Abstract
The stoichiometry of low-pressure chemical vapor deposition SiNx surface passivation is shown to change vertical conductivity at the top of the epitaxial stack in GaN-on-Si power high-electron mobility transistors (HEMTs). This changes the charge stored in the carbon-doped GaN layer during high-voltage operation, and allows direct control of buffer-related current collapse in HEMTs. Substrate bias ramps are used to identify the changes in C:GaN charge trapping and vertical leakage. Channel length dependence indicates a lateral conductivity in the C:GaN with a localized increase in vertical conductivity under the ohmic contacts. An optimum SiNx recipe is identified which simultaneously delivers low current collapse and low drain leakage.
Original language | English |
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Article number | 8013764 |
Pages (from-to) | 4044-4049 |
Number of pages | 6 |
Journal | IEEE Transactions on Electron Devices |
Volume | 64 |
Issue number | 10 |
Early online date | 21 Aug 2017 |
DOIs | |
Publication status | Published - 1 Oct 2017 |
Research Groups and Themes
- CDTR
Keywords
- AlGaN/GaN
- buffer trapping
- high-electron mobility transistor (HEMT)
- passivation