| 摘要 |
PURPOSE: To make the channel length of a MOSFET short by equipping the multi-layered wafer of the MOSFET, which is formed in the multi-layered wafer, with at least four layers formed of at least two different materials, and accurately controlling the thickness. CONSTITUTION: An n<+> -silicon substrate layer 100 is equipped with a silicon drain layer 102 of thickness 0.1 to 0.3μm grown on it. The substrate 100 and an n-silicon layer 102 have 5×10<18> /cm<3> and 10<17> /cm<3> dopant densities respectively. Then a 1st channel of 200 angstroms consisting of p<-> -doped Si1-x Gex (x: mol.% of germanium) is grown on the plane of the n-silicon layer 102. A 2nd channel layer 106 of a p-type silicon is grown on a layer 104. The layer thickness is 1μm and the dopant density Nar is 10<15> /cm<3> . A source layer 108 of 0.2μm, consisting of an n-type silicon with a dopant density Ndt=10<18> /cm<3> , is made to grow on the layer 106.
|
