Quasi three-section CAD model for MODFETs

A purely analytical model for MODFETs based on two-dimensional device simulation is proposed. In this model, proper treatment of the diffusion effect in two-dimensional electron gas (2-DEG) transport due to the gradual channel opening along the 2-DEG channel was used to explain the enhanced mobility and increased threshold voltage. By introducing the finite channel opening and an effective channel-length modulation, the slope of the saturation region of the I-V curves was modeled. The smooth transition of the I-V curves from linear-to-saturation region of the I-V curves was possible using the continuous Troffimenkoff-type of field-dependent mobility. A correction factor f was introduced to account for the finite transition section forming between the GCA and the saturated section. This factor removes the large discrepancies in the saturation region of the I-V curves predicted by previous one-dimensional models