A dielectric insulating composite for insulating a floating gate from a control gate in a non-volatile memory is described. A material, such as an undoped polysilicon, amorphous silicon, or amorphous polysilicon or a silicon rich nitride, is inserted in the gate structure. The oxide film that results from the oxidation of these films is relatively free from impurities. As a result, charge leakage between the floating gate and control gate is reduced.