Patent Number: 7,820,515

Title: Nonvolatile semiconductor memory element excellent in charge retention properties and process for producing the same

Abstract: A process for producing a nonvolatile semiconductor memory having a mixed or laminated structure of a hardly oxidizable material composed of a hardly oxidizable element having Gibbs' free energy for forming oxide higher than that of Si under the same temperature condition at 1 atm and in temperature range of 0.degree. C. to 1,200.degree. C. and an oxide of an easily oxidizable material composed of an element having Gibbs' free energy for forming oxide lower than that of Si under the same temperature condition at 1 atm in the temperature range and Si. The process includes forming a portion of the hardly oxidizable material and a portion of the oxide by physical forming method and carrying out heat treatment in oxidizing and reducing gas mixture. The ratio of the gases and the temperature are controlled so that the hardly oxidizable material is reduced and the oxide is oxidized in the temperature range.

Inventors: Takata; Masaaki (Chiyoda-ku, JP), Koyanagi; Mitsumasa (Sendai, JP)

Assignee: Asahi Glass Company, Limited

International Classification: H01L 21/336 (20060101)

Expiration Date: 2018-10-26 0:00:00