Limitation of Hot-Carrier Generated Heat Dissipation on the Frequency of Operation and Reliability of Novel Nitride-Based High-Speed HFETs
Abstract
A novel fluctuation-based approach is applied to consider the unsolved problems in the realm of nitride heterostructure field effect transistors (HFETs). Fluctuations originate at a microscopic level and provide information on the processes responsible for device operation and degradation. The novel fluctuation-based approach is impelled by recent demonstration of strong correlation of microwave hot-electron fluctuations with frequency performance and degradation of nitride HFETs. The correlation has its genesis in the dissipation of the LO-mode heat accumulated by the non-equilibrium longitudinal optical phonons (hot phonons) confined in the channel that hosts the high-density hot-electron gas subjected to a high electric field. The LO-mode heat causes additional scattering of hot electrons and facilitates defect formation in a different manner than conventional heat accumulated by acoustic phonons. The heat accumulation depends on the supplied electric power and the rate of heat dissipation. We treat the problem in terms of the hot-phonon lifetime responsible for conversion of non-migrant optical phonons into migrant modes. The lifetime is measured over wide ranges of electron densities and supplied electric power. The optimal conditions for heat dissipation are determined and associated with plasmon-assisted disintegration of LO phonons. Signatures of plasmons are experimentally resolved in fluctuations, dissipation, hot-electron transport, transistor frequency performance, and device reliability. In particular, a slower degradation and a faster operation of GaN-based HFETs is demonstrated when the plasmon-assisted ultrafast dissipation of the LO-mode heat comes into play.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 19, 2010
- Accession Number
- ADA542888
Entities
People
- Arvydas Matulionis
- H. Morkoc
- J. H. Leach
- Junfei Xie
- Jung‐Hee Lee
- Min Wu
- R. Katilius
- X. Ni
- Xiangchong Li
- Ümit Özgür
Organizations
- Semiconductor Physics Institute