Patent ID: 6756559
Filing Date: 2004-06-29
Classification: H01J

Abstract:
A plasma etching apparatus, comprising:a reaction chamber having a diffusion area and a reaction area; an upper electrode disposed in the top of the reaction area; a lower electrode spaced apart from the upper electrode and arranged at the bottom of the reaction area; a RF power supply for applying RF power to the upper and lower electrodes so as to form the plasmas between the upper and lower electrodes; a gas inlet for applying processing gases to the diffusion area; gas-exhausting members for sucking the residual plasmas and byproducts of the plasma etch; a buffer plate surrounding the lower electrode at the bottom of the reaction chamber and having a plurality of vent holes and vent hole protectors; and a shielding member between the lower electrode and the buffer plate, the shielding member protecting the lower electrode from the plasmas; wherein the buffer plate is divided into a first portion, a second portion and a third portion; wherein the first portion has a size defined by multiplying a length of the shielding member by a distance between the top edge of the shielding member and the top edge of the buffer plate; wherein the second portion has a size defined by multiplying a length of the shielding member by a distance between the bottom edge of the shielding member and the bottom edge of the buffer plate; wherein the plurality of vent holes are arranged in the third portion of the buffer plate; wherein the vent hole protectors are arranged in the first and second positions; and wherein the each vent hole protector corresponds to each gas-exhausting member.