Patent ID: 6271144
Filing Date: 2001-08-07
Classification: H01L

Abstract:
Process for etching a layer of a polycrystalline Si.sub.1-x Ge.sub.x [(0<.times..ltoreq.1)] (0.5.ltoreq..times..ltoreq.1) mixture deposited on a substrate or for etching a stack comprising a first layer of a polycrystalline Si.sub.1-x Ge.sub.x [(0<.times..ltoreq.1)] (0.5.ltoreq..times..ltoreq.1) mixture deposited on a substrate and a second silicon layer deposited on the first layer, the said layer or the said stack including, on its surface, a mask of inorganic material, comprising a main etching of the said layer or the said stack in which the said Si.sub.1-x Ge.sub.x layer or the said stack is anisotropically etched, using the said mask, by means of a high-density gas plasma of a gas mixture comprising chlorine (Cl.sub.2) and either nitrogen (N.sub.2) or ammonia (NH.sub.3) or a nitrogen/ammonia mixture.