JPH0650982Y2 - Immersion type substrate processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> This invention applies a required treatment such as a chemical treatment or a cleaning treatment to a thin substrate (hereinafter simply referred to as a substrate) such as a semiconductor substrate or a glass substrate for liquid crystal. More particularly, the present invention relates to an immersion type substrate processing apparatus in which a substrate processing tank is provided with a drainage port for rapidly discharging a processed exhausted processing solution.

<Prior Art> As this type of substrate processing apparatus, the one shown in FIG. 3 (Japanese Utility Model Publication No. 63-93633) proposed by the present applicant has been conventionally known.

That is, the processing liquid supply unit 103A is arranged in the lower portion of the substrate processing tank 103 that stores the processing liquid 111, and the substrate W is provided above the processing liquid supply unit 103A.
A substrate processing unit 103B for immersing the
A drain port 108 with a relatively large diameter is provided at the bottom of the side wall of 3
An opening / closing valve 120 is provided at 108 so as to be opened and closed, and is configured to rapidly discharge a used exhaust treatment liquid. In FIG. 3, reference numeral 101 is a drainage tank in which a substrate processing bath is arranged, 102 is a drain continuous from a bottom wall 101a of the drainage tank 101,
106 is a cassette containing the substrate W to be processed, 105 is a cassette mounting table arranged in the substrate processing bath 103, and 110 is a liquid supply pipe having a large number of liquid supply holes.

<Problems to be Solved by the Invention> In recent years, the degree of integration of semiconductors has been greatly increased, and along with this, higher processing quality has been required for general glass substrates for liquid crystals and the like. Therefore, the following problems have been pointed out in the above conventional example.

Most of the exhausted processing liquid is rapidly discharged from the large-diameter drain port 108, but a part of the liquid droplets remains in the lower corners of the substrate processing tank 103, etc., and is continuously stored. It may be mixed in the liquid and become an obstacle in obtaining higher processing quality. In particular, it is a non-negligible obstacle in the cleaning process of the substrate.

Further, in the conventional example, the liquid level is lowered by the discharge of the exhaustion treatment liquid, and when the liquid level is about a few millimeters from the bottom surface, it takes time to discharge after that, and it is considerably long before the drainage is completed. Need time.

The present invention takes such a situation into consideration, and an object of the present invention is to quickly discharge the used exhaustion treatment liquid without remaining.

<Means for Solving the Problems> In order to solve the above problems, the present invention is an improvement of the conventional substrate processing apparatus as follows.

That is, the processing liquid supply unit and the substrate processing unit in the substrate processing tank are partitioned by a straightening perforated plate, and the straightening perforated plate is arranged so that its surface is substantially at the height of the lower end edge of the drainage port or higher. At the same time, the drain port communicates only with the substrate processing unit,
The present invention is characterized in that a flow rate switching valve for switching a minute amount of the processing liquid to be supplied to the processing liquid supply unit is attached when the processing liquid is discharged.

<Operation> In the present invention, the processing liquid supply unit and the substrate processing unit are separated by the rectifying porous plate, and when processing the substrate, the rectifying porous plate is interposed so that the inside of the substrate processing unit is provided with an appropriate positive pressure. A uniform upward flow of the processing liquid is formed on the substrate, and the surface of the substrate is uniformly processed by the upward flow. When the surface treatment of the substrate is completed, the open / close valve is opened and the exhausted treatment liquid is rapidly discharged from the liquid discharge port. In addition,
The lower edge of the drainage port is located at a height corresponding to the partition position of the straightening perforated plate or at a height lower than that, and the drainage port is communicated only with the substrate processing section. At times, by switching the flow rate switching valve to a very small amount of processing liquid supplied to the processing liquid supply unit, with the drain port open,
When a small amount of the processing liquid is supplied to the processing liquid supply unit, a small amount of fresh processing liquid overflows from the upper surface of the rectifying porous plate and the upper surface of the rectifying porous plate is washed away. In other words, the used up processing solution is not retained in the lower part of the substrate processing tank and is quickly discharged without leaving by the fresh processing solution supplied.

<Embodiment> FIG. 1 is a vertical sectional view of a substrate cleaning apparatus showing an embodiment of the present invention, and FIG. 2 is a vertical sectional view taken along the line II-II of FIG.

In this cleaning processing apparatus, a substrate cleaning tank 3 is arranged in a drainage tank 1, and a drainage port 8 having a relatively large diameter is provided below a side wall of the substrate cleaning tank 3.
Is provided and an opening / closing valve 20 is provided at the drainage port 8 so that the used exhaustion treatment liquid is rapidly discharged.

The on-off valve 20 is provided in the drainage port 8 in this embodiment, but an on-off valve (electromagnetic valve) may be attached to a drainage pipe connected to the drainage port 8.

In the substrate cleaning tank 3, a processing liquid supply unit 3A is arranged in the lower part, and a substrate processing unit 3B for immersing the substrate W is arranged in the upper part thereof, and the processing liquid supply unit 3A and the substrate processing unit 3B are a rectifying porous plate 4. The rectifying perforated plate 4 is partitioned and the surface thereof is the lower edge of the drainage port 8.
It is arranged to match 8a.

In addition, in FIG. 1, the lower end edge 8a of the drainage port 8 is illustrated so as to coincide with the surface of the rectifying porous plate 4, but it goes without saying that the lower end edge 8a may be mounted lower than that.

