JPH02134820A - Cleaning and drying device - Google Patents

Abstract

PURPOSE:To obtain a device which can clean and completely dry an object to be treated even with solution of relatively high viscosity attached thereto by providing a first nozzle device which sprays a first cleaning solution to the object to be treated and a second nozzle device which sprays a second cleaning solution to the object to be treated to lower the viscosity of the first cleaning solution. CONSTITUTION:A device is provided with a spin head 2 to hold, rotate and dry a treatment object 7, a first nozzle device 11 to spray a first cleaning solution to the object 7 to be treated and a second nozzle device 21 to spray a second cleaning solution to lower a viscosity of the first cleaning solution to the treatment object 7. For example, a cleaning and drying device to eliminate a foreign material of photosensitive polyimide attached to a rear side of a wafer 7 is integrally incorporated in an application device to apply photosensitive polyimide 5 onto the wafer 7. The first nozzle 11 is made to supply pyrrolidine being a solvent of photosensitive polyimide solution as the first cleaning solution from the first cleaning solution supply device 13 through a control valve 15. The second nozzle, 1 is made to supply pure water 22 as the second cleaning solution from a second cleaning solution supply device 23 through a control valve 25.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cleaning/drying apparatus, especially when a part of a film formed on a workpiece is attached to an unnecessary place as a foreign substance. For example, in the manufacturing process of semiconductor devices, when a photosensitive polyimide film coated on the front surface of a wafer wraps around to the back side and adheres as a foreign substance, the photosensitive polyimide film attached to the back side can be removed by cleaning. This invention relates to an effective material that can be used to remove foreign substances from polyimide.

[Conventional technology]

In the manufacturing process of semiconductor devices, the wafer is placed and held on a rotatable spin head installed inside a processing container as a device for coating photosensitive polyimide onto a wafer, and the wafer is rotated by the spin head and exposed to light. Some devices are configured to supply and apply a solution of polyimide onto the surface of a wafer.

In such a coating device, a photosensitive polyimide solution supplied to the front surface of the wafer and diffused by rotation wraps around the back surface of the wafer as it rotates, so that a part of the photosensitive polyimide film coats the outer periphery of the back surface of the wafer. may adhere as foreign matter to the parts.

Therefore, in such coating equipment, while rotating the wafer, pyrrolidione, which is used as a solvent for the photosensitive polyimide solution, is sprayed onto the photosensitive polyimide film that is attached as a foreign substance to the outer peripheral edge of the back surface of the wafer and melted. It is conceivable to remove the melt and pyrrolidione by centrifugal force.

Examples that describe spinner coating technology include "Electronic Materials November 1983 Special Issue" published by Kogyo Research Association Co., Ltd., pages 92 to 96, November 15, 1983, and Japanese Patent Publication No. 53-37189. be.

[Problem to be solved by the invention]

However, when the configuration is configured to spray pyrrolidione to remove foreign substances from photosensitive polyimide, since pyrrolidione is a relatively high viscosity solvent, the pyrrolidione attached to the back surface of the wafer is not removed by centrifugal force and remains. The inventor of the present invention has revealed that there is a problem.

An object of the present invention is to provide a cleaning/drying apparatus that can clean and completely dry even when a relatively high viscosity liquid adheres to a treated object.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

An overview of typical inventions disclosed in this application is as follows.

That is, a spin head that holds and rotates the workpiece to dry it, a first nozzle device that sprays the first cleaning liquid onto the workpiece, and a second nozzle device that reduces the viscosity of the first cleaning liquid onto the workpiece.
A second nozzle device for spraying cleaning liquid is provided.

[Effect]

The object to be processed is rotated while being held by the spin head. During this rotation, first, the part to be cleaned of the workpiece is
The first cleaning liquid is sprayed by the nozzle device to perform primary cleaning.

Subsequently, the second cleaning liquid is sprayed onto the primary cleaning section by the second nozzle device. Thereby, secondary cleaning is performed in which the first cleaning liquid that has adhered to the object to be processed due to being used in the primary cleaning is washed off by the second cleaning liquid.

Next, the supply of the second cleaning liquid is stopped, and the object to be processed is rotated idly to perform centrifugal dewatering. At this time, the first cleaning liquid is washed off by being used for secondary cleaning, and only the second cleaning liquid is attached to the object, and furthermore, this second cleaning liquid has a lower viscosity than the first cleaning liquid. Therefore, the object to be treated must be sufficiently dried by centrifugal dehydration.

〔Example〕

FIG. 1 is a longitudinal cross-sectional view showing a coating device incorporating a cleaning and drying device according to an embodiment of the present invention, and FIGS.
The figures are longitudinal cross-sectional views for explaining the effects.

