Optimized strained Si/strained Ge dual-channel heterostructures for high mobility P- and N-MOSFETs

Strained Si/strained Ge double heterostructures grown on relaxed Si/sub 1-x/Ge/sub x/ can be used to fabricate extremely high mobility P-MOSFETs. We present the first mobility results to date on N-MOSFETs fabricated on these heterostructures. By optimizing the layer thicknesses and strain, we have demonstrated hole and electron mobility enhancements of 10 and 1.8 times, respectively. Our work also shows that the electron mobility in these heterostructures cannot be increased by allowing electrons to populate the buried Ge.