Performance and analytical modeling of Metal–Insulator-Metal Field Controlled Tunnel Transistors

The authors investigate the performance of a Metal–Insulator-Metal Field Controlled Tunneling Transistor (MIMT). In this structure, the flow of electrons between the source and the drain is due to a Fowler–Nordheim like tunneling mechanism through a dielectric whose potential barrier is modulated by the gate bias. This silicon-free device is immune to dopant fluctuations or band to band tunneling and its performance is solely limited by the tunneling mechanism. We have evaluated the theoretical device performance and proposed an analytical model capturing the underlying physics. The impact of material properties (dielectric permittivity, bandoffset) and geometrical parameters (gate oxide and tunneling oxide thickness, channel length) is discussed and guidelines for the fabrication of an optimized device are provided. We show that, with appropriate materials and architecture, a well tempered MIMT can demonstrate OFF current as low as 1 nA/um and ON current on the order of 1 mA/um for a voltage swing of 0.5 V, making it an excellent candidate for ultra low power applications and thin film transistors. We also demonstrate that although its operation is based on tunneling, this device does not exhibit sub-60 mV/dec subthreshold slope, but maintains nearly 60 mV/dec between the OFF and ON-states.