Patent ID: 6010968
Filing Date: 2000-01-04
Classification: H01L

Abstract:
A multilevel contact etching method for forming a plurality of contact openings, the method comprising:providing a semiconductor substrate, wherein a patterned polysilicon or polycide structure and a silicide layer are separately formed over the semiconductor substrate at different locations, a silicon-nitrogen compound layer is formed on top of the patterned polysilicon or polycide structure, and an oxide layer is formed over the substrate; andperforming a patterning process on the oxide layer and the silicon-nitrogen compound layer to form the contact openings, which are simultaneously formed to separately just expose the semiconductor substrate, the patterned polysilicon or polycide structure, and the silicide layer,wherein the patterning process comprises a plasma etching process with a gas etchant, which is obtained by flushing perfluoro-cyclobutane (C.sub.4 F.sub.8) with a flushing rate of about 5-25 sccm, C.sub.x H.sub.y F.sub.z with a flushing rate of about 5-30 sccm, CO with a flushing rate of about 10-100 sccm, and argon with a flushing rate of about 100-600 sccm.