Distribution of Ge in high concentration Ge-doped Czochralski-Si crystal

摘要

SiGe bulk single crystals were grown by Czochralski method by means of varying the pulling rate along the growth direction. The distribution of impurity Ge in SiGe crystals were measured by SEM-energy dispersive X-ray (EDX) spectroscopy together with secondary ion mass spectroscopy (SIMS) and inductively coupled plasma (ICP) atomic emission spectrometer (AES) methods. The variation of the Ge composition along the growth direction was discussed. It was found that the Ge concentration varied from a lower value at head to a higher one at the tail. The distribution form of Ge between this growth method and the normal freezing one was compared. According to the measured data, the effective segregation coefficient K_e value was calculated and found to be 0.62 +- 0.005 approximately under this growth technique.