JP2005268331A - Vapor dryer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor dryer capable of suppressing the production of watermarks even when the pattern face of a wafer is directed to the wall face of a processing tank. <P>SOLUTION: The vapor dryer is provided with an IPA supply tube 14 for supplying IPA, a vapor generating tank 13 for generating IPA vapor V; the processing tank 17 located inside the vapor generating tank and containing cleaned wafers W; a vapor rising duct 21 located between the vapor generating tank and the processing tank to introduce the IPA vapor from the upper part of the processing tank to its inside; a cooling coil 22 located at the upper part of the vapor rising duct for liquefying the IPA vapor rising through the vapor rising duct; and a surrounding wall 25 provided inside the cooling coil for suppressing variations of the vapor level at the upper part of the processing tank, and a temperature gradient inside the processing tank is selected higher at an upper region and lower at a lower region on the basis of a position of the wafers contained in the processing tank. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vapor drying apparatus for drying an object to be dried such as a cleaned semiconductor wafer, a substrate for a liquid crystal display device, and a substrate for a recording disk.

  As an apparatus for drying an object to be dried such as a semiconductor wafer (hereinafter simply referred to as a wafer) after processing such as a cleaning process and a water washing process (hereinafter referred to as a rinsing process), as a processing liquid adhering to the surface of the wafer There is known a steam drying apparatus that replaces the pure water with an organic solvent or the like and then evaporates the organic solvent adhering to the surface.

  The vapor drying apparatus includes an apparatus main body that forms an outer shell of the apparatus, a robot arm that holds a wafer, a liquid recovery unit, and the like. The apparatus main body includes a drying tank for storing an organic solvent. As an example of the organic solvent, isopropyl alcohol (hereinafter referred to as IPA) is used. A heating device is provided at the bottom of the drying tank. The heating device heats the IPA and generates steam containing the IPA.

  That is, as shown in FIG. 6, the conventional drying apparatus has a stainless steel apparatus main body 2 that constitutes an outline of the drying apparatus 1, and a drying tank 3 having an upper opening is provided inside the apparatus main body 2. ing. The drying tank 3 is made of a material that is not easily corroded by an organic solvent such as IPA (for example, quartz). An IPA supply pipe 4 as an organic solvent supply means for supplying an organic solvent such as IPA is connected to the drying tank 3.

  A heater block 5 is provided at the bottom of the drying tank 3, and a cooling coil 6 formed of a material (for example, quartz glass) that is not easily corroded by IPA is provided at the upper inner periphery. Further, a semiconductor wafer (hereinafter referred to as a wafer W) as an object to be dried is accommodated in the drying tank 3, and below the wafer W is hardly corroded by an organic solvent such as IPA. A tray 7 made of a material (for example, quartz) is provided.

  The tray 7 has a reverse taper shape and receives a drain containing heated IPA, and one end of a drain pipe 9 for discharging the drain containing IPA to the outside of the apparatus main body 2 is connected to the lower end discharge port 8 thereof. Has been. Further, a waste pipe 10 for draining an organic solvent such as IPA is provided at the bottom of the drying tank 3 so as to penetrate the side wall of the apparatus body 2 in the lateral direction.

  In addition, in the state where sufficient IPA vapor | steam of about 82 degreeC is produced | generated in the drying tank 3, in FIG. 6, 11 is a vapor | steam, 12 is air, 13 is a vapor | steam interface (gas phase interface).

  Before being inserted into the drying tank 3, the wafer W is cleaned by a cleaning liquid such as hydrogen fluoride or pure water as a processing liquid in the cleaning process, and in the rinsing process after the cleaning process, It is washed with a rinse solution such as pure water. For this reason, the wafer W before being inserted into the drying tank 3 has a treatment liquid Wb such as pure water attached to its surface Wa.

  For example, 50 wafers W to which a processing liquid Wb such as pure water adheres are held in a standing state at a predetermined interval on a wafer boat. Then, the wafer boat is gripped by, for example, a robot arm and is exposed to steam by being inserted into the drying tank 3. In this state, the vapor condenses on the surface of the wafer W, and IPA adheres to the surface Wa of the wafer W.

