Abstract
Sputter-deposited W Schottky contacts on n-GaN show as-deposited barrier heights (φb) of 0.80eV for optimized conditions. Subsequent annealing at 500-600°C reduces the barrier height to ∼0.4eV, its theroretical value from the relation φb = φm- χs (where φm is the metal work function and χs the electron affinity of GaN). The lowest specific resistance for the W is obtained for high power, low pressure (< 20mTorr) deposition conditions where the incident ion energy and deposition rate are optimized to minimize damage to the GaN surface. At higher annealing temperatures the W reacts with the GaN to form β-phase W2N.
Original language | English |
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Pages (from-to) | 95-98 |
Number of pages | 4 |
Journal | Materials Science in Semiconductor Processing |
Volume | 7 |
Issue number | 1-2 |
DOIs | |
State | Published - Feb 2004 |
Externally published | Yes |
Funding
The work at UF is partially supported by NASA Kennedy Space Center (NAG10-316, Dr. Daniel Fitch) and the UCF-UF Space Research Initiative, and also by NSF DMR-0101438.
Keywords
- GaN
- Schottky contact
- Thermal stability
- W contact