Polysilicon Dry Etching Using Reactive Ion Etching and Plasma Etching
Original Publication Date: 1984-Jan-01
Included in the Prior Art Database: 2005-Feb-02
Barrel plasma etching techniques for polysilicon pattern definition are inadequate for VLSI technologies. The line-width resolution required by new technique for etching polysilicon provides both line-width control and edge-profile control. Barrel plasma etching of polysilicon is isotropic -- the etch rates in the lateral and vertical directions are comparable. The etch rate is a function of dopant concentration, wafer temperature, and the degree of crystallinity of the polycrystalline silicon. In addition, the etch rate tends to be nonuniform across the surface of an individual wafer, and changes with the amount of exposed area being etched (loading).