  For this reason, the treatment liquid Wb such as pure water that has adhered to the surface Wa of the wafer W replaces the IPA. The replaced processing liquid Wb flows down from the surface of the wafer W and is recovered by the liquid recovery unit. As the IPA on the surface Wa of the wafer W evaporates, the wafer W is dried in a short time. In addition, particles, which are foreign matters attached to the surface Wa of the wafer W, flow down together with the processing liquid Wb when the processing liquid Wb flows down from the surface Wa of the wafer W.

  Furthermore, to add a description, in the drying tank 3, a sufficient IPA vapor of about 82 ° C. is generated, and the wafer W having a low temperature (20 to 25 ° C.) in the final cleaning process is in the drying tank 3. , A large amount of vapor condensation (liquefaction) occurs instantaneously on the surface Wa of the wafer W, and the vapor zone temporarily lowers because the amount of vapor generated cannot catch up with the condensation amount (see FIG. 7). .

  With the IPA vapor generated one after another from the state where the vapor zone is lowered, the wafer W is heated and condensation is reduced, the vapor zone is raised, the entire wafer W is covered with the vapor, and condensed IPA is generated on the entire surface of the wafer W. At this point, condensation of IPA has occurred on both sides of the wafer W. This condensation IPA continues until the temperature of the wafer W itself reaches the vapor temperature.

  Hereinafter, this condensation process is called initial condensation. The processing liquid Wb on the surface of the wafer W is dissolved in the condensed IPA and removed from the IPA waste liquid pipe 10 through the tray 7 as a drain flowing down on the surface of the wafer W (see FIG. 8). Even after the temperature of the wafer W itself reaches the vapor atmosphere temperature, the condensation continues on the surface Wa of the wafer W. In this case, the condensation absorbs the heat of the vapor due to the low temperature of the wafer W itself. This is different from the situation where the temperature of the wafer W itself rises to the vapor temperature.

  Hereinafter, this condensation process is referred to as condensation during thermal equilibrium. In the vapor zone, condensation on the surface Wa of the thermally saturated wafer W is performed as follows. In other words, for example, 50 wafers W are held on the wafer boat at a predetermined interval. Then, as shown in FIGS. 9A and 9B, when the inside of the wafer W held by the wafer boat (the surface adjacent to the other wafer W) is the A side and the outside is the B side, When condensation occurs on the B-side surface, the heat (vapor latent heat) is absorbed by the wafer W. However, in order to maintain thermal equilibrium in this vapor atmosphere, the same amount is received from the A-side surface, which is the back side. The heat is released. This gives heat of vaporization to IPA which is to be condensed (or condensed) on the surface on the A side, and as a result, the steam cannot be condensed on the surface on the A side and becomes dry.

  Since the vapor involved in the surface condensation of the wafer W exists in the same state on both the A side and the B side of the wafer W, the phenomenon that the back surface of the wafer W is in a dry state when either surface is condensed. It is in a very unstable state that is easy to move to either side. As a result, both surfaces of the wafer W are alternately condensed and dried.

  At the end of the immersion time, as shown in FIG. 10, the wafer W is raised, the wafer W is moved out of the vapor atmosphere, and the substituted IPA is naturally evaporated (about 5 minutes), thereby completing the drying process.

  However, at the moment when the wafer W is immersed, a decrease in the vapor level occurs, the condensation gradually proceeds upward from the lower part of the wafer W, the vapor level is restored, and it takes a considerable time until the wafer W is again enveloped in the vapor atmosphere. (For example, in the case where heating is performed by the heater block 5 of 8.4 kW with 50 wafers of 8 inches, about 30 seconds). Further, since the IPA vapor is instantaneously condensed at a low temperature portion, the condensation starts from the peripheral portion of the wafer W, and the whole surface of the wafer W tends to be condensed as the temperature of the wafer W rises. Therefore, non-uniform condensation occurs in the plane of the wafer W.

  In addition, the IPA vapor drying method is characterized by the fact that water droplets and adhering water on the wafer W after washing are almost completely replaced with condensed IPA, so that it is difficult for water marks and natural oxide films to occur. is there. However, even in the case of the IPA vapor drying method, when the surface of the wafer W is hydrophobic as after the cleaning treatment with hydrofluoric acid, a water mark is generated in the drying process in which the surface of the wafer W is activated. There are many, and the most attention is needed. Further, as described above, when the wafer W after the final process of the cleaning apparatus is put into the drying tank 3, the vapor zone is temporarily lowered, and as a result, condensed IPA is generated in the entire wafer W to remove water. This is because the wafer W is exposed to the air (oxygen atmosphere) until it is processed, and thus a natural oxide film formation reaction proceeds.

