ETCHING METHODS FOR SEMICONDUCTOR MATERIAL

摘要

PURPOSE: A method of etching semiconductor device is provided to enhance etching margin by using the etching gas having a silicon nitride layer and the high selectivity. CONSTITUTION: A silicon insulation layer is deposited on the semiconductor substrate. On the silicon insulation layer one more than one conductive layers are formed. An interlevel insulation layer is formed to surround the conductive layer. A semiconductor layer is formed on the interlevel insulation layer and the silicon insulation layer. The semiconductor layer is etched in the RIE device by mixing a first and a second main etching gases having a high etching selectivity with respect to the silicon insulation layer of the semiconductor layer. The semiconductor layer is etched in the RIE device to expose the silicon nitride layer by mixing the silicon insulation layer and the second and third etching gases having the selectivity of more than 30 with the main etching gases.