A novel electron beam-inspection technique for high-impedance contact plugs

We here present a novel electron beam inspection technique for non-annealed high impedance poly-Si plugs. At this new method, interval time between each electron beam scan is varied to enhance the difference of surface voltage of normal plug, disconnected plug and SiO
₂
. Based on experimental results using our experimental tool with the new interval scan technique, contrast between SiO
₂
and poly-Si plug, between normal plug and disconnected plug have been dramatically enhanced.