  Further, in the IPA vapor drying apparatus, when a large number of wafers W are mounted on a wafer boat, if the pattern surface faces the wall surface of the drying tank 3 in the wafers W at both ends, a watermark is likely to occur. For example, in the case of processing 50 wafers of 8 inches, when the wafer W is immersed, the vapor concentration between the first and 50th wafers becomes thin, but the vapor level does not decrease. On the surface of W, condensation of IPA occurs instantaneously. This is because the distance between the wafers W is as narrow as 6.35 mm and is immersed in the drying bath 3 at a high speed, so there is no escape (diffusion) place for the steam between the wafers W. Is retained.

  However, since the gap between the wall surface of the drying tank 3 and the first wafer W and the 50th wafer W is generally about 60 mm or more, the moment when the wafer W is immersed in the drying tank 3, The vapor level between the wall surface of the drying tank 3 and the wafer W is lowered and the vapor is diffused, so that the IPA is not condensed instantaneously as on the surface of the wafer W between the first wafer W to the 50th wafer. . Accordingly, when the pattern surfaces of the first wafer W and the 50th wafer W face the wall surface of the drying tank 3, a watermark may occur.

  Further, when the wafer W is immersed in the drying tank 3, IPA is condensed (initially condensed) on the surface of the wafer W due to a temperature difference between the wafer W (20 to 25 ° C.) and the IPA vapor (82 ° C.). . When the wafer W reaches the vapor temperature, the wafer W and the vapor are in a thermal equilibrium state. Unlike the condensation state (initial condensation) when the temperature of the wafer W is lower than the vapor temperature, both surfaces of the wafer W (pattern surface) And backside) do not condense at the same time, but condense alternately. This condensation greatly contributes to the removal of residual particles when immersed in the drying tank 3 while particles remain on the wafer W surface.

  For example, when processing an 8-inch wafer W and 50 wafers, in the second wafer W to the 49th wafer W in a thermal equilibrium state, the pattern surface and the back surface are condensed alternately, and there is almost no problem of residual particles. Although not generated, in the case of the first wafer W and the 50th wafer W, condensation tends to occur on the surface facing the wall surface of the drying tank 3, and condensation does not occur on the opposite surface. Therefore, when the pattern surface is opposite to the wall surface of the drying tank 3, condensation of IPA that contributes to the removal of residual particles cannot be obtained on the pattern surface, and when particles remain on the pattern surface, particles remain. There are times when it is dried.

  This is because the drying tank 3 is generally covered with a cooled stainless steel tank, and the wall surface of the drying tank 3 in the drying tank 3 functions as a heat sink. Heat is released to the apparatus main body 2 through the wall surface of the drying tank 3. Further, in order to compensate for the released heat inside the drying tank 3, a flow of IPA vapor to the wall side of the drying tank 3 is generated, and the wall surface of the drying tank 3 and the first wafer W (the 50th sheet) When the IPA vapor temperature between the wafers W) and the IPA vapor temperature between the first wafer W (the 50th wafer W) and the second wafer W (the 49th wafer W) are compared, a drying bath The temperature between the wall surface 3 and the first wafer W (the 50th wafer W) is lower, and condensation occurs on the surface facing the wall surface of the drying tank 3, and no condensation occurs on the opposite surface.

  Furthermore, in the conventional tray 7, since the depth of the tray 7 is low and close to the heater block 5, IPA vapor and IPA mist, water droplets, and the like are mixed therein. Mist, water droplets and the like also enter the tray 7. Since these are processed as waste liquid from the drain pipe 9 in the standby state of the wafer W, there is a problem that the IPA is consumed in the standby state.

  The present invention has been made paying attention to the above circumstances, and the object of the present invention is to suppress the generation of watermarks on the surface of the wafer and to process the particles while remaining on the pattern surface of the wafer. It is an object of the present invention to provide a steam drying apparatus that can remove residual particles even when immersed in a bath, and further shortens processing time and reduces IPA consumption.

