3-D CMOS transistors with high ESD reliability

摘要

The present invention discloses a method for manufacturing 3-D transistors with high electrostatic discharge (ESD) reliability. Pad oxide layers are on a silicon substrate and a thick field oxide is on the silicon substrate between the pad oxide layer. An oxygen amorphized region is formed in the substrate by using an ion implantation having oxygen ions as dopants and the field oxide as a hard mask. A high-temperature thermal annealing is implemented to convert the oxygen amorphized region into an oxygen implant-induced oxide regions. Then, the pad oxide layers and the field oxide are removed to form a field oxide region on the substrate and silicon islands on the oxygen implant-induced oxide regions. A thin gate oxide is deposited on the surface of the substrate and the silicon islands to seal the silicon islands. Finally, PMOSFETs are formed on the silicon islands and bulk NMOSFET buffers are formed on the field oxide region of the substrate.