SP Industrial NAND Flash Products Data Retention
Introduction
NAND Flash technology is subject to physical degradation that can eventually lead to device failure. There are two end-of-life parameters to
specify the performance of NAND Flash products: Program/Erase endurance and data retention. This application note provides a perspective
on NAND Flash technology reliability testing methodology and discusses the influence of key factors in terms of data retