[10a-Z04-1~9] 13.7 Compound and power electron devices and process technology

[10a-Z04-6] Characterization of contactless photoelectrochemical-etched Ni/n-GaN Schottky contacts
--Comparison in different electrolytes--

〇(M2)Ryo Matsuda¹, Fumimasa Horikiri², Noboru Fukuhara², Yoshinobu Narita², Takehiro Yoshida², Tomoyoshi Mishima³, Kenji Shiojima¹ (1.Univ. of Fukui, 2.SCIOCS, 3.Hosei Univ.)

Keywords:GaN, Schottky contacts, photo-electrochemical etching

We characterized contactless-photoelectrochemical-etched n-type GaN Schottky electrodes using three different types of electrolytes ; (A)KOH : K₂S₂O₈ = 1 : 1,(B)H₃PO₄ : K₂S₂O_{8 =} 1 : 1,(C)K₂S₂O₈. For the samples A and C, the Schottky barrier height (qf_B) decreased proportional to the ratio of etching area, but for B, qf_B increased. Typical variations in qf_B, when the entire surface was etched, were (A)~ -0.14, (B)~ +0.09, (C)~ -0.17 eV. It was found that the amount of variations in qf_B by photo-electrochemical etching was smaller than that by dry etching, but the qf_B variation depends on the electrolyte.