ENGINEERING STRAIN IN THICK STRAINED-SOI SUBSTRATES

摘要

A semiconductor fabrication process preferably used with a semiconductor on insulator (SOI) wafer (101). The wafer's active layer (106) is biaxially strained and has first (110-1) and second regions (110-2). The second region (110-2) is amorphized to alter its strain component(s). The wafer is annealed to re-crystallize the amorphous semiconductor. First and second types of transistors (150-1, 150-2) are fabricated in the first region and the second region respectively. Third (110-3) and possibly fourth regions (110-4) of the active layer may be processed to alter their strain characteristics. A sacrificial strain structure (130) may be formed overlying the third region. The strain structure may be a compressive. When annealing the wafer with the strain structure in place, its strain characteristics may be mirrored in the third active layer region (110-3). The fourth active layer region (110-4) may be amorphized in stripes that run parallel to a width direction of the transistor strain to produce uniaxial stress in the width direction.