| 摘要 |
PURPOSE:To provide an accurately fine pattern on a semiconductor element by sputter etching a polysilicon by inert gas or O2 with a metal layer as a mask when patterning two layer wirings of the polysilicon and the metal layer. CONSTITUTION:An opening is perforated at a SiO2 film 4 for coating the element regions 2, 3 of a silicon substrate 1, and a PSG5, a polysilicon 6 and aluminum layer 7 are sequentially superimposed thereon. A resist mask 8 of predetermined pattern is formed thereon, the aluminum 7 is etched with phosphoric acid, and the polysilicon 6 is then sputter etched by Ar or O2 or the like. Since the sputter etching can be controlled in etching rate readily and have low etching rate, it can suitably stop the etching process of the layer 6 without almost etching the lower PSG5, does not etch the side surface without eliminating the protecting effect of the PSG so as to form faithfully a pattern to the mask. |
