Manufacture of nonvolatile memory

Abstract

Abstract PURPOSE:To relax discontinuity, to reduce defects and strain and to stabilize the interface by forming an SiO2 thin-film on an Si substrate, nitriding the surface through treatment at a specific temperature in NH3 and vapor-growing an Si3N4 film up to predetermined thickness. CONSTITUTION:The SiO2 film 4 on an Si substrate 1 is bored and source and drain 3 are formed, and the opening is coated with the SiO2 thin-film 5 of approximately 25Angstrom . A thermally nitrided SiO2 film 8 is formed through treatment for thirty-five min at 700-1,000 deg.C in NH3, and the film 5 is further thinned. The film 5 is prepared in approximately 20Angstrom thickness, through which the film 5 can function as a tunnel medium, by selecting the conditions of growth of the film 5 and the conditins of NH3 treatment. When the Si3N4 film 6 is superposed through a vapor growth method, the defects and strain of the interface of the film 6 are reduced. An Al electrode 7 is formed, and the MNOS type nonvolatile memory is completed. According to the constitution, a threshold voltage value, memory holding characteristics, etc. hardly vary due to the defects and strain of the interface, and the nonvolatile memory can be manufactured with excellent accuracy.

Inventors

• 👤 Kazuo Sato
• 👤 和夫 佐藤
• 👤 Ichizo Kamei
• 👤 亀井　市蔵

Bibliographic Details