Elimination of Nitride Ribbon Fragments at F Photo by Incorporation of a Tapered Oxide RIE Process at Base Photo
Original Publication Date: 1988-Nov-01
Included in the Prior Art Database: 2005-Feb-15
This article discloses an improvement in semiconductor processes required for a particular masterslice design by use of a more reliable means of removing nitride ribbon fragments generated by an anisotropic RIE (reactive ion etch) process. The disclosed process can be applied in conjunction with a tapered oxide etch at base photo, or by itself, to give sloped nitride sidewalls for better chrome coverage. (Image Omitted) Fig. 1 illustrates the nature of the undesirable Si3N4 ribbon-like elements generated during the fabrication of certain masterslice structures. These ribbons are believed due to the anisotropic RIE process employed at the F photo step. They must be entirely removed to avoid yield degradation and reliability concerns.