METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE

A method for fabricating a semiconductor device is provided to prevent happening of etching unbalance by forming a floating gate with only one polysilicon layer. A pattern having an aperture(114) is formed on a substrate(100) to expose a surface of the substrate. The substrate is heated at a temperature of 570 to 700 deg.C. A polysilicon layer(130) is formed to cover the pattern in such a way that the aperture of the pattern is buried at a deposition rate of 60 Angstrom per minute. The substrate is subjected to annealing by heating the substrate at a temperature of 780 to 900 deg.C for 10 to 50 minutes. In the annealing step, the substrate is heated at a rate of 1 to 10 deg.C per minute.