In scaled technologies, large cell-to-cell interference and FN tunneling disturbance degrade threshold voltage (Vt) window which we can place program states. Moreover, in Triple Layer Cell (TLC) NAND Flash we should place seven program states (P1 ~ P7) in the narrow Vt window, incurring large bit-error rate (BER). In this paper, we propose a state re-ordering technique to increase the efficiency of Vt window utilization in TLC NAND Flash memories. Our simulation results show that under equivalent Vt window sizes, the proposed technique provides 12.5~18.4% smaller BER compared to conventional Gray-code mapping.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering