Effects of the RF bias power of ICP etching on the electrical properties of n-type Ohmic contact on high-Al-fraction AlGaN

The effects of the radio frequency (RF) bias power of inductively coupled plasma etching on the electrical properties of n-type Ohmic contact have been investigated. By reducing the RF bias power, a high-quality n-type Ohmic contact has been achieved on n-Al0.70Ga0.30N, with a specific contact resistivity of 1.2 × 10−4 Ω cm2. It is confirmed that low-power etching introduces fewer acceptor-state defects on the etched surface, which not only reduces the compensation for electrons but also reduces the degree of oxidation on the etched surface, providing favorable conditions for improving the electrical properties of metal–semiconductor contacts.