X-RAY CRYSTAL TRUNCATION ROD SCATTERING ANALYSIS OF REACTIVE ION ETCHED SILICON

We have investigated lattice damage in reactive ion etched silicon by using x-ray crystal truncation rod (CTR) scattering. The x-ray intensi ty associated with the rod in the reciprocal space depends on the etch ing-induced lattice distortion. To estimate the magnitude of the latti ce distortion, we analyzed the obtained data with a kinematic x-ray di ffraction model on the assumption that the lattice distortion decays e xponentially with the depth. We found that the lattice distortion exte nds to a depth of about 9 nm. In addition, we propose a method for qua ntitatively evaluating lattice damage based on our analysis. This meth od allows us to compare lattice damage among samples etched under diff erent conditions. This study indicates that x-ray CTR experiments prov ide a useful means of characterizing lattice distortions near processe d surfaces. (C) 1998 American Institute of Physics. [S0021-8979(98)071 22-9].