Detailed analysis of oxide related charges and metal-oxide barriers in terrace etched Al2O3and HfO2on AlGaN/GaN heterostructure capacitors
| Autor: | F. Schubert, Rico Hentschel, N. Szabó, J. Ocker, Jan Gärtner, Annett Winzer, M. Schuster, Andre Wachowiak, Thomas Mikolajick |
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| Rok vydání: | 2015 |
| Předmět: |
Materials science
business.industry Analytical chemistry Oxide General Physics and Astronomy Charge density Heterojunction High-electron-mobility transistor Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Threshold voltage Condensed Matter::Materials Science Atomic layer deposition chemistry.chemical_compound chemistry MOSFET Optoelectronics Work function Physics::Chemical Physics business |
| Zdroj: | Journal of Applied Physics. 118:124106 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.4931884 |
| Popis: | In this work, we present the terrace etching technique to obtain excessive thickness series of atomic layer deposition (ALD) grown Al2O3 and HfO2 on GaN-cap/AlGaN/GaN heterostructures allowing for the detailed study of oxide charge distribution and its impact of the metal-insulator-semiconductor high electron mobility transistor (MISHEMT) threshold voltage. By modeling the experimental plot of threshold voltage versus oxide thickness on the basis of experimentally determined two-dimensional electron gas charge density in AlGaN/GaN MISHEMTs, we separated the interface and bulk charge components and determined the oxide-metal barrier height for the investigated gate dielectrics. In both Al2O3 and HfO2 gate dielectrics, the oxide charges are mainly located at the oxide/GaN interface. Determining the interface trap charges from comparison of the pulsed capacitance-voltage (CV) technique with very fast voltage sweep to the modulation type CV method with slow DC voltage ramp, we extracted positive fixed charges... |
| Databáze: | OpenAIRE |
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