An Analytical I-V characteristics model for Au-AlxGa1-xAs GaAs VMT heterojunctions based on non-linear charge-control and field-dependent mobility formulations

Abstract EN

The velocity modulation transistor (VMT) has two channels with differing velocities.

Small vertical distance between these channels can be achieved using epitaxial growth, opening the opportunity for higher speed than any other heterostructure field-effect transistor (FET).

The non-linear charge-control formulation of the two-dimensional electron gas (2DEG) sheet carriers concentration (ns), which consider the variation of ns with Fermi-potential in the triangular potential quantum well of the VMT, has led to a bias-dependent effective offset distance of the 2DEG from the heterointerface.

The consideration of variable 2DEG offset distance pushes the model characterization to great accuracy then the linear characterization does.

Based on non-linear charge-control and a single set of analytical expressions for field-dependent mobility formulations for AlxGa1-xAs/GaAs heterostructure, we developed an analytical I-V characteristics model for VMT device.

This model incorporates effects of both composition (x) and doping concentration (Nd) dependences.

The model is suitable for computer aided design (CAD) applications in the analysis, design, and optimization of microwave and digital VMT devices.