H2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

摘要:

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H2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 H2,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4.0 nm 减少至2.1 nm；适量 H2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.

Abstract:

AlN epitaxial films were grown on Si(111)substrates by metal-organic chemical vapor deposition (MOCVD).The surface morphology,crystalline quality,and interfacial 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.