Effects of gamma-ray irradiation on the microstructural and luminescent properties of radio-frequency magnetron-sputtered GaN thin films

Abstract

The microstructural and luminescent properties of sputtered GaN thin films preiiradiated and γ-ray irradiated were systematically investigated. Analytical results revealed that the increasing doses of γ rays could enhance the occurrence of more nitrogen vacancies, which not only created a prominent deep level luminescence but also destroyed the crystallinity of GaN thin films. For low dose of γ-ray irradiation [≦4 Mrad (GaN)], evidence showed that by raising the irradiation dose, more associated Ga–H complexes would be effectively promoted, yielding an enhanced yellow band emission. However, for high dose of γ-ray irradiation [>4 Mrad (GaN)], further higher doses of γ rays could lead to the dissociation of Ga–H complexes in GaN samples, resulting in a repressed yellow band emission. From both the Fourier transform infrared spectroscopy and yellow band emission results, it is strongly suggested that Ga–H complexes in the vicinity of N most probably act as the origin of yellow band emission in GaN material.

Electrical characterization of 60Co gamma radiation-exposed InAlN/GaN high electron mobility transistors

“…Most of the radiation studies involving GaN-based HEMTs have involved proton or electron damage. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] In terms of heterostructures, preliminary data from proton damage studies suggests that the radiation hardness decreases in the order AlN/GaN > AlGaN/GaN > InAlN/GaN, consistent with the average bond strengths in the Al-based materials. 13 The effects of gamma-ray irradiation are also of fundamental interest for space applications and electronics in nuclear plants.…”

“…[20][21][22] Most of these defects can migrate and recombine or create complexes, which are stable even at room temperature. 22,23 The saturation currents were significantly degraded after 500 Mrad irradiation, as shown in Figs. 2(a) and 2(b).…”

Effects of γ-Ray Irradiation on AlGaN/GaN Heterostructures and High Electron Mobility Transistor Devices

“…Studies have reported both improvements and degradation in material properties following c-ray irradiation. [9][10][11][12][13][14][15][16] Membreno et al 17 reported the effect of cirradiation on n-GaN material through transient capacitance measurements. The generation of two defect levels with thermal activation energies of 89 meV and 132 meV, respectively, was reported after the material was subjected to a c-irradiation dose of 210 kGy.…”

“…However, the defects present during the pristine stage were unresolved. Wang et al 10 also investigated the effect of c-irradiation on GaN films and reported enhanced yellow band emission at low c-irradiation doses (£ 40 kGy). The yellow band emission increased as a result of the formation of nitrogen vacancy (V N ) related deep Ó 2020 The Minerals, Metals & Materials Society traps.…”

Characteristics of GaN Thin Films Using Magnetron Sputtering System

“…The sputter grown GaN thin films are preferred because of the ease of operation, thickness control, low temperature deposition, sequential deposition of different films, and less toxicity [9]. Although sputtering of GaN has not yet been fully explored, sputtering of GaN has achieved polycrystalline and single crystal GaN by sputtering of a GaN target [10] [11] [12] [13] [14], a gallium (Ga) target [15] [16] [17], and GaN powder target [18] [19] [20].…”