Wolfspeed, Inc.
Power semiconductor devices having top-side metallization structures that include buried grain stop layers

Abstract:

Semiconductor devices include a plurality of gate fingers extending on a wide bandgap semiconductor layer structure. An inter-metal dielectric pattern is formed on the gate fingers, the inter-metal dielectric pattern including a plurality of dielectric fingers that cover the respective gate fingers. A top-side metallization is provided on the inter-metal dielectric pattern and on exposed portions of the upper surface of the wide bandgap semiconductor layer structure. The top-side metallization includes a first conductive diffusion barrier layer on the inter-metal dielectric pattern and on the exposed portions of the upper surface of the wide bandgap semiconductor layer structure, a conductive contact layer on an upper surface of the first conductive diffusion barrier layer, and a grain stop layer buried within the conductive contact layer.