition, a supply port 253 a in a discharge nozzle supply mechanism 253 that is an example of a liquid surface pure water supply mechanism that supplies pure water to the discharge nozzle 251 is fixed to the discharge nozzle 251. The blowing nozzle supply mechanism 253 is a flow adjusting air that adjusts the supply amount of pure water to the blowing nozzle 251 that is connected to the supplying port 253a, the flexible hose 253b connected to the supplying port 253a, and the flexible hose 253b. An operation valve 253c is provided, and a pure water supply passage 254 is formed by these.
[0031]
The suction nozzle 252 is fixed with a suction port 255 a in a suction nozzle drainage mechanism 255 that is an example of a liquid surface pure water drainage mechanism that drains pure water from the suction nozzle 252. The suction nozzle drain mechanism 255 includes the suction port 255a, a flexible hose 255b connected to the suction port 255a, and a drain pump 255c connected to the flexible hose 255b. A passage 256 is formed.
[0032]
Thus, pure water can be supplied to the blow nozzle 251 by the blow nozzle supply mechanism 253 and pure water can be drained from the suction nozzle 252 by the suction nozzle drain mechanism 255.
[0033]
Further, the blowout nozzle 251 and the suction nozzle 252 are integrally formed along the respective side surfaces by a nozzle lifting mechanism 214 which is an example of a lifting mechanism while maintaining a state substantially parallel to the liquid level of the pure water 40 inside the drying chamber 201. It can be moved in parallel (that is, can be moved up and down). The nozzle lifting mechanism 214 is provided on the left side of the processing chamber 212 in FIG. 3, and the processing chamber 212 and the nozzle lifting mechanism 214 are fixed on the machine base 215 of the wafer drying apparatus 501. The nozzle elevating mechanism 214 includes a ball screw shaft portion 214a that is vertically fixed to the machine base 215 so as to be rotatable about a rotation shaft, a drive portion 214b that rotates the ball screw shaft portion 214a forward and backward, and a ball screw shaft portion 214a. And a nut portion 214c that can be moved up and down along the ball screw shaft portion 214a by rotating the ball screw shaft portion 214a in the forward and reverse directions, and a nut portion that is fixed to the machine base 215 and in the forward and reverse rotation direction. A guide 214e that fixes 214c and guides the ascending / descending operation, and is formed in a gate shape by a plurality of rigid bodies, one lower end is fixed to the nut portion 214c, and the other lower end penetrates the upper surface of the processing chamber 212; It is comprised by the raising / lowering flame | frame 214d fixed to each upper surface edge part of the blowing nozzle 251 and the suction nozzle 252. FIG. As an example of the drive unit 214b, a motor that is fixed to the lower end of the ball screw shaft 214a and rotates the ball screw shaft 214a directly forward and backward, or a pulley that is fixed to the lower end of the ball screw shaft 214a. There is a motor that indirectly rotates the ball screw shaft 214a indirectly through a belt or the like. In the nozzle lifting / lowering mechanism 214, the ball screw shaft 214a is rotated forward / reversely by the driving unit 214b to lift / lower the lifting / lowering frame 214d, and the blowing nozzle 251 and the suction nozzle 252 are lifted / lowered along the side surfaces of the drying chamber 201. Is possible.
[0034]
Thereby, in the drying chamber 201 in which pure water is supplied and the wafer 2 is fully filled and all the wafers 2 supported by the wafer carrier 13 are immersed, the height position near the liquid level by the blowing nozzle supply mechanism 253. The pure water is supplied to the liquid level through the blowout nozzle 251 located at the liquid level, and the liquid level or liquid level is drawn through the suction nozzle 252 located at a height position near the liquid level by the suction nozzle drainage mechanism 255. The liquid surface side pure water in the vicinity can be drained. Also, the drainage of pure water from the drainage port 19 on the bottom surface is started to lower the liquid level of the pure water 40 in the drying chamber 201, and the blowout nozzle 251 is located at a height position near the liquid level. In addition, the suction nozzle 252 is lowered by the nozzle lifting mechanism 214 in accordance with the lowering of the liquid level, thereby supplying the pure water on the liquid surface and discharging the liquid surface-side pure water. The pure water can be drained.
[0035]
Further, the raising / lowering range of the blowing nozzle 251 and the suction nozzle 252 by the nozzle raising / lowering mechanism 214 is, for example, a height position (elevating / lowering) slightly above the upper end position of all the wafers 2 supported by the wafer carrier 13. The range from the upper end position of the operation) to the height position (lower end position of the raising / lowering operation) located below the lower ends of all the wafers 2 with a slight margin. In the case where pure water is supplied by the blow nozzle 251 and liquid level side pure water is discharged by the suction nozzle 252, and the liquid level of the pure water 40 is lowered, the blow nozzle 251 Each supply hole 251 a and each drainage hole 252 a of the suction nozzle 252 are in the vicinity of the liquid level and are lowered by the nozzle lifting mechanism 214.
[0036]
In this embodiment, the liquid-side pure water in the drying chamber 201 is drained by the blow nozzle 251, the suction nozzle 252, the blow nozzle supply mechanism 253, the suction nozzle drain mechanism 254, and the nozzle lift mechanism 214. The liquid surface side pure water draining apparatus to perform is comprised.
[0037]
Here, the liquid surface side pure water is a liquid in the vicinity of the liquid surface including the liquid surface of the pure water 40, and indicates, for example, a liquid in a liquid layer below about 20 mm from the liquid surface. Moreover, when this liquid is comprised only with pure water, the case where foreign materials, such as IPA or a silicon compound, are further mixed (or melt | dissolved) in pure water is also included.
[0038]
In addition, instead of the case where both the blowing nozzle 251 and the suction nozzle 252 are formed in the above-mentioned rectangular tube shape, for example, both may be formed in a cylindrical shape, or both may be formed in the same shape instead of the same shape. The case where it forms in a different shape may be sufficient.
[0039]
Further, in the drying chamber 201, overflow receiving portions 217 having grooves with a U-shaped cross section having an open portion upward are installed along the outside of the upper portions of the four side surfaces of the drying chamber 201, and the entire upper outer periphery of the drying chamber 201 is disposed. Further, the groove having the U-shaped cross-sectional shape of the overflow receiving portion 217 is integrally formed in a square shape in plan view. Further, the side surface of the overflow receiving portion 217 on the drying chamber 201 side of the groove is formed by the upper outer side surface of the drying chamber 201, and the height of the upper end of the other side surface is higher than the upper end of the drying chamber 201. It is formed to become. Thereby, when the pure water overflows in the drying chamber 201, the overflow pure water can be received by the overflow receiving unit 217. Further, a drainage port 217a is provided on the bottom surface of the overflow receiving part 217, and the overflowed from the drainage port 18 provided at the bottom of the processing chamber 212 to the outside of the processing chamber 212 through a pipe or the like. Pure water can be drained.
[0040]
In addition, a plurality of triangular weirs 201a having a V-shaped cut shape are formed at regular intervals, for example, on the inner edge of the overflow receiving portion 217 in the above-mentioned rectangular shape, that is, at the upper end of the drying chamber 201. When the pure water 40 flows into the overflow receiving part 217 (that is, overflows), the pure water 40 flows smoothly into the overflow receiving part 217 from each triangular weir 201a, so that the inflow can be performed smoothly. ing.
