ACTA

Signature of Hot Phonons in Reliability of Nitride Transistors and Signal Delay

A. Matulionis^a, J. Liberis^a, I. Matulionienė^a, E. Šermukšnis^a, J.H. Leach^b, M. Wu^b, X. Ni^b and H. Morkoç^b
^aSemiconductor Physics Institute, Centre for Physical Sciences and Technology, Vilnius, Lithuania
^bDepartment of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond, VA, USA

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Lifetime of non-equilibrium (hot) phonons in biased GaN heterostructures with two-dimensional electron gas channels was estimated from hot-electron fluctuations. Dependence of the lifetime on the electron density is not monotonous - the resonance-type fastest decay serves as a signature of hot phonons. The signature is resolved in nitride heterostructure field effect transistors when the gate voltage is used to change the channel electron density. The transistor cut-off frequency decreases on both sides of the resonance in agreement with the enhanced electron scattering caused by longer hot-phonon lifetimes. The signature is also noted in device reliability experiment: the enhanced temperature of hot phonons, possibly, triggers formation of new defects and accelerates device degradation.

DOI: 10.12693/APhysPolA.119.225
PACS numbers: 72.70.+m, 73.50.Fq, 73.61.Ey