JPS59203655A - Mechanism for preventing dust adhesion during venting in wafer process apparatus - Google Patents

Abstract

PURPOSE:To prevent the contamination of a wafer by utilizing electrostatic force, by positively charging dust by ionizing venting gas by discharge while adhering floated dust by utilizing the electric field generated between the wafer and a grid. CONSTITUTION:In introducing gas into a process chamber 1 through a vent gas arranged pipe 2, said gas is ionized by the discharge of a discharge electrode 3 and the electron in the ionized gas is removed by a grid held to positive potential while the positively charged gas is introduced into the chamber 1. Floating dust is positively charged by the adhesion of the positive ion in the charged gas and attracted to a dust collecting grid 5 which is held to negative potential and has a sticky surface to be adhered to the surface of the grid 5. In this case, by applying positive potential to a wafer holder 6 and a wafer 7, buoyance to dust in generated. Therefore, purification can be performed during wafer processing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanism for preventing dust generated during vacuum venting from adhering to wafers in a wafer processing apparatus having a vacuum processing chamber.

Conventional devices of this type have taken measures such as installing a filter in the vent piping to remove dust from the vent gas, but this has been caused by dust entering the chamber from the connecting section and by friction inside the chamber. When dust was blown up by the vent gas, it was not possible to prevent dust contamination of the wafer.

In order to minimize the amount of dust adhering to the wafer surface in such cases, the present invention uses electrostatic force to collect floating dust on a dust collection grid with an adhesive surface and remove it. The purpose is to prevent contamination.

A feature of the present invention is that, in a wafer processing apparatus that processes wafers while maintaining a vacuum inside, venting gas is ionized by discharge from a discharge electrode provided in the vacuum venting gas piping, and the positive ions generated thereby are ionized. By attaching it to floating debris and positively charging it, we utilize the electric field generated between Ueno, to which a positive DC voltage has been applied in advance, and a sticky grid or plate to which a negative DC voltage has been applied. The mechanism is to prevent dust from adhering during venting by selectively adhering floating dust to the clit or board.

An embodiment will be described below with reference to one drawing.

As shown in the figure, gas is introduced into the gross chamber 1 through the vent gas piping 2. At this time, the gas is completely ionized by two discharges with the discharge electrode 3, and the grid 4 kept at a positive potential removes the ionized gas. Electrons are removed and positively charged gas is introduced into the chamber 1. Floating dust becomes positively charged when positive ions in the charged gas attach to it. This charged dust is kept at a negative potential and is attracted to the vehicle collection grid 5 having an adhesive surface, and adheres to the surface of the grid. By applying a positive potential to the wafer holder 6 and the sea urchin 7, some amount of dust is generated.

By using the present invention, it is possible to selectively attach fine dust that could not be adhered to the wafer surface to the wafer surface. Enables greater cleanliness in the wafer process.

[Brief explanation of drawings]

FIG. 11 is an explanatory diagram of the dust adhesion prevention mechanism according to the present invention. In Hikoozu, l...Gross Channok, 2
・・・・・・vent piping, 3・・・discharge electrode, 4
. . . Grid, 5 . . . Handled glyphs, 6 . . . Ueno holder, 7 . . . Wafer. i〜１・・－＼、Representative Patent Attorney Hihara Uchihara（－１□gu ゛

Claims (1)

[Claims] In wafer processing equipment that processes wafers while maintaining a vacuum inside, a vacuum vent gas, x, and percentage? The wafer to which a direct current positive voltage has been applied in advance is charged by applying a venting gas to the discharge electrode provided inside the wafer and causing the generated positive ions to land on the floating dust Kf-1 to positively charge the fumiwo. A mechanism for preventing dust build-up during venting, characterized in that floating dust is selectively attached to the lid or plate by using an electric field generated between the lid or plate having adhesive properties and a negative DC voltage applied thereto.