Composition Determination of Si/Si1-xGex/Si by Photoreflectance Spectroscopy

UHVCVD-grown Si/Si(1-x)Ge(x)/Si heterostructure is investigated by photoreflectance spectroscopy (PR). The principle of PR in determining Ge content of a Si(1-x)Ge(x) epilayer is thoroughly described. The unambiguous E1 transition energy in the Si(1-x)Ge(x) epilayer is very useful to determine Ge content during PR analysis. R&R study with 10 repeats at the same point indicates that the measurements of PR are reproducible. These results demonstrate that PR is very promising for analysis of Si(1-x)Ge(x) epilayer characterization with constant Ge content.