Application of cathodoluminescence to SiGe epitaxial process control

A new in-line monitoring method to easily and quickly detect dislocations and defects generated before and after the SiGe epitaxial process is storongly needed. We focus on the cathodoluminescence (CL) method which can directly observe regions within devices and determine dislocations and defects in Si/SiGe/Si double hetero-structures. We systematically investigate the correlation between CL spectra and epitaxial process parameters and demonstrate that CL measurements can detect dislocations and defects that could not be observed by light point defect (LPD) detection or transmission electron microscopy (TEM). The results of evaluation experiments for the proposed CL method indicate that it is effective for the SiGe epitaxial process control.