A novel analysis method of threshold voltage shift due to detrap in a multi-level flash memory

• DOI: 10.1109/vlsit.2001.934976
• Publication Date: 2002-11-13T11:55:27Z
• Authors: R. Yamada; T. Sekiguchi; Y. Okuyama; J. Yugami; H. Kume
• Keywords: Flash Memory; Non-Volatile Memory; Degradation

With the aim of improving flash-memory retention characteristics, we investigated threshold voltage shift (/spl Delta/V/sub th/) due to charge detrapping from tunnel oxide. Accordingly, propose a new parameter that can reveal main origin (hole/electron) and detrap centroid. We found changes holes electrons depending on degree tunnel-oxide degradation. Since hole increases V/sub th/ programmed memory cell, this increase must be considered, especially when designing multi-level flash memory.