[0041]
In the drying chamber 201, nitrogen gas is injected into the space 4 on the liquid surface of the pure water 40 in the drying chamber 201 in the processing chamber 212 by each mist spraying device 3 installed on the lid 211 of the processing chamber 212. At the same time, it is higher than the temperature of the wafer 2 immersed in the pure water 40 and supported by the wafer carrier 13 (for example, room temperature), preferably at least 5 ° C. higher than the temperature of the wafer 2, more preferably the wafer. The liquid phase IPA is sprayed at a temperature higher than the temperature of 2 from 5 ° C. to 60 ° C. to spray the mist IPA into the space 4, and the pure water 40 in the drying chamber 201 is drained. Thus, when the wafer 2 is exposed above the liquid surface from the pure water 40 in the drying chamber 201, the IPA is transferred from each mist spraying device 3 to the surface of the wafer 2. In the mist state, that is, instead of using nitrogen as a carrier, the IPA itself is continuously sprayed in a state of floating in the nitrogen gas, and the pure water 40 adhering to the surface of the wafer 2 becomes the mist-like state. Replacement with the IPA is performed.
[0042]
Here, the structure of the mist spraying device 3 will be described in detail with reference to FIGS. 6A and 6B. As shown in FIGS. 6A and 6B, each mist spraying device 3 is made of a fluororesin. And a liquid phase IPA passage 3c extending substantially from the nitrogen gas passage 3a toward the wafer 2 (details). Includes a large number of thin nitrogen gas ejection passages 3b each having an opening 3e that is open (toward a position corresponding to the center of the wafer 2 in the space between adjacent wafers 2) and extends from the IPA passage 3c. A large number of narrow IPA ejection passages 3d having injection holes 3f opened toward the injection holes 3e at the opening ends of the nitrogen gas ejection passages 3b are provided. Accordingly, nitrogen gas is injected from the injection hole 3e of the nitrogen gas injection passage 3b, and at the same time, liquid phase IPA is injected from the injection hole 3f of the IPA injection passage 3d to spray the mist-like IPA in the space 4. Can be made. The injection hole 3e of the nitrogen gas injection passage 3b and the injection hole 3f of the IPA injection passage 3d constitute a set of mist spray nozzles, and each set of mist spray nozzles is arranged at a predetermined interval. Further, for example, by arranging the nozzles for mist spraying in the space 4 so as to be opposed to the space between the adjacent wafers 2 out of about 50 wafers 2, the mist spray nozzles are also arranged outside the wafers 2 at both ends in the space 4. The mist of IPA can be sprayed from the nozzle for mist spraying over the entire surface of the wafer 2.
[0043]
As described above, instead of spraying mist-like IPA as an example of the replacement medium in the space 4 by the mist spraying device 3, the gaseous IPA is jetted into the space 4 by a known jetting device. It may be the case. In such a case, when the wafer 2 is exposed above the liquid level from the pure water 40 in the drying chamber 201, IPA is gasified from the known spraying device onto the surface of the wafer 2. By continuing to spray, the pure water 40 adhering to the surface of the wafer 2 can be replaced by the gaseous IPA (or by the liquid phase IPA in which the gaseous IPA is condensed).
[0044]
On the other hand, the nitrogen gas is supplied at normal temperature or the temperature of the wafer 2, or is supplied at a temperature higher than normal temperature (for example, normal temperature or a temperature higher than the temperature of the wafer 2 up to 60 ° C.), preferably at least It is supplied at room temperature or higher than the temperature of the wafer 2 by 5 ° C. or more, more preferably at room temperature or higher temperature in the range from 5 ° C. to 60 ° C. than the temperature of the wafer 2, and as shown in FIG. 1 is supplied to the mist spraying devices 3 arranged on the left and right of the lid 211 of the processing chamber 212 in FIG. 1 via the valve 29, the first air operated valve 30, and the flow meter 31, respectively. It is preferable that the first air operated valve 30 automatically adjusts the flow rate of nitrogen gas based on the flow rate of nitrogen gas detected by the flow meter 31. As a result, the temperature of the mist is normal temperature or higher than the temperature of the wafer 2, preferably at least 5 ° C. higher than the normal temperature or the temperature of the wafer 2, more preferably in the range from 5 ° C. to 60 ° C. higher than the normal temperature or the temperature of the wafer 2. Sprayed at a high temperature. When supplying nitrogen gas to each of the left and right mist spraying devices 3, the nitrogen gas can be supplied into the nitrogen gas passage 3a in one direction from one end side to the other end closing portion of each mist spraying device 3. That's fine. Such a thing has an advantage that the structure becomes simple. However, when a pressure loss occurs in the nitrogen gas passage 3a and nitrogen gas cannot be uniformly injected from the injection holes 3e of all the nitrogen gas injection passages 3b, one end side of each mist spraying device 3 and If nitrogen gas is supplied into the nitrogen gas passage 3a simultaneously from both ends on the other end side, pressure loss can be prevented in the nitrogen gas passage 3a. It can spray uniformly from the injection hole 3e.
[0045]
As shown in FIG. 4, the nitrogen gas is supplied to the drying nozzle 5 disposed in the center of the lid 211 of the processing chamber 212 in FIG. 1 through the pressure reducing valve 20 and the eighth air operated valve 28. After the pure water 40 adhering to the surface of the wafer 2 is replaced by IPA, evaporation and drying of IPA can be promoted by spraying nitrogen gas at the drying nozzle 5.
[0046]
In FIG. 4, the IPA pumps nitrogen gas into the IPA pressurizing tank 41 via the pressure reducing valve 20, the second air operated valve 21, and the filter 22, and the IPA pressurizing tank 41 by the pressure of the nitrogen gas. The IPA liquid 42 in the inside of the lid 211 of the processing chamber 212 in FIG. 1 passes through the third air operated valve 24 and further through the respective filter 25, the flow meter 26, and the fourth air operated valve 27. It is supplied to the mist spraying devices 3 arranged on the left and right respectively. Reference numeral 23 denotes an IPA pressure tank relief valve. Each of the fourth air operated valves 27 is disposed in each of the left and right mist spraying devices 3 and automatically adjusts the flow rate of the IPA liquid based on the flow rate of the IPA liquid detected by the respective flowmeters 26. Thus, when the mist is sprayed from the left and right mist spraying devices 3 into the space 4 on the liquid surface of the pure water 40 in the drying chamber 201, the balance between the left and right mist spraying states is automatically adjusted. When supplying the IPA liquid to each of the left and right mist spraying apparatuses 3, the IPA liquid is supplied in one direction from the one end side of each mist spraying apparatus 3 toward the other end closing portion into the IPA passage 3c. That's fine. Such a thing has an advantage that the structure becomes simple. However, in the case where pressure loss occurs in the IPA passage 3c and the IPA liquid cannot be uniformly sprayed from the injection holes 3f of all the IPA ejection passages 3d to spray the uniform IPA mist, By supplying the IPA liquid into the IPA passage 3c from both the one end side and the other end side of the spraying device 3 at the same time, the pressure loss in the IPA passage 3c can be prevented. Thus, it is possible to spray the IPA liquid uniformly from the injection holes 3f to spray a uniform IPA mist.