  In order to achieve the above object, the present invention provides an organic solvent supply means for supplying an organic solvent and a steam generation tank having an upper opening provided with a steam generation means for generating a vapor containing the organic solvent, and the steam generation tank. A treatment tank having an upper opening for accommodating a to-be-dried material provided therein, and a vapor containing an organic solvent provided between the vapor generation tank and the treatment tank and generated by the vapor generation means. A vapor rising passage leading from the upper portion of the vapor to the inside thereof, a cooling means for liquefying the vapor containing the organic solvent that rises in the vapor rising passage, and provided inside the cooling means, Suppression means for suppressing fluctuations in the vapor level in the upper part of the processing tank, and the upper region has a higher temperature gradient inside the processing tank based on the installation position of the object to be dried accommodated in the processing tank, and the lower part Lower the area To generate supersaturated steam from organic solvent vapor and removing residual moisture from the material to be dried.

  According to the present invention, the following effects can be obtained.

  a. Suppresses the generation of watermarks on the surface of the wafer, holds a large number of wafers on a wafer boat, etc., and suppresses the generation of watermarks even when the pattern surface of the wafers on both ends of the wafer faces the wall of the processing tank be able to.

  b. Even when the particles remain on the pattern surface of the wafer and are immersed in the processing tank, the remaining particles can be removed.

  c. As the temperature of the wafer rises, it is condensed over the entire surface of the wafer, and uniform condensation is obtained.

  d. Since condensation occurs simultaneously on the entire surface of the wafer, the processing time is shortened.

  e. IPA consumption during standby is extremely reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 is a longitudinal front view of the steam drying apparatus, FIG. 2 is a longitudinal side view of the same, FIG. 3 is a perspective view of a treatment tank, and FIG. 4 is a longitudinal front view of the steam drying apparatus.

  As shown in FIGS. 1 and 2, a steam generation tank 13 having an upper opening is provided inside a stainless steel apparatus main body 12 that constitutes the outline of the steam drying apparatus 11. The steam generation tank 13 is formed of a material that is not easily corroded by an organic solvent such as IPA (for example, quartz glass). An IPA supply pipe 14 as an organic solvent supply means for supplying an organic solvent such as IPA is connected to the steam generation tank 13. Further, a waste pipe 15 for draining an organic solvent such as IPA is provided at the bottom of the steam generation tank 13 so as to penetrate the side wall of the apparatus main body 2 in the lateral direction.

  A heater block 16 is provided at the bottom of the steam generation tank 13. Inside the steam generation tank 13, there is provided a processing tank 17 having an upper opening in which a wafer W as a dried object to be dried is accommodated.

  As shown in FIG. 3, the processing tank 17 is formed of a material that is not easily corroded by an organic solvent such as IPA (for example, quartz glass), and the body portion 17 b having a reverse-tapered bottom portion 17 a is, for example, 50 wafers. It is formed in a size that can be accommodated together with a wafer boat (not shown) that holds W in a standing position with a certain interval.

  The bottom 17a of the treatment tank 17 receives drain containing heated IPA, and one end of a drain pipe 19 for discharging drain containing IPA to the outside of the apparatus main body 2 is connected to the lower end discharge port 18 thereof. . In addition, laterally long rectangular openings 20 are provided in the vicinity of the upper edge of the trunk portion 17b on the left and right side surfaces of the trunk portion 17b.

  A steam rising passage 21 is provided between the inner peripheral surface of the steam generation tank 13 and the outer peripheral surface of the processing tank 17 to guide steam containing IPA to the upper part of the processing tank 17. The upper part of the steam rising passage 21 communicates with the inside of the processing tank 17 through the opening 20 of the processing tank 17 so that steam containing IPA is supplied into the processing tank 17.

  A quartz cooling coil 22 is provided above the steam rising passage 21 and above the opening 20 of the processing tank 17 as a cooling means for liquefying the steam containing IPA along the inner peripheral surface of the steam generating tank 13. Is provided. A flange 23 is provided at the lower part of the cooling coil 22, and the cooling coil 22 is partitioned from the steam rising passage 21 by the flange 23. Therefore, most of the steam containing IPA rising through the steam rising passage 21 is guided toward the cooling coil 22 having a low temperature, and the remaining steam containing IPA is introduced into the processing tank 17 from the opening 20. It has come to be.

