The influence of Fermi-level pinning at the GaAs substrate on HEMT threshold voltage
| Autor: | Richard J. Krantz, Walter L. Bloss, D.C. Mayer |
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| Rok vydání: | 1990 |
| Předmět: |
Condensed matter physics
Chemistry Quantum limit Fermi level Substrate (electronics) High-electron-mobility transistor Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter Physics Acceptor Electronic Optical and Magnetic Materials Threshold voltage Condensed Matter::Materials Science symbols.namesake Materials Chemistry symbols Field-effect transistor Electrical and Electronic Engineering Quantum well |
| Zdroj: | Solid-State Electronics. 33:1189-1195 |
| ISSN: | 0038-1101 |
| DOI: | 10.1016/0038-1101(90)90098-y |
| Popis: | A two-dimensional quantum well, strong-inversion model of threshold in AlGaAs/GaAs high-electron-mobility transistors (HEMTs) has been extended to include the effects of Fermi-level pinning at the semi-insulating boundary of the thin active GaAs layer. The pinning of the Fermi level at the semi-insulating boundary results from an abundance of mid-gap traps in the substrate and couples the carrier channel at the AlGaAs/GaAs interface to the substrate. This communication between the carrier channel and the substrate causes the threshold voltage characteristics of the pinned devices to be substantially different from those of a conventional, semi-infinite HEMT structure. The discrepancy in the threshold voltage approaches 250 mV for a 0.1-μm active-layer device having a typical acceptor doping of ∼1014 cm−3. The quantum-well HEMT threshold model has also been compared to a classical analysis of the threshold voltage. For low acceptor doping and thin GaAs layers ( |
| Databáze: | OpenAIRE |
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