Power device with self-aligned source regions
AssigneeFairchild Semiconductor Corporation
InventorsRobert Herrick, Becky Losee, Dean Probst
Life of this patent
Estimating the term…
Abstract
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.
Claims20
1-12. (canceled)
A field effect transistor (FET) comprising:
- a plurality of trenches extending into a silicon layer, each trench having upper sidewalls that fan out;
- contact openings extending into the silicon layer between adjacent trenches such that each trench and an adjacent contact opening form a common upper sidewall portion;
- body regions extending between adjacent trenches;
- and
- source regions extending in the body regions adjacent opposing sidewalls of each trench, the source regions having a conductivity type opposite that of the body regions, wherein the source regions are self-aligned to corresponding trenches.
A field effect transistor (FET) comprising:
- an epitaxial layer of a first conductivity type extending over a substrate of the first conductivity type, the epitaxial layer having a lower doping concentration than the substrate;
- a body region of a second conductivity type extending in an upper portion of the epitaxial layer, the second conductivity type being opposite the first conductivity type;
- a plurality of trenches extending through the body region and terminating within the epitaxial layer below the body region, each trench having upper sidewalls that fan out;
- contact openings extending into the body region between adjacent trenches such that each trench and an adjacent contact opening form a common upper sidewall;
- and
- source regions of the first conductivity type extending in the body region adjacent opposing sidewalls of each trench, wherein the source regions are self-aligned to corresponding trenches.
Dependencies are inferred from the claim text.