采用锗(Ge)浓缩技术对绝缘层上锗硅(SGOI)材料进行循环氧化、退火,制备出19nm厚的绝缘层上锗(GOI)材料。然后对该GOI材料在400℃下进行O_3氧化,以进一步减薄GOI的厚度。采用高分辨透射电镜(HRTEM)、X射线反射(XRR)和原子力显微镜(AFM)等对样品形貌和结构进行表征。测试结果显示,O_3氧化减薄后的GOI晶体质量得到提高,且表面更加平整(厚度减薄2.5nm,粗糙度RMS降低0.26nm)。通过循环的O_3氧化减薄,可获得高质量的超薄(小于10nm)GOI材料,用于制备超薄高迁移率沟道Ge MOSFET。Ultra-thin germanium-on-insulator(GOI) was fabricated by modified Ge condensation process of SiGe on SOI substrate.The prepared GOI was then oxidized in an atomic layer deposition chamber with O_3 at 400 ℃ and the Ge oxides was removed with dilute hydrofluoric acid to get a thinner Ge layer.The GOI materials after O_3 oxidation were characterized by HRTEM、XRR and AFM measurements,indicating better crystal quality and smoother surface than those of the as-prepared GOI by Ge condensation techniques.When the GOI was oxidized at 400℃for 30 min,the thinning thickness was about 2.5nm and the surface roughness was reduced from 1.23 nm to 0.97 nm.High crystal quality ultra-thin(below 10nm)GOI can be expected by cyclic O_3 oxidation and thinning of Ge condensed GOI,which is one of the most promise candidates for high speed MOSFETs.国家自然科学基金项目(61474094,61176092);; 国家重点基础研究发展计划项目(2012CB933503,2013CB632103
