Two strain-state samples of GaN, labelled the strain-relief sample and the quality-improved sample, were grown by hydride vapour phase epitaxy （HVPE）, and then characterized by high-resolution X-ray diffraction, pho...Two strain-state samples of GaN, labelled the strain-relief sample and the quality-improved sample, were grown by hydride vapour phase epitaxy （HVPE）, and then characterized by high-resolution X-ray diffraction, photoluminescence and optical microscopy. Two strain states of GaN in HVPE, like 3D and 2[） growth modes in metal-organic chemical vapour deposition （MOCVD）, provide an effective way to solve the heteroepitaxial problems of both strain relief and quality improvement. The gradual variation metbod （GVM）, developed based on the two strain states, is characterized by growth parameters＇ gradual variation alternating between the strain-relief growth conditions and the quality-improved growth conditions. In GVM, the introduction of the strain-relief amplitude, which is defined by the range from the quality-improved growth conditions to the strain-relief growth conditions, makes the strain-relief control concise and effective. The 300-μm thick bright and crack-free GaN film grown on a two-inch sapphire proves the effectiveness of GVM.展开更多
A new layer transfer technique which comprised double bonding and a step annealing process was utilized to transfer the GaN epilayer from a sapphire substrate to a Mo substrate. Combined with the application of the th...A new layer transfer technique which comprised double bonding and a step annealing process was utilized to transfer the GaN epilayer from a sapphire substrate to a Mo substrate. Combined with the application of the thermal-stable bonding medium, the resulting two-inch-diameter GaN template showed extremely good stability under high temperature and low stress state. Moreover, no cracks and winkles were observed. The transferred GaN template was suitable for homogeneous epitaxial, thus could be used for the direct fabrication of vertical LED chips as well as power electron devices. It has been confirmed that the double bonding and step annealing technique together with the thermal-stable bonding layer could significantly improve the bonding strength and stress relief, finally enhancing the thermal stability of the transferred GaN template.展开更多
基金Project supported by the National Basic Research Program of China (Grant No.2007CB307004)the National High Technology Research and Development Program of China (Grant No.2009AA03A198)+1 种基金the National Natural Science Foundation of China (Grant Nos.60776041 61076012,60876063,and 60676032)the Science and Technology Fund of Beijing,China (Grant No.Z101103050410003)
文摘Two strain-state samples of GaN, labelled the strain-relief sample and the quality-improved sample, were grown by hydride vapour phase epitaxy （HVPE）, and then characterized by high-resolution X-ray diffraction, photoluminescence and optical microscopy. Two strain states of GaN in HVPE, like 3D and 2[） growth modes in metal-organic chemical vapour deposition （MOCVD）, provide an effective way to solve the heteroepitaxial problems of both strain relief and quality improvement. The gradual variation metbod （GVM）, developed based on the two strain states, is characterized by growth parameters＇ gradual variation alternating between the strain-relief growth conditions and the quality-improved growth conditions. In GVM, the introduction of the strain-relief amplitude, which is defined by the range from the quality-improved growth conditions to the strain-relief growth conditions, makes the strain-relief control concise and effective. The 300-μm thick bright and crack-free GaN film grown on a two-inch sapphire proves the effectiveness of GVM.
基金supported by the Guangdong Innovative Research Team Program(No.2009010044)the China Postdoctoral Science Foundation(No.2014M562233)+1 种基金the National Natural Science Foundation of Guangdong,China(No.2015A030312011)the Opened Fund of the State Key Laboratory on Integrated Optoelectronics(No.IOSKL2014KF17)
文摘A new layer transfer technique which comprised double bonding and a step annealing process was utilized to transfer the GaN epilayer from a sapphire substrate to a Mo substrate. Combined with the application of the thermal-stable bonding medium, the resulting two-inch-diameter GaN template showed extremely good stability under high temperature and low stress state. Moreover, no cracks and winkles were observed. The transferred GaN template was suitable for homogeneous epitaxial, thus could be used for the direct fabrication of vertical LED chips as well as power electron devices. It has been confirmed that the double bonding and step annealing technique together with the thermal-stable bonding layer could significantly improve the bonding strength and stress relief, finally enhancing the thermal stability of the transferred GaN template.