[0047]
Further, in order to prevent the pressure in the space 4 in the processing chamber 212 from increasing abnormally, the processing chamber 212 is provided with an exhaust passage 43, a manual valve 7 for adjusting the exhaust flow rate, and start or stop of exhaust. A fifth air operated valve 8 is provided. In addition, a pressure sensor can be arrange | positioned in the space 4, and the 5th air operated valve 8 can also be opened and closed automatically according to the pressure in the space 4 detected by the pressure sensor.
[0048]
Further, a sixth air operated valve 35 is provided at the drain outlet 19 at the bottom of the drying chamber 201 to adjust the drain flow rate. In the present embodiment, the drain port 19 and the sixth air operated valve 35 are an example of a drying chamber drain device. Further, a drainage passage 44 is provided in the drainage port 18 at the bottom of the processing chamber 212, and a pure water drainage passage 256 from the suction nozzle drainage mechanism 255 is connected to the drainage passage 44, so that the drying chamber The liquid is discharged from the suction nozzle 252 in 201 to the outside of the wafer drying apparatus 501 through the pure water drain passage 256. In the processing chamber 212, the drainage passage 44 is connected to the drainage passage 44 from the drainage port 217 a of the overflow receiving portion 217, and the drainage passage 44 is connected to the outside of the wafer drying apparatus 501 from the overflow receiving portion 217. Draining is performed. Although not shown, a water sealing mechanism is provided on the drainage passage 44 in order to maintain the pressure of the space 4 in the processing chamber 212.
[0049]
In addition, a pure water supply passage 45 is connected to the pure water supply unit 210 installed in the drying chamber 201, and the pure water is a manual valve provided on the route of the pure water supply passage 45. 32, the flowmeter 33, and the seventh air operated valve 34 are supplied to the pure water supply unit 210. The seventh air operated valve 34 preferably adjusts the flow rate of pure water automatically based on the flow rate of pure water detected by the flow meter 33.
[0050]
A pure water supply passage 254 is connected to a blow nozzle 251 installed in the drying chamber 201 and a blow nozzle supply mechanism 253 connected to the blow nozzle 251, and the pure water is pure water. The gas is supplied to the blow nozzle 251 through the blow nozzle supply mechanism 253 via the manual valve 258 and the flowmeter 257 provided on the supply passage. Note that the flow rate adjusting air operated valve 253 c in the blowing nozzle supply mechanism 253 automatically adjusts the flow rate of pure water based on the flow rate of pure water detected by the flow meter 257.
[0051]
The first air operated valve 30, the second air operated valve 21, the third air operated valve 24, the fourth air operated valve 27, the fifth air operated valve 8, the sixth air operated valve 35, and the seventh air operated valve 34. The eighth air operated valve 28 and the flow adjusting air operated valve 253c are connected to the control device 47 and automatically supplied to the space 4 in the processing chamber 212 based on a predetermined program or the like. And the flow rate of the IPA liquid, that is, the spraying state of the IPA mist, the exhaust amount from the space 4, the drainage amount of the pure water 40, and the like can be controlled. The control device 47 also controls each operation in the nozzle lifting mechanism 214, the blow nozzle supply mechanism 253, and the suction nozzle drain mechanism 255.
[0052]
A procedure for performing the drying process of the wafer 2 in the wafer drying apparatus 501 having the above configuration will be described below.
[0053]
First, the seventh air operated valve 34 of the pure water supply passage 45 is opened, pure water is supplied into the drying chamber 201 by the pure water supply unit 210, and the drying chamber 201 is filled with pure water. Thereafter, the lid 211 is opened, the wafer carrier 13 on which the plurality of wafers 2 are supported is carried into the processing chamber 212, and the wafer carrier 13 is immersed in the pure water 40 in the drying chamber 201, so that the carrier fixing unit 9 Fix it. At this time, by allowing pure water to overflow from the drying chamber 201 to the overflow receiving portion 217, foreign matter in the drying chamber 201 in which the wafer 2 is immersed is floated near the liquid surface of the pure water 40, and these foreign matter overflows. The purified water is discharged out of the drying chamber 201 for cleaning. Thereafter, the supply of the pure water is stopped. At this time, the blowing nozzle 251 and the suction nozzle 252 are positioned at the upper end position of the lifting operation by the nozzle lifting mechanism 214.
[0054]
Next, in a state in which the exhaust passage 43 is closed, that is, in a state in which the space 4 of the processing chamber 212 is sealed, the IP gas is injected near the nitrogen gas injection opening at the same time as nitrogen gas is injected from each mist spraying device 3. Then, the IPA mist is sprayed into the space 4 at, for example, about 2 cc / min. The direction in which the mist is sprayed is generally directed downward toward the wafer 2 in the pure water 40 (specifically, the direction between the adjacent wafers 2 and the position corresponding to the center of the wafer 2). It is preferable to keep the mist uniformly on the liquid surface of the pure water 40. At this time, when the pressure in the space 4 of the drying chamber 201 becomes abnormally high, it is preferable to open the exhaust passage 43 to reduce the pressure.
[0055]
Next, in a state where the mist is continuously sprayed so that the vicinity of the liquid surface of the pure water 40 in the space 4 is covered with the mist of IPA as described above, the pure water is controlled by the control device 47. The air operation valve 253c for adjusting the flow rate of the supply passage 254 is opened to start supplying pure water to the liquid surface of the pure water 40 or near the liquid surface from the blowout nozzle 251, and the liquid is passed through the suction nozzle 252 by the suction nozzle drain mechanism 255. Begin draining surface-side pure water.
[0056]
Each wafer from the blowing nozzle 251 side to the suction nozzle 252 side on the liquid surface in the pure water 40 of the drying chamber 201 by the supply of pure water from the blowing nozzle 251 and the drainage of the liquid surface side pure water by the suction nozzle 252. A unidirectional surface flow in the direction along the two surfaces can be produced. Further, with this surface flow, the liquid surface side pure water near the liquid surface is positively flowed in the one direction, that is, the direction from the blowing nozzle 251 side to the suction nozzle 252 side, and the suction nozzle 252 is made to flow. The liquid surface side pure water can be drained by the suction nozzle draining mechanism 255.
[0057]
Next, in the state in which the liquid surface-side pure water is actively drained by the surface flow as described above, the sixth air operated valve 35 is opened under the control of the control device 47, and the drying chamber is opened. The drainage of pure water 40 is started from the drainage port 19 on the bottom surface of 201. At this time, the opening degree of the sixth air operated valve 35 is controlled by the control device 47, and the drainage amount of the pure water 40 from the drainage port 19 is controlled.
