JP2567413Y2 - Drying equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying apparatus for rapidly drying, for example, a silicon semiconductor wafer as a plate-like material to be dried by infrared rays.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, impurities adhering to the surface of a semiconductor wafer adversely affect the performance of the semiconductor device.

[0003] Therefore, the manufacturing process of a semiconductor wafer includes a cleaning and drying process. In the cleaning process, the wafer is cleaned by various methods. And chemical cleaning methods.

[0004] As the former physical cleaning method, a method of directly removing impurities adhered to the wafer surface using a cleaning brush or the like, a method in which a pressurized fluid is jetted from a jet nozzle toward a part or the whole of the wafer, Thus, there are a method of removing impurities, a method of immersing a wafer in a liquid and applying ultrasonic waves to the wafer to remove impurities attached to the wafer (ultrasonic cleaning method), and the like.

[0005] The latter chemical cleaning methods include:
There is a method of chemically decomposing and removing impurities attached to the wafer surface by various chemicals, enzymes and the like. Incidentally, a physical cleaning method and a chemical cleaning method may be used in combination.

[0006] Thus, the wafer after the mirror polishing is finished,
After passing through several washing steps by the above method, it is dried in a clean space and stored as a product in a wafer storage container.

[0007] In the above-mentioned mirror wafer drying step, in the portion of the wafer mirror surface immediately after the cleaning where water droplets adhere,
Specular wafers must be quickly drained and dried because spots occur, which are often attributed to the hydration reaction of silicon with water and air. For the rapid drying for that purpose, conventionally, centrifugation, steam drying,
A hot air drying method or the like is employed.

[0008]

In the field of semiconductor manufacturing, semiconductor wafers have become larger in diameter with the recent trend toward higher integration of semiconductor devices, and a plurality of wafers are accommodated in a carrier for cleaning and cleaning. The conventional method of drying requires a great deal of labor.

[0009] In addition, if a method is adopted in which a wafer is accommodated in a carrier and transported, there is also a problem that particles (fine dust) adhere to the wafer due to contact between the wafer and the carrier and the wafer is contaminated.

Therefore, a wafer-by-wafer automatic cleaning / drying apparatus for supporting wafers one by one and successively immersing the wafers in a plurality of cleaning baths to wash the wafers one by one and then drying the wafers one by one. Suggested.

However, especially when the drying apparatus is applied to the above-mentioned automatic wafer cleaning / drying apparatus of every leaf type, a centrifugal separation system such as a spin dryer conventionally used or a steam drying using IPA (isopropyl alcohol) is used. The method is not suitable for a wafer-by-wafer type wafer cleaning / drying apparatus that processes wafers one by one, and cannot always realize efficient rapid drying. In other words, the demand for larger diameter wafers and stricter particle management is
If this occurs, the size and complexity of the apparatus will be increased, and as a result, new problems will be caused in terms of the quality of the wafer, its cost, and the safety during manufacturing.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a drying apparatus capable of rapidly drying plate-like objects to be dried one by one.

[0013]

In order to achieve the above object, the present invention provides a quartz cylindrical or flat, rectangular, rectangular cross-section container which accommodates a plate-shaped material to be dried in a vertically suspended state. It is housed in a housing, covers the upper part of the container with a slight gap around it, and has a shower device for jetting pure water on the upper part, and the lower part of the container has a drain pipe for discharging fluid. And an inert gas supply pipe to be supplied with an inert gas, the drain pipe flows only when the shower device operates, and the inert gas supplied from the inert gas supply pipe into the container is a container. A plurality of infrared heaters are arranged around the entire length of the container in the vertical direction so as to surround the container, and a cooling fan is provided in the heat insulating housing to dry the container. And its characterized by being configured to location.

[0014]

According to the present invention, the shower device provided in the container for spraying pure water provides a means for cleaning the inside of the container and a means for assisting the finishing of the previous step. That is, after the washed wafer is re-washed in the drying device, it can be immediately subjected to rapid drying by infrared heat.

[0015] The infrared heater on the short wavelength side according to the present invention sets the plate-like material to be dried at a predetermined position in the container,
Alternatively, by turning on after setting and re-cleaning, the plate-shaped material to be dried is heated and heated in a short time. At this time, the effect of rapid drying can be enhanced by keeping the entire container inside warm while the infrared heater on the middle wavelength side is kept on, or by simultaneously turning on the infrared heater on the short wavelength side.

