ETCH GAS COMPOSITION OF POLYCRYSTALLINE SILICON LAYER AND TUNGSTEN SILICIDE LAYER FOR MANUFACTURING SEMICONDUCTOR DEVICE AND PLASMA ETCH METHOD USING THE SAME

摘要

PURPOSE: A plasma etch method using an etch gas composition of a polycrystalline silicon layer and a tungsten silicide layer is provided to improve an isotropic etch characteristic and etch selectivity regarding an oxide layer, by using an etch gas composition composed of chlorine gas and oxygen gas or etch gas composition composed of chlorine gas, inert gas and oxygen gas. CONSTITUTION: The etch gas composition composed of chlorine gas and oxygen gas is inserted into an etch chamber maintaining a pressure of 100 milliTorr. Power of 200 watt is supplied to the etch chamber to transform the etch gas composition to a plasma state. A magnetic field of 30 Gauss is formed inside the etch chamber to etch the tungsten silicide layer and the polycrystalline silicon layer(14) formed on the semiconductor substrate(10).