ONO inter-poly dielectric scaling for nonvolatile memory applications

• Published in: IEEE transactions on electron devices 1991-02, Vol.38 (2), p.386-391
• Main Authors: Mori, S., Sakagami, E., Araki, H., Kaneko, Y., Narita, K., Ohshima, Y., Arai, N., Yoshikawa, K.
• Format: Article
• Language: English
• Subjects: Applied sciences; Degradation; Design for quality; Dielectrics; Electronics; EPROM; Exact sciences and technology; Integrated circuits; Integrated circuits by function (including memories and processors); Leakage current; Nonvolatile memory; Oxidation; Random access memory; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon compounds; Thickness control
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/16.69921

The ONO (oxide/nitride/oxide) inter-poly dielectric thickness scaling effect on electric-field-leakage-current characteristics and charge retention characteristics in nonvolatile memories are investigated. Surface top-oxide thickness strongly affects the charge leakage and retention characteristics. Thicker than 3 nm top oxide can block hole injunction from the anode. Thick top oxide can reduce leakage current in both high and low electric field regions. Moreover, it can improve charge retention characteristics in nonvolatile memory cells. Therefore, a certain amount of top oxide is required to preserve good charge retention characteristics. SiN thickness scaling leads to an improvement in charge retention characteristics. Bottom oxide has an important role in suppressing electron leakage in a low electric field region. A degraded quality thin bottom oxide leads to charge retention capability degradation. Therefore, bottom-oxide quality and thickness control is an important subject for ONO thickness scaling.< >