SrTiO_3同质外延过程中的反射高能电子衍射图案分析

Analysis of reflection high-energy electron diffraction pattern during SrTiO_3 homoepitaxy

在激光分子束外延实验中 ,用RHEED原位监测了SrTiO3基片初始、退火以及同质外延过程中的表面形态 .通过对RHEED图案分析 ,获取了表面面内的晶格常数振荡与衍射条纹的半高宽振荡现象 ,前者是由退火重构表面与薄膜之间的界面造成的 ,后者与二维岛边界的弛豫相关 .

SrTiO3 surface was monitored in-situ by reflection high-energy electron diffraction (RHEED) during annealing and homoepitaxial growth in laser molecular beam epitaxy (LMBE). By analyzing RHEED pattern, we show the oscillation behavior of in-plane lattice constant and full-width at half maximum (FWHM) of diffraction streaks; the former is due to the interface between the annealed reconstruction surface and the growing film, and the origin of the latter is related to the relaxation of 2D islands by their edges. In addition, the phase shift of RHEED intensity oscillation was observed, due to plasma influence on the incident electron beam.