Intrinsic Gettering of RIE Damage on Silicon Studied by Scanning DLTS and EBIC Methods

Abstract

The degradation of silicon substrates due to reactive ion etching (RIE) damage and its elimination by intrinsic gettering (IG) are studied using scanning DLTS (SDLTS) and EBIC methods in an SEM. The SDLTS study clarifies that a hole trap of Ev+0.37 eV is introduced uniformly by RIE. Surface stacking faults are grown from latent defects associated with the trap during subsequent annealing. The EBIC analysis can predict macroscopic lifetime degradation due to the defect generation. IG is found to be successful in eliminating the degradation, when subsequent annealing is performed in O2, but not successful in N2 annealing. The gettering mechanism for RIE damage is also discussed in terms of the dependence on the annealing ambient.