JPH06283496A - Dryer of substrate after washing - Google Patents

Abstract

PURPOSE:To reduce running cost, to eliminate the need for the installation of steaming facilities and to avoid the complication of device constitution and the increase of cost by improving thermal efficiency as the whole device in a device, in which a substrate is heated by steam at the time of the drying a substrate after washing. CONSTITUTION:A heat exchange type feedwater heater 58 is interposed in a pure-water feed passage 56 connecting a pure-water supply source and a steam generator 30, and a steam exhaust passage 34 for exhausting steam 26b used for heating a substrate W pulled up from the inside of pure water 18 in a washing tank 12 in a substrate heating section 14 from the substrate heating section is communicated and connected with the heat receiving side condensing section 62 of the heat exchange type feedwater heater.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicon wafer, a semiconductor device manufacturing process, a liquid crystal display (LCD) manufacturing process, a manufacturing process related to electronic parts, etc.
The present invention relates to a substrate drying processing apparatus that cleans various substrates such as glass substrates for LCDs and electronic components and then performs a drying process on the surfaces of these substrates.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, for example, various kinds of contamination that adversely affects the operating characteristics of the device, that is, formation of a natural oxide film on the surface of a silicon wafer, organic substances and inorganic substances on the surface of a silicon wafer. It is conceivable that contamination such as adhesion of harmful substances such as the above or particles will occur. In particular, as the degree of integration of semiconductor devices has improved in recent years, the influence of contaminants such as metals, organic substances and particles has become an increasingly serious problem. For this reason, various measures and measures have been taken to reduce various pollutants, but the cleaning process of the substrate plays a central role. As a method for cleaning the substrate, a chemical solution such as sulfuric acid, hydrofluoric acid, hydrochloric acid, phosphoric acid is used.
There are a wet cleaning method in which a substrate is immersed in the cleaning chemical solution for cleaning, and a dry cleaning method in which a cleaning gas such as hydrofluoric acid vapor or hydrogen fluoride gas is supplied to the substrate for cleaning.
Here, when the substrate is wet-cleaned, or after the substrate is chemically or dry-cleaned, the substrate is rinsed by immersing it in pure water to remove residual chemicals, residual ions, etc. from the substrate surface. After processing, if the surface of the substrate is left wet, particles tend to adhere, and if the surface of the substrate in a wet state is naturally dried, it may cause water marks (water stains). Alternatively, it is necessary to quickly dry the surface of the substrate pulled up from pure water. In this case, generally, when the substrate is subjected to a cleaning treatment and the surface of the substrate is at a high level of cleanliness, on the contrary, secondary contamination is likely to occur. Therefore, in the drying step that is performed subsequent to the cleaning treatment, it is required to perform treatment so that the substrate surface is in a good dry state while maintaining a high degree of cleanliness.

As one of methods for drying the surface of a substrate after cleaning with a chemical solution or after rinsing, there is disclosed in Japanese Patent Laid-Open No. 2519/1992.
In JP-A-30, when a substrate that is immersed in pure water or a cleaning chemical liquid and subjected to a rinse treatment or a cleaning treatment is pulled out from the pure water or cleaning chemical liquid, the substrate is pulled out from the pure water or cleaning chemical liquid. Steam (high-temperature steam of water) is supplied to the substrate midway or after being pulled up, or to the substrate immediately after being pulled out from pure water or cleaning chemicals to raise the temperature of the substrate and then supply steam. Stopping and supplying a cleaned drying gas to the heated substrate to completely evaporate the moisture adhering to the substrate surface, and to quickly dry the surface of the substrate after the cleaning treatment, There is disclosed a method capable of suppressing adhesion of particles to the surface and generation of water stains. FIG. 4 schematically showing a part of the configuration of an apparatus for carrying out this substrate drying treatment method.
Will be described in more detail below with reference to.

In the substrate drying processing apparatus shown in FIG. 4, a cleaning tank (pure water rinsing tank) 12 is disposed in the lower part of the housing 10, and above the cleaning tank 12 and adjacent thereto, a substrate heating unit 14 is provided.
However, a substrate drying unit 16 is disposed above and adjacent to the substrate heating unit 14, and the cleaning tank 12, the substrate heating unit 14, and the substrate drying unit 16 are continuously arranged in the vertical direction. have. Pure water (or cleaning chemicals) is supplied into the cleaning tank 12 through a supply pipe (not shown),
Pure water overflows from the upper edge of 12 and flows out to the outside, so that pure water 18 is always stored in the cleaning tank 12. Pure water stored in this cleaning tank 12
A rinsing process is performed by immersing the substrate in 18.

