H_2气氛对采用MOCVD法在Si衬底上外延生长AlN薄膜性能的影响

Effect of hydrogen atmosphere on the properties of AlN films epitaxially grown on Si substrate by MOCVD

采用金属有机化合物气相沉积法(MOCVD)在Si(111)衬底上外延生长AlN薄膜,用高分辨X射线衍射、扫描电子显微镜和原子力显微镜对外延生长所得AlN薄膜的性能进行表征,并研究了适量H_2的引入对AlN薄膜的晶体结构和表面形貌的影响.结果表明:在Si衬底上外延生长AlN薄膜过程中引入适量H_2,有利于提高AlN岛间愈合程度,薄膜表面缺陷减少,表面粗糙度由4.0nm减少至2.1nm;适量H_2的引入可使AlN薄膜的(0002)和(10-12)面的X射线摇摆曲线的半峰宽(FWHM)值从0.7"及1.1"分别减小到0.6"和0.9",即刃型穿透位错密度和螺型穿透位错密度减少.

AlN epitaxial films were grown on Si （111） substrates by metal-organic chemical vapor deposition （MOCVD）. The surface morphology, crystalline quality, and interracial property of as-grown AlN films have been investigated systematically, and the effect of hydrogen atmosphere on the properties of AlN films were studied in detail. The results reveal that the root- mean-square （RMS） roughness of -110 nm-thick AlN films is greatly reduced from 4.0 nm to 2.1 nm, and the full-width at half-maximum （FWHM） value of X-ray rocking curve of AlN （10-12） is dramatically decreased from 1. 1° to 0. 9° by introducing a certain amount of hydrogen when compared with that grown without hydrogen.