Hot phonons in Si-doped GaN

Abstract

Microwave noise and electron transport are studied in silicon-doped GaN channels grown by molecular beam epitaxy and subjected to a high electric field. The drift velocity of 2.8×107cm∕s is reached at 290kV∕cm for n∼1×1018cm−3 channel. No negative differential resistance is observed. The noise temperature exceeds ∼5000K at ∼110kV∕cm for n∼3×1017cm−3 channel. The hot-phonon effect on power dissipation in GaN:Si is 3–4 times weaker as compared with the effect in an undoped AlGaN∕GaN two-dimensional channel. Monte Carlo simulation shows a weak effect of hot phonons on hot-electron energy distribution.