Granted Patent B2

US 8,759,909 · App. 13/609,281 · Granted Jun 24, 2014

Inventors: Peilin Wang (Beijing, CN); Edouard D. de Fresart (Tempe, AZ); Wenyi Li (Beijing, CN)

Assignee: Freescale Semiconductor, Inc.

Abstract

Claims (13)

1. An insulated gate field effect transistor, comprising:

a semiconductor containing substrate having a first surface;

a cavity formed in the substrate and having a sidewall extending to a first depth from the first surface;

a dielectric liner in the cavity;

a gate conductor within the dielectric liner, at least filling the cavity and extending a first distance above the first surface;

one or more body regions within the substrate, extending to a second depth from the first surface and laterally proximate to but separated from the gate conductor in part by a first portion of the dielectric liner of a first lateral thickness; and

one or more source regions within the body region extending from the first surface and having a lower extremity at a third depth less than the second depth below the first surface, wherein the source regions are separated from the gate conductor by a second portion of the dielectric liner of a lateral second thickness at least in part greater than the first lateral thickness, and

wherein the dielectric liner includes a dielectric protrusion extending laterally into the gate conductor away from the body region and to a fourth depth below the first surface.

2. The transistor of claim 1 , wherein the second thickness decreases at least partly with increasing depth from the first surface toward the dielectric protrusion.

3. The transistor of claim 1 , wherein the source region has a curved shape along the second portion of the cavity sidewall.

4. The transistor of claim 1 , wherein the third depth is greater than or equal to the fourth depth.

5. The transistor of claim 1 , wherein the first distance is greater than zero.

6. The transistor of claim 5 , wherein the gate conductor has a first cross-sectional width proximate the second portion of the dielectric liner and a larger second cross-sectional width proximate the first portion of the dielectric liner.

Assignments (31)

Priority Claims (1)

Continuity (1)