JPH01286425A - Deposit eliminating method and its equipment - Google Patents

Abstract

PURPOSE:To enable easily eliminating deposit foreign matter which can not be eliminated by ordinary cleaning by bringing the foreign matter attaching to a sample into contact with liquid in a vessel, converging and projecting laser light pulse on the liquid in the vicinity of interface between at least the vicinity of the foreign matter and the sample, and utilizing a force generated at the time of rapid vaporization expansion of the liquid. CONSTITUTION:A glass substrate 4 is mounted on the upper surface of a vessel 7; from a liquid feeding pipe 10, liquid is supplied in an inner chamber 8 until the liquid surface comes into contact with the glass substrate 4; from a laser oscillator 1', laser light 2' is projected and converged at a focus point 2a' in the vicinity of an interface between the liquid and the glass substrate 4 in the vicinity of the foreign matter 5a; the liquid 11 is rapidly heated by high power density of the Iaser light 2', rapidly vaporized, and expands in the explosive manner. By the effect of this force, the adjacent liquid 11 is impulsively pushed out, so that the foreign matter 5a is removed from the glass substrate 4 by the impulsive pushing force of the liquid 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for removing foreign matter, and more particularly to a method and apparatus for removing foreign matter suitable for removing foreign matter adhered to a photomask.

[Conventional technology]

Conventionally, in order to remove foreign substances, for example,
As described in Japanese Patent No. 795 and shown in FIG. 2, the workpiece material 5 of the substrate glass 4 is applied to the open end surface of the stage 6
The air in the vacuum chamber 6a is exhausted from the exhaust pipe 7, and the workpiece material 5 is fixed on the stage 6 due to the difference in atmospheric pressure. Next, the laser beam 2 from the laser oscillator 1 is focused by the objective lens 3, and the laser beam passes through the transparent substrate glass 4 and is irradiated onto the workpiece 5 on the back side, and the workpiece material 5 is placed in a vacuum atmosphere. A laser processing method has been proposed.

[Problem to be solved by the invention]

With the above-mentioned conventional technology, thin films can be removed relatively easily, but for example, when cleaning spherical metal materials or transparent materials that are firmly attached to a substrate, normal scrub cleaning or cleaning using acid or alkali can also remove thin films. In the case of attached foreign matter that cannot be removed and remains, it is difficult to remove it.

An object of the present invention is to provide a method and apparatus for removing deposits that can easily remove deposits that cannot be removed by ordinary cleaning.

[Means to solve the problem]

In order to achieve the above object, in the deposit removal method of the present invention, the foreign matter attached to the sample is brought into contact with the liquid in the container, and a pulse of laser light is applied to the liquid near the interface with the sample at least in the vicinity of the foreign matter. It uses focused irradiation and the force generated during rapid vaporization and expansion of liquid to remove foreign substances from the sample.

It also has means for adjusting the liquid level within the container.

Further, in the deposit removal device of the present invention, a sample is placed on the upper surface so as to seal the inside, a container is connected to a liquid supply pipe inside, and stores a liquid that comes into contact with foreign matter adhering to the sample; A liquid adjustment means installed in the supply pipe adjusts the liquid level of the liquid, and a laser beam irradiation means that transmits pulses of laser light through the sample and focuses and irradiates the liquid at least near the foreign object and near the interface with the sample. It is something that

[Effect]

In the foreign matter removal method using the method described above, the liquid in the vicinity of the foreign matter and near the interface with the sample is instantaneously vaporized and expanded by focused irradiation with high power density pulses of laser light.
At that time, the impact causes the firmly attached foreign matter to be removed by mechanically peeling it off, making it possible to easily remove foreign matter from the sample, which was previously difficult to remove.

Furthermore, since the level of the liquid can be adjusted, after removing foreign matter from the sample, the level of the liquid can be lowered to prevent foreign matter from adhering to the sample.

In addition, since the sample is placed on top of the container that stores liquid inside, the sample can be easily brought into contact with the liquid surface.
This allows the explosion phenomenon in liquid to be easily utilized.

Further, since the liquid level can be brought into contact with the sample or lowered by the liquid adjusting means, it is possible to prevent the liquid from leaking from inside the container.

〔Example〕

Hereinafter, FIG. 1 showing an embodiment of the present invention will be described.

As shown in FIG. 1, the upper surface of the container 7 has an inner chamber 8
A liquid supply pipe 10 for placing the glass substrate 4 and supplying the liquid 11 into the internal chamber 8 through the QIJing 9 so as to seal the internal chamber; It has a liquid adjusting means 12 for adjusting the height of the liquid level of the liquid 11 in the liquid 8.

Further, at a position above the glass substrate 4, the laser beam 2' emitted from the laser oscillator 1' is focused by an objective lens 37, and the focused point 2a' is transmitted through the glass substrate 4 and near the foreign object 5a. It has a laser beam irradiation means 12 that focuses and irradiates the vicinity of the interface with the glass substrate 4.

Next, its operation will be explained.

First, the glass substrate 4 is placed on the upper surface of the container 7, and after the liquid is supplied from the liquid supply pipe 10 into the internal chamber 8 until the liquid surface contacts the substrate glass 4, a laser beam 2' is emitted from the laser oscillator 1'.
When the liquid 11 is focused on the converging point 2a' near the interface with the glass substrate 4 in the vicinity of the foreign object 5a, the liquid 11 emits the high power density of the laser beam 2'(10' W/ct1 near the visible light range).
(above), it heats up rapidly, vaporizes rapidly, and expands explosively. This force causes the nearby liquid 11 to be pushed out impulsively, so that the foreign matter 5a adhering to the glass substrate 4 is detached from the glass substrate 4 due to the impulsive extrusion force of the liquid 11. Thereafter, when the liquid adjusting means 12 operates to lower the level of the liquid 11 in the internal chamber 8, the glass substrate 4 is removed from the upper surface of the container 7, and the operation is completed.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

Foreign matter adhering to a sample, which was conventionally difficult to remove, can be easily removed.

Furthermore, since the level of the liquid in the container is lowered when removing the sample from which foreign matter has been removed, it is possible to prevent foreign matter from adhering to the sample.

Further, it is possible to prevent liquid from leaking from inside the container.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a deposit removing device showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a conventional deposit removing device. 1'... Laser oscillator, 2'...
・Laser beam, 3'...Objective lens, 4
...Glass substrate, 7...Container,
8...Internal chamber, 9...0 ring, 10...Liquid supply pipe, 11...
...Liquid, 12...Liquid adjustment means. 1'...Shi-Saizugo main name 44--Glass base 4 pieces
10. = N (A 1 A 5 thread a tube 2'... Shizu 9 58... F, Thing 11.
・ ) (3′・j [4 years old], nu ζ° 7... daytime each 12...shi 4 vines, 41 vines, 1 lily; H.

Claims (1)

[Claims] 1. A foreign substance attached to a sample is brought into contact with a liquid in a container, and a pulse of laser light is focused and illuminated at least in the vicinity of the foreign substance and the liquid near the interface with the sample, so that the liquid rapidly vaporizes and expands. A method for removing foreign matter from a sample by using the force generated during the process. 2. The method for removing deposits according to claim 1, further comprising means for adjusting the level of the liquid in the container. 3. Place the sample on the top surface so that the inside is sealed, and connect the inside to the liquid supply tube. What is claimed is: 1. A deposit removal device comprising a liquid adjusting means for adjusting a surface and a laser beam illumination means for transmitting pulses of laser light through a sample and focusing illumination on a liquid near a boundary surface with the sample at least in the vicinity of a foreign object.