Origin of improved RF performance of AlGaN/GaN MOSHFETs compared to HFETs
| Autor: | K. M. Indlekofer, Hans Lüth, G. Heidelberger, A. Fox, J. Bernat, Michel Marso, Peter Kordos |
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| Rok vydání: | 2006 |
| Předmět: |
Materials science
Passivation business.industry Wide-bandgap semiconductor Electrical engineering Heterojunction Gallium nitride High-electron-mobility transistor Electronic Optical and Magnetic Materials chemistry.chemical_compound chemistry Hall effect MOSFET Optoelectronics Field-effect transistor Electrical and Electronic Engineering business |
| Zdroj: | IEEE Transactions on Electron Devices. 53:1517-1523 |
| ISSN: | 0018-9383 |
| DOI: | 10.1109/ted.2006.875819 |
| Popis: | In this paper, the influence of a 10-nm-thick silicon-dioxide layer, as a passivation or as a gate insulation, on the performance of heterojunction field-effect transistors (HFETs) and metal-oxide-semiconductor HFETs (MOSHFETs), based on an undoped AlGaN/GaN heterostructure on a SiC substrate, was investigated. Channel-conductivity results yield a nearly 50% increase of mobility in the MOSHFET samples compared to the unpassivated HFETs. This increase of the transport properties of the MOSHFET channel is confirmed by a similar 45% increase of the cutoff frequency, from 16.5 to 24 GHz. Hall measurements, however, show a 10% decrease of the mobility in the heterostructure with a SiO2 top layer. In this paper, the superior performance of the MOSHFET transistor, in contradiction to the Hall results, is attributed to the screening of the Coulomb scattering of the charged surface defects by the gate-metallization layer |
| Databáze: | OpenAIRE |
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