| 摘要 |
A process is described for anisotropically etching semiconductor products which include a lower dielectric layer, an intermediate polysilicon layer, and an upper silicide layer such as titanium silicide. A pattern-defining layer will normally overlie the silicide layer to define target areas to be etched. In a first step, the silicide is etched through using Freon 115 chloro, pentafluoroethane (C2ClF5) in a plasma etching chamber conditioned to provide a reactive ion etch. The etch is completed in the same chamber using a second gas which includes an amount of Cl2 selected to etch anisotropically through the polysilicon layer without substantially etching the dielectric layer. Preferably, both etches occur after covering inner surfaces of the etching chamber with a material which releases molecules of the character included in the pattern-defining layer, such as Kapton, a polymide, in the disclosed example. |