A substrate accommodating chamber 20 is formed in the substrate heating section 14 so as to penetrate therethrough in the vertical direction.
The steam 26a is horizontally blown into the substrate housing chamber 20 on both sides of the substrate, and the steam is held by the substrate supporter 22 and washed.
A steam supply unit 24 that uniformly disperses and supplies steam 26a to the surface of the substrate W pulled from the pure water 18 inside the substrate 12, and the steam supply unit 24 blows the steam W into the substrate accommodating chamber 20. The steam exhaust part 28 for sucking and exhausting the steam 26b used for heating is arranged so as to face it. The steam supply section 24 has a steam supply path 32.
A steam generator 30 such as a pure water boiler or a hydrogen external combustion device is connected to and connected via the. Then, in the steam generator 30, the pure water supplied from the pure water supply source is heated to evaporate, the generated saturated steam is superheated, and steam (superheated steam) is supplied from the steam generator 30 to the steam supply unit 24. ) From the steam supply unit 24, for example, 135
The steam 26a having a temperature of about 150 ° C. is blown out. Further, a damper 36 for adjusting the flow rate is inserted in the steam exhaust passage 34 connected to the steam exhaust unit 28. Further, openable and closable shutters 38 and 40 are provided at the lower opening and the upper opening of the substrate storage chamber 20, respectively, and the substrate storage chamber 20 is cleaned when the substrate W is heated.
The upper space of the substrate and the substrate drying unit 16 are individually partitioned to seal the inside of the substrate storage chamber 20 so that moisture (humidity) due to steam does not flow into the substrate drying unit 16 and the steam supply unit 24 to the steam exhaust unit 32. I try to make the steam flow smoothly.

The substrate drying section 16 is provided with a downflow device for supplying purified air 44 through the HEPA filter 42. Although not shown in FIG. 4, in this apparatus, the substrate W immersed in the pure water 18 contained in the cleaning tank 12 is pulled out from the pure water 18, and the substrate heating unit 14 and the substrate drying unit are used. A substrate moving mechanism for sequentially moving to 16 is provided. The substrate W is transferred to the cleaning tank 12 by this substrate moving mechanism.
After being pulled up from inside, moved to the substrate heating unit 14, stopped by the substrate heating unit 14 for a predetermined time, when heating by steam is completed, the substrate heating unit 14 to the substrate drying unit 16
Is moved to and stopped by the substrate drying unit 16,
Hold for a period of time to dry.

Further, when the substrate drying processing apparatus is used in a clean room or the like, it is necessary to guide the steam exhaust passage 34 to the steam processing facility 46 and steam process the steam discharged from the steam exhaust section 28. In FIG. 4, 48 is a water tank, 50 is a water supply valve (ball tap valve), 52 is an overflow pipe, and 54 is a vent (atmosphere communication pipe).

When the substrate drying processing apparatus as shown in FIG. 4 is used and the steam 26a is supplied to the substrate W pulled from the pure water 18 (or cleaning chemical solution), the surface temperature of the substrate W is gradually increased. As the temperature rises, the steam 26a is cooled and condensed on the surface of the substrate W, and the entire surface of the substrate W is covered with water. Then, when the surface temperature of the substrate W rises to the vicinity of the temperature of the steam 26a and rises to such an extent that water condensation on the surface of the substrate W is reduced, when the supply of the steam 26a to the surface of the substrate W is stopped, Since the surface of W is heated to a high temperature, the attached water quickly evaporates from the entire surface of the substrate W. In this way, the temperature of the substrate W is raised while the entire surface of the substrate W remains wet, and when the surface temperature of the substrate W becomes high, the attached water is evaporated at a stroke, so that the substrate W Particles will not adhere to the surface and water stains will not occur.

[0009]

As shown in FIG. 4, in the conventional substrate drying processing apparatus, the steam 26b after being used for heating the substrate W is exhausted from the steam exhaust unit 28 through the steam exhaust passage 34. Alternatively, it is sent to the steam treatment facility 46 through the steam exhaust passage 34, condensed in the steam treatment facility 46, and then discharged. In this way, since the used steam is either exhausted as it is or condensed and then discharged, the thermal efficiency of the entire substrate drying processing apparatus including the steam generator 30 becomes poor, and the running cost is high. There is a problem such as being attached.

Further, when the substrate drying apparatus is used in a clean room, it is necessary to install equipment for treating the exhaust steam in parallel, and moreover it is necessary to treat high-temperature steam. Must be installed under the floor of a maintenance room or a clean room, and piping equipment for connecting the substrate drying processing apparatus and the steam processing equipment to the flow path is required. For this reason, there are problems that the device configuration of the entire system becomes complicated and the cost becomes disadvantageous.

The present invention has been made in view of the above circumstances, and improves the thermal efficiency of the apparatus as a whole to reduce the running cost and eliminates the need to install steam treatment equipment, thereby reducing the apparatus cost. The purpose is to avoid complicated structure and high cost.

[0012]

According to the present invention, a heat exchange type feed water heater is inserted in a pure water supply passage connecting a pure water supply source and a steam generator, and a substrate connected to a substrate heating section is connected. A steam exhaust passage for exhausting steam used for heating a substrate in the heating unit from the substrate heating unit is connected to the heat-condensing side condensing unit of the heat exchange feed water heater.

[0013]

In the substrate drying processing apparatus according to the present invention having the above-described structure, when the substrate is pulled up from the pure water or the cleaning chemical solution in the cleaning tank by the substrate moving mechanism and moved to the upper substrate heating section, In the heating unit, steam is supplied to the substrate to heat the substrate. This allows
As the surface temperature of the substrate rises, steam is cooled and condensed on the surface of the substrate, and the entire surface of the substrate is covered with water. Then, when water condensation on the surface of the substrate is reduced and the surface temperature of the substrate rises to near the temperature of steam, the substrate moving mechanism moves the substrate from the substrate heating unit to the upper substrate drying unit. Since the substrate is heated to a high temperature, the attached water is quickly evaporated from the entire surface of the substrate in the substrate drying section.
In this way, the temperature of the substrate is raised while the entire surface of the substrate remains wet, and when the surface temperature of the substrate rises, the attached water evaporates all at once, so particles or water stains adhere to the substrate surface. Does not occur and the surface of the substrate is not charged with static electricity. Then, in this apparatus, the steam used for heating the substrate is sent from the substrate heating unit to the heat-condensing side condensing unit of the heat exchange feed water heater through the steam exhaust passage. In this heat exchange type feed water heater, while steam is cooled and condensed in the heat-condensing side condensing section, the pure water flowing from the pure water supply source and flowing in the heat receiving side water supply passage of the heat exchange type feed water heater,
It is heated by being given heat such as condensation heat from steam through the heat transfer wall. Then, the pure water whose temperature has risen due to heat exchange with the steam while passing through the heat exchange type feed water heater is fed from the heat exchange type feed water heater to the steam generator through the pure water supply passage. Therefore, in the steam generator, the amount of heat required to generate steam can be reduced by the amount of heat received by the pure water in the heat exchange feed water heater. On the other hand, the pure water produced by steam condensation in the heat-condensing side condensing part of the heat exchange feed water heater is discharged as a drain.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing one embodiment of the present invention and schematically showing the construction of a substrate drying processing apparatus after cleaning processing. In FIG. 1, members given the same reference numerals as those used in FIG. 4 indicate the same members having the same operations as those described with reference to FIG. 4, and description thereof will be omitted.

In this substrate drying processing apparatus, a heat exchange type feed water heater 58 is inserted in a pure water supply passage 56 for feeding pure water from a pure water supply source to the steam generator 30. The heat receiving side water supply passage 60 and the pure water supply passage 56 communicate with each other. On the other hand, the steam exhaust passage 34 connected to the steam exhaust unit 28 of the substrate heating unit 14 is connected to the heat-condensing side condensation unit 62 of the feed water heater 58 and is used for heating the substrate W in the substrate heating unit 14. The steam 26b is the condenser section 62 on the heating side of the feed water heater 58.
Will be sent to. And the water heater 58
The heat condensing section 62 has a drain trap 66 at its bottom.
The drain pipe 64 in which is inserted is connected and connected, and on top of it,
A vent pipe 68 in which a check valve 70 is inserted is communicatively connected. The feed water heater 58 may be installed near the substrate drying processing apparatus main body, and by doing so, the steam exhaust passage 34 becomes short, piping becomes easy, and cost is also advantageous.

FIG. 2 is a vertical sectional view showing an example of the feed water heater. This feed water heater 58 is a shell-and-tube (straight pipe) type heat exchanger in which a large number of small tubes are contained in a large outer tube. A water supply inlet side connecting pipe 72 and a water supply outlet side connecting pipe 74 are attached so as to respectively communicate with 60. on the other hand,
The space outside the small pipe inside the outer pipe serves as the heat-condensing side condensing part 62, the steam exhaust passage 34 communicates with the heat-condensing side condensing part 62 via the steam introducing pipe 76, and the drain pipe via the drain discharge pipe 78. 64 is connected, and a vent pipe 68 is communicatively connected to the upper portion of the heat-condensing side condenser section 62. A baffle plate (baffle plate) may be provided inside the heat-condensing side condenser section 62 as necessary. The drain trap 66 has various configurations, and FIG. 2 shows an example thereof.

