Patent ID: 11967625
Assignee: SHANGHAI BRIGHT POWER SEMICONDUCTOR CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 18:
19. A method of fabricating a metal-oxide semiconductor field-effect transistor (MOSFET) device, the method comprising:
forming an epitaxial region of a first conductivity type on an upper surface of a substrate of the first conductivity type, the substrate serving as a drain region in the MOSFET device;
forming at least two body regions of a second conductivity type in the epitaxial region, the second conductivity type being opposite in polarity to the first conductivity type, the body regions being disposed proximate an upper surface of the epitaxial region and spaced laterally from one another;
forming at least two source regions of the first conductivity type, each of the source regions being disposed in a corresponding one of the body regions proximate an upper surface of the body region; and
forming a gate structure comprising at least two planar gates and a trench gate, each of the planar gates being disposed on the upper surface of the epitaxial region and overlapping at least a portion of a corresponding body region, the trench gate being formed at least partially through the epitaxial region between the body regions;
wherein the trench gate includes a dielectric material formed on sidewalls and a bottom of the trench gate for electrically isolating the trench gate from the epitaxial region, and wherein the epitaxial region surrounds the dielectric material of the trench gate to isolate the dielectric material of the trench gate from the plurality of body regions.