Since the present invention does not use a centrifugal mechanical device, the manufacturing cost of the device can be reduced, and damage to the plate-like material to be dried due to mechanical work can be avoided. In addition, since a flammable organic solvent for steam drying is not used, it is safe and the cost of the solvent can be saved. In addition, turning on / off the infrared heater
Since the drying can be relatively easily performed only by the OFF and the power control, the drying apparatus is suitable as a wafer-by-wafer drying apparatus for surely processing the plate-like objects to be dried one by one.

Further, since the inert gas is supplied into the container from below, particles hardly adhere to the plate-like material to be dried.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 4, 5 and 6 are a front view, a plan view and a side view of a wafer-type automatic cleaning / drying apparatus provided with a drying apparatus according to the present invention. , Loader section A, wafer receiving tank B, pre-cleaning tank C,
It has a brush cleaning tank D, cleaning tanks E, F, G, H and I, two preliminary tanks J and K, a drying device L and an unloader section M according to the present invention.

As shown in FIG. 5, the wafers W whose surfaces have been mirror-polished in the previous polishing step are continuously carried one by one into the loader section A, as shown in FIG.
The wafer is sent into the wafer receiving tank B along the flow of pure water.

The wafer receiving tank B is provided with a wafer raising device (not shown), and the wafer W carried into the wafer receiving tank B is raised by the wafer raising device. Then, the vertically standing wafer W
Is vertically supported by the transfer robot 20 and is automatically transferred from the wafer receiving tank B to the pre-cleaning tank C. In the pre-cleaning tank C, the wax immersed in the cleaning liquid and attached to the back surface thereof is removed. Then, the wafer W from which the wax has been removed in the pre-cleaning tank C is vertically supported by the transfer robot 20 and sent to the brush cleaning tank D. Etc. are removed.

The wafer W brush-cleaned as described above.
Are transferred by the transfer robot 20 to the cleaning tanks E, F, G,
H and I are sequentially transported and subjected to a cleaning process.

The wafer W cleaned by the pre-cleaning tanks C to I is transported by the transport robot 20 to the drying apparatus L according to the present invention, where it is quickly dried.

Here, the configuration of the drying apparatus L will be described in detail with reference to FIG.

The drying device L has a housing 141 made of SUS having high heat resistance, and a cylindrical or flat container 142 made of quartz and having a flat rectangular section is provided in the center of the housing 141. The upper portion of the container 142 is covered by a lid member 149, and a small gap δ is formed around the upper portion. A shower device 143 for ejecting pure water is provided at an upper end of the container 142, and an inert gas supply pipe 144 and a pure water drain pipe 145 are connected to a lower end of the container 142.

The container 142 is covered at its periphery by a cylindrical shielding plate 146, and the inner surface of the shielding plate 146 has an infrared heater (hereinafter referred to as a short-wave infrared heater) 147 on the short wavelength side. And a middle-wavelength infrared heater (hereinafter, referred to as a mid-wavelength infrared gland heater) 148 are arranged over substantially the entire vertical direction of the container 142 so as to surround the container 142.

Further, the upper part of the housing 141
The cooling fans 150 of the stand are installed.

The interior of the container 142 is washed with pure water spouted from the shower device 143, and the pure water that has been washed is discharged out of the housing 141 through the pure water drain pipe 145. In addition, pure water drain pipe 1
45 flows only when the shower device 143 operates.

Thereafter, the middle wavelength infrared heaters 148 and the cooling fans 150 are turned on, and the container 142 is first warmed by the middle wavelength infrared heaters 148.
The wavelength range of the middle-wave infrared rays emitted from the middle-wave infrared heater 148 is near the maximum value of 2.6 μm or less, and the middle-wave infrared heaters 148 and 148 (8
FIG. 2 shows the relationship between the irradiation time of the middle-wavelength infrared ray (00W × 2) and the temperature in the bath.

Next, when the wafer W is set in a vertically suspended state in the container 142, the short-wavelength infrared heaters 147 are turned on, and the inert gas supply pipe 144 is supplied with N2 from the inert gas supply pipe 144. An inert gas such as gas or clean air is sealed therein.
The wafer W is discharged to the outside through the upper gap δ, and the mirror surface (polished surface) of the wafer W is irradiated with short-wavelength infrared rays by the short-wavelength infrared heaters 147. The inert gas is supplied to the container 14.
Since the wafer 2 is supplied from below, particles hardly adhere to the wafer W.

Here, the short-wave infrared heater 147, 1
FIG. 3 shows the relationship between the irradiation time of short-wavelength infrared rays and the temperature in the bath according to 47 (1.5 KW × 2), and the maximum value of the short-wavelength infrared rays emitted from the short-wavelength infrared heater 147 is 1 0.3 μm or less.

Incidentally, the middle wavelength infrared heater 148,
When the medium wavelength infrared ray is irradiated for 30 seconds by 148, the temperature in the bath becomes about 25 ° C. (see FIG. 2), whereas when the short wavelength infrared ray is irradiated by the short wavelength infrared heaters 147 and 147 for the same time (30 seconds), about 25 ° C. It can be seen that the temperature rises to 70 ° C. The short-wave infrared heater 147,1
47, when the middle wavelength infrared heaters 148, 148 are turned on, the cooling fans 150, 150 are driven, and the short wavelength infrared heaters 147, 147 and the middle wavelength infrared heaters 148, 148 are cooled.

As described above, the wafers W quickly dried by infrared rays are taken out of the wafer drying apparatus L by the transfer robot 20 and stored one by one in a wafer cassette (not shown) set in the unloader section M.
Here, the cleaning of the wafer W is performed continuously and automatically one by one.

In the above, since the drying apparatus L according to the present invention does not use a centrifugal machine, the manufacturing cost of the apparatus can be reduced and the wafer W can be prevented from being damaged by mechanical work.

Further, since no flammable organic solvent for steam drying is used, it is safe and the cost of the solvent can be saved.

Further, infrared heaters 147, 147, 1
Since the drying is relatively easily performed only by electrical ON / OFF and power control of 48, 148, the drying device L is suitable as a wafer-by-wafer drying device that surely processes wafers W one by one. is there.

[0037]

As is apparent from the above description, according to the present invention, a quartz cylindrical or flat container having a rectangular cross section and containing a plate-shaped material to be dried suspended vertically is heat-resistant. It is housed in a housing, covers the upper part of the container with a slight gap around it, and has a shower device for jetting pure water on the upper part, and the lower part of the container has a drain pipe for discharging fluid. And an inert gas supply pipe to be supplied with an inert gas, the drain pipe flows only when the shower device operates, and the inert gas supplied from the inert gas supply pipe into the container is a container. A plurality of infrared heaters are arranged around the entire length of the container in the vertical direction so as to surround the container, and a cooling fan is provided in the heat-insulating housing and the drying device is provided around the container. Since the structure and the plate-shaped object to be dried 1
The effect that rapid drying can be performed one by one is obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a drying device according to the present invention.

FIG. 2 is a diagram showing a relationship between irradiation time of medium-wavelength infrared rays by a medium-long-wavelength-side infrared heater and temperature in a bath.

FIG. 3 is a diagram showing a relationship between irradiation time of short-wavelength infrared rays by a short-wavelength-side infrared heater and temperature in a bath.

FIG. 4 is a front view of an automatic wafer cleaning / drying apparatus.

FIG. 5 is a plan view of an automatic wafer cleaning / drying apparatus.

FIG. 6 is a side view of the automatic wafer cleaning / drying apparatus.

[Explanation of symbols]

 141 Housing 142 Container 143 Shower device 144 Inert gas supply pipe 145 Drain pipe 147 Short wavelength infrared heater 148 Medium wavelength infrared heater 150 Cooling fan L Drying device W Wafer (plate-like material to be dried) δ Gap at upper part of container

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiharu Kimura Fukushima Prefecture Nishishirakawa-gun Nishigo-mura Ohira 150 Odakura-shi Semiconductor Shirakawa Research Laboratory (72) Inventor Morie Suzuki Nishishirakawa-gun Nishishirakawa-gun Fukushima Prefecture 150 Odakura Ohira Shin-Etsu Semiconductor Co., Ltd.

Claims (2)

(57) [Scope of request for utility model registration] 1. A quartz cylindrical or flat container having a rectangular cross section for accommodating a plate-shaped material to be dried suspended in a vertical direction is accommodated in a heat-resistant housing, and an upper portion of the container is placed around the container. In addition to covering with leaving a slight gap, a shower device for ejecting pure water is provided on the upper part, and a lower part of the container is provided with a drain pipe for discharging fluid and an inert gas supply pipe for supplying inert gas. Connected, the drain pipe is circulated only when the shower device operates, and the inert gas supplied into the container from the inert gas supply pipe is discharged to the outside through a gap at the top of the container, A drying device, comprising a plurality of infrared heaters arranged around the entire length in the vertical direction so as to surround the same, and a cooling fan provided inside the heat insulating housing. 2. The infrared heater according to claim 1, wherein said infrared heater has a short wavelength side having a maximum value of 1.3 μm or less and a wavelength region having a maximum value of 2.6 μm.
2. The drying apparatus according to claim 1, wherein the drying apparatus is a medium-wavelength infrared heater which is in the vicinity of the following.