Study of SiO2 Modifications Induced by Oxygen Plasmas and Their Effect on Wet Processes

Oxygen plasmas, commonly used in typical C-MOS process flow, cause silicon oxide structure to be significantly modified: as a consequence wet processes, that are sensitive to oxide defectivity, need to be retargeted. In this paper structure modifications, induced in boron implanted SiO2 by RF and TCP plasma have been studied by thermally stimulated luminescence, charging measurements and Electron Paramagnetic Resonance (EPR). Different kind and quantity of point defects have been identified by thermally stimulated luminescence technique as a function of plasma generator. These results match with EPR analysis, charging measurements and HF etches rate profile.