Optimizing the orientation of β-Ga_(2)O_(3) has emerged as an effective strategy to design high-performance β-Ga_(2)O_(3) device,but the orientation growth mechanism and approach have not been revealed yet.Herein,by...Optimizing the orientation of β-Ga_(2)O_(3) has emerged as an effective strategy to design high-performance β-Ga_(2)O_(3) device,but the orientation growth mechanism and approach have not been revealed yet.Herein,by employing AlN buffer layer,the highly preferred orientation of β-Ga_(2)O_(3)(100)film rather than(-201)film is realized on 4H-SiC substrate at low sputtering power and temperature.Because β-Ga_(2)O_(3)(100)film exhibits a slower growth speed than(-201)film,the former possesses the higher dangling bond density and the lower nucleation energy,and a large conversion barrier exists between these two ori-entations.Moreover,the AlN buffer layer can suppress the surface oxidation of the 4H-SiC substrate and eliminate the strain of β-Ga_(2)O_(3)(100)film,which further reduces the nucleation energy and en-larges the conversion barrier.Meanwhile,the AlN buffer layer can increase the oxygen vacancy formation energy and decrease the oxygen vacancy concentration of β-Ga_(2)O_(3)(100)film.Consequently,the solar-blind photodetector based on the oriented film exhibits the outstanding detectivity of 1.22×10^(12) Jones and photo-to-dark current ratio of 1.11×10^(5),which are the highest among the reported β-Ga_(2)O_(3) solar-blind photodetector on the SiC substrate.Our results offer in-depth insights into the preferred orientation growth mechanism,and provide an effective way to design high-quality β-Ga_(2)O_(3)(100)orientation film and high-performance solar-blind photodetector.展开更多
GaN films grown on(111)Si substrate with different lattice parameters of the AlN buffer layer by metal–organic chemical vapor deposition are studied.The stress states obtained by different test methods are compared a...GaN films grown on(111)Si substrate with different lattice parameters of the AlN buffer layer by metal–organic chemical vapor deposition are studied.The stress states obtained by different test methods are compared and it is found that the lattice parameter of the AlN buffer layer may have a significant effect on the stress state in the initial stage of subsequent GaN film growth.A larger compressive stress is beneficial to improved surface morphology and crystal quality of GaN film.The results of further orthogonal experiments show that an important factor affecting the lattice parameter is the growth rate of the AlN buffer layer.This work may be helpful for realizing simple GaN-on-Si structures and thus reducing the costs of growth processes.展开更多
Unintentionally doped AlGaN thin films are grown on c-plane(0001) sapphire substrate by metal-organic chemical vapor deposition, and low-temperature AlN is deposited onto sapphire substrate used as a bu?er layer. AlGa...Unintentionally doped AlGaN thin films are grown on c-plane(0001) sapphire substrate by metal-organic chemical vapor deposition, and low-temperature AlN is deposited onto sapphire substrate used as a bu?er layer. AlGaN metal-semiconductor-metal ultraviolet photodetectors with Ni/Au interdigitated contact electrodes are then fabricated by lift-off technology. The dark current of the AlGaN photodetectors is 5.61×10-9 A at 2-V applied bias and the peak response occurrs at 294 nm.展开更多
基金supported by the National Key Research and Development Program of China(No.2021YFA0715600)the National Natural Science Foundation of China(Nos.62274125,52192611)+2 种基金the Guangdong Basic and Applied Basic Research Fund(No.2023A1515030084)the Key Research and Development Program of Shaanxi Province(Grant No.2024GX-YBXM-410)the fund of the State Key Laboratory of Solidification Processing in NWPU(No.SKLSP202220).
文摘Optimizing the orientation of β-Ga_(2)O_(3) has emerged as an effective strategy to design high-performance β-Ga_(2)O_(3) device,but the orientation growth mechanism and approach have not been revealed yet.Herein,by employing AlN buffer layer,the highly preferred orientation of β-Ga_(2)O_(3)(100)film rather than(-201)film is realized on 4H-SiC substrate at low sputtering power and temperature.Because β-Ga_(2)O_(3)(100)film exhibits a slower growth speed than(-201)film,the former possesses the higher dangling bond density and the lower nucleation energy,and a large conversion barrier exists between these two ori-entations.Moreover,the AlN buffer layer can suppress the surface oxidation of the 4H-SiC substrate and eliminate the strain of β-Ga_(2)O_(3)(100)film,which further reduces the nucleation energy and en-larges the conversion barrier.Meanwhile,the AlN buffer layer can increase the oxygen vacancy formation energy and decrease the oxygen vacancy concentration of β-Ga_(2)O_(3)(100)film.Consequently,the solar-blind photodetector based on the oriented film exhibits the outstanding detectivity of 1.22×10^(12) Jones and photo-to-dark current ratio of 1.11×10^(5),which are the highest among the reported β-Ga_(2)O_(3) solar-blind photodetector on the SiC substrate.Our results offer in-depth insights into the preferred orientation growth mechanism,and provide an effective way to design high-quality β-Ga_(2)O_(3)(100)orientation film and high-performance solar-blind photodetector.
基金supported by Beijing Municipal Science&Technology Commission,Administrative Commission of Zhongguancun Science Park(Grant Nos.Z211100007921022 and Z211100004821001)the National Natural Science Foundation of China(Grant Nos.62034008,62074142,62074140,61974162,61904172,61874175,62127807,and U21B2061)+3 种基金Key Research and Development Program of Jiangsu Province(Grant No.BE2021008-1)Beijing Nova Program(Grant No.202093)Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB43030101)Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2019115).
文摘GaN films grown on(111)Si substrate with different lattice parameters of the AlN buffer layer by metal–organic chemical vapor deposition are studied.The stress states obtained by different test methods are compared and it is found that the lattice parameter of the AlN buffer layer may have a significant effect on the stress state in the initial stage of subsequent GaN film growth.A larger compressive stress is beneficial to improved surface morphology and crystal quality of GaN film.The results of further orthogonal experiments show that an important factor affecting the lattice parameter is the growth rate of the AlN buffer layer.This work may be helpful for realizing simple GaN-on-Si structures and thus reducing the costs of growth processes.
基金supported by the National Natural Science Foundation of China(No.61006052)the Fundamental Research Funds for the Central Universities(No.K5051325009)
文摘Unintentionally doped AlGaN thin films are grown on c-plane(0001) sapphire substrate by metal-organic chemical vapor deposition, and low-temperature AlN is deposited onto sapphire substrate used as a bu?er layer. AlGaN metal-semiconductor-metal ultraviolet photodetectors with Ni/Au interdigitated contact electrodes are then fabricated by lift-off technology. The dark current of the AlGaN photodetectors is 5.61×10-9 A at 2-V applied bias and the peak response occurrs at 294 nm.
基金Project supported by the National Natural Science Foundation of China(60890192,60877006,50872146)the Chinese Science and Technology Ministry(“863”,No.2009AA033101)~~
