High-performance fully depleted silicon-on-insulator transistors

Thin single-crystal silicon-on-insulator films with defect densities as low as 800,000 dislocations/sq cm were formed by implantation of 1.5 x 10 to the 18th O(+)/sq cm at 150 kV into bare Si and annealing at 1350 C for 6 h in N2. Thin-film submicrometer MOS transistors were fabricated with self-aligned TiSi2 fully covering sources, drains, and gates, and with p(+) and n(+) polysilicon gates for PMOS and NMOS transistors, respectively, but without a lightly doped drain. Transistors with gate lengths as short as 400 nm exhibited essentially long-channel behavior with no kink and with a high saturation current. The device physics was investigated using PISCES simulations, which agreed well with the experimental results. A ring-oscillator stage delay of 58 psec was obtained for 1.0-micron-gate CMOS circuits operating at 5 V.