REACTIVE ION-ETCHING METHOD

摘要

PURPOSE: To precisely control the etching profile of multi-layer metal silicide/ polysilicon structure, which is selective by etching a metallic silicide layer with plasma, generated from the mixed gas of hydrogen bromide and chlorine gas at a specified mixture ratio. ;CONSTITUTION: A substrate is placed on a platform 12 and radio-frequency power 14 is applied. Thus, it is etched by a plasma, generated from a gas in a reactive room 10. A valve 28 holds vacuum in the reactive room 10 to be not more than 30 millitorr. Gas used for plasma is obtained by mixing HBr with a chlorine gas (Cl₂, HCl or BCl₃) at a ratio of 1:1-1:9. When an etching gas is used, the under cut of a silicide layer constituted of an insulating mask, the metal silicide layer and the polysilicon layer, which are arranged in the thin layer of gate oxide, does not exist.;COPYRIGHT: (C)1994,JPO