METHOD TO FORM STRAINED CHANNEL IN THIN BOX SOI STRUCTURES BY ELASTIC STRAIN RELAXATION OF THE SUBSTRATE

摘要

Methods and structures for forming strained-channel FETs are described. A strain-inducing layer may be formed under stress in a silicon-on-insulator substrate below the insulator. Stress-relief cuts may be formed in the strain-inducing layer to relieve stress in the strain-inducing layer. The relief of stress can impart strain to an adjacent semiconductor layer. Strained-channel, fully-depleted SOI FETs and strained-channel finFETs may be formed from the adjacent semiconductor layer. The amount and type of strain may be controlled by etch depths and geometries of the stress-relief cuts and choice of materials for the strain-inducing layer.

主权项

1. A strained-channel FET comprising:
a source region; a drain region; a channel region; a strain-inducing layer of a first semiconductor material adjacent the channel region and extending laterally across an area that includes the source, channel, and drain regions; and at least one stress-relief trench formed in the strain-inducing layer adjacent the strained-channel FET such that a region of the strain-inducing layer at which stress is relieved by the at least one stress-relief trench imparts strain to the channel region.