【摘要】 对在GaAs (0 0 1)衬底上用金属有机物气相外延 (MOVPE)方法生长的GaN薄膜的湿法腐蚀特性进行了研究 .所用腐蚀液包括HCl、H3PO4 、KOH水溶液以及熔融KOH ,腐蚀温度为 90～ 30 0℃ .实验发现不同的腐蚀液在样品表面腐蚀出不同形状的腐蚀坑 .KOH溶液腐蚀出长方形的坑 ,长边平行于 (111)A面 ,表明沿相互垂直的〈110〉晶向的腐蚀特性不同 .用不同晶面相对反应性的差别定性解释了腐蚀的这种非对称性 .此外 ,还发现KOH水溶液更有可能用于显示立方相GaN外延层中的层错 .更多还原

【Abstract】 Wet etching characteristics of cubic GaN (c GaN) thin films grown on GaAs(001) by metalorganic vapor phase epitaxy (MOVPE) are investigated.The samples are etched in HCl,H 3PO 4,KOH aqueous solutions,and molten KOH at temperatures in the range of 90～300℃.It is found that different solution produces different etch figure on the surfaces of a sample.KOH based solutions produce rectangular pits rather than square pits.The etch pits elongate in 1 0] direction,indicating asymmetric etching behavior in the two orthogonal <110> directions.An explanation based on relative reactivity of the various crystallographic planes is employed to interpret qualitatively the asymmetric etching behavior.In addition,it is found that KOH aqueous solution would be more suitable than molten KOH and the two acids for the evaluation of stacking faults in c GaN epilayers. direction,indicating asymmetric etching behavior in the two orthogonal <110> directions.An explanation based on relative reactivity of the various crystallographic planes is employed to interpret qualitatively the asymmetric etching behavior.In addition,it is found that KOH aqueous solution would be more suitable than molten KOH and the two acids for the evaluation of stacking faults in c GaN epilayers.更多还原