摘要 |
A method for simultaneously patterning-over field oxide, gate oxide, and sidewall oxide-high conductivity metal-silicide electrode metallization for semiconductor integrated circuits involves (1) formation of an unpatterned polycrystalline silicon (polysilicon) layer everywhere on the exposed surface of all the oxides, (2) formation of a patterned photoresist layer on the polysilicon layer, (3) deposition of a layer of the metal-silicide over all exposed surfaces, (4) removal of the patterned photoresist layer to lift off metal-silicide, and (5) oxidation of only exposed portions of the polysilicon layer to form silicon dioxide. The polysilicon layer can be originally doped, so that the doped silicon dioxide can then be removed (without removing undoped silicon dioxide) by means of an etchant which attacks the dopant.
|