Monte Carlo Analysis of Secondary Hot Electrons Induced Program Disturb in SONOS Memory Array

• Main Authors: Chih-Wei Li, 李致維
• Other Authors: Tahui Wang
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/27412836717004962712

碩士 === 國立交通大學 === 電子工程系所 === 95 === This thesis is focused on a new program disturb in a two-bit storage buried diffusion bit-line SONOS flash memory. In a NOR-type SONOS flash memory, channel hot electron program and band-to-band hot hole erase are usually employed. In channel hot electron program operation, channel hot electrons will cause impact ionizations. Generated holes from impact ionizations will be accelerated by the drain-to-substrate voltage and cause second impact ionization. The second impact ionization generated electrons, referred to as secondary electrons, may flow to a neighboring cell and cause a program disturb. In this thesis, a multi-step Monte Carlo simulation is used to explore this mechanism for it can accurately obtain the high energy tail of the secondary electron distribution function. Both electron and hole Monte Carlo simulations in this thesis include a full-band structure. In addition, the effects of substrate bias, bit-line dimension and pocket implant on the program disturb will be characterized and evaluated by a Monte Carlo simulation.