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US 9,793,393 B2Granted
MOSFET device and fabrication
AssigneeAlpha and Omega Semiconductor Incorporated
InventorsJohn Chen, Il Kwan Lee, Hong Chang, Wenjun Li, Anup Bhalla, Hamza Yilmaz
Life of this patent
Estimating the term…
Abstract
A semiconductor device includes a substrate, an active gate trench in the substrate; a source polysilicon pickup trench in the substrate; a polysilicon electrode disposed in the source polysilicon pickup trench; and a body region in the substrate. The top surface of the polysilicon electrode is below the bottom of the body region.
Claims16
A semiconductor device, comprising:
- a substrate;
- an active gate trench in the substrate;
- a source polysilicon pickup trench in the substrate;
- a polysilicon electrode disposed in the source polysilicon pickup trench;
- a body region in the substrate;
- and
- an insulating spacer that is adjacent to a top portion of the source polysilicon pickup trench, that extends above the polysilicon electrode disposed in the source polysilicon pickup trench, that allows the source polysilicon pickup trench to be formed by self-aligned etching, that is at least in part in contact with the body region, and that separates the body region from a sidewall of the source polysilicon pickup trench;
- wherein:
- a top side of the polysilicon electrode is below a bottom of the body region.
6 more elements
A method of fabricating a semiconductor device, comprising:
- forming an insulating spacer;
- forming an active gate trench and a source polysilicon pickup trench in a substrate, including performing self-aligned etching using at least the insulating spacer to form the source polysilicon pickup trench, wherein the insulating spacer is adjacent to a top portion of the source polysilicon pickup trench;
- forming an active gate electrode in the active gate trench and a polysilicon electrode in the source polysilicon pickup trench, wherein the insulating spacer is adjacent to a top portion of the source polysilicon pickup trench and extends above the polysilicon electrode in the source polysilicon pickup trench;
- and
- implanting a body region;
- wherein:
- the polysilicon electrode has a top side that is below a bottom of the body region;
- and
- the insulating spacer and the body region are formed in such a way that the insulating spacer is at least in part in contact with the body region and the insulating spacer separates the body region from a side wall of the source polysilicon pickup trench.
6 more elements
Dependencies are inferred from the claim text.