Effects of various RIE process-induced damages on MOSFET characteristics

Abstract

A systematic study of the degradation of MOSFETs performance and reliability caused by various reactive ion etching (RIE) process steps are conducted. It is found that the polysilicon RIE process significantly increases the electron trapping as an active damage, thus causing higher initial V<SUB>t</SUB> and lower initial G<SUB>m</SUB> of NMOSFETs. In addition, while NMOSFETs with via antenna structures show largest RIE- induced degradation compared to other antenna devices. Our results also indicate Fowler-Nordheim stress results are well correlated with those from hot carrier stressing for monitoring RIE-induced latent damages, suggesting that Fowler-Nordheim stress is an efficient method to monitor RIE damage in a short time.