Anneal technique for reducing amount of electronic trap in gate oxide film of transistor

Abstract

A memory cell of EEPROM having a floating gate, a control gate, a drain region, and a source region is formed on a silicon substrate. Thereafter, a BPSG film (interlayer insulating film) covering the memory cell is formed by CVD. After a wire including a bit line, an SiON film (passivation film), covering the silicon substrate and serving as an uppermost layer, is formed on an upper portion of the silicon substrate. Thereafter, annealing is performed to discharge water in the BPSG film to an outer portion of an LSI. The annealing is performed under a condition satisfying the following equation of t≧7.86×10−11×L2×exp (9115/T) where t is anneal time (minutes), L is a thickness (nm) of the passivation film, and T is anneal temperature (absolute temperature). Thereby, an amount of electronic trap in a gate oxide film of the transistor can be reduced.

Dependencies are inferred from the claim text.