JP2000068197A - Bubble preventer and eliminator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of microbubbles and remove bubbles mixed in a chemical by sending the chemical, a developing solution, into hollow fibers through fine holes formed on the outer surfaces of the hollow fibers in a housing, and passing it through the hollow fibers to be discharged onto a wafer through a discharge nozzle. SOLUTION: When discharging a developing solution onto a wafer W through a discharge nozzle 5, with a valve 3 opened, a developing solution is sent out from a source 1 of the developing solution into a housing 8 through hollow pipes 2a, 2b. The developing solution then fills a space around the outer surfaces of hollow fibers 6 stored in the housing 8 and finally fills the entire housing 8. At that time, the air existing in the space 7 is exhausted through an exhaust pipe 10. Meanwhile, the developing solution enters each of the hollow fibers 6 through fine holes formed on the outer surfaces and passes through the hollow fibers 6 along the inner surfaces to be discharged onto a wafer W from a discharge nozzle 5 through a hollow pipe 2c. At that time, even if bubbles are mixed in the developing solution, the ones having the larger diameter than that of the fine holes formed on the outer surfaces of the hollow fibers 6 never enter the hollow fibers 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing and generating air bubbles which is used in a resist developing apparatus in a developer process of a semiconductor manufacturing apparatus. The present invention relates to an apparatus using a large number of hollow fibers having a predetermined length and a small inner diameter.

[0002]

2. Description of the Related Art Conventionally, in a resist developing apparatus in a developer process of a semiconductor manufacturing apparatus, microbubbles called microbubbles mixed into a developing solution have been problematic. If these bubbles are mixed in the developing solution, when the paddle is formed on the wafer from the nozzle, the bubbles adhere to the surface of the resist, and the portion cannot contact the developing solution, resulting in poor development. It is. For this reason, there has been proposed an apparatus in which a deaeration mechanism is provided in a pipe between a valve and a discharge nozzle in order to remove the bubbles. Now, this will be described with reference to FIG. 5. In the conventional apparatus, the developing solution sent from the developing solution supply source 20 passes through the hollow tube 21a, passes through the hollow tube 21b through the control valve 22, and passes through the hollow tube 21b. Then, after passing through the deaerator 23, the developing solution is further poured from the hollow tube 21 c onto the wafer W from the discharge port of the nozzle 25 attached to the tip of the hollow tube. At this time, a hollow fiber permeable to air is used in a housing as a deaerator, and the housing is connected to a vacuum pump 24, and the housing is dissolved in a developer by reducing the pressure in the housing. The microbubbles were configured to be removed from the inside of the hollow fiber. (For example, Japanese Patent Application Laid-Open No.
75, JP-A-8-243306, JP-A-9-7936,
JP-A-9-45615, JP-A-9-75704, etc.)

[0003]

However, the conventional apparatus required an expensive decompression device such as a vacuum pump to remove the microbubbles during the dissolution of the developer. Therefore, the present invention is to provide a device that does not substantially generate microbubbles and removes air bubbles mixed in for some reason at a relatively low cost, even without these expensive vacuum pumps and other decompression devices. It is.

[0004]

A device for discharging a chemical solution pumped from a chemical solution supply source to the outside from a discharge nozzle by opening and closing a valve, wherein the device is provided in the middle of a piping path between the discharge nozzle and the valve. A housing having micro holes on the outer peripheral surface and containing a hollow fiber having a predetermined length and a small inner diameter is provided. Then, the chemical solution is allowed to pass through the hollow fibers through the fine holes on the outer peripheral surface of the hollow fibers of the housing. At this time, air bubbles mixed for some reason are blocked by the fine holes on the outer peripheral surface of the hollow fiber. Further, the pressure fluctuation in the chemical solution caused by the opening and closing of the valve is configured to be absorbed by the space outside the hollow fiber in the housing.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows a semiconductor developing apparatus, for example, a resist developing apparatus, in which a semiconductor wafer is rotated by a spinner mechanism. The structure is such that a developing solution is supplied from a nozzle onto the wafer, and the solution is filled by the surface tension of the developing solution. That is, the developing solution sent from the developing solution supply source 1 passes through the hollow tube 2 a and passes through the control valve 3 to the hollow tube 2.
b, passes through the bubble generation preventing / bubble removing device 4 of the apparatus of the present invention, and further passes from the hollow tube 2c onto the wafer W from the discharge port of the nozzle 5 attached to the tip of the hollow tube. The developer is loaded. At this time, the wafer W is held by vacuum suction by spin chuck via the rotation shaft of the motor M.

[0006] A bubble removing device 4 for preventing and generating bubbles according to the present invention.
Has micropores on the outer peripheral surface, as shown in FIGS.
And a large number of hollow fibers 6 having a predetermined length and a small inside diameter.
Is fixed to the left end and the right end with an adhesive, respectively, and housed in the housing 8. That is, as the hollow fiber 6 used here, for example, cellulose, cellulose diacetate, cellulose triacetate, etc., cellulose derivatives such as cellulose ethers, polyamide derivatives, polyester derivatives, methacrylic materials such as polymethyl methacrylate, Acrylic polymer, polyvinyl polymer such as polyvinyl chloride, polyurethane,
It is formed of a polyolefin such as polyethylene or polypropylene, a hydrophilized fluororesin, polysulfone, polyethersulfone, polyarylate, polyimide, or a mixed material of these materials.