In this embodiment, this coating device is configured to coat photosensitive polyimide onto a wafer, and this coating device is equipped with a cleaning and drying device according to the present invention to remove foreign matter from the photosensitive polyimide attached to the back surface of the wafer. As something to do,
integrated. This coating device is a processing container 1.
A spin head 2 is provided inside the container 1 so as to be rotated by a suitable drive means (not shown). The spin head 2 is configured to be able to hold a wafer 7 as an object to be processed by vacuum suction or the like. This spin head 2 is used for both coating work and cleaning and drying work. An air supply port 3 is provided approximately at the center of the upper surface of the processing container 1, and an exhaust port 4 is provided at a position outside the spin head 2 on the bottom wall of the processing container 1. Directly above the center of the spin head 2 in the processing container 1, a dropping tube 6 for dropping a coating material 5 using a photosensitive polyimide solution is inserted, and the dropping tube 6 and the processing container 1 are connected to each other. are adapted to be raised and lowered relative to each other by suitable means (not shown).

This coating device incorporates a first nozzle device and a second nozzle device in the cleaning/drying device. That is,
The nozzle 11 of the first nozzle device 10 is installed on the bottom wall of the processing container l.
A first cleaning liquid supply device 13 is connected to this nozzle 11 via a liquid supply path 14 and a control valve 15.

This supply device 13 is configured to supply pyrrolidione 12, which is a solvent for the photosensitive polyimide solution, as a first cleaning liquid. Further, a nozzle 21 of a second nozzle device 20 is installed on the bottom wall of the processing container 1, with its outlet facing closer to the inside of the outer peripheral edge of the back surface of the wafer 7 than the outlet of the first nozzle 11. A second cleaning liquid supply device 23 is connected to the second nozzle 21 via a liquid supply path 24 and a control valve 25 . This supply device 23 supplies pure water 22 to a second
It is designed to be supplied as a cleaning liquid.

Next, the method of using and the operation of the coating apparatus equipped with the cleaning and drying apparatus according to the above structure will be described in connection with coating a photosensitive polyimide solution on a wafer and cleaning and drying it.

Here, the photosensitive polyimide resin liquid used as the coating material 5 is made by adding a resist to a polyimide resin such as polyimide iso indolo cina zolinedione (P[Q), etc.
It is a solution obtained using a solvent for polyimide resin such as normal methyl pyrrolidione (NMP), and has a relatively high viscosity for spinner coating, such as 20 to 4.0 voids. It is made of wood. In the manufacturing process of semiconductor devices, this photosensitive polyimide is used to form a protective film on a wafer and to punch holes in the protective film to expose electrode pads (hereinafter referred to as holes). Processing can be simplified.

First, as shown in FIG. 1, when a wafer 7 as an object to be coated is placed on the spin head 2 and held by means such as vacuum suction, the wafer 7 is rotated. When this rotation becomes stable, the coating material 5 is dropped onto the center of the wafer 9 from the dropping tube 6, and the coating material 5 is spread in the radial direction by centrifugal force, forming a coating film 8 on the surface of the wafer 7. That will happen. At this time, as shown by the solid line arrow in FIG. will be prevented.

By the way, when a photosensitive polyimide solution is used as a coating material to form a protective film with holes on a wafer, it is necessary to obtain the desired photosensitive performance and film thickness as a retention film.
It is necessary to set the viscosity of the photosensitive polyimide solution as a coating material to be relatively high. In order to uniformly spread such a highly viscous coating material by centrifugal force, the rotation speed of the spin head is set high. As a result, the coating material applied to the wafer surface wraps around to the back surface of the wafer due to the centrifugal force of the spin head, and as shown in FIG.
It will be attached as.

In this manner, if the wafer is sent to the next process with foreign matter attached to the outer peripheral edge of the back surface, the foreign matter may accidentally fall off the wafer, contaminating the surfaces of that wafer and other wafers. Further, when a wafer with foreign matter still attached is baked or cured by heating with a heater, the heater becomes contaminated. Further, when the back surface of a wafer is removed by wet etching using hydrofluoric acid, etching remains are generated because the slopes on the back surface of the wafer to which foreign matter has adhered are not etched.

Therefore, in this embodiment, the foreign matter adhering to the back surface of the wafer is completely removed by the following cleaning and drying operations.

First, when the desired coating film 8 is formed on the surface of the wafer 7, as shown in FIG.
By opening the control valve 15 in
4 to the first nozzle 11, and the pyrrolidione 1
2 is sprayed by the first nozzle 11 onto the foreign matter 9 attached to the outer peripheral edge of the back surface of the rotating wafer 7. Since this pyrrolidione 12 is a solvent for the photosensitive polyimide solution forming the coating film 8, the homogeneous foreign matter 9 is melted.

The melted foreign matter 9 is scattered from the back surface of the wafer 7 together with the pyrrolidione 12 by centrifugal force.

However, since the pyrrolidione 12 is a solvent with relatively high viscosity, after the foreign matter 9 is melted and scattered, a small amount remains attached to the back surface of the wafer 7.

Therefore, in this embodiment, after spraying the pyrrolidione 12 as the first cleaning liquid, the second nozzle device 20 sprays the pure water 22 as the second cleaning liquid onto the wafer 7 to wash away the remaining pyrrolidione.

