The NROM cell concept [1] has received much interest as one of the most promising technologies to replace standard Flash memories. A deep knowledge of the features and evolution of the nitride storage charge is crucial for reliability, future scalability, and multi-level operation. The misalignment between electron and hole charge distributions in the nitride, which is due to Channel Hot Electron Injection (CHEI) program and Hot Hole Injection (HHI) erase mechanisms, is believed to be the root cause of retention losses observed in cycled devices [2-3]. In this scenario, the purpose of this paper is twofold: 1) to show a combined simulative-experimental technique allowing profiling of hole distribution; 2) to monitor through this technique the nitride charge evolution. Interesting correlation was found between the lateral field in the nitride and the degradation of memory retention after cycling. NROM, nitride-based trapping storage, device simulations, Flash memory, semiconductor devic...
Hole Distributions in NROM Devices: Profiling Technique and Correlation to Memory Retention
PADOVANI, Andrea;
2007
Abstract
The NROM cell concept [1] has received much interest as one of the most promising technologies to replace standard Flash memories. A deep knowledge of the features and evolution of the nitride storage charge is crucial for reliability, future scalability, and multi-level operation. The misalignment between electron and hole charge distributions in the nitride, which is due to Channel Hot Electron Injection (CHEI) program and Hot Hole Injection (HHI) erase mechanisms, is believed to be the root cause of retention losses observed in cycled devices [2-3]. In this scenario, the purpose of this paper is twofold: 1) to show a combined simulative-experimental technique allowing profiling of hole distribution; 2) to monitor through this technique the nitride charge evolution. Interesting correlation was found between the lateral field in the nitride and the degradation of memory retention after cycling. NROM, nitride-based trapping storage, device simulations, Flash memory, semiconductor devic...I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