  Furthermore, an enclosure wall 25 is provided inside the cooling coil 22 as a suppression means for suppressing fluctuations in the steam level L at the top of the treatment tank 17, and the enclosure wall 25 is integrated by the upper edge of the treatment tank 17. It is configured.

  According to the steam drying device 11 configured as described above, when IPA is supplied from the IPA supply pipe 14 to the steam generation tank 13, the IPA is heated by the heater block 16 and the IPA steam V is generated in the steam generation tank 13. Occurs.

  The IPA vapor V rises in the vapor rising passage 21, and most of the IPA vapor V is guided toward the cooling coil 22 having a low temperature, and the vapor containing the remaining IPA passes through the opening 20 to the treatment tank 17. Led inside. The IPA vapor V supplied into the processing tank 17 is supersaturated and stored in the processing tank 17, and the entire processing tank 17 has a uniform flow from top to bottom.

  The IPA supersaturated vapor Va reaching the bottom 17a of the treatment tank 17 is reheated at the temperature of the bottom 17a, becomes IPA vapor V again, rises in the treatment tank 17, and again reaches the IPA supersaturated vapor Va at a location where the temperature is low. Then it flows down to the bottom again. That is, a cycle of IPA supersaturated steam Va → IPA steam V → IPA supersaturated steam Va occurs in the processing tank 17.

  In addition, the IPA vapor V cooled by atmospheric radiation in the vicinity of the upper opening of the treatment tank 17 generates a large amount of condensed nuclei entirely in an environment where there is no turbulence in the surrounding wall portion 25. The condensed nuclei absorb the IPA supersaturated vapor Va and become large particles, and descend in the IPA vapor V as droplets.

  These droplets are heated by passing through the vapor and generate heat of condensation to evaporate a part of the surface to create a supersaturated state. When the droplet comes into contact with the bottom surface of the treatment tank 17, it is heated and re-evaporates to take the surrounding energy, and the temperature of the portion drops. Since these droplets are always supplied from the lower part of the vapor level L, the IPA droplets fall like rain in the treatment tank 17 uniformly over the entire surface.

  In this state, the wafers W after washing with water (50 wafers W held in a standing state with a predetermined interval on the wafer boat) are immersed in the processing tank 17 from the upper opening of the processing tank 17. At this time, the water droplet 27 is attached on the surface of the wafer W, and the temperature of the wafer W is 20 to 25 ° C. Then, the IPA supersaturated vapor Va in the processing tank 17 is instantaneously and uniformly supplied to the gap between the 50 wafers W, and initial condensation (liquefaction) occurs on the surface of the wafers W. At the same time, a large amount of condensed IPA 26 is generated on the surface of the wafer W, whereby the inside of the processing tank 17 is depressurized, and the IPA vapor V flows into the processing tank 17 from the opening 20 of the processing tank 17 without being continuously interrupted. Happens.

  As described above, the IPA vapor V becomes the IPA supersaturated vapor Va in the processing tank 17, and the surface of the wafer W is not exposed from the IPA supersaturated vapor atmosphere, so that the wafer W It is uniformly supplied to the gap between the 50 wafers W from the top to the bottom. Condensation of IPA continues continuously on the surface of the wafer W, and the condensed IPA 26 and water droplets 27 are mixed to form IPA + water droplets 28, which are dropped from the lower portion of the wafer W. The IPA + water droplets 28 are collected at the bottom 17a of the processing tank 17 and discharged from the drain pipe 19 to the outside of the apparatus main body 12.

  Here, when the temperature in the steam generation tank 13 and the processing tank 17 is described, the processing tank 17 is lower than the steam generation tank 13. Therefore, the IPA vapor V is continuously supplied to the processing tank 17 from the opening 20 while the wafer W is immersed in the processing tank 17. And IPA supersaturated vapor | steam Va is continuously produced | generated in the processing tank 17. FIG.

  Therefore, when the water droplets 27 on the surface of the wafer W are completely replaced by the IPA vapor V, and the temperature of the wafer W becomes the same as the temperature of the IPA supersaturated vapor Va, the condensation of IPA on the surface of the wafer W is finish. However, the IPA supersaturated vapor Va is uniformly supplied to the gaps between the 50 wafers W from the upper part to the lower part of the wafers W without interruption.

