Title :
An Accurate Compact Model Considering Direct-Channel Interference of Adjacent Cells in Sub-30-nm nand Flash Technologies
Author :
Kang, Myounggon ; Park, Il Han ; Chang, Ik Joon ; Lee, Kyunghwan ; Seo, Seongjun ; Park, Byung-Gook ; Shin, Hyungcheol
Author_Institution :
Interuniv. Semicond. Res. Center, Seoul Nat. Univ., Seoul, South Korea
Abstract :
We propose an accurate compact model of NAND Flash memory, which is fully compatible with a BSIM-4 model. In sub-30-nm NAND Flash, adjacent cells directly affect the channel-edge potential of the selected cell. Due to such direct-channel interference, previous compact models cannot accurately simulate the characteristics of sub-30-nm NAND strings. In this letter, we describe the interference as the threshold voltage variation due to adjacent cells and change the threshold voltage equation of the BSIM-4 model. The equation is semitheoretically derived. Using the proposed model, we simulated several behaviors of 27-nm NAND Flash strings. The results show more than 90% accuracy compared with the silicon measurements.
Keywords :
NAND circuits; flash memories; BSIM-4 model; NAND Flash memory; accurate compact model; adjacent cells; direct-channel interference; threshold voltage variation; Capacitance; Equations; Flash memory; Interference; Logic gates; Mathematical model; Transistors; Cell-to-cell interferences; compact model; direct field effect; nand Flash; nand string;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2012.2201442
