Abstract
Low-resistance Ag ohmic contacts to semi-polar (1 1 -2 2) p-GaN were developed by controlling interfacial oxide using a Zn layer. The 300 °C-annealed Zn/Ag samples showed ohmic behavior with a contact resistivity of 6.0 × 10-4 Ω cm2 better than that of Ag-only contacts (1.0 × 10-3 Ω cm2). The X-ray photoemission spectroscopy (XPS) results showed that annealing caused the indiffusion of oxygen at the contact/GaN interface, resulting in the formation of different types of interfacial oxides, viz. Ga-oxide and Ga-doped ZnO. Based on the XPS and electrical results, the possible mechanisms underlying the improved electrical properties of the Zn/Ag samples are discussed.
Original language | English |
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Pages (from-to) | 962-967 |
Number of pages | 6 |
Journal | Superlattices and Microstructures |
Volume | 75 |
DOIs | |
Publication status | Published - 2014 Oct 16 |
Keywords
- Light-emitting diode
- Ohmic contact
- Semi-polar GaN
- Zn/Ag
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Electrical and Electronic Engineering