[0058]
With the start of drainage of the pure water 40 from the drainage port 19 on the bottom surface of the drying chamber 201, the liquid level of the pure water 40 starts to drop. At this time, the control device 47 controls the nozzle raising / lowering mechanism 214 so that the blowing nozzle 251 and the suction nozzle 252 positioned at the upper end position of the raising / lowering operation are, for example, constant according to the lowering speed of the liquid level. It slowly descends at the speed of. As an example of the lowering speed of the liquid level, that is, the lowering speed of the blow nozzle 251 and the suction nozzle 252, a lowering speed of about 10 mm or less per second, preferably mist is sprayed at about 2 cc / min, for example. In this case, the lowering speed is about 2 mm per second. In addition, since the blower nozzle 251 and the suction nozzle 252 are lowered by the nozzle elevating mechanism 214 in accordance with the lowering of the liquid level, the liquid surface side pure water has a surface flow in one direction on the liquid surface of the pure water 40. While the liquid is actively drained, the liquid level is lowered.
[0059]
The supply amount of pure water from the blow nozzle 251 by the blow nozzle supply mechanism 253 is controlled by the control device 47 according to the drain amount of the liquid surface side pure water by the suction nozzle drain mechanism 255 through the suction nozzle 252. It is controlled by a flow rate adjusting air operated valve 253 c using a flow meter 257. For example, the amount of pure water supplied from the blowing nozzle 251 is set in the control device 47 so as to be substantially the same as the amount of liquid-side pure water discharged from the suction nozzle 252. That is, new pure water is always supplied from the blowing nozzle 251 at the liquid level of the pure water 40 in the drying chamber 201 or in the vicinity of the liquid level, and the supplied new pure water is sucked in by the surface flow. It is moved to the vicinity (flowed), and the new pure water is discharged as the liquid surface side pure water by the suction nozzle 252. In addition, IPA in the vicinity of the liquid surface in the space 4 is dissolved in the liquid surface side pure water, and foreign matter or the like may be floating. Pure water in which IPA is dissolved and floating foreign matter may be present. And the like can be discharged through the suction nozzle 252 together with the liquid surface side pure water with the above surface flow.
[0060]
By lowering the liquid level of the pure water 40 in such a state, the upper part of the wafer 2 is exposed upward from the liquid level of the pure water 40, but the surface of the wafer 2 is exposed to oxygen and is naturally exposed. The IPA mist that is continuously sprayed uniformly on the liquid surface of the pure water 40 without being oxidized is immediately replaced with the pure water adhering to the surface of the wafer 2. Further, the temperature of the mist of IPA is higher than the temperature of the wafer 2, that is, normal temperature (for example, higher in the range of the temperature of the wafer 2, that is, normal temperature to 60 ° C.), preferably higher by at least 5 ° C., more preferably 5 When the temperature is raised in the range of from 60 ° C. to 60 ° C., it dries quickly.
[0061]
Further, when a part of each wafer 2 is exposed above the liquid level of the pure water 40, the liquid surface side pure water between the adjacent wafers 2 is caused to flow along the surface of the wafer 2. The liquid can be drained, and the drainage of the pure water in which IPA is dissolved in the liquid surface between the wafers 2 or in the vicinity of the liquid surface and the floating foreign matters can be improved.
[0062]
Thereafter, when the liquid level in a state where the surface flow is further formed is lowered and the lower ends of all the wafers 2 supported by the wafer carrier 13 are positioned above the liquid level with a slight margin, The blowing nozzle 251 and the suction nozzle 252 that are lowered together with the liquid level are also positioned at the lower end position of the raising / lowering operation, the lowering operation by the nozzle raising / lowering mechanism 214 is stopped, and pure water by the blowing nozzle supply mechanism 253 is stopped. Supply operation and the liquid surface side pure water draining operation by the suction nozzle draining mechanism 255 are stopped. Thus, each wafer 2 is completely exposed from the pure water 40, and the replacement of the pure water attached to the surface of each wafer 2 with IPA is completed. Thereafter, spraying of mist from the mist spraying device 3 is stopped, and injection of nitrogen gas from the drying nozzle 5 is started. Thereby, the evaporation of the IPA from the surface of each wafer 2 is promoted, and the surface of each wafer 2 is dried. After completion of the drying, the injection of nitrogen gas from the drying nozzle 5 is stopped, and the drying process of the wafer 2 is completed. Instead of performing the nitrogen gas injection from the drying nozzle 5, the IPA may be naturally evaporated from the surface of each wafer 2 by leaving each wafer 2 as it is.
[0063]
Thereafter, the lid 211 of the processing chamber 212 is opened, the fixation of the wafer carrier 13 by the carrier fixing unit 9 is released, and each wafer 2 is carried out upward from the processing chamber 212 for each wafer carrier 13.
[0064]
When the wafer 2 is at room temperature, IPA or nitrogen gas, or IPA and nitrogen gas is set to a high temperature in the range of 5 ° C. to 60 ° C. from the room temperature, and an IPA mist higher than room temperature is applied to the wafer 2. It is possible to dry more quickly by spraying. For example, 50 wafers can be dried in 10 minutes or less.
[0065]
Moreover, it may replace with the case where the wafer carrier 13 is the said well-known thing, and may use the wafer holder 213 as shown in FIG. 7A and 7B are partially enlarged side views of the wafer holder 213. FIG.
[0066]
As shown in FIG. 7, the wafer holder 213 has a wafer support portion 213a that can support the wafer 2 at two positions symmetrical to each other along the surface of the lower portion of the disk-shaped wafer 2 at a constant interval. A plurality of formed frames 213b are provided. Further, as shown in FIG. 7B, each wafer support portion 213a is formed in a skewer shape on the frame 213b, and each wafer support adjacent to each other along the arrangement direction of each wafer 2 is supported. A space is secured between the portions 213a at a constant interval. As a result, a space can be secured between the adjacent wafers 2 from the upper end to the lower end of the wafer 2 in the direction along the surface of the wafer 2 and along the liquid surface of the pure water 40.
[0067]
By using such a wafer holder 213, when the wafer 2 immersed in the pure water 40 is exposed above the liquid surface, the above-mentioned generated on the liquid surface and in the direction along the surface of the wafer 2. Due to the surface flow, it is possible to further improve the discharge performance of pure water in which IPA is dissolved in the liquid surface between the wafers 2 or in the vicinity of the liquid surface, and floating foreign matters.
[0068]
In the above description, the case where the formation interval of the supply holes 251a in the blow nozzle 251 and the formation interval of the drain holes 252a in the suction nozzle 252 are the same has been described. The arrangement (including the formation interval) of each drainage hole 252a is not limited to such a case, but the support interval of each wafer 2 supported by the wafer carrier 13, the size of the drying chamber 201, The descending speed of the liquid surface of the pure water 40, the hole diameter of the supply hole 251a, the blowing speed of pure water, the hole diameter of the drain hole 252a, the suction speed of the pure water on the liquid surface side, the shapes of the supply hole 251a and the drain hole 252a, etc. Based on the above, it is possible to select an arrangement in which a more uniform surface flow can be formed in the portion of the liquid surface where the wafer 2 is exposed.
[0069]
Further, the one-way surface flow formed on the liquid surface by the supply of pure water from the blowing nozzle 251 and the drainage of the liquid surface side pure water by the suction nozzle 252 causes the wafer 2 to be exposed upward from the liquid surface. In this case, the surface flow is formed at least in the portion where the wafer 2 is exposed at the liquid level because the purpose is to improve the drainage of the liquid surface side pure water between the wafers 2 at the liquid level. If it does, the said objective can be achieved.
[0070]
Further, the case where the supply amount of pure water by the blow nozzle 251 and the discharge amount of the liquid surface side pure water by the suction nozzle 252 are substantially the same has been described, but instead of such a case, the supply amount of the pure water is described above. The amount of drainage of the liquid surface side pure water may be larger than that. In such a case, liquid surface side pure water can be drained in the same manner by the suction nozzle 252, so that the surface flow can be formed in the same manner, and further from the vicinity of the liquid surface. In addition, the lower pure water can be pushed up to the vicinity of the liquid level and drained by the suction nozzle 252 as the liquid surface side pure water, and foreign matters floating in the lower pure water can be removed together with the lower pure water. Can be discharged.
[0071]
In the wafer drying apparatus 501, the blow nozzle 251 and the suction nozzle 252 provided on the inner sides facing each other in the drying chamber 201 have been described as being lowered along the side face. The lowering operation of the suction nozzle 252 is not limited to such an operation. As a modification of the above embodiment, FIG. 8 shows a longitudinal sectional view of a wafer drying apparatus 502 that performs an operation different from the above operation on the blowout nozzle 251 and the suction nozzle 252.
[0072]
As shown in FIG. 8, the wafer drying apparatus 502 is provided with a blowing nozzle 251 and a suction nozzle 252 in the vicinity of the insides of the opposite sides of the drying chamber 201. Further, the wafer drying apparatus 502 includes a nozzle lifting / lowering device 214 that lifts and lowers the blowing nozzle 251 and the suction nozzle 252. Further, during the lowering operation of the blowing nozzle 251 and the suction nozzle 252 by the nozzle lifting / lowering device 214, There is provided a nozzle interval variable mechanism (not shown) that translates the interval 251 and the suction nozzle 252 so that the interval between them is variable while keeping the state where the nozzle 252 and the suction nozzle 252 face each other. The nozzle interval variable mechanism has a middle position between the blow nozzle 251 and the suction nozzle 252 as a reference position, and each of the blow nozzle 251 and the suction nozzle 252 approaches or moves away from the reference position (that is, the horizontal direction in FIG. 8). It is possible to vary the interval by moving to. The nozzle interval variable mechanism includes, for example, a ball screw shaft that is rotated by a motor or the like and a nut that is screwed to the ball screw shaft and is moved along the ball screw shaft by rotating the ball screw shaft. A mechanism such as a ball screw shaft mechanism provided with a portion or a cylinder mechanism that moves the piston in the cylinder using compressed air or hydraulic pressure can be used.
[0073]
When the wafer 2 immersed in the pure water 40 is exposed above the liquid level in the wafer drying apparatus 502 as described above, the pure water 40 is first filled in the drying chamber 201 as shown in FIG. In this state, the blowout nozzle 251 and the suction nozzle 252 are immersed in the pure water 40 so as to move away from the mutually facing side surfaces of the drying chamber 201 and approach the reference position which is the intermediate position. The wafer 2 is positioned so as not to contact the wafer 2. That is, the blowing nozzle 251 and the suction nozzle 252 are positioned so that the distance between them is small so as not to contact the wafer 2. In such a state, liquid surface side pure water is drained by the suction nozzle 252 while pure water is supplied from the blow nozzle 251, and the surface flow is formed on the liquid surface.
[0074]
Thereafter, when the drainage of the pure water 40 from the bottom surface of the drying chamber 201 is started and the liquid level starts to descend, the nozzle raising / lowering mechanism 214 adjusts the blowout nozzle 251 and the suction nozzle 252 so that the liquid level is lowered. The descent operation is started. At the same time, the nozzle interval variable mechanism moves the blowing nozzle 251 and the suction nozzle 252 away from the reference position, that is, the interval increases. At this time, the surface flow is still formed.
[0075]
When the liquid level is further lowered and a part of the wafer 2 is exposed above the liquid level and the liquid level is positioned below the wafer 2, the nozzle 251 is blown to the reference position by the nozzle interval variable mechanism. In addition, the surface flow is formed while the suction nozzles 252 are moved so as to approach each other, that is, while the interval is reduced.
[0076]
That is, the blow nozzle 251 and the suction nozzle 252 are lowered by the nozzle lifting / lowering mechanism 214 as the liquid level is lowered, while the blow nozzle 251 and the suction nozzle 252 are immersed in the wafer 2 by the nozzle interval variable mechanism. The surface flow is formed by moving in an arc shape along the circumference and changing the interval.
[0077]
Accordingly, the wafer drying apparatus 502 is provided with the nozzle interval variable mechanism, so that the blow-out nozzle 251 and the suction nozzle 252 move downward along the circumference of the wafer 2 in accordance with the drop in the liquid level. , The surface flow can be formed, and the surface flow having a more reliable and stronger directivity can be formed in the portion where the wafer 2 is exposed on the liquid surface. Accordingly, when a part of the wafer 2 is exposed above the liquid level, the IPA dissolved in the liquid surface between adjacent wafers 2 or pure water near the liquid level, floating foreign matters, etc. are removed on the liquid level side. Together with pure water, it can be discharged with a surface flow having the above-mentioned reliable and strong directivity.
[0078]
According to the above-described embodiment, the wafer 2 immersed in the pure water 40 is exposed above the liquid surface of the pure water 40 by lowering the liquid level by draining the pure water 40 from the bottom surface of the drying chamber 201. However, when this exposure is performed, the liquid surface side pure water is discharged by the suction nozzle 252 while supplying pure water to the liquid surface by the blow nozzle 251 provided to face each other on the liquid surface of the pure water 40. By forming a surface flow in one direction on the liquid surface, foreign matter floating in the pure water near the liquid surface or near the liquid surface is discharged out of the drying chamber 201 together with the liquid surface-side pure water. Can do. Thereby, when the wafer 2 is exposed from the liquid surface, the foreign matter can be prevented from adhering to the surface of the wafer 2.
[0079]
Further, since the wafer 2 immersed in the pure water 40 of the drying chamber 201 is exposed upward from the liquid surface while discharging the liquid surface side pure water with the surface flow on the liquid surface, Even when the mist of IPA sprayed in the space 4 above the liquid surface is dissolved in the liquid surface of the pure water 40 or in the vicinity of the liquid surface, the IPA is dissolved as the liquid surface-side pure water. Pure water can be drained by the above surface flow. As a result, an increase in the amount of IPA dissolved in the liquid surface or in the vicinity of the liquid surface can be prevented, and the efficiency of wafer drying can be improved by improving the replacement efficiency of pure water and IPA on the surface of the wafer 2. Improvement can be achieved and the occurrence of uneven drying on the wafer surface can be prevented.
[0080]
Further, the one-way surface flow formed by the blowing nozzle 251 and the suction nozzle 252 provided so as to face each other in the drying chamber 201 is immersed in the pure water 40 while being supported by the wafer carrier 13. When the liquid surface of the pure water 40 is lowered due to the flow along the surface of the wafer 2 and along the liquid surface, the surface of the wafer 2 is positioned above the liquid surface. The liquid surface side pure water can be discharged well between the wafers 2 adjacent to each other by the flow, and the replacement efficiency between the pure water and the IPA on the wafer 2 surface is further improved to improve the drying efficiency of the wafer. And the occurrence of uneven drying on the wafer surface can be prevented, and the discharge of the foreign matter and the like on the liquid surface can be further improved. The adhesion to the surface of the wafer 2 and the like can be prevented.
[0081]
Each supply hole 251a in the blow nozzle 251 and each drain hole 252a in the suction nozzle 252 are formed so as to face each other, and further, a virtual connecting the supply hole 251a and the drain hole 252a facing each other is formed. In the case where the straight line is located between the wafers 2 adjacent to each other in each wafer 2 supported by the wafer carrier 13, it is pure from the supply hole 251 a toward the liquid surface between the wafers 2. The liquid surface side pure water can be discharged from the liquid surface between the wafers 2 through the liquid discharge holes 252a while blowing water, and the direction along the liquid surface and along the surface of the wafer 2 with stronger directivity. The surface flow of the liquid surface side pure water between the wafers 2 can be further improved.
[0082]
Further, the wafer drying apparatus 501 is provided with a nozzle raising / lowering mechanism 214 that lowers the blowing nozzle 251 and the suction nozzle 252 in accordance with the liquid level lowered by the drainage of the pure water 40 from the bottom surface of the drying chamber 201. As a result, the liquid level of the pure water 40 can be lowered while the surface flow is formed on the liquid level by the blowing nozzle 251 and the suction nozzle 252. Accordingly, the surface flow is continuously formed on the liquid surface of the pure water 40 to discharge the liquid surface-side pure water, that is, IPA dissolved in the liquid surface or in the vicinity of the liquid surface and floating foreign matter. Etc. can be exposed upward from the liquid surface of the wafer 2 while being continuously discharged together with the liquid surface side pure water.
[0083]
Further, since the wafer 2 is supported by the wafer carrier 13 and the exposure operation is performed above the liquid surface in a state where the support position is fixed to the drying chamber 201, the wafer 2 is removed from the pure water 40. Compared with a case where the wafer 2 is exposed above the liquid level by pulling up, the occurrence of shaking of the wafer 2 during the exposure operation can be eliminated. Occurrence can be prevented.
[0084]
In addition, since nitrogen gas is always held in the space 4 on the surface of the pure water in which the wafer 2 is immersed, the upper portion of the wafer 2 is exposed from the pure water 40. The IPA mist uniformly supplied to the liquid surface of the pure water 40 is immediately replaced with the pure water adhering to both the front and back surfaces of the wafer 2 without being naturally oxidized by contact with oxygen. Further, if the temperature of the IPA is higher than the temperature of the wafer 2, that is, room temperature, preferably higher by at least 5 ° C., more preferably in the range of 5 ° C. to 60 ° C., the IPA is condensed on both the front and back surfaces of the wafer 2. It becomes easy to attach and easily replaces the pure water adhering to both the front and back surfaces of the wafer 2 and the surface of the wafer 2 dries quickly. Therefore, after replacing the pure water on the surface of the normal temperature wafer with the normal temperature IPA, the drying time is faster than the conventional case of drying the normal temperature IPA, and the drying efficiency can be increased. Moreover, since it sprays on the liquid level of the pure water 40 in a mist state, the consumption of IPA can be reduced significantly compared with the conventional case where IPA is supplied by steam. In addition, when IPA is supplied by steam, it is necessary to cover the outside of the pipe with a heat insulating material in order to maintain the steam state. In this embodiment, for example, room temperature liquid phase IPA is simply sprayed on the left and right mist sprays. Since it suffices to supply to each of the apparatuses 3, it is not necessary to cover the piping with a heat insulating material, and the apparatus becomes simple. Further, when the IPA is vaporized, energy for heating is required. However, in the present embodiment, it is sufficient if there is sufficient energy to inject nitrogen gas and IPA from the mist spraying device 3, and it is inexpensive. An IPA mist can be formed with a simple apparatus configuration. In this way, it is possible to inject nitrogen gas from the sides facing each other, and at the same time, to inject liquid phase IPA, filling the space of the drying chamber with the IPA mist on both the front and back surfaces of the wafer. The IPA mist can be sprayed, and the IPA mist can be supplied to the entire front and back surfaces of the wafer.
[0085]
In addition, the liquid phase IPA is not misted by the electrical energy such as ultrasonic waves, but the IPA is injected from the IPA injection nozzle in the vicinity of the nitrogen gas injection hole without using the electrical energy. Since the liquid phase IPA can be misted, the IPA mist spraying operation can be performed more safely and more stably with respect to the highly flammable IPA.
[0086]
It is to be noted that, by appropriately combining arbitrary embodiments of the various embodiments described above, the effects possessed by them can be produced.
[0087]
【The invention's effect】
According to the first aspect or the second aspect of the present invention, the substrate immersed in the pure water by lowering the liquid level by draining pure water from the bottom surface of the drying chamber is used for the pure water. When exposing above the liquid level, the pure water is supplied from the vicinity of one of the side surfaces facing each other in the drying chamber, and the pure water is discharged from the vicinity of the other side surface along the liquid level. In addition, a unidirectional surface flow along the surface of the substrate is formed, and with the surface flow, foreign matters floating in the pure water on the liquid surface or in the vicinity of the liquid surface together with the liquid surface side pure water It can be discharged out of the drying chamber. Accordingly, it is possible to provide a substrate drying method that can prevent the foreign matter from adhering to the surface of the substrate when the substrate is exposed from the liquid surface.
[0088]
Further, because the substrate immersed in the pure water in the drying chamber is exposed upward from the liquid surface while draining the liquid surface-side pure water with the surface flow on the liquid surface, Even if the gaseous or mist-like isopropyl alcohol supplied in the space above the liquid level dissolves in the liquid surface of the pure water or in the vicinity of the liquid surface, the liquid surface-side pure water is Pure water in which isopropyl alcohol is dissolved can be discharged with the above surface flow. As a result, an increase in the amount of isopropyl alcohol dissolved in the pure water near the liquid level or the liquid level can be prevented, and the substitution efficiency between the pure water and the gaseous or mist-like isopropyl alcohol can be improved. Thus, it is possible to provide a substrate drying method capable of improving the drying efficiency of the substrate and preventing the occurrence of uneven drying on the substrate surface.
[0089]
According to the third aspect of the present invention, the surface flow formed on the liquid surface of the pure water is formed at least in a portion where the substrate is exposed on the liquid surface, so that the liquid surface is above the liquid surface. When the substrate is exposed to the liquid surface, the liquid surface side pure water can be drained with the surface flow at the liquid surface in the exposed portion of the substrate, and the liquid surface or the vicinity of the liquid surface can be discharged. Substrate drying method capable of discharging the isopropyl alcohol dissolved in the pure water and floating foreign matters together with the liquid surface side pure water, and obtaining the effect of the first aspect or the second aspect Can be provided.
