Rapid thermal annealing for H passivation of polysilicon MOSFETs from Si/sub 3/N/sub 4/ overcoat

It is shown that rapid thermal annealing is an effective technique for H passivation of the Si dangling bonds using Si/sub 3/N/sub 4/ as a solid source of H. Rapid thermal annealing (RTA) can yield passivated MOSFETs with an on/off ratio of 10/sup 7/ compared to 10/sup 6/ for passivation by furnace annealing. The subthreshold slope, threshold voltage, and channel transconductance also improve because passivation by RTA is more effective and, consequently, the grain boundary potential heights in the channel are smaller than after furnace passivation. A direct correlation between grain boundary potential barrier height, Hall mobility, and MOSFET behavior as a function of H passivation by both furnace annealing and RTA is obtained.<
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