Hole transport properties of B-doped relaxed Si/sub 0.7/Ge/sub 0.3/ epitaxial films grown by MBE

Strain-engineered Si/SiGe heterostructures are attracting much attention because they have a potential for applications to high-speed electronics. Although the novel hetero field effect transistors (FETs), such as strained Si, strained SiGe and strained Ge FETs have been immensely investigated and showed improved performances, numerous significant issues in transport properties are still not fully understood. This is due to the fact that the fundamental experimental data on transport properties of SiGe alloys and Si/SiGe heterostructures are still insufficient. This study is directed towards a study on one of the most important transport properties, i.e., impurity-concentration dependence on the drift mobility (Irvin´s curve) for B-doped relaxed Si/sub 0.7/Ge/sub 0.3/ epitaxial films grown by MBE.