High-hole and electron mobility in complementary channels in strained silicon (Si) on top of strained Si0.4Ge0.6, both grown on a relaxed Si0.7Ge0.3 virtual substrate is shown for the first time. The buried Si0.4Ge0.6 serves as a high-mobility p-channel, and the strained-Si cap serves as a high-mobility n-channel. The effective mobility, measured in devices with a 20-μm gate length and 3.8-nm gate oxide, shows about 2.2∼2.5 and 2.0 times enhancement in hole and electron mobility, respectively, across a wide vertical field range. In addition, it is found that as the Si cap thickness decreased, PMOS transistors exhibited increased mobility especially at medium - and high-hole density in this heterostructure.
- Dual heterostructure
- Effective mobility
- Virtual substrate
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering