Study on Formation and Structure of Pores in P-Rich InP Single Crystals

3-inch diameter〈100〉P-rich InP single crystals were prepared by a rapid P-injection in situ synthesis liquid encapsulated Czochralski( LEC) method. The formation and structure of the pores on P-rich InP wafers were analyzed. The surface morphology and energy dispersive spectrometer( EDS) of the sample were tested with scanning electron microscope( SEM). The crystal quality of the sample was investigated with X-ray diffraction( XRD). The results show that during the crystal growth process, the surplus phosphorus exist as gas bubbles in the melt,the phosphorus gas bubbles accumulate at the groove extending into pores with the growth of crystal,more and bigger pores are found at the edge of the wafers. The surplus phosphorus condense and deposit onto the wall of the pores after growth process. Furthermore, during the annealing process, high temperature thermal shock makes the surplus phosphorus gasified at the beginning,and in the next cooling process,due to the higher temperature in the interior of the ingot,the surplus phosphorus can deposit onto the side near the edge of the ingot. Crystalline quality around the pores is much lower than the position without pores.