That is, as shown in FIG. 3, by opening the control valve 25 in the second nozzle device 20, the second
Pure water 22 as a cleaning liquid is supplied to the second nozzle 21 via the liquid supply path 24, and the pure water 22 is
It is sprayed onto the pyrrolidione 12 remaining attached to the outer peripheral edge of the back surface of the rotating sea urchin huff. And this pure water 2
2 mixes into the pyrrolidione 12 adhering to the wafer and lowers its viscosity, and its spraying causes the force to wash off the pyrrolidione 12 from the wafer.

In this way, the pyrrolidione 12 remaining on the wafer 7 is completely washed away by the pure water 22, but the pure water 22 now remains on the back surface of the wafer 7.

Therefore, in this embodiment, the wafer 7 is rotated at high speed by the spin head 2, so that the pure water 22 adhering to the wafer 7 is centrifugally dehydrated. At this time, since the pure water 22 has a lower viscosity than the pyrrolidione 12, it can be sufficiently dehydrated by centrifugal force alone. As a result, the wafer 7 will be completely dried.

According to the embodiment described above, the following effects can be obtained.

(1) After the object to be treated is primarily cleaned with the first cleaning liquid, it is secondly cleaned using a second cleaning liquid that reduces the viscosity of the first cleaning liquid, and the first cleaning liquid is washed away by this secondary cleaning, and then, By removing the second cleaning liquid used for the secondary cleaning from the processed material through centrifugal dehydration, the first
Even when a relatively high viscosity liquid is used as a cleaning liquid, the object to be processed can be completely cleaned and dried, thereby preventing secondary contamination of the object, contamination of peripheral equipment, and the object to be processed. It is possible to prevent the occurrence of post-processing defects.

(2) In the process of applying the photosensitive polyimide film to the wafer, the photosensitive polyimide foreign matter adhering to the back side of the wafer is completely cleaned, and the wafer is completely dried. Since it is possible to realize the formation of the protective film, the lithography process can be carried out in the process of forming the protective film.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the first cleaning liquid is not limited to using pyrrolidione, but other solvents may also be used.

Further, the second cleaning liquid is not limited to pure water, but may also be alcohol such as isopropyl alcohol (IPA), acetone, thinner, xylene, or the like.

In addition, the shape and structure of the nozzle, the amount of cleaning liquid supplied, the supply time, the spraying shape, the flow rate, the flow velocity, the flow pressure, and the temperature, etc., are determined by the type of film to be formed on the object to be treated, the viscosity, the film thickness to be formed,
It is desirable to optimize the process in accordance with various conditions such as the diameter of the object to be processed, the shape and structure of the processing container, and the displacement volume.

In the above explanation, the invention made by the present inventor was mainly applied to the technology for coating photosensitive polyimide on a wafer, which is the background application field, but it is not limited to this. It can also be applied to the case where a resist is applied to the object to be processed, and furthermore, the case where a developing solution is supplied onto the object to be processed to form a film. In particular, according to the present invention, excellent effects can be obtained when applied to the case where a high viscosity solution is supplied and stretched onto an object to be processed to form a film on the object to be processed.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

After the object to be processed is first washed with the first washing liquid, it is secondly washed using a second washing liquid that reduces the viscosity of the first washing liquid, and the first washing liquid is washed off by this second washing, and then centrifugal dehydration work is performed. By removing the second cleaning liquid used for the secondary cleaning from the workpiece, even if a relatively high viscosity liquid is used as the first cleaning liquid,
Since the object to be processed can be completely cleaned and dried, it is possible to prevent secondary contamination of the object, contamination of peripheral equipment, and poor post-processing of the object.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing a coating device incorporating a cleaning and drying device according to an embodiment of the present invention, and FIGS.
The figures are longitudinal cross-sectional views for explaining the effects. DESCRIPTION OF SYMBOLS 1... Processing container, 2... Spin head, 3... Air supply port, 4... Exhaust port, 5... Coating material (photosensitive polyimide), 6... Dripping pipe, 7... ...Wafer (processed object)
, 8... Coating film (photosensitive polyimide film), 9... Foreign matter, 10... First nozzle device, 11... Nozzle, 1
2... Pyrrolidione (first cleaning liquid), 13... Pyrrolidione supply device, 20... Second nozzle device, 21.
...Nozzle, 22...Pure water (second cleaning liquid), 23...
・Pure water supply device. Fig. 1 Fig. 2 Fig. 2 Spin Δγ de γ・ Yaruha O bite e fracture (sum)

Claims (1)

[Claims] 1. A spin head that holds and rotates the object to be processed to dry it, a first nozzle device that sprays the first cleaning liquid onto the object, and a first nozzle device that reduces the viscosity of the first cleaning liquid onto the object. 2. A washing/drying device comprising: a second nozzle device for spraying a second washing liquid. 2. The object to be processed is a wafer coated with a photosensitive polyimide film, a solvent for the photosensitive polyimide film is used as the first cleaning liquid, and a liquid that reduces the viscosity of this solvent is used as the second cleaning liquid. The washing/drying apparatus according to claim 1, characterized in that: