High Performance Nanocrystal Based Embedded Flash Microcontrollers with Exceptional Endurance and Nanocrystal Scaling Capability

Abstract

In this paper, we present the first-ever commercially available embedded Microcontrollers built on 90nm-node with silicon nanocrystal memories that has intrinsic capability of exceeding 500K program/erase cycles. We also show that the cycling performance across temperature (-40C to 125C) is very well behaved even while maintaining high performance that meets or exceeds the requirements of consumer, industrial, and automotive markets. In specific EEPROM implementation, such high endurance is capable of delivering in excess of 200M data updates. In addition, we also demonstrate that the nanocrystal flash memory is highly scalable to the next generation nodes and the scaling can be accomplished without degradation of program/erase speed, endurance and reliability. ( IntroductionRecently we announced the launch and qualification of high performance, low-power embedded 32-bit microcontrollers based on either ARM® Cortex™ -M4 core or ColdFire™ cores that are built using NC-based embedded flash (referred to as TFS for Thin Film Storage). The mixed-signal low-power microcontroller families have memories for with flash memory sizes ranging from 256Kb to 8Mb [1,2]. In addition, the unique capability of TFS has enabled inclusion of fully configurable embedded EEPROM functionality called 'FlexMemory.' With appropriate trade-off between endurance and memory density, the FlexMemory is capable of delivering as many as 10M data update operations when the intrinsic flash endurance is 10K. However, there has been an increasing demand for eFlash that can cover from low-end to high-end products, but capable of high flash endurance (≥ 100K) and reliability for markets, such as, automotive and smartcard applications. Evaluation of Kinetis Microcontrollers demonstrate that nanocrystal flash is intrinsically capable of achieving 500K+ cycling performance, and we also show reliable performance with extended endurance capability (≥ 100K) across temperature (-40C to 125C). With such substantially enhanced endurance capability of nanocrystal memories, FlexMemory can deliver an excess of 200M updates when appropriately configured.

A Comparative Study of Single-Poly Embedded Flash Memory Disturbance, Program/Erase Speed, Endurance, and Retention Characteristic

“…Traditional dual-poly [2] and split-gate [3], [4] eFlash technologies are optimized for high-density nonvolatile code and data storage applications. The former employs a floating gate (FG) device while the latter utilizes charge trap material for achieving nonvolatile storage.…”