Novel strained-Si heterostructure NMOSFETs on solid phase epitaxially grown relaxed Si1-xGex

The use of single-step Ge implantation followed by high-temperature solid phase epitaxy to form relaxed Si1-xGex layers is reported. Upon this film, a 2000 Angstrom buffer layer of Si0.85Ge0.15 followed by a 200 Angstrom strained-Si layer has been grown by ultra-high-vacuum chemical vapor deposition, This method of growing strained-Si layer eliminates the need for the growth of several microns thick-graded relaxed layer. A self-aligned poly-gate process modified to achieve low-thermal budget was used to fabricate NMOSFETs of gate lengths ranging from 10 mu m to 0.8 mu m using. the strained silicon as the channel Strained-Si devices show a 17.5% higher peak linear G(m) than the control devices as a result of higher electron mobility in the strained-Si channel.