FIG. 3 is a vertical sectional view showing another example of the feed water heater. This heat exchange type feed water heater 84 has a structure in which one continuous coil tube 88 is housed in an outer pipe 86. Then, the inside of the coil tube 88 serves as a heat receiving side water supply passage, and the space inside the outer tube 86 outside the coil tube 88 serves as a heat receiving side condensation section.
As the feed water heater, those having various structures can be used, and for example, a plate heat exchanger or a radiator (radiator) may be used.

In the substrate drying processing apparatus shown in FIGS. 1 and 2, the steam 26b used for heating the substrate W in the substrate heating unit 14 is heated from the steam exhaust unit 28 of the substrate heating unit 14 through the steam exhaust passage 34. It is sent to the heat-condensing side condensation section 62 of the exchange-type feed water heater 58. In the feed water heater 58, steam is cooled and condensed in the heat-condensing side condenser unit 62,
Water supply channel 60 on the heat receiving side of the water heater 58 that is supplied from the pure water supply source
Pure water 80 flowing inside is heated by heat such as condensation heat given from steam through a heat transfer wall. And water heater
Pure water whose temperature has risen while passing through the heat receiving side water supply channel 60 of 58
Is sent from the feed water heater 58 to the steam generator 30 through the pure water supply path 56. On the other hand, the pure water 82 generated by steam condensation in the heat-condensation side condensing part 62 of the feed water heater 58 is discharged as a drain through the drain pipe 64, and non-condensed gas such as air is absorbed in the heat-condensing side condensing part 62. It is discharged from 62 through the vent pipe 68 to the outside.

[0020]

Since the present invention is constructed and operates as described above, the use of the substrate drying processing apparatus according to the present invention improves the thermal efficiency of the entire apparatus including the steam generator, and improves the running efficiency. The cost is reduced, and even when the substrate drying processing apparatus is used in a clean room or the like, it is not necessary to install steam processing equipment, so that it is possible to avoid complication of the apparatus configuration and high cost.

[Brief description of drawings]

FIG. 1 is a front view schematically showing a schematic configuration of a substrate drying processing apparatus after cleaning processing according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing an example of a heat exchange type feed water heater used in this substrate drying processing apparatus.

FIG. 3 is a vertical cross-sectional view showing another example of a heat exchange type feed water heater used in this substrate drying processing apparatus.

FIG. 4 is a schematic front view showing an example of the configuration of a conventional substrate drying processing apparatus.

[Explanation of symbols]

 10 Housing 12 Cleaning tank (pure water rinse tank) 14 Substrate heating section 16 Substrate drying section 18 Pure water (chemical solution for cleaning) 20 Substrate storage chamber 22 Substrate support 24 Steam supply section 26a, 26b Steam 28 Steam exhaust section 30 Steam generation Heater 32 Steam supply passage 34 Steam exhaust passage 56 Pure water supply passages 58, 84 Heat exchange feed water heater 60 Heat receiving side water supply passage of feed water heater 62 Heat supply side condensing part of feed water heater 64 Drain pipe 68 Vent pipe 86 Outside Tube 88 coil tube W board

Claims (1)

[Claims] 1. A substrate moving mechanism for lifting a substrate immersed in pure water or a cleaning chemical solution contained in the cleaning tank from the pure water or the cleaning chemical solution and moving it upward, and a substrate moving mechanism above the cleaning tank. Substrates are provided adjacent to each other by supplying steam to the substrate during or after being pulled out from pure water or the cleaning chemical solution or to the substrate immediately after being pulled out from the pure water or cleaning chemical solution. And a steam generator connected to a pure water supply source for supplying steam generated by heating pure water to the substrate heating unit, and a steam generator disposed above and adjacent to the substrate heating unit. A substrate drying unit after the cleaning process, which is provided with a substrate drying unit for evaporating moisture adhering to the surface of the substrate heated by steam, wherein a pure water supply source and the steam generator are provided. A steam exhaust for exhausting the steam used for heating the substrate in the substrate heating section, which is connected to the pure water supply path to which a heat exchange type feed water heater is inserted, and which is connected to the substrate heating section in communication. A drying treatment apparatus for a substrate after cleaning treatment, characterized in that the passage is connected to the heat-condensing side condensing portion of the heat exchange type feed water heater.