METHOD FOR FABRICATING SOI SUBSTRATE WITH ALL ISOLATION AND HYBRID CRYSTAL ORIENTATION

摘要

Disclosed in the invention are a method for fabricating a SOI substrate with all isolation and hybrid crystal orientation and a method for fabricating a CMOS integrated circuit base on the method. The method for fabricating the SOI substrate with all isolation and hybrid crystal orientation provided by the invention employs a SiGe layer as a first crystal orientation epitaxial and dummy substrate layer, thus forming a first crystal orientation top-layer strain silicon; employs polysilicon supporting material as a support for connecting the first crystal orientation top-layer strain silicon and a second crystal orientation top-layer silicon, thus removing the SiGe layer under the first crystal orientation top-layer strain silicon; and fills insulating material to form an insulating buried layer. The thickness of the top-layer silicon and the insulating buried layer formed by the method is uniform and controllable. The strain silicon formed inside a window and the top-layer silicon outside the window have different crystal orientation, and can provide higher mobility for NMOS and PMOS, thus improving the performance of the CMOS integrated circuit.