Investigation of Ohmic mechanism for chlorine-treated p-type GaN using x-ray photoelectron spectroscopy

Abstract

To investigate the function and mechanism of oxidation, the surface of the chlorine-treated p-type GaN semiconductor was analyzed using x-ray photoelectron spectroscopy. The chlorinated surface treatment was performed by electrolyzing HCl chemical solution to generate HClO, which in turn could be used to oxidize the p-type GaN. The chlorinated surface treatment enhances the formation of GaOx on the GaN surface and removing GaOx layer from the surface thereafter leads to the creation of additional Ga vacancies. Consequently, more holes are generated as a result of the generated Ga vacancies. Therefore, a relatively higher Ohmic performance with a specific contact resistance of 6.1×10−6Ωcm2 can be obtained for Ni∕Au metal contact subsequently patterned on the chlorine-treated p-type GaN via the enhanced formation of GaOx.

Investigation of the Ti/Al/Pt/Au and Ti/Au contact materials on the N‐face surface of oxygen doped GaN

“…In this study, we find that the binding energy of N-Ga bonds was 398.5 eV higher than the report value, 397.5 eV [13,20], due to the N-face surface of GaN:O with opposite polarization direction, leading to the higher upward surface band bending. According to the results shown in Fig.…”

Performance Improvement and Mechanism of Chlorine-Treated InGaN–GaN Light-Emitting Diodes

“…A detailed study of the chlorine-treated p-type GaN was reported previously. 15 Because an interfacial insulating oxide with a thickness of 1-2 nm has a serious influence on the electrical performance of metal contact on GaN, 16 it is necessary to remove GaO x from the chlorinetreated p-type GaN surface using aqua regia. The removal of GaO x can also induce additional Ga vacancy.…”

Performance improvement of GaN-based ultraviolet metal–semiconductor–metal photodetectors using chlorination surface treatment

“…Prior to the deposition of the Ni/Au Schottky metals, the native oxide residing on the GaN surface was removed using a chlorination surface treatment, [13][14][15] wherein an aqueous solution of 1 HCl þ 10 H 2 O was used as the electrolytic solution. A 700-nm-thick undoped GaN buffer layer and a 100nm-thick undoped Al 0.2 Ga 0.8 N buffer layer were grown on cplane sapphire substrates and then a 300-nm-thick undoped GaN absorption layer was grown.…”

“…6,7 Further, ultraviolet radiation detection devices have attracted much attention in emerging civil and military applications, such as chemical analysis, biological analysis, flame sensors, space-based optical communications, emitter calibration, and astronomical studies. [11][12][13] Among them, the chlorination surface treatment was verified to be a promising technology for the reduction of the surface states by passivating the Ga dangling bonds and the N vacancies residing on the surface of GaN-based semiconductors. [8][9][10] Among them, not only do metal-semiconductor-metal photodetectors (MSM-PDs) exhibit an ultralow intrinsic capacitance, but the related fabrication processes are compatible with field-effect-transistor-based electronic devices.…”

“…Various types of GaN-based ultraviolet photodetectors (PDs) have been reported previously. 13 In this work, in order to investigate the function of the chlorination surface treatment used on GaN-based MSM-PDs, the dark current, photoresponsivity, low-frequency noise, and detectivity of chlorine-treated GaN-based MSM-PDs were measured and compared with those of untreated ones. Consequently, GaN-based MSM-PDs are expected to be easily integrated with GaNbased electronic devices to produce GaN-based optoelectronic integrated circuits.…”