Study of semiconductor super thin heterostructures with synchrotron radiation X-ray standing wave technique

The X-ray standing wave experiment method is established with the double-cr ystal monochromator and precision 2-circle goniometer at Beijing Synchrotro n Radiation Facility. It is used combined with the X-ray diffraction, to in vestigate the heterostructure of super thin Ge atomic layer within Si cryst als. The results show that the GexSi1-x alloy layer with average x = 0.13 w as formed in the Si crystal sample due to the segregation of Ge atoms durin g the preparation. Due to the diffusion of Ge atoms to the crystal surface, the GexSi1-x alloy layer was disappeared and nearly pure C;e layer was for med on the Si crystal surface after annealing at 650 degreesC.