GSMBE外延生长SGOI材料的退火行为

Annealing Behavior of SGOI Thin Films Grown by Gas Source Molecular Beam Epitaxy

在SIMOXSOI超薄硅衬底上外延生长了高质量SiGe合金薄膜来制备SGOI(SiGeoninsulator)样品,并研究了其在1050℃氧化气氛中的高温退火行为.用Raman,DCXRD,RBS和光学显微镜等分析手段对SGOI样品在退火前后的性能进行了表征.分析结果表明:SGOI样品表面的穿透位错密度约为5×105cm-2;高温退火处理可以促进SGOI样品中异质外延生长SiGe合金薄膜的弛豫化和超薄Si夹层向SiGe合金薄膜的转化,进一步提高SiGe薄膜的晶体质量,并且有助于获得高Ge组分的SGOI材料.

SiGe-on-insulator (SGOI) samples are prepared by gas-source molecular beam epitaxy (GSMBE) through growing a high quality SiGe epilayer on ultra-thin silicon-on-insulator (SOI) substrates using Si 2H 6 and Ge as source materials.The samples are then annealed at 1050℃ in an oxidizing atmosphere for more than 5h.The effect of high temperature annealing on properties of SGOI samples is investigated,and Raman,DCXRD,RBS,and optical microscope are used to characterize the samples before and after annealing process.A surface threading dislocation density of about 5×105cm -2 is achieved for the SGOI samples.The high temperature anneal process can promote strain relaxation of the hetero-epitaxial SiGe alloy film as well as transformation of the ultra-thin Si underlayer into the SiGe alloy film.The crystalline quality of SiGe epilayer could be improved and also help to prepare high quality Ge-rich SGOI materials.