On the upper side of the rectifying perforated plate 4, a bowl-shaped cassette mounting table 5 is provided, and is configured to wash a large number of substrates W housed vertically in a cassette 6 at once.

On the other hand, in the processing liquid supply unit 3A, a liquid supply port 10 is provided below the liquid discharge port 8 and is connected to a flow rate switching valve 12, and an N ₂ gas pipe 15 for bubbling is provided below the flow straightening plate 4. When cleaning the substrate, the inside of the processing liquid supply unit 3A is set to a constant positive pressure and the pure water cleaning liquid 11
And the rising rectification of the N ₂ gas are formed, and the large number of substrates W are uniformly processed by the rising rectification.

It should be noted that the flow rate switching valve 12 normally uses the valve 13 at the time of processing the substrate, and switches it to the valve 14 at the time of draining the processing liquid to switch a small amount of the processing liquid supplied to the processing liquid supply unit.

A flange 17 is externally fitted and fixed to the drainage port 8, and a fluororesin seal 18 is arranged on an end surface of the flange 17 to form a valve seat 18, and a valve 21 of the on-off valve 20 is pressed against the valve seat 18. It is configured to close the drainage port 8. The valve element 21 is fixed to the side wall of the drainage tank 1 through a fluororesin bellows 24, and the valve shaft 22 extending from the valve element 21 has a compression spring 23 attached to the operating shaft 26 of the air cylinder 25 in the bellows 24. The valve 21 is brought into contact with the valve seat 18 by the advancing operation of the air cylinder 25 to seal the drainage port 8 and the drainage port 8 is opened by the withdrawal action.

The bottom wall 3a of the substrate processing tank 3 has a gentle slope toward the drain port 8, and a drain port 16 for draining cleaning drainage for maintenance is arranged below the liquid feed port 10.

In the substrate processing tank having the above structure, the cleaning liquid 11 and the N ₂ gas bubbles are ejected from the small holes 4a formed on the entire surface of the straightening porous plate 4 during the substrate processing to form a uniform upward flow,
A large number of substrates W can be uniformly processed. The cleaning liquid overflowing from the substrate processing bath 3 is purified from a drain 2 and purified by a purification device (not shown) attached to the circulation channel, and reused.

On the other hand, at the time of discharging the cleaning liquid, the flow rate switching valve 12 is switched to the valve 14 for supplying a small amount, and the fresh cleaning liquid is ejected from the small holes 4a of the rectifying porous plate 4 to cover the surface of the rectifying porous plate 4. This prevents a part of the cleaning liquid used for cleaning the substrate W from staying in the lower part of the substrate processing bath 3.

That is, at the time of drainage, the exhaustion treatment liquid can be quickly drained without remaining by the pure water cleaning liquid supplied in a small amount. As a result, dead water is not generated and bacteria are not generated in the pipe due to dead water, and the water saving effect is large as a whole.

In the above-described embodiment, the substrate cleaning processing apparatus has been described, but the present invention is not limited to this, and can be widely implemented in the case of a chemical processing apparatus in which the remaining exhausted processing solution is harmful. Further, it is not necessary to say anything else that various modifications can be made to the hole diameter and arrangement of the rectifying perforated plate, the on-off valve, the flow rate switching valve, and the like.

<Effect of the Invention> As is clear from the above description, in the present invention, the substrate processing section and the processing liquid supply section are vertically divided by the straightening porous plate, and the surface of the straightening porous plate is almost the bottom edge of the drainage port. In addition to arranging so that the height is the same or higher, the drain port communicates only with the substrate processing unit, and when the processing liquid is drained, a flow rate switching valve that switches a small amount of the processing liquid supplied to the processing liquid supply unit is provided. Since it is attached, by supplying a small amount of fresh treatment liquid to the upper surface of the rectifying porous plate, the exhaustion treatment liquid can be quickly discharged without remaining. Further, as described above, by supplying a small amount of the processing liquid at the time of discharging the liquid, the effect of saving the discharged processing liquid is great.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a cleaning processing apparatus showing an embodiment of the present invention, FIG. 2 is a vertical sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a conventional example corresponding to FIG. It is a figure. 3 ... Substrate processing tank, 3A ... Treatment liquid supply unit, 3B ... Substrate treatment unit, 4 ... Rectifying perforated plate, 8 ... Drain port, 8a ... Bottom edge of drain port, 11 ... Treatment Liquid (pure water cleaning liquid), 12 ... Flow switching valve, 20 ... Open / close valve, W ... Substrate.

Claims (1)

[Scope of utility model registration request] 1. A processing liquid supply unit is arranged in a lower portion of a substrate processing tank for storing a processing liquid, and a substrate processing unit for dipping a substrate is arranged in an upper portion of the processing liquid supply unit, and a drainage liquid is disposed under a side wall of the substrate processing tank. An immersion-type substrate processing apparatus that has a port and an opening / closing valve at the drainage port that is configured to rapidly discharge the used exhausted processing liquid. The part is separated by a straightening porous plate, and the straightening porous plate is arranged such that the surface thereof is substantially at the height of the lower end edge of the drainage port or higher, and the drainage port is communicated only with the substrate processing part, An immersion type substrate processing apparatus characterized in that a flow rate switching valve for switching a minute amount of the processing liquid to be supplied to the processing liquid supply unit is provided when the processing liquid is discharged.