Semiconductor devices having torsional stresses

摘要

A FET structure is provided in which at least one stressor element provided at or near one corner of an active semiconductor region applies a stress in a first direction to one side of a channel region of the FET to apply a torsional stress to the channel region of the FET. In a particular embodiment, a second stressor element is provided at or near an opposite corner of the active semiconductor region to apply a stress in a second direction to an opposite side of a channel region of the FET, the second direction being opposite to the first direction. In this way, the first and second stressor elements cooperate together in applying a torsional stress to the channel region of the FET.