NUMERICAL-SIMULATION OF TUNNEL EFFECT TRANSISTORS EMPLOYING INTERNAL FIELD-EMISSION OF SCHOTTKY-BARRIER JUNCTION

Tunnel transistors employing internal field emission of the Schottky barrier junction (SBTT) are expected to be a promising component for high-density and low-cost integrated circuits. In order to characterize the performance of SBTT, we carried out 2-D numerical simulation on four typical device structures. The output characteristics of SBTT are basically triodelike; that is, the drain current increases exponentially with increasing gate voltage, having high and nonlinear transfer performance, as elucidated by the simulation. This triodelike characteristic is observed when the channel layer is thicker than the depletion layer width formed by gate bias near the drain. In the case of a thin channel layer, a saturation feature of the drain current with increasing gate bias appears due to a pinch-off effect, which is favorable for reducing the leakage current in the off state. A prototype n-channel SBTT of crystalline silicon was fabricated and its transistor action was confirmed.