Growth of Low Dislocation Density GaSb Single crystals by Horizontial Method
Wu Guangheng Huang Ximin Fu Shuging Ma Kai Jing Yumei Xuan Li Zhang Chuanping(Changchun Institute of Physics, Chinese Academy of Sciences, Changchun, 130021
GaSb single crystals witn large diameter (D25mm) and low dislocation demsity (10cm~(-2)) grown by a horizontial method are reported forthe first time Novel procedures for suppressing dislocation, such as controlling she shape of interface, expelling the factor of occurrence twin, melting-back of seed, have been diseribed in detial. By zone refining the ingots for 2-3 tirues prior to the growth, crystals can be successfully grown at a low temperature gradient (AT=4℃/cm). It is the most important for the reduction of axial thermal stress which allways generate a high density dislocation at the growth interface, in particular to GaSh. Chemical EPD observation and X-ray diffraction rocking curves show that there is a higher dislocation density on the wafers cut from the end of the crystal ingots. The generation of those defects is also discussed.