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High-performance PMOSFETs with sub-50-nm gate-length are reported. A self-aligned double-gate MOSFET structure (FinFET) is used to suppress the short-channel effects. This vertical double-gate SOI MOSFET features: 1) a transistor channel which is formed on the vertical surfaces of an ultrathin Si fin and controlled by gate electrodes formed on both sides of the fin; 2) two gates which are self-aligned to each other and to the source/drain (S/D) regions; 3) raised S/D regions; and 4) a short (50 nm) Si fin to maintain quasi-planar topology for ease of fabrication. The 45-nm gate-length p-channel FinFET showed an dsat of 820 A/ m at ds = gs = 1 2 V and ox = 2 5nm. Devices showed good performance down to a gate-length of 18 nm. Excellent short-channel behavior was observed. The fin thickness (corresponding to twice the body thickness) is found to be critical for suppressing the short-channel effects. Simulations indicate that the FinFET structure can work down to 10 nm gate length. Thus, the FinFET is a very promising structure for scaling CMOS beyond 50 nm.

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A new method of growing multiple gate oxide thicknesses below 5 nm using masked oxygen implantation is presented. Multiple thicknesses can be achieved on the same wafer without degradation in the oxide properties. The oxygen implanted oxide quality is comparable to that of thermally grown oxides. Moreover, the effects of oxygen implant damage is minimized with higher implant energies, thicker sacrificial oxides, and low-temperature annealing.

A new approach to reducing the tunnel oxide thickness in floating gate memories is introduced for RAM applications. Experimental measurements and two-dimensional (2-D) device simulations are used to investigate the operating principles of a direct tunneling RAM (DT-RAM) cell. DT-RAM targets memory applications in which manufacturability, scalability, low-power, high-density, and long retention times are important considerations.