Theoretical investigation of GaN permeable base transistors for microwave power applications

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.