Etching windows in thick dielectric coatings overlying semiconductor device surfaces

摘要

Windows in a glass coating on a semiconductor wafer surface are opened to an underlying semiconductor device region without inadvertently exposing adjacent device portions within the window. In the preferred process a precisely etchable silicon nitride coating is initially applied and windows precisely etched in it. The glass is applied later and preferentially etched, whereby undesired lateral etching of the glass can occur without unintentionally exposing adjacent device portions.