Technical Solutions to Mitigate Reliability Challenges due to Technology Scaling of Charge Storage NVM

Abstract

Charge storage nonvolatile memory (NVM) is one of the main driving forces in the evolution of IT handheld devices. Technology scaling of charge storage NVM has always been the strategy to achieve higher density NVM with lower cost per bit in order to meet the persistent consumer demand for larger storage space. However, conventional technology scaling of charge storage NVM has run into many critical reliability challenges related to fundamental device characteristics. Therefore, further technology scaling has to be supplemented with novel approaches in order to surmount these reliability issues to achieve desired reliability performance. This paper is focused on reviewing critical research findings on major reliability challenges and technical solutions to mitigate technology scaling challenges of charge storage NVM. Most of these technical solutions are still in research phase while a few of them are more mature and ready for production phase. Three of the mature technical solutions will be reviewed in detail, that is, tunnel oxide top/bottom nitridation, nanocrystal, and phase change memory (PCM). Key advantages and reported reliability challenges of these approaches are thoroughly reviewed in this paper. This paper will serve as a good reference to understand the future trend of innovative technical solutions to overcome the reliability challenges of charge storage NVM due to technology scaling.