CAJ | 학술논문

低温下用MBE方法生长了Ge/Si超晶格.X射线反射及横向散射研究表明,Ge亚层上下表面的粗糙度呈反对称,下表面大的粗糙度来源于Ge向Si亚层中扩散形成SiGe混合组分结构.这种组分结构可以用一平均成分的SiGe合金层加以拟合,从而使得各亚层均有一个合理的粗糙度.旋转样品进行的X射线散射研究表明,这种SiGe的混合是各向同性的,这与透射电子显微镜的研究结构相一致.
저온하용MBE방법생장료Ge/Si초정격.X사선반사급횡향산사연구표명,Ge아층상하표면적조조도정반대칭,하표면대적조조도래원우Ge향Si아층중확산형성SiGe혼합조분결구.저충조분결구가이용일평균성분적SiGe합금층가이의합,종이사득각아층균유일개합리적조조도.선전양품진행적X사선산사연구표명,저충SiGe적혼합시각향동성적,저여투사전자현미경적연구결구상일치.
Si/Ge superlattices were grown at low temperature with modified Stranski-Krastanov (SK) MBE method.X-ray specular,off-specular reflectivity, and X-ray transverse scattering measurements were done to characterize the structure of the Ge/Si superlattice.The fitted roughness and the thickness of the Ge-layer indicate that Ge may diffuse into Si-layer and form the inverted trapezium or nano-scaled hut at the Si/Ge interface.The inverted trapezium extends to form islands, which can be estimated from the volume of the Ge-Si alloy in the structure.These islands can be averaged as a Ge-Si alloy sub-layer, the averaged thickness was fitted from the pure X-ray specular reflectivity.The composition of Ge in the SiGe dots was estimated as 15 % -25 % by X-ray specular reflectivity and by the thickness of Ge sub-layer.These results were confirmed by TEM observation.