Investigation on the leakage of triple split-gate flash device and its improve solution

摘要

In this paper, the leakage issue of triple split-gate flash device was studied and P out-gassing from high doping floating gate poly is found to be the root cause for high leakage issue. Base on the formula of P diffusion in silicon material, we get the ideal silicon oxide thickness to be 1.72A as the limit value for P out-gassing prevention from floating gate poly. By introducing of rapid temperature oxidation anneal(RTO) method for oxide forming, we found that oxide thickness above 2A can suppress P out-gassing effectively, which is similar as the ideal value calculated by formula.