[0090]
According to the fourth aspect of the present invention, the drainage amount of the pure water from the vicinity of the other side surface in the drying chamber is substantially the same as the supply amount of the pure water from the vicinity of the one side surface. Therefore, in the liquid surface of the pure water or in the vicinity of the liquid surface, the supplied pure water is drained while always supplying new pure water, so that the liquid surface or the vicinity of the liquid surface is discharged. The surface flow can be reliably formed only by the above-described method, and the liquid surface side pure water can be drained more quickly and smoothly with the surface flow, and the effects of the respective aspects can be obtained. It becomes possible to provide a substrate drying method.
[0091]
According to the fifth aspect of the present invention, in addition to the effects of the respective aspects, by fixing the substrate in the drying chamber until the substrate is completely exposed from the pure water, for example, Compared with the case where the substrate is lifted from the pure water and exposed upward from the liquid surface, the substrate can be prevented from shaking during the exposure operation, and the substrate caused by the shaking can be eliminated. It is possible to provide a substrate drying method capable of preventing the occurrence of uneven isopropyl alcohol substitution on the surface of the substrate, that is, the occurrence of dry unevenness.
[0092]
According to the sixth aspect of the present invention, when the substrate is a wafer or a liquid crystal glass substrate that requires cleanliness or the like on its surface, the effects of the first to fifth aspects can be obtained. It is possible to provide a substrate drying method that can be used.
[0093]
According to the seventh aspect of the present invention, the substrate immersed in the pure water is lowered by the drying chamber draining device by lowering the liquid level by draining pure water from the bottom surface of the drying chamber. When the liquid surface is exposed above the liquid level, the liquid surface side pure water drainage device supplies pure water from one of the side surfaces facing each other in the drying chamber while supplying the pure water near the other side surface. More pure water is drained to form a unidirectional surface flow along the liquid surface and along the surface of the substrate, and the surface flow causes the liquid surface to float in the pure water at or near the liquid surface. It is possible to discharge the foreign matter and the like outside the drying chamber together with the liquid surface side pure water. This makes it possible to provide a substrate drying apparatus that can prevent the foreign matter from adhering to the surface of the substrate when the substrate is exposed from the liquid surface.
[0094]
Further, the exposure of the substrate immersed in the pure water in the drying chamber upward from the liquid level is caused by the surface flow of the liquid level formed by the liquid surface side pure water drainage device. In order to perform while draining the liquid surface side pure water, the gaseous or mist-like isopropyl alcohol supplied into the space above the liquid surface by the replacement medium supply device is the liquid surface of the pure water or the vicinity of the liquid surface. Even if it is dissolved in the liquid, the drainage of pure water in which the isopropyl alcohol is dissolved as the liquid surface-side pure water can be carried out by the surface flow. As a result, an increase in the amount of isopropyl alcohol dissolved in the pure water near the liquid level or the liquid level can be prevented, and the substitution efficiency between the pure water and the gaseous or mist-like isopropyl alcohol can be improved. By doing so, it is possible to provide a substrate drying apparatus capable of improving the drying efficiency of the substrate and preventing the occurrence of uneven drying on the surface of the substrate.
[0095]
According to the eighth aspect of the present invention, the liquid surface side pure water drainage apparatus has a liquid surface pure water supply section provided near the one side surface in the drying chamber, and the liquid surface pure water. A liquid level pure water supply mechanism for supplying pure water to the level of the pure water through the supply unit; and a liquid level pure water drainage part provided near the other side surface in the drying chamber. A liquid surface pure water drainage mechanism for draining the liquid surface side pure water through the pure water drainage section, and a lift for raising and lowering the liquid surface pure water supply section and the liquid surface pure water drainage section in the drying chamber. The liquid level pure water supply unit and the liquid level pure water drainage unit are lowered by the elevating mechanism as the liquid level is lowered in the drying chamber. Pure water is supplied by the liquid level pure water supply mechanism through the water supply unit and through the liquid level pure water drainage unit. Substrate drying apparatus capable of forming the surface flow on the liquid surface by draining the liquid surface-side pure water by the liquid surface pure water draining mechanism and obtaining the effect of the seventh aspect. Can be provided.
[0096]
According to the ninth aspect of the present invention, the liquid surface pure water supply section and the liquid surface pure water drainage section are provided in the drying chamber so as to face each other, and the liquid surface pure water supply section faces each other. The pure water is supplied from a plurality of holes formed at the position, and the liquid surface side pure water is drained through the plurality of holes formed at the opposed positions in the liquid surface pure water drainage part. By doing so, it is possible to provide a substrate drying apparatus in which the surface flow can be uniformly formed on the liquid surface and the effects of the eighth aspect can be obtained.
[0097]
According to the tenth aspect of the present invention, the surface flow formed on the liquid surface of the pure water is formed at least at a portion where the substrate is exposed on the liquid surface, so that the liquid surface is above the liquid surface. When the substrate is exposed to the liquid surface, the liquid surface side pure water can be drained with the surface flow at the liquid surface in the exposed portion of the substrate, and the liquid surface or the vicinity of the liquid surface can be discharged. It is possible to provide a substrate drying apparatus that can discharge the isopropyl alcohol dissolved in the pure water and floating foreign matters together with the liquid surface-side pure water and obtain the effects of the above aspects. It becomes possible.
[0098]
According to the eleventh aspect of the present invention, the drying chamber draining device that drains the pure water in the drying chamber drains the pure water from the vicinity of the bottom surface of the drying chamber, whereby the liquid It is possible to provide a substrate drying apparatus capable of lowering the liquid level without affecting the formation of the surface flow on the surface, and obtaining the effects of the above aspects.
[0099]
According to the twelfth aspect of the present invention, in addition to the effects of the respective aspects, the substrate is fixed in the drying chamber by the substrate support mechanism until the substrate is completely exposed from the pure water. Thus, for example, compared to the case where the substrate is pulled up from the pure water and exposed above the liquid surface, the occurrence of shaking of the substrate during the exposure operation can be eliminated. It is possible to provide a substrate drying apparatus capable of preventing occurrence of unevenness of substitution of the isopropyl alcohol on the surface of the substrate due to shaking, that is, generation of unevenness in drying.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a wafer drying apparatus according to an embodiment of the present invention.
2 is a cross-sectional view taken along the line AA of the wafer drying apparatus of FIG.
3 is a cross-sectional view taken along the line BB of the wafer drying apparatus of FIG.
FIG. 4 is a flowchart showing a schematic configuration of the wafer drying apparatus of the embodiment.
5A is a partially enlarged plan view of the blowout nozzle and the suction nozzle of the wafer drying apparatus of FIG. 2, and FIG. 5B is a cross-sectional view taken along the line CC in FIG. 5A.
6A is a plan view and FIG. 6B is a cross-sectional view in the mist spraying apparatus of the wafer drying apparatus of the embodiment.
7A is a partially enlarged view of the wafer holder in the wafer drying apparatus of the embodiment, and FIG. 7B is a side view of FIG. 7A.
FIG. 8 is a longitudinal sectional view of a wafer drying apparatus according to a modification of the embodiment.
