Si衬底上用反应蒸发法制备AlN单晶薄膜

Epitaxial Growth of Single Crystalline Aluminum Nitride Films by Reactive Evaporation

本文首次报道了在硅衬底上用反应蒸发法沉积AlN薄膜的技术．实验发现在衬底温度为470～850℃的范围内均可得到单晶薄膜，X射线衍射分析表明，薄膜只在2θ=58．9°处出现一个衍射峰，其生长晶面为（1120），是AlN的解理面．在较高的生长温度下，生长速率较低，得到的AlN薄膜具有更窄的衍射半峰宽（0．5°）、Al和N更趋向于化学计量比结合．从扫描电镜测试看出，薄膜表面平整光滑、无裂纹，说明用反应蒸发法外延生长的薄膜表面状况优良．最后，NH3对Si表面的原位清洗也作了一些讨论．

This paper reports the deposition of AlN film on Si (111) by reactive evaporation for the first time. The experiment results show that the films deposited at substratetemperature between 470℃ and 850℃ are single crystal. X ray diffraction measurementsdetect one peak only locating at 2θ= 58. 9°, which is due to the diffraction of (1120) AlNplane. At a higher substrate temperature,the growth rate is low,however,a narrower fullwidth at half maximum(FWHM=0.5°) of the x diffraction for the films occurred,meanwhile N and Al are closer to stoichiometrical composition. Surfaces of the films preparedby reactive evaporation are smooth. No cracks are observed by using Scan Electron Microscopy.Finally, the possibility and mechanism to clean SiO2 on the Si surface in situ byNH3 is also discussed.