Power semiconductor devices, methods, and structures with embedded dielectric layers containing permanent charges

摘要

Power devices using refilled trenches with permanent charge at or near their sidewalls. These trenches extend vertically into a drift region.

主权项

1. A semiconductor power device, comprising:
an array of active device cells, including both an upper array of current-controlling structures, and a lower array of permanently charged trenches within a semiconducting drift region; said trenches individually containing permanent electrostatic charge at or near sidewalls thereof; and a transitional structure surrounding said array, said transitional structure including at least some trenches which are fabricated in the same steps as said trenches in said array, but which have smaller maximum width, and a different ratio of charge density between upper and lower portions of the walls of said trenches.