Agere Systems Inc.

Zhijian Xie

Shuming Xu

Muhammed Ayman Shibib

Isik C Kizilyalli

Peter Ledel Gammel

Marco Mastrapasqua

John Michael Hergenrother

In a metal-oxide semiconductor device including first and second source/drain regions of a first conductivity type formed in a semiconductor layer of a second conductivity type proximate an upper surface of the semiconductor layer, a drift region 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 formed on at least a portion of the upper surface of the semiconductor layer, and a gate formed on the insulating layer and at least partially between the first and second source/drain regions, a method for controlling an amount of hot carrier injection degradation in the device includes the steps of: forming a shielding structure on the insulating layer above at least a portion of the drift region and substantially between the gate and the second source/drain region; and adjusting an amount of coverage of the shielding structure over an upper surface of the drift region so as to minimize the amount of hot-carrier injection degradation while maintaining a breakdown voltage in the device which is greater than or equal to a prescribed value.

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

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.

An MOS device is formed comprising a semiconductor layer of a first conductivity type, a first source/drain region of a second conductivity type formed in the semiconductor layer, and a second source/drain region of the second conductivity type formed in the semiconductor layer and spaced apart from the first source/drain region. The MOS device further comprises a gate formed proximate an upper surface of the semiconductor layer and at least partially between the first and second source/drain regions, and a shielding structure formed proximate the upper surface of the semiconductor layer and between the gate and the second source/drain region, the shielding structure being electrically connected to the first source/drain region, the shielding structure being spaced laterally from the gate and being non-overlapping relative to the gate. In this manner, the MOS device is substantially compatible with a CMOS process technology.

Shielding structure for use in a metal-oxide-semiconductor device

A diffused MOS device comprises one or more strained silicon portions formed in a carrier transit path of the DMOS device. The one or more strained silicon portions may comprise a layer of strained silicon, generally formed above a layer of lattice mismatch material such as silicon germanium or silicon carbide. The carrier transit path is at least partially defined by a body of the DMOS device, and may also include other regions, such as a diffusion area, channel region, or accumulation region. The one or more strained silicon portions may be formed only in selected regions of the DMOS device or may be formed as a layer throughout. The one or more strained silicon portions may be formed through patterning of a hard mask, forming a lattice mismatch layer, forming a strained silicon layer, and removing the hard mask. Trenches may also be formed prior to forming the lattice mismatch material on the patterned hard mask.

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Oak Ridge, NC, United States of America

Zhijian Xie