Treatment of the sige layer for selective etching

摘要

The present invention relates to a process for removing a layer of silicon - germanium (si1 - xgex) (106) arranged on a layer of strained silicon (104). The layer of silicon - germanium (si1 - xgex) (106) is intended to be removed by selective chemical etching to expose the silicon layer stressed (104). the process of the invention comprises, before the step (s5) of selective etching, a step (s3) of oxidation of the layer of silicon - germanium (si1 - xgex) (106) to form a surface layer of silicon oxide (sio2) (108) and a lower layer (107) enriched with a concentration (x) of germanium greater than that of the layer of silicon - germanium (si1 - xgex (106)). The layer of silicon oxide (sio2) (108) is then eliminated by a deoxidation step (s4).