Patent ID: 7897480
Filing Date: 2011-03-01
Classification: C23C,H01L

Abstract:
1. A method of forming a thin strained semiconductor-on-insulator substrate comprising: forming a SiGe etch stop followed by a thin strained semiconductor layer having the desired thickness atop a structure that comprises a fully relaxed SiGe layer located on a sacrificial substrate; first annealing said structure including said low temperature oxide at a first temperature to form an interfacial layer comprising the elements of Si, Ge and O between the low temperature oxide and said fully relaxed SiGe layer; providing a low temperature implant region within said fully relaxed SiGe layer using a combination of H bonding said low temperature oxide to a surface of a semiconductor substrate, wherein said bonding comprises contact bonding to foam a bond between said exposed surface of said low temperature oxide and said semiconductor substrate, a second anneal at a second temperature to strengthen said bond, and a third anneal performed at a third temperature that is greater than the second temperature to cause separation at said implant region within said fully relaxed SiGe layer, whereby said sacrificial substrate and a portion of the fully relaxed SiGe layer are removed leaving a portion of the relaxed SiGe layer, the SiGe etch stop and the thin strained semiconductor layer atop of the oxide that is now bonded to a second semiconductor substrate; performing sequential selective etching to first remove the remaining portions of the relaxed SiGe layer followed by the second selective etching of the SiGe etch stop leaving only the thin strained semiconductor layer atop of the bonded oxide layer; and re-annealing the structure at a fourth temperature that is greater than the third temperature to form a strained semiconductor directly-on-insulator substrate that comprises the semiconductor substrate, said low temperature oxide located on said semiconductor substrate, and said tensilely strained semiconductor layer having a defect density of about 10