AbstractThe use of alternative channel materials such as germanium [1,2] and strained silicon (ε-Si) [3-5] is increasingly being considered as a method for improving the performance of MOSFETs. While ε-Si grown on relaxed Si1-x Gex is drawing closer to widespread commercialization, it is currently believed that almost all of the performance benefit in CMOS implementations will derive from the enhanced mobility of the n -MOSFET [5]. In this paper, we demonstrate that ε-Si p -MOSFETs can be engineered to exhibit mobility enhancements that increase or remain constant as a function of inversion density. We have also designed and fabricated ε-Si / ε-Ge dual-channel p -MOSFETs exhibiting mobility enhancements of 10 times. These p -MOSFETs can be integrated on the same wafers as ε-Si n -MOSFETs, making symmetric-mobility CMOS possible.
Phosphorus Donors in Highly Strained Silicon
