Terahertz Compact SPICE Model

M. Shur (Rensselaer Polytech. Inst., USA)

The cutoff frequencies and maximum frequencies of operation of short channel transistors have reached the terahertz (THz) range. In such devices, the ballistic electron transport, which was first proposed nearly 40 years ago, affects all the device characteristics – from the linear region (dominated by the so-called “ballistic mobility”) to a high field region affected by the ballistic injection. The rectification of the resonant or overdamped waves of the electron density in the device channel (“plasma waves”) enables the detection of the THz radiation. Conventional SPICE models do not account for the electron inertia that is important at THz frequencies. The THz SPICE model is based on a distributive transmission line equivalent circuit incorporating incremental inductive, capacitive and resistive elements and the incremental transistors controlled by a joint gate and. This SPICE model was validated up to 4.5 THz for Si CMOS and InGaAs HEMTs.