Power device with self-aligned source regions

摘要

A field effect transistor (FET) includes a plurality of trenches extending into a silicon layer, each trench having upper sidewalls that fan out. Contact openings extend into the silicon layer between adjacent trenches such that each trench and an adjacent contact opening form a common upper sidewall portion. Body regions extend between adjacent trenches. Source regions that are self-aligned to corresponding trenches extend in the body regions adjacent opposing sidewalls of each trench, and have a conductivity type opposite that of the body regions.