摘要:
A semiconductor-on-insulator transistor (10) has a channel region (30) in a semiconductor film (16) under a gate insulating layer (26). The channel region has a top dopant concentration N.sub.T at a top surface (32) of the film that is significantly greater than a bottom dopant concentration N.sub.B at a bottom surface (34) of the film. This non-uniform doping profile provides an SOI device that operates in a fully-depleted mode, yet permits thicker films without a significant degradation of sub-threshold slope.
摘要:
Insulated gate field effect transistors (10, 70) having process steps for setting the V.sub.T and a device leakage current which are decoupled from the process steps for providing punchthrough protection, thereby lowering a subthreshold swing. In a unilateral transistor (10), a portion (37, 45) of a dopant layer (25, 30) between a source region (48, 51) and a drain region (49, 52) serves as a channel region and sets the V.sub.T and the device leakage current. A halo region (34, 39) contains the source region (48, 51) and sets the punchthrough voltage. In a bilateral transistor (70), both a source region (83, 86) and a drain region (84, 87) are contained within halo regions (75, 74, 79, 81). A portion (76, 82) of a dopant layer (25, 30) sets the V.sub.T and a leakage current, whereas the halo region (75, 79) sets the punchthrough voltage.