Semiconductor memory device and its manufacture

Abstract

Abstract PURPOSE:To realize the higher integration and the larger capacity of a semiconductor memory device by a method wherein a diffusion layer is formed inside a well region, a first conductive layer which is connected electrically to the diffusion layer is formed, a titanium nitride film and a tantalum oxide film are formed on it and a second conductive layer is formed. CONSTITUTION:A P-type well 2 is formed on a silicon substrate 1; an isolation oxide film 3 and, in addition, a transistor 4 for memory-cell selection use are formed on the well; an N-type diffusion layer 5 is formed in a source region and a drain region; an oxide film 6 is deposited; a contact window is opened in a prescribed part of the oxide film 6 on the N-type diffusion layer 5 in the source region of the selection transistor 4; a polycrystalline silicon electrode 7 to be used as a capacity electrode is formed. In succession, a titanium nitride (TiN) film 8 is formed; a tantalum oxide (Ta2O5) film 9 is deposited; a tungsten electrode 10 as another cell capacity electrode is formed.

Inventors

• 👤 Kenji Yoneda
• 👤 健司 米田

Bibliographic Details