Explaining the Different Time Constants Extracted from Low Frequency Y22 and $I_{DS}$-DLTS on GaN HEMTs
| Autor: | Luis C. Nunes, Jose C. Pedro, Joao L. Gomes |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science Transistor Time constant 020206 networking & telecommunications 02 engineering and technology Trapping Physical identity Low frequency 01 natural sciences law.invention law 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Charge carrier Transient (oscillation) Atomic physics High electron |
| Zdroj: | 2020 IEEE/MTT-S International Microwave Symposium (IMS). |
| DOI: | 10.1109/ims30576.2020.9223822 |
| Popis: | This paper presents an explanation for the observed differences on the trapping time constants extracted from low frequency $Y_{22}$ and $I_{DS}$ -Deep-Level Transient Spectroscopy (DLTS) on GaN high electron mobility transistors (HEMTs). It is shown that the trapping time constant, not being a physical identity but a parameter of a model, can vary according to the conditions of extraction. This dependence is thus clearly seen in $Y_{22}$ and $I_{DS}$ -DL TS measurements, as they are made respectively under small-signal steady-state and large-signal transient conditions. A theoretical explanation supported by the Shockley-Read-Hall (SRH) model is proposed, showing how time-constants extracted from $I_{DS}$ -DLTS, i.e. under charge carrier emission, must be longer than the ones obtained from $Y_{22}$ , i.e. under equilibrium and thus where both emission and much faster capture processes play a role. |
| Databáze: | OpenAIRE |
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