Control of hot carrier injection in a metal-oxide semiconductor device

摘要

An MOS device is formed including a semiconductor layer of a first conductivity type, and first and second source/drain regions of a second conductivity type formed in the semiconductor layer proximate an upper surface of the semiconductor layer, the first and second source/drain regions being spaced apart relative to one another. A drift region is formed in the semiconductor layer proximate the upper surface of the semiconductor layer and at least partially between the first and second source/drain regions. An insulating layer is formed on at least a portion of the upper surface of the semiconductor layer and above at least a portion of the drift region. A gate is formed on the insulating layer and at least partially between the first and second source/drain regions. The MOS device further includes a shielding structure formed on the insulating layer above at least a portion of the drift region. The shielding structure is configured such that an amount of hot carrier injection degradation in the MOS device is controlled as a function of an amount of coverage of the shielding structure over an upper surface of the drift region.