Strained-Si channel super-self-aligned back-gate/double-gate planar transistors

We present a reproducible approach to the fabrication of super-self-aligned back-gate/double-gate n-channel and p-channel transistors with thin silicon channels and thick source/drain polysilicon regions. The device structure provides capability for scalable control of channel electrostatics, threshold variability without sacrificing source/drain series resistance, and capability of introducing strain to improve carrier transport. The separate device, circuit, and functional level back-gate access that is available through bottom interconnection also provides capability for adaptive power control and novel circuit design. Both n-channel and p-channel devices are demonstrated with the threshold tuning capability. © 2007 IEEE.