JPS5853829A - Electron beam exposing device - Google Patents

Abstract

PURPOSE:To prevent the dust infiltration into an exposing device, by providing a sample carry in-out part an automatic loader part in the adjacency to the exposing device, and containing therein a discharge electrode part and a dust collecting electrode part. CONSTITUTION:An electron beam exposing device is constituted of the exhaust system consisting of an electron gun 1, three-stage electron lenses 2-2'', movable sample base 4 and a cryopump 3, and an Si wafer 5 to be exposed is mounted on the sample base 4. In this constitution, the automatic loader part 6 is provided in the adjacency to the exposing device to load the wafer 5 on the sample base 4, gate valves 7 and 7' are respectively provided at the inlet and outlet thereof, and the electric dust collector is contained therebetween. This dust collector is constituted of the negative pole 8 of the discharge part and the positive pole 9 of the duct collecting part which are opposed each other and removes dusts in the air containing dusts coming into the loader part 6 resulting in clean air and the prevention of deposits onto the wafer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam exposure apparatus, and more particularly, to an improved electron beam exposure apparatus that can prevent dust from entering the apparatus.

The development of high-density and highly integrated LSIs, which can be called ultra-LSIs, is progressing. Further, as part of the development of such a VLSI, various types of electron beam exposure devices (hereinafter referred to as EB exposure devices for simplicity) have been proposed. EB exposure apparatuses are widely used in practice because they can meet the ultimate goal of miniaturization. However, such an EB device also has drawbacks.

That is, fine dust enters into the apparatus when the sample is carried in, resulting in a decrease in the yield rate during turning and a defect in the 7f turning. In order to overcome the drawbacks caused by such dust, a method of removing dust using nitrogen gas has been used, but satisfactorily results have not been obtained.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a highly desired EB optical device with a high yield.

゛As a result of research to achieve the above object, the present inventor has developed an electrostatic precipitator that can collect extremely fine surface powder of approximately α1μ or more with a very high collection rate of approximately 99% or more. It has been found that it is effective to introduce the method into the EBj1 system.

This is because the invading dust is mainly silicon fragments during carpet feeding, dust generated from the clothes of workers in the CvD process, and others, and the size of these dust is Mainly in the range of 0.1 to 10μ)
Therefore, dust can be sufficiently removed by a normal electrostatic precipitator.

The EB exposure apparatus according to the present invention is characterized in that an electrostatic precipitator including a discharge electrode part and a dust collecting electrode part is disposed in an attached sample loading/unloading section adjacent to the apparatus. As the ``sample loading/unloading section,'' for example, an autoloader section commonly used in EB exposure apparatuses is useful.

It is advantageous for the electrostatic precipitator to configure and arrange the discharge electrode section and the dust collection electrode section so that they can function effectively within the sample loading/unloading section. It is advantageous to construct the discharge electrode part as a linear shape with a cross section such as a flat plate, a star shape, a round shape, or a rectangular shape. It is advantageous to configure it as a shape, a double plate shape, an eggplant shape, a jigdeda shape, etc. In any case, a DC high-pressure tube is applied to the discharge electrode part to generate a discharge,
The dust in the air inside the sample loading/unloading section is charged, the charged large dust is separated from the air by electric force within the electric field of the dust collection electrode, and finally the dust that is subjected to K is attached to the dust collection electrode. This electrostatic precipitator mechanism has been established because of the fact that the voltage applied to the discharge electrode is approximately 1000~1000~
It has been found that good dust collection efficiency can be obtained when the voltage is as high as 3000V.

According to the present invention, various types of dust, which could not be prevented from entering the EB exposure apparatus in the past, can be almost completely removed before entering the EB exposure apparatus, so that the efficiency of the EB exposure apparatus can be greatly improved. Furthermore, according to the present invention, additional advantages such as, for example, the reliability of the produced 'VLSI can be improved can be obtained.

Next, with reference to the accompanying drawings, a preferred 1 m of the present invention will be described.
! iIJ will be explained.

The illustrated EB exposure device uses a tungsten cathode as the electron gun.

The electron optical system includes three stages of electron lenses 2.
2' and 2''. To exhaust the lens barrel and sample chamber, an exhaust system using a cryo-I ring 3t is employed here.

Reference numeral 4 denotes a movable sample stage, above which a sample (here, a silicon blade) 5 is placed. Reference numeral 6 is a part of an auto peg for automatically loading and unloading wafers), and each 148 (Dl''-) is installed at the wafer entrance and exit of this chamber to ensure the sealing of the chamber. Pulps 7 and 7' are provided.Although not shown here, a conveyor belt and a handling mechanism tube can be used to transport the pulps 2^ into and out of the sample chamber.

In the autorome part 6, there are a discharge electrode (negative electrode) 8 which constitutes the discharge electrode tube and a dust collection electrode (positive electrode) which constitutes the dust collection electrode part.
9 are arranged to complete one electrostatic precipitator. Therefore, if a high voltage of, for example, 100 OV is applied to the negative electrode 8, the dust that has been brought into a part of the i\oag) attached to the wafer will be transferred to the positive electrode 9
You can wear it. Among the illustrated arrows, those marked with an M line represent dust-containing air pipes, and those without diagonal lines represent clean air. In this way, E
It is possible to prevent dust from entering the B exposure apparatus, thereby providing a dust-free EB exposure apparatus.

Although the present invention has been described above using a special KEB exposure apparatus KIJA, the idea is that the use of the electric dust collection method can be applied to other conductor manufacturing apparatuses, such as evaporation apparatuses, etching apparatuses, and lumbar tucking apparatuses. It is understood that it can be applied to reduced pressure vapor phase growth equipment and others.

[Brief explanation of the drawing]

The drawing is a schematic diagram showing a preferred 1!1-like tube of the EBM optical device according to the present invention, in which 1 is an electron gun, 2.2' and 2'' are electron lenses, 3 is a cryopump, and 4 is a cryopump. A sample stage, 5 a wafer, 6 a part of an autoloader, 7 and 7' pulp, 8 a discharge electrode, and 9 a dust collecting electrode.

Claims (1)

[Scope of Claims] 1. An electron beam exposure apparatus characterized in that an electrostatic precipitator comprising a discharge electrode part and a precipitate electrode part is disposed in an attached sample loading/unloading section adjacent to the apparatus. 2. The electron beam exposure apparatus according to claim 1, wherein the sample loading/unloading section is a part of an autoloader.゛