Homogeneity study of wafers of InP single crystal grown from P-rich melt

A 4-inch InP single crystal has been grown from P-rich melt by the P-injection synthesis LEC method. Due to the non-stoichiometric condition, there are many pores in the tail of the ingot. The wafers cut from it are experimented by means of PL mapping and EPD mapping. The PL peak intensity standard deviation of the 4-inch InP wafer is higher. The EPDs around the pores are larger than the other regions. Besides the stress releasing, the pores and the high concentration of dislocations around them presents the leading factors causing the inhomogeneity of the wafer. We have explained the phenomena.