US 7629634

Here's a concise summary of US Patent 7,629,634:

Title: Trenched MOSFET with trenched source contact

Assignee: FORCE MOS TECHNOLOGY Co Ltd

Inventors: Fu-Yuan Hsieh

Filing Date: 2008-02-23

Issue Date: 2009-12-08

Abstract: A trenched MOSFET with trenched source contact is described, comprising a semiconductor region with a silicon substrate, an epitaxial layer (drain), a base layer (body), and a source layer (source), stacked in sequence. It also includes an interlayer oxide film, a front metal layer, a back metal layer, trenched gates extending through the source and base layers to the epitaxial layer, and source contact trenches extending through the interlayer oxide film and source layer to the base layer. A key feature is that the sidewalls of the source contact trenches in the base layer include a lateral contact layer.

Plain-Language Overview of Independent Claims:

• Claim 1: This claim describes a trenched MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor). It includes a stacked semiconductor structure (silicon substrate, drain region, body region, source region). On top, there's a front metal layer, and at the bottom, a back metal layer. Trenches are formed for the gates, extending down into the drain region. Separately, other trenches, called source contact trenches, are formed, extending down to the body region. A key feature is that the sides of these source contact trenches, within the body layer, are covered by a "lateral contact layer," and the bottom of these trenches in the body layer are covered by a "base contact layer."

• Claim 6: This claim describes a variation of the trenched MOSFET in Claim 1. The primary difference is the doping types are inverted. Specifically, the silicon substrate, epitaxial layer (drain), and source layer are P-type, while the base layer (body) and the lateral contact layer are N-type. Similar to Claim 1, each source contact trench also has an N-type base contact layer at its bottom. The lateral contact layer has a lower doping concentration than the base contact layer at the bottom.

Uncertainty Regarding CAFC Dockets:
While the patent information indicates "US case filed in Court of Appeals for the Federal Circuit", a specific docket number for US Patent 7,629,634, active in 2026, was not found in the search results. The search results for CAFC dockets in 2026 mentioned other patent numbers and general patent litigation trends, but did not explicitly refer to 7,629,634. Therefore, I cannot provide details about any specific CAFC litigation involving this patent in 2026 with authoritative information.