Calculating plasma damage as a function of gate oxide thickness

Plasma damage as a function of gate oxide thickness is a primary concern as oxides scale below 5 nm. A methodology is developed to theoretically calculate damage trends. Through a load line analysis, the stress condition during the plasma process is determined, and this stress condition is correlated to damage by the anode hole injection model (Scheugraf and Hu, Semicond. Sci. Tech. vol. 9, pp. 989-1004, 1994). The calculations show that damage peaks at an oxide thickness around 6 nm (depending on the exact plasma process). Further oxide scaling results in reduced stress voltages and electric field, curtailing the damage.