衬底取向对Al掺杂3C-SiC薄膜微结构的影响（英文）  

Effect of Substrate Orientation on Microstructure of Al-doped 3C-SiC Films

作　　者：苏剑峰[1] 肖宏宇[1] 牛强[1] 唐春娟[1] 张永胜[1] 傅竹西[2] 

机构地区：[1]洛阳理工学院数理部,洛阳471023 [2]中国科学技术大学物理系,合肥230026

出　　处：《硅酸盐学报》2015年第7期986-990,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金项目(51302128);河南省自然科学基金项目(14B140008;13A140792)

摘　　要：采用低压化学气相沉积(LPCVD)法分别在Si(100)和Si(111)衬底上制备了Al掺杂的3C-Si C薄膜。采用X射线衍射、扫描电子显微镜、Raman光谱对所制备薄膜的微结构、形貌以及内部应力的演变进行分析。结果表明:在Si(100)衬底上制备的Al掺杂Si C薄膜具有较好的结晶质量,而且结晶质量受Al掺杂浓度的影响比较大。Al掺杂Si C薄膜的生长模式为二维层状生长模式。Si(100)衬底上所制备的Al掺杂Si C薄膜表面为层状的四边形结构,而Si(111)衬底上的Al掺杂Si C薄膜表面为层状的截角三角形结构。Si(100)衬底上的薄膜厚度略大于Si(111)衬底上的。由于Al离子的掺入和薄膜厚度的增加,Si(100)衬底上所制备的Al掺杂Si C薄膜内部的应力得到很好的释放。Si(111)衬底上的Al掺杂Si C薄膜内部的应力则由张应力模式转为压应力模式,而且纵光学声子(LO)、横光学声子(TO)特征峰分离变大,出现这种现象的原因可能与Al3+替代Si4+使Si C离子性增强和生长模式的转变有关。Al-doped 3C-SiC films were deposited on Si （100） and Si （111） substrates via low-pressure chemical vapor deposition （LPCVD）. The microstructure and the evolution of strain stress in SiC films were analyzed by X-ray diffraction （XRD） and Raman spectroscopy, respectively. The surface morphology of SiC films was determined by scanning electron microscopy （SEM）. The results indicate that the concentration of Al doping has a dominant effect on the crystal quality of SiC film grown on Si （100） substrate. The Al-doped 3C-SiC film can be obtained on Si （100） substrate when an appropriate amount of trimethylaluminum （TMA） is added. The growth of Al-doped SiC film follows a step-flow growth mode. The surface of SiC films grown on Si （100） substrate presents a square-shaped structure, and that of SiC films grown on Si （111） substrate exhibits a triangular-shaped structure. The thickness of films grown on Si （100） substrate is thicker. For the film deposited on Si （100） substrate, the strain stress of SiC films releases due to the incorporation of Al ion and the increase of film thickness. For the films deposited on Si （111） substrate, the strain stress varies from tensile to compressive, and the split between longitudinal optical （LO） phonon peak and transverse optical （TO） phonon peak increases due to the enhancement of SiC film ionicity and the transformation of growth mode.

关 键 词：低压化学气相沉积 铝掺杂 碳化硅薄膜 衬底取向 微结构 

分 类 号：O469[理学—凝聚态物理]