Patent ID: 7943451

Claim:
A method for forming an integrated circuit substrate containing regions with two different crystal orientations, comprising the steps of: providing a single crystal substrate, comprised of silicon with a first crystal lattice orientation; forming a layer of directly bonded silicon (DSB) with a second crystal lattice orientation on a top surface of said single crystal substrate; forming an amorphization hard mask layer on a top surface of said DSB layer; patterning said amorphization hard mask layer whereby regions defined for said first crystal lattice orientation are exposed and regions defined for said second crystal lattice orientation are covered with photoresist; etching said amorphization hard mask layer in said regions defined for said first crystal lattice orientation, whereby said DSB layer is exposed in said regions defined for said first crystal lattice orientation; performing an amorphization ion implant process whereby said DSB layer in said regions defined for said first crystal lattice orientation is amorphized and a portion of said DSB layer in said regions defined for said second crystal lattice orientation is amorphized to a depth less than a thickness of said DSB layer; forming a recrystallization dielectric cap layer on a top surface of said regions defined for said first crystal lattice orientation and on a top surface of said regions defined for said second crystal lattice orientation; performing a solid phase epitaxy (SPE) process in which said amorphized DSB layer in said regions defined for said first crystal lattice orientation is recrystallized on said first crystal lattice orientation, and said amorphized portion of said DSB layer in said regions defined for said second crystal lattice orientation is recrystallized on said second crystal lattice orientation; forming a sacrificial layer of silicon dioxide on a top surface of said regions defined for said first crystal lattice orientation and on a top surface of said regions defined for said second crystal lattice orientation; and forming a region of field oxide at a lateral boundary between said regions defined for said first crystal lattice orientation and said regions defined for said second crystal lattice orientation.