Manufacture of semiconductor nonvolatile memory

Abstract

Abstract PURPOSE:To enable to operate the write and erase of an EEPROM with a low voltage and improve integration degree by thickening the film thickness of a semi-insulation film by a method wherein a polycrystalline Si film is adhered on an Si substrate, a crystal grain diameter is grown into a larger grain diameter, and next the polycrystalline Si is changed into an SiO2 film by high temperature treatment. CONSTITUTION:The polycrystalline Si film 11 of the film thickness of 50-200 deg.C is adhered on an Si substrate 10 by a reduced pressure chemical vapor growing method. Next, it is heated in the flow of the mixed gas of oxygen and argon, and then formed into the SiO2 film 12 of the film thickness approximately twice by oxidation. The polycrystalline Si film requires complete oxidation to the inside, and thereat oxygen is infiltrated from the crystal grain boundary to the surface of the Si substrate, which is accordingly oxidized. Thereby, unnevennesses proportional to the size of crystal grains are formed between the Si substrate and the SiO2 film. When an electric field is impressed by forming an insulation film composed of an SiO2 film having unevenness between the substrate surface, field concentration generates on projections, and then electrons can be injected with a low voltage. Since the SiO2 film can be formed thick as a whole, the capacity Ct thereof can be reduced.

Inventors

• 👤 Yoshihiro Oshikawa
• 👤 押川　圭弘

Bibliographic Details