Patent ID: 6736987
Filing Date: 2004-05-18
Classification: H01L

Abstract:
A method for etching a silicon wafer using XeF2 not disassociated by plasma generating means, comprising steps of:(a) etching a silicon wafer using an etching apparatus comprising a loading chamber for loading XeF2, an expansion chamber for collecting sublimated XeF2 from the said loading chamber, and an etching chamber for etching using XeF2 not disassociated by plasma generating means supplied from the said expansion chamber; (b) eliminating air moisture in each chamber to prevent formation of HF by injecting nitrogen to the loading chamber, the expansion chamber and the etching chamber, and exhausting the injected nitrogen therefrom prior to the said step (a); and (c) controlling the internal pressure of the loading chamber at a level between sublimation pressure of XeF2 and atmospheric pressure to prevent sublimation of the residual XeF2 in the loading chamber after the said step (a).