Titanium and titanium nitride contacts were fabricated on n-type GaN and characterized by specific contact resistance measurements and by x-ray photoelectron spectroscopy depth profiling. Ti contacts were annealed between 400 and 900 °C in AR and N2 to observe the effects of annealing environment on ohmic contact formation. Ti contacts annealed in N2 became ohmic after 1 min at 700 °C and reacted at minimum specific contact resistance of 4×10-6 Ω cm2 after 1 min at 800 °C. Ti contacts annealed in Ar required 20-25 min at 700 °C to become ohmic and also reached a minimum specific contact resistance after 1 min at 900 °C. Depth profiles of Ti contacts showed that the presence of TiN at the metal GaN interface was necessary for ohmic contact formation.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry