Patent ID: 6716682
Filing Date: 2004-04-06
Classification: H01L

Abstract:
A method of creating complementary transistor devices each having a retrograde doping profile in an active layer of silicon positioned above a buried oxide (BOX) layer, the method comprising:implanting dopants through device regions of the active layer into the BOX layer so as to form dopant source regions comprising borophosphosilicate glass (BPSG) within the BOX layer substantially adjacent the interface between the BOX layer and the active layer; implanting dopants into gate regions of the device regions so as to adjust threshold voltages of the complementary devices; forming complementary transistor devices in the active layer so that the transistor devices have a channel region in the active layer and a gate positioned over the channel region; and forming a passivation layer over the transistor devices with a high temperature process wherein the forming of the passivation layer results in high temperature processing of the dopant source regions such that dopant diffuses out of the dopant source regions into the channel regions to thereby define retrograde doping profiles in the channel regions.