Theoretical investigation of GaN permeable base transistors for microwave power applications

Abstract

An electrical and thermal study of submicron GaN multi-finger permeable base transistors (PBTs) is presented. Carrier transport in the intrinsic finger is studied with drift-diffusion and energy balance models, validated against ensemble Monte Carlo simulation; device performances are optimized through an aggressive geometrical scaling. Non-isothermal analysis of the complete multi-finger structure demonstrates the need for a mobility model whose temperature dependence is not confined to low-field parameters. The potential of GaN PBTs for microwave power applications is finally investigated by evaluating the relevant figures of merit.

Transport Parameters for Electrons and Holes

“…In this work we use a similar full-band Monte Carlo simulation technique and employ an up-to-date electronic structure [3] to compute the steady state drift velocity. A similar analytical expression of the drift velocity as a function both of the electric field and temperature is given in [50]. The peak velocity for transport along the Γ-A direction is 2.85 × 10 7 cm s −1 reached at a field strength of 215 kV cm −1 .…”