METHOD FOR FORMING TUNNEL OXIDE LAYER AND METHOD FOR FORMING FLOATING GATE OF FLASH MEMORY DEVICE USING THE SAME

摘要

PURPOSE: A method for forming a tunnel oxide layer and a method for forming a floating gate of a flash memory device using the same are provided to reduce leakage current, to increase the charge to breakdown, to intensify retention characteristics by using an SiON layer as a tunnel oxide layer. CONSTITUTION: An N+ doping layer is formed in a semiconductor substrate(102) by carrying out an ion implantation using N2+ or N+ ions. The N+ doping layer is transformed into an SiON layer(102b) by carrying out an oxidation on the resultant structure. The ion implantation is carried out by applying energy of 1-10 KeV using N2, NH4, or NH3 as source gas. The dose of N2+ or N+ is in the range of 1E13-1E16 ions/cm2.