U-grooved SIT CMOS technology with 3 fJ and 49 ps (7 mW, 350 fJ) operation

Static induction transistor (SIT) CMOS is analyzed by a circuit simulation method. According to the results, the propagation delay time of the SIT CMOS could be represented as the ratio of the load capacitance to the transconductance. The U-grooved structure plays an important role in the fabrication of MOS SIT with large transconductance and small parasitic capacitance. U-grooved SIT CMOS has been fabricated by anisotropic plasma etching, and its switching speed has been evaluated by a 31-stage ring oscillator. A minimum rho - tau product of 3 fJ/gate has been obtained for a design rule of 1- mu m channel length. A minimum propagation delay time of 49 ps/gate has also been obtained at a dissipation power of 7 mW/gate, which corresponds to a rho - tau product of 350 fJ/gate.<
>