Nagoya University researchers develop low-resistance GaN contacts

Researchers at Nagoya University have developed a new method to lower contact resistance in p-type Gallium Nitride (GaN) semiconductors. The team, led by Haitao Wang and Jia Wang, utilized an ultrathin magnesium layer deposited onto the p-GaN surface followed by a five-minute heat treatment at 600°C.

This ‘soft annealed’ magnesium layer achieves a contact resistivity of (1–3) × 10⁻⁴ Ω cm² without damaging the surface. This result is among the lowest reported for thin p-type GaN. The breakthrough addresses a long-standing efficiency bottleneck in semiconductor devices, where high resistance at the metal-semiconductor boundary typically requires costly and laborious heavy doping processes to overcome.

The findings, published in Applied Physics Letters, could lead to increased energy efficiency in various electronic applications, including electric vehicles (EVs) and data centers.