JPH0774137A - Method and apparatus for removing particle on substrate surface - Google Patents

Abstract

PURPOSE:To provide a method and an apparatus for removing particles on a substrate surface which can remove the particles on the substrate surface efficiently and eliminate mutual contamination. CONSTITUTION:(a) A semiconductor wafer W to which partcles P adhere is set on a rotary coater. (b) Coating solution 2 is dropped onto the semiconductor wafer W. (c) The vacuum attracting part 1 of the rotary coater is made to rotate to form a thin film 3 of the coating solution on the semiconductor wafer W. (d) The thin film 3 on the semiconductor wafer W is cured by a hot plate 4. (e) The thin film 3 formed on the surface of the semiconductor wafer W is removed. By following the above mentioned procedure, the particles P on the surface of the semiconductor wafer W can be removed from the semiconductor wafer W together with the thin film 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for physically removing particles such as dust adhering to a semiconductor wafer or a glass substrate for a photomask.

[0002]

2. Description of the Related Art There are the following two typical methods of physically removing particles such as particles and dust adhering to a microfabricated semiconductor wafer or a glass substrate for a photomask.

1) Ultrasonic cleaning A substrate such as a semiconductor wafer is immersed in an organic solvent such as isopropyl alcohol or pure water in an ultrasonic cleaning tank at 34 kH.
By applying ultrasonic vibration of about z, the particles are removed by vibration separation. Recently, ultrasonic vibration of about 1 MHz may be used.

2) Brushing cleaning A substrate such as a semiconductor wafer is vacuum-sucked and rotated on a rotating table, and a brush is brought into contact with the surface of the substrate while spraying an organic solvent such as isopropyl alcohol or pure water onto the surface to remove particles. Remove by wiping.

[0005]

However, the conventional method having such a structure has the following problems. That is, it is difficult for the ultrasonic cleaning to remove particles firmly attached to the surface of the substrate. Also,
In the brushing cleaning, particles removed from the substrate adhere to the brush, and the substrate to be processed next tends to adhere to and contaminate each other.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a particle removing method and an apparatus for efficiently removing particles and preventing mutual contamination between substrates. .

[0007]

The present invention has the following constitution in order to achieve such an object. That is, the invention according to claim 1 is characterized in that the coating liquid is supplied to the surface of the substrate to form a thin film, and the thin film is peeled off to remove particles on the surface of the substrate.

According to the second aspect of the present invention, the adhesive member is brought into close contact with the surface of the substrate on which the thin film is formed by supplying the coating liquid to the surface of the substrate, and the adhesive member is moved upward. A means for peeling the thin film from the surface of the substrate is provided.

[0009]

The operation of the present invention is as follows. That is,
According to the invention of claim 1, in the process of forming the thin film on the surface of the substrate by supplying the coating liquid, the thin film and the particles on the surface of the substrate are combined, and the thin film is peeled off from the surface of the substrate. Are removed from the substrate surface with the thin film.

According to the second aspect of the invention, the adhesive member is brought into close contact with the substrate surface on which the thin film is formed, and the adhesive member is moved upward to peel the thin film from the substrate surface. , Particles are removed from the substrate surface together with the thin film.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As an example, removal of particles attached to a semiconductor wafer will be described. 1 and 2 relate to an embodiment of the present invention. FIG. 1 is a diagram showing a procedure from dropping a coating liquid on a surface of a semiconductor wafer to removing a formed thin film, and FIG. It is a figure which shows the apparatus which removes the thin film formed in the surface.

First, the procedure from dropping the coating liquid on the surface of the semiconductor wafer to removing the thin film will be described. (1) Set the semiconductor wafer on the spin coater (Fig. 1
(Refer to (a)) By rotating a substrate such as a semiconductor wafer at an appropriate rotation speed, the excess amount of the coating liquid dropped on the substrate is scattered to apply the coating liquid to a desired thickness by spin coating. The semiconductor wafer W on which the particles P are attached is placed on the vacuum suction unit 1 of the apparatus (spin coater), and the semiconductor wafer W is held by vacuum suction.

(2) Under coating droplet (see FIG. 1 (b)) An appropriate amount of coating solution 2 such as vinyl acetate or polyurethane is dropped on the surface of the semiconductor wafer W held by the vacuum suction unit 1. To do. The type of coating liquid 2 is not particularly limited,
It is preferable that the thin film be easily peeled off from the semiconductor wafer W so that no residue remains on the wafer surface. Further, it is preferable that the semiconductor wafer W does not contain sodium ions or metals that adversely affect the characteristics of the semiconductor wafer W.

(3) Thin film formation (see FIG. 1 (c)) As an example, the vacuum suction part 1 is rotated at a speed of 1000 revolutions per minute, and the coating liquid 2 dropped on the semiconductor wafer W is, for example, The thin film 3 having a thickness of 2 to 3 μm is formed.

(4) Thin film curing (see FIG. 1 (d)) An appropriate electric current is applied to the heater 5 provided inside the hot plate 4 to heat the hot plate 4, and the semiconductor wafer is placed on the hot plate 4. By mounting W,
The organic solvent contained in the thin film 3 formed on the surface of the semiconductor wafer W is volatilized to cure the thin film 3. At this time, the particles P attached to the surface of the semiconductor wafer W
Cures in a state of being bonded to the thin film 3. When a highly volatile coating liquid is used, the thin film of the coating liquid is hardened during the spin coating in the thin film forming step 3 described above, so that this thin film hardening step can be omitted. Alternatively, it may be cured by natural drying. Alternatively, a coating liquid of an ultraviolet curable resin is used, the coating liquid is spin-coated on the semiconductor wafer W, and then the wafer W is carried into a chamber 7 equipped with an ultraviolet irradiation lamp 6 as shown in FIG. The thin film 3 of the coating liquid may be cured by irradiating the surface of the wafer with ultraviolet UV. As described above, the curing method is appropriately changed and implemented depending on the type of the coating liquid used.

(5) Thin film peeling (see FIG. 1 (e)) In the thin film hardening step of the above-mentioned 4, the thin film 3 which is bonded to the particles P and hardened is mechanically peeled from the semiconductor wafer W. At this time, the particles P are removed from the surface of the semiconductor wafer W together with the thin film 3.

Next, an apparatus for peeling the thin film 3 formed through the above steps (1) to (4) from the semiconductor wafer W will be described with reference to FIG. FIG. 2 is a diagram showing a schematic configuration of an example of a particle removing apparatus for a substrate surface according to the present invention. In the figure, reference numeral 10 is an adhesive tape having an adhesive surface on the side of the thin film 3 on the semiconductor wafer W, and the adhesive tape 10 having an appropriate length is wound around the tape supply unit 11. The adhesive tape 10 delivered from the tape supply unit 11 is pressed against the thin film 3 by the rotating roller 12 and is wound up by the tape winding unit 13 which is rotationally driven by a motor or the like.

The semiconductor wafer W is adsorbed and held by a moving plate 20 having a vacuum adsorbing section and moves from the rotating roller 12 toward the tape winding section 13 at an appropriate speed. Rotating roller 1
In the semiconductor wafer W reaching below 2, the thin film 3 formed on the upper part of the semiconductor wafer W contacts the adhesive surface of the adhesive tape 10 and is pressed by the rotating roller 12, whereby the thin film 3 adheres to the adhesive surface of the adhesive tape 10. To be done. When the moving plate 20 further advances, that is, when the semiconductor wafer W moves, the adhesive tape 10 is pulled up by the winding operation of the tape winding portion 13 located above the rotation roller 12, so that the semiconductor wafer W is moved upward. The thin film 3 is peeled from the surface of the.

Next, referring to FIG. 3, the effect of removing particles on the surface of a semiconductor wafer by the method of this embodiment and the conventional method will be compared.

As the sample, as shown in FIG. 3C, a semiconductor wafer having approximately 2000 silicon particles having a size of about 0.2 μm adhered to its surface almost uniformly was used.

(A) Conventional Example The above semiconductor wafer was immersed in pure water and particles were removed by an ultrasonic device with a frequency of 1 MHz.
It shows in (a). The residual particles after the particle removal processing measured by the particle counter are 614
And the removal rate was about 70%.

(B) This Example A polyurethane-based coating liquid was formed on the surface of the above-mentioned semiconductor wafer into a thin film having a thickness of 2 μm, and then a removing treatment was performed. The processed semiconductor wafer is shown in FIG. Similarly, the number of residual particles after the particle removal treatment measured by a particle counter was 176, and the removal rate was about 90%.

As described above, it can be seen that the method of this embodiment significantly improves the particle removal rate as compared with the conventional method.

In the present embodiment, a spin coater is used for forming a thin film, a hot plate is used for hardening the thin film, and a peeling device is used for peeling the thin film, and separate devices suitable for the respective processes are used. A particle removing device that performs the series of processes described above may be used.

Further, while the spin coater was used for forming the thin film, the coating may be performed by "brush", "roller" or the like instead. Further, although the peeling device was used at the time of peeling the thin film, a person may peel the film manually by using tweezers or the like instead.

[0026]

As is apparent from the above description, according to the invention described in claim 1, when the thin film is formed on the substrate surface by supplying the coating liquid, the particles on the substrate surface are bonded to the thin film. By peeling off the thin film, the particles firmly attached to the substrate surface can be removed. Further, according to the present invention, there is no problem of cross-contamination between substrates such as brushing cleaning.

According to the second aspect of the present invention, since the adhesive tape is attached to the substrate surface on which the thin film is formed and the adhesive tape is peeled off, the thin film is peeled off from the substrate surface. Can be removed efficiently.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic procedure of a method of removing particles from a substrate surface according to the present invention.

FIG. 2 is a diagram showing a schematic configuration of a substrate surface particle removing apparatus according to the present invention.

FIG. 3 is a diagram for comparative explanation of the present embodiment and a conventional method.

FIG. 4 is a diagram showing an example in which a thin film is cured by irradiation with ultraviolet rays.

[Explanation of symbols]

 W ... Semiconductor wafer P ... Particle 2 ... Coating liquid 3 ... Thin film 10 ... Adhesive tape 11 ... Tape supply unit 12 ... Rotating roller 13 ... Tape winding unit 20 ... Moving plate

Claims (2)

[Claims] 1. A method of removing particles on a substrate surface, comprising: supplying a coating liquid to the surface of a substrate to form a thin film; and removing the thin film to remove particles on the substrate surface. 2. An adhesive member is brought into close contact with the surface of the substrate on which the thin film is formed by supplying a coating liquid to the surface of the substrate,
A particle removing device for a substrate surface, comprising means for separating the thin film from the substrate surface by moving the adhesive member upward.