GaN Schottky barrier diodes with nickel nitride anodes sputtered at different nitrogen partial pressure

• Published in: Vacuum 2019-04, Vol.162, p.72-77
• Main Authors: Li, Xiaobo, Pu, Taofei, Taiki, Hoshi, Zhang, Tong, Xie, Tian, Luke Fujiwara, Shigeki Joseph, Kitahata, Hiroshi, Li, Liuan, Kobayashi, Sachio, Ito, Motoo, Li, Xianjie, Ao, Jin-Ping
• Format: Article
• Language: English
• Subjects: Gallium nitride; Nickel nitride; Reactive sputtering; Schottky barrier diode
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2019.01.030

Nickel nitride (NixN) films were deposited by magnetron reactive sputtering under varying N2 partial pressure (P(N2)) conditions range from 0.005 to 0.184 Pa. With the increasing P(N2), the deposition rate decreased while the resistivity and root mean square roughness increased. X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS) indicate that Ni4N and Ni3N phases dominate the films at low and medium P(N2), respectively. In addition, Ni2N phase can be also obtained at high P(N2). The Ni/N ratio evaluated from the energy dispersive X-ray spectrum is consistent with the NixN phases showed in the XRD spectra of different P(N2). Compared with the GaN diodes with Ni anode, the Schottky barrier height and turn-on voltage of the Schottky barrier diodes with NixN anode were increased by 0.03–0.18 eV and 0.03–0.15 V, respectively. Capacitance-voltage curves demonstrated that good interface quality with no obvious hysteresis was realized. Ni3N anode diodes obtained at medium P(N2) possess a high barrier height and a low reverse leakage current are regarded as a promising anode material. •NixN films were deposited by sputtering under P(N2) from 0.005 to 0.184 Pa.•Ni4N, Ni3N and Ni2N phases were observed and analyzed.•SBH of the NixN-GaN SBDs were 0.03–0.18 eV higher than Ni.•Ni3N was regarded as a promising anode material.