  As described above, the temperature in the processing tank 17 when the cycle of IPA supersaturated vapor Va → IPA steam V → IPA supersaturated steam Va is generated in the processing tank 17 is shown by a curve (A) in the graph of FIG. It is 81-82 degreeC as shown by. In this state, when the temperature of the upper portion, the central portion and the lower portion of the wafer W when the wafer W after rinsing was immersed in the processing bath 17 from the upper opening of the processing bath 17 was measured, the upper portion of the wafer W was curved ( B) The center of the wafer W is shown by a curve (c), and the lower part of the wafer W is shown by a curve (d). That is, at the moment when the wafer W is immersed in the processing tank 17 (after about 4 seconds), the temperature in the processing tank 17 drops to around 60 ° C., but from the moment when the wafer W is immersed for about 30 seconds, the temperature below the wafer W As the temperature rises, the temperature of the upper portion of the wafer W also rises after 6 seconds, and the initial condensation has begun in the wafer W. Then, after 30 seconds, the temperature in the processing tank 17 recovers to 81 to 82 ° C., and accordingly, the temperature of the wafer W approaches the temperature in the processing tank 17 and thermal equilibrium condensation starts.

Further, when a temperature sensor is arranged in the processing tank 17 and the vertical temperature distribution in the atmospheric state before the wafer W is put into the processing tank 17 is seen, it is as shown in Table 1 and FIG. That is, when the center position Wo of the wafer W accommodated in the processing tank 17 is used as a reference, four temperature sensors are disposed above the center position Wo (1, 2, 3, 4) and below the center position Wo. In the temperature distribution in which three temperature sensors are arranged (5, 6, 7) in the region, the upper region (1, 2, 3, 4) is higher than the center position Wo, and the lower region (5, 6) from the center position Wo. 7) is low and the temperature difference is less than 1 ° C. The reason why the temperature in the lower area is slightly lower than the upper area of the processing tank 17 is that the water droplets 27 on the surface of the wafer W are vaporized in the lower area of the processing tank 17, so that heat is taken away by the heat of vaporization. It is thought that the temperature in the lower area decreases.

  As described above, the IPA supersaturated vapor Va continues from the upper part to the lower part of the wafer W by increasing the temperature gradient in the processing tank 17 installed in the steam generation tank 13 in the upper region and lowering the lower region. Flow down. Therefore, when the wafer W is immersed, the IPA vapor V is continuously supplied from the opening 20 and, at the same time, the IPA supersaturated vapor Va is generated. The IPA supersaturated vapor Va is different from the IPA vapor V at a low temperature. Condensation occurs over the entire surface of the wafer W. Since the IPA supersaturated vapor Va continuously flows from the upper part to the lower part of the wafer W, the uniform IPA supersaturated vapor Va is supplied to the gap between the 50 wafers W, and from the moment when the wafer W is immersed. Uniform condensation is obtained. Therefore, no time is required until the equilibrium state is reached.

  Furthermore, by providing the treatment tank 17 inside the steam generation tank 13, the waste liquid mixed with the IPA vapor V and the water droplets 27 cannot return to the steam generation tank 13 and is entirely discharged from the drain pipe 19. The surface of the wafer W is constantly supplied with only fresh IPA.

  Since the processing tank 17 is provided inside the steam generation tank 13, the wafer W is always immersed in the atmosphere of the IPA supersaturated vapor Va from the immersion to the carry-out, so that there is an effect of suppressing the generation of the watermark. Further, the flow of the IPA supersaturated vapor Va is the same between the wall of the processing tank 17 and the wafer W as the flow between the wafer W and the wafer W, so the pattern surfaces of the wafers W (first and 50th) at both ends Even when facing the wall surface of the processing tank 17 (regardless of the orientation of the pattern surface with respect to the wall surface), there is an effect of suppressing the generation of watermarks.

  When the pattern surfaces of the first and 50th wafers W are opposite to the wall surface of the processing tank 17, condensation of IPA that contributes to the removal of residual particles cannot be obtained on the pattern surface, and particles remain on the pattern surface. If this is the case, there is a tendency that this cannot be completely removed. However, in the processing tank 17, the IPA supersaturated vapor Va continuously flows from the upper part to the lower part of the wafer W between the wall surface of the processing tank 17 and the first wafer W and between the 50th wafer W. The gap is evenly supplied. Therefore, even when the particles remain on the pattern surfaces of the first and 50th wafers W and are immersed in the processing bath 17, the residual particles are removed regardless of the orientation of the pattern surface with the wall surface. The

Further, the processing tank 17 has a structure having a bottom portion 17a and a body portion 17b continuous from the opening edge of the bottom portion 17a, and an opening portion 20 for continuously supplying the IPA vapor V to the body portion 17b. Therefore, the IPA vapor V supplied from the opening 20 becomes IPA supersaturated vapor Va, flows down from the upper part of the processing tank 17 to the lower part, and rises again as IPA vapor V on the lower wall surface in the processing tank 17. Since the cycle of this IPA steam V → IPA supersaturated steam Va → IPA steam V is generated, the discharge of IPA from the drain pipe 19 is suppressed. Table 2 shows comparison data of the amount of IPA discharged from the drain pipe 19 during the standby for 1 hour using the conventional tray and the treatment tank 17 of the present invention.

  In addition, the steam drying apparatus of this invention is not restrict | limited to embodiment mentioned above. The present invention can also be applied to applications for drying various substrates such as glass substrates for liquid crystal display devices and recording disk substrates such as optical recording disks and magnetic recording disks, other than semiconductor wafers.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal front view of a steam drying apparatus according to a first embodiment of this invention. The vertical side view of the steam drying apparatus of the embodiment. The perspective view of the processing tank of the embodiment. Explanatory drawing which shows the arrangement | positioning state of the temperature sensor which measures the temperature distribution of the processing tank of the embodiment. The graph which shows the relationship between the temperature of a process chamber and a wafer, and time. The longitudinal front view of the conventional steam dryer. The longitudinal front view of the conventional steam dryer. The longitudinal front view of the conventional steam dryer. (A) is a longitudinal front view of a conventional steam drying apparatus, (b) is a side view of a wafer. The longitudinal front view of the conventional steam dryer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 ... Apparatus main body, 13 ... Steam generation tank, 14 ... IPA supply pipe, 16 ... Heater block, 17 ... Processing tank, 19 ... Drain piping, 20 ... Opening part, 21 ... Steam rise passage, 22 ... Cooling coil, W ... Wafer (to be dried)

Claims (7)

A steam generation tank having an upper opening provided with an organic solvent supply means for supplying an organic solvent and a steam generation means for generating a vapor containing the organic solvent;
A treatment tank with an upper opening that accommodates the object to be dried provided inside the steam generation tank;
A vapor rising passage for introducing a vapor containing an organic solvent generated between the vapor generation tank and the treatment tank and generated by the vapor generation means from an upper portion of the treatment tank;
A cooling means provided at an upper portion of the vapor rising passage, for liquefying vapor containing an organic solvent that rises in the vapor rising passage;
A suppression means provided inside the cooling means, for suppressing fluctuations in the vapor level at the top of the treatment tank,
The temperature gradient inside the treatment tank is high in the upper area and the lower area is lowered based on the installation position of the object to be dried contained in the treatment tank, and a supersaturated vapor is generated from the organic solvent vapor to generate the dried object. A steam drying apparatus for removing residual moisture from the water.   2. The organic solvent repeats a steam-supersaturated steam-steam cycle inside the treatment tank, and removes residual moisture on the material to be dried by the condensation action of the organic solvent. Steam drying equipment.   The steam drying apparatus according to claim 1, wherein a difference in temperature gradient in the processing tank is less than 1 ° C.   The steam drying apparatus according to claim 1, wherein the treatment tank has an opening that guides a vapor containing an organic solvent that rises in the vapor rising passage in the vicinity of an upper opening to the inside of the treatment tank.   The steam drying apparatus according to claim 1, wherein the cooling means is a cooling coil provided in an upper portion of the steam rising passage, and is partitioned from the steam rising passage.   The steam drying apparatus according to claim 1, wherein the suppressing unit is configured by a peripheral wall of the processing tank and is provided to protrude inside the cooling unit.   The steam drying apparatus according to claim 1, wherein the organic solvent is isopropyl alcohol.

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