The diameter of the micropores on the outer peripheral surface of the hollow fiber 6 is
The thickness is preferably from 5 to 100 nm, and more preferably from 7 to 60 nm. Further, the porosity of the hollow fibers is preferably 40 to 80%. Further, the inner diameter of the hollow fiber 6 is 0.1 mm to 0.5 m.
m. When the inner diameter is 0.1 mm or less, the developer does not easily flow, which is not preferable.

The hollow fibers 6 housed in the housing 8
Is formed in the order of 1,000 to 32,000, preferably 6,000 to 10,000. That is, the number of the hollow fibers is determined by the discharge amount of the developer and the inner diameter of the hollow fibers, and the discharge amount of the developer is now 20 cc / s to 75 cc / s.
When the inner diameter of the hollow fiber is set to 0.1 mm to 0.5 mm, this range can be stably prevented from generating bubbles, and bubbles can be removed with a small pressure loss.

It is preferable that the ratio of the cross-sectional area of the hollow fiber bundle to the cross-sectional area of the hollow fiber storage portion in the housing 8 (hereinafter referred to as the hollow fiber filling rate) is in the range of 30 to 60%, and more preferably. A range of 40 to 50% is good. If the hollow fiber filling ratio is less than 30%, it is difficult to uniformly disperse the hollow fibers in the housing, and it is difficult to integrate the developer discharged through the hollow fibers. or,
If the hollow fiber filling ratio exceeds 60%, the separated air bubbles are difficult to escape to the upper part, which is not preferable.

The length of the hollow fiber varies depending on the setting conditions such as the inner diameter of the hollow fiber, the type of the developing solution, the pressure loss, and the material. The length is determined empirically by observing the air bubble removal state in the housing. , 15 mm or more and 300 mm or less. The reason for the need of 15 mm or more is to fix the right end and the left end with an adhesive, and in the case of 15 mm or less, when discharging the developer from the micropores on the outer surface of the hollow fiber to the outside through the hollow fiber, This is because the flow of the developer is not uniformly rectified, and although it depends on the structure of the nozzle, a swirling flow is easily generated in the discharge flow from the nozzle, which is not preferable. 3
This is because if the length is more than 00 mm, the length of the entire device becomes too large and is not practical.

The housing 8 is made of a synthetic resin and is formed in a cylindrical shape, and communicates with the hollow tube 2b at a lower portion thereof.
On the other hand, the left side communicates with the middle space 2c, and the upper part communicates with the discharge pipe 10.

As shown in FIG. 1, when the developing solution is discharged from the developing solution discharging nozzle 5 onto the wafer W, the valve 3
Is opened, the developer enters the housing 8 from the developer supply source 1 through the hollow tube 2a, passes through the valve 3 and passes through the hollow tube 2b. Here, the developing solution fills the voids 7 on the outer peripheral surface of the hollow fibers 6 housed in the housing 8, the liquid level gradually rises, and the inside of the housing 8 is filled with the developing solution. At this time, the air existing in the gap 7 of the housing 8 is discharged from the discharge pipe 10. On the other hand, the developer passing through the hollow fibers 6 from the fine holes on the outer peripheral surface of each hollow fiber 6 moves from right to lower left toward the space 9 along the inner peripheral surface. Then, the developer is discharged from the discharge nozzle 5 onto the wafer W via the hollow tube 2c. At this time, the developer supply source 1
Even if bubbles are mixed in the developing solution sent from the valve 3 through the valve 3, among the bubbles, bubbles larger than the diameter of the fine holes on the outer peripheral surface of the hollow fiber 6 pass through the fine holes. And cannot enter the hollow fiber.

In addition, when the valve 3 is normally opened and closed, bubbles are easily generated in the developer in the hollow tube 2b near the valve 3 due to the pressure fluctuation accompanying the opening and closing of the valve 3. The pressure fluctuation caused by the opening and closing of the valve 3 is absorbed and mitigated by the bundle of the hollow fibers 6 in the housing 8, and the developer in the hollow tube 2b has no pressure fluctuation, so that no bubbles are generated near the valve 3. .

FIG. 4 shows the result of measuring the pressure fluctuation in the developing solution in the hollow tube 2b interposed between the valve 3 and the apparatus of the present invention with the opening and closing of the valve 3. On the other hand, the case of a conventional apparatus is shown in FIG. That is, in FIGS. 4 and 6,
The vertical axis indicates the pressure (* 10-1 MPa) in the hollow tube 2b, while the horizontal axis indicates time (s).
The relation of the pressure fluctuation accompanying the opening and closing of is shown. In the case of the present invention, the pressure does not become negative, so that the gas dissolved in the developer does not become microbubbles (bubbles). On the other hand, in the conventional case, as shown in FIG. 6, there is a pressure fluctuation that becomes a negative pressure between 2 s and 3 s. As a result, the pressure fluctuation that becomes the negative pressure causes The gas dissolved in becomes microbubbles (bubbles). For this reason, as shown in FIG.
And remove it.

