Gas Mixing To Prevent Polymer Formation During Reactive Ion Etching
Original Publication Date: 1979-Mar-01
Included in the Prior Art Database: 2005-Feb-20
Etching silicon dioxide layers in a glow discharge atmosphere of CHF(3) using a cathode coupled diode etch system provides a high selectivity of etch between silicon dioxide and silicon. At power levels which avoid excessive attack of resist masking layers, organic polymer formation (residues) causes slowing or even stopping of the etch process. The use of mixtures of CF(4) and CHF(3) maintains the preferred etch rate ratios of SiO(2) to Si, SiO(2) to Si(3)N(4) and SiO(2) to resist to allow etch processing of semiconductor device structures without formation of polymer residues.