[Explanation of symbols]
2 ... Wafer, 3 ... Mist spraying device, 3a ... Nitrogen gas passage, 3b ... Nitrogen gas ejection passage, 3c ... IPA passage, 3d ... IPA ejection passage, 3e, 3f ... Injection hole, 4 ... Space, 5 DESCRIPTION OF SYMBOLS ... Drying nozzle, 7 ... Manual valve, 8 ... Fifth air operated valve, 9 ... Carrier fixing part, 13 ... Wafer carrier, 18 ... Drain port, 19 ... Drain port, 20 ... Pressure reducing valve, 21 ... Second air Operate valve 22 ... filter 23 ... IPA pressure relief valve 24 ... third air operated valve 25 ... filter 26 ... flow meter 27 ... fourth air operated valve 28 ... eight air operated valve 29 ... Pressure reducing valve, 30 ... First air operated valve, 31 ... Flow meter, 32 ... Manual valve, 33 ... Flow meter, 34 ... Seventh air operated valve, 35 ... Sixth air operated 40 ... pure water, 41 ... IPA pumping tank, 42 ... IPA, 43 ... exhaust passage, 44 ... drain passage, 45 ... drain passage, 46 ... drain passage, 47 ... control device, 201 ... drying chamber, 201a ... Triangular weir 210 ... Pure water supply unit 211 ... Lid 212 ... Processing chamber 213 ... Wafer holder 213a ... Wafer support unit 213b ... Frame 214 ... Nozzle lifting mechanism 214a ... Ball screw shaft 214b ... Drive unit, 214c ... Nut part, 214d ... Elevating frame, 214e ... Guide, 215 ... Machine base, 217 ... Overflow receiving part, 217a ... Drain outlet, 251 ... Blowout nozzle, 251a ... Supply hole, 252 ... Suction nozzle 252a ... Drain hole, 253 ... Blowout nozzle supply mechanism, 253a ... Supply port, 253b ... Flexible hose, 253c ... Air flow adjustment air flow Rate valve, 254 ... pure water supply flow path, 255 ... suction nozzle drain mechanism, 255a ... suction port, 255b ... flexible hose, 255c ... pump, 256 ... pure water drain passage, 257 ... flow meter, 258 ... manual valve , 501 and 502... Wafer drying apparatus.

Claims (10)

Substrate drying that exposes and dries a plurality of substrates immersed in the pure water so that their surfaces are substantially parallel to each other and substantially perpendicular to the level of pure water in the drying chamber In the method
Supply nitrogen gas and mist or gaseous isopropyl alcohol into the space above the pure water level in the drying chamber,
In the liquid level of the pure water, provided on one of the other of the side surfaces near while supplying the liquid level deionized water supplying pure water from a nozzle provided on the side surface near one of the side surfaces facing each other in the drying chamber Pure water is drained from the liquid surface pure water draining nozzle to form a unidirectional surface flow along the liquid surface and along the surface of the substrate. The liquid surface side pure water is drained from the vicinity of the surface , and while suppressing the increase in the amount of isopropyl alcohol dissolved in the liquid surface side pure water, the pure water in the drying chamber is drained from the vicinity of the bottom surface to the Rukoto lowers the surface, the drying chamber at the substrate from the pure water is exposed above the said liquid surface, therewith, the exposed adhering to the surface of the substrate was the pure water the mist or The gaseous isopate It was replaced by a pill alcohol,
Then, the substrate is dried by evaporating the isopropyl alcohol from the surface of the substrate. The substrate drying method according to claim 1, wherein the surface flow is formed at least at a portion of the liquid surface where the substrate is exposed. 3. The substrate drying method according to claim 1, wherein a drainage amount of the pure water from the vicinity of the other side surface is substantially the same as a supply amount of the pure water from the vicinity of the one side surface. From the pure water the substrate to be completely exposed from the liquid surface, substrate drying method according to any one of claims 1-3, which allowed to secure the substrate in the drying chamber. Substrate drying method according to the substrate any one of claims 1 a wafer or a liquid crystal glass substrate 4. A drying chamber having side surfaces facing each other and capable of immersing a plurality of substrates arranged in the pure water so that their surfaces are substantially parallel to each other and substantially perpendicular to the liquid surface of the pure water. When,
A replacement medium supply device for supplying nitrogen gas and mist-like or gaseous isopropyl alcohol into the space above the surface of the pure water in the drying chamber;
A liquid surface pure water supply nozzle that is disposed in the vicinity of one of the side surfaces facing each other in the drying chamber and supplies pure water to the liquid surface of the pure water, and the other side surface in the drying chamber A liquid level pure water draining nozzle that is disposed in the vicinity and drains liquid level side pure water from the liquid level of the pure water or near the liquid level, and at the liquid level of the pure water , discharging more pure water in the upper Symbol one above the other side surface are arranged near the liquid surface of pure water drainage nozzle while supplying more pure water to the liquid surface pure water supply nozzle which is arranged in the vicinity of the side surface of A liquid that forms a unidirectional surface flow along the liquid surface and along the surface of the substrate, and drains liquid-side pure water from the liquid surface of the pure water or near the liquid surface by the surface flow. A surface-side pure water drainage device;
A drying chamber drainage device for draining the pure water in the drying chamber from the vicinity of the bottom thereof ,
By draining the liquid surface side pure water from the liquid surface of the pure water or near the liquid surface with the surface flow formed by the liquid surface side pure water draining device , the liquid surface side pure water is while suppressing an increase in the penetration of isopropyl alcohol, by Rukoto lowering the liquid level of the pure water by drainage of the pure water from the vicinity of the bottom surface due to the drying chamber drainage device, the substrate from the pure water And the pure water adhering to the exposed surface of the substrate is replaced with the mist-like or gaseous isopropyl alcohol supplied by the replacement medium supply device. and, thereafter, by the isopropyl alcohol evaporates from the surface of the substrate the substrate drying apparatus is characterized in that as the substrate is dried. The liquid surface-side pure water drainage device includes an elevating mechanism that lifts and lowers the liquid surface pure water supply nozzle and the liquid surface pure water drainage nozzle in the drying chamber,
While the liquid level is lowered in the drying chamber, the liquid level pure water supply nozzle and the liquid level pure water discharge nozzle are lowered by the lifting mechanism while the liquid level is lowered . substrate drying device according to claim 6 for forming the surface flow and draining the liquid surface of pure water by a nozzle for the liquid surface of pure water drainage supplies pure water by the nozzle. The liquid surface pure water supply nozzle and the liquid surface pure water drain nozzle are provided in the drying chamber so as to face each other.
The liquid surface pure water supply nozzle includes a plurality of holes for supplying the pure water formed at the opposed positions,
The substrate drying apparatus according to claim 6 or 7 , wherein the liquid surface pure water draining nozzle includes a plurality of holes for draining the liquid surface side pure water formed at the facing positions. The substrate drying apparatus according to any one of claims 6 to 8 , wherein the surface flow is formed at least at a portion of the liquid surface where the substrate is exposed. Further comprising a substrate support mechanism for supporting the upper Symbol substrate,
The substrate supporting position by the substrate support mechanism is fixed in the drying chamber until the substrate is completely exposed from the liquid surface by the drainage of the pure water by the drying chamber drainage device. The substrate drying apparatus according to any one of claims 6 to 9 .

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