[0015]

[Example] Test conditions Developer used: TMAH 2.38% Discharge flow rate: 65 cc / s, Discharge time: 2 s Hollow tube inner diameter: 6.35 mm Housing: inner diameter 50 mm, length 150 m
m Hollow fiber filling ratio: 45% Hollow fiber material: Polymer alloy of polyether sulfone / polyarylate Hollow fiber outer peripheral surface fine pore diameter: 7 nm Porosity: 70% Hollow fiber length: 140 mm Room temperature: 22 ° C. Developer temperature: 22 The present invention, the conventional device,
And the distance L between the valve 3 and the device of the present invention is divided into
Table 1 shows the results of visually judging the state of bubble generation when the (length of the hollow tube 2b) was changed.

[0016]

[Table 1]

As described above, the present invention is applied to the case where the apparatus of the present invention is applied to a semiconductor manufacturing apparatus. However, the present invention is not limited to this. If there is any adverse effect, it can of course be applied to other devices because it can be removed.

[0018]

As described above, the present invention has a fine hole in the outer peripheral surface in the middle of the piping path between the discharge nozzle and the valve,
In addition, a housing having a built-in hollow fiber having a predetermined length and a small inner diameter is provided, and a chemical solution is allowed to pass through the hollow fiber from the fine hole on the outer surface of the hollow fiber of the housing, and the developer is discharged from the discharge nozzle. Since it is discharged onto the wafer, it absorbs pressure fluctuations in the chemical solution due to the opening and closing of the valve compared to conventional devices, preventing the generation of bubbles generated near the valve and the bubbles mixed in for some reason. Is blocked by the micropores on the outer peripheral surface of the hollow fiber, which has an effect of substantially eliminating the bubble problem.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of a main part outline of a resist developing step of a semiconductor manufacturing apparatus provided with the apparatus of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a perspective view of one hollow fiber used in the device of the present invention.

FIG. 4 is an explanatory diagram showing a pressure fluctuation state in a pipe between the device of the present invention and a valve when the valve is opened and closed.

FIG. 5 is an explanatory view showing an example of an outline of a main part of a resist developing step of a semiconductor manufacturing apparatus provided with a conventional apparatus.

FIG. 6 is an explanatory diagram showing a pressure fluctuation state in a pipe between a conventional device and a valve when the valve is opened and closed.

[Explanation of symbols]

 Reference Signs List 1 developer supply source 2a, 2b, 2c hollow tube 3 valve 4 device of the present invention 5 discharge nozzle 6 hollow fiber 7 void 8 housing 9 space W wafer

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 22, 1998 (1998.12.
22)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of a main part outline of a resist developing step of a semiconductor manufacturing apparatus provided with the apparatus of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a perspective view of one hollow fiber used in the device of the present invention.

FIG. 4 is an explanatory diagram showing a pressure fluctuation state in a pipe between the device of the present invention and a valve when the valve is opened and closed.

FIG. 5 is an explanatory view showing an example of an outline of a main part of a resist developing step of a semiconductor manufacturing apparatus provided with a conventional apparatus.

[Description of Signs] 1 Developer supply source 2a, 2b, 2c Hollow tube 3 Valve 4 Device of the present invention 5 Discharge nozzle 6 Hollow fiber 7 Void 8 Housing 9 Space W W Wafer

 ──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant 000226242 Nikkiso Co., Ltd. 3-43-2, Ebisu, Shibuya-ku, Tokyo (72) Inventor Tadaoki Mitani 1-50 Asahidai, Tatsunokuchi-cho, Nomi-gun, Ishikawa Pref. University A-34 (72) Inventor Hidenobu Hori 2-27-25 Heiwa-cho, Kanazawa-shi, Ishikawa Pref.Heiwa-shukusha B33-42 (72) Inventor Toshikazu Niki 353 Takanami, Tonami-shi, Toyama Pref. (72) Inventor Yoshihiko Doo Ishikawa 2-89-3 Izumimotocho, Kanazawa-shi (72) Inventor Toshiaki Chiba 3-1-1 Hokuyodai, Kanazawa-shi, Ishikawa Nikkiso Co., Ltd. Kanazawa Works F-term (reference) 2H096 AA25 GA23 GA30 5F046 LA03 LA04

Claims (1)

[Claims] 1. A device for discharging a chemical solution pumped from a chemical solution supply source onto a substrate such as a wafer from a discharge nozzle by opening and closing a valve. A housing having micropores on its surface and housing a hollow fiber having a predetermined length and a small inner diameter is provided, and the chemical solution passes through the hollow fiber from the micropores on the outer surface of the hollow fiber of the housing. This absorbs pressure fluctuations in the chemical solution caused by opening and closing the valve, preventing the generation of bubbles near the valve and blocking air bubbles mixed in the chemical solution with micropores on the outer peripheral surface of the hollow fiber. A bubble generation preventing / bubble removing device, characterized in that the bubble removing device is configured to perform the operation.