Silicon-germanium thin layer semiconductor structure with variable silicon-germanium composition and method of fabrication

摘要

A SiGe thin layer semiconductor structure containing a substrate having a dielectric layer, a variable composition Si_xGe_1-x layer on dielectric layer, and a Si cap layer on the variable composition Si_xGe_1-x layer. The variable composition Si_xGe_1-x layer can contain a Si_xGe_1-x layer with a graded Ge content or a plurality of Si_xGe_1-x sub-layers each with different Ge content. In one embodiment of the invention, the SiGe thin layer semiconductor structure contains a semiconductor substrate having a dielectric layer, a Si-containing seed layer on the dielectric layer, a variable composition Si_xGe_1-x layer on the seed layer, and a Si cap layer on the variable composition Si_xGe_1-x layer. A method and processing tool for fabricating the SiGe thin layer semiconductor structure are also provided.