Effects of postetching treatments on electrical characteristics of -thermal oxides on reactive-ion-etched silicon substrates

Thin oxides thermally grown on the reactive-ion-etched (RIE) silicon substrates in N₂О and diluted O₂ ambients have been studied. The RIE will strongly affect the silicon surface microroughness and lead to poor oxides properties. Using the after-treatment-chamber (АТС) process, CF₄ addition in the O₂ plasma can further improve the time-zero-to-dielectric-breakdown (TZDB) characteristics of the thin oxides as compared with pure O₂ plasma. This is because CF₄ addition in the АТС can remove the damaged silicon layer and smooth the silicon surface since the O₂ plasma can effectively only strip the polymeric layer. In addition, the N₂0-grown oxides can enlarge the process window of the CF₄/O₂ АТС treatments with respect to pure oxides.