内生富镓对GaSb单晶表面、异质结界面及相关性质的影响

不同方法（熔体、液相和气相）生长的GaSb单晶材料均含有高浓度的镓反位本征受主缺陷，导致原生GaSb单晶化学配比为富镓，对材料的电学和光学性质产生了不利影响。面对InAs/GaSb II类超晶格红外探测器日益提高的性能要求，有必要研究内生富镓特性对GaSb单晶表面、异质结界面及产生的复合缺陷的影响作用。本项目拟开展GaSb单晶表面氧化、杂质吸附及化学态、InAs/GaSb等异质结界面态及复合缺陷等研究，探讨其内生富镓特性对界面扩散、组份偏析等的影响作用和规律。通过对GaSb单晶衬底和外延层的表面缺陷、氧化层成分及其化学状态等的调控，促进晶片表面制备技术及外延材料质量和器件性能的提高。

All of GaSb single crystals grown by different methods (melt, liquid phase and gas phase) contain high concentration of Ga antisite intrinsic defects, resulting in endogenous gallium-rich properties of the stoichiometric in native GaSb single crystals, which have a negative effect on the electrical and optical properties. With the increasingly improved performance requirements of InAs/GaSb type-II superlattice infrared detectors, it is necessary to study the effects of the endogenous gallium-rich properties on GaSb single crystal surface, heterojunction interface and the generated complex defects. The surface oxidation, adsorption of impurity atoms and chemical state in GaSb single crystals, as well as heterojunction interface states and complex defects of InAs/GaSb, etc. are to be studied in this project to discuss the influence of endogenous gallium-rich properties on interface diffusion, component segregation and so on. The surface preparation technology of wafer, the quality of epitaxial material and the performance of device will be promoted by controlling surface defects, oxide composition and the chemical state of the GaSb substrate and epitaxial layer.