Trenched semiconductor devices and their manufacture
First Claim
1. A semiconductor device including an insulated trench electrode in a trench, the trench extending in a semiconductor body portion of the device, wherein the trench electrode is dielectrically coupled to the body portion by an insulating layer at a side-wall of the trench, and there is a cavity located adjacent only a lower portion of the trench electrode and having a gaseous content between the bottom of the trench electrode and the bottom of the trench to provide a structure for reducing the dielectric coupling between the trench electrode and the body portion at the bottom of the trench.
2 Assignments
0 Petitions
Accused Products
Abstract
In semiconductor devices which include an insulated trench electrode (11) in a trench (20), for example, trench-gate field effect power transistors and trenched Schottky diodes, a cavity (23) is provided between the bottom (25) of the trench electrode (11) and the bottom (27) of the trench (20) to reduce the dielectric coupling between the trench electrode (11) and the body portion at the bottom (27) of the trench in a compact manner. In power transistors, the reduction in dielectric coupling reduces switching power losses, and in Schottky diodes, it enables the trench width to be reduced.
10 Citations
7 Claims
- 1. A semiconductor device including an insulated trench electrode in a trench, the trench extending in a semiconductor body portion of the device, wherein the trench electrode is dielectrically coupled to the body portion by an insulating layer at a side-wall of the trench, and there is a cavity located adjacent only a lower portion of the trench electrode and having a gaseous content between the bottom of the trench electrode and the bottom of the trench to provide a structure for reducing the dielectric coupling between the trench electrode and the body portion at the bottom of the trench.
Specification