Method for improving data storage capacity of NOR flash memory

The invention provides a method for improving the data storage capacity of an NOR flash memory. The method includes the first step used for preparing an SiO2 layer through an active oxidation process, and the second step used for executing N2O process nitrating on the SiO2 layer after the active oxidation process is completed so as to form a tunneling layer of a floating gate transistor unit of the NOR flash memory. The special reaction gas of the active oxidation process includes H2 and O2. In the active oxidation process, O2 and H2 chemically react on the surfaces of hot silicon wafers so that oxygenic active groups can be generated, and the oxygenic active groups react with silicon on the surfaces of the silicon wafers so that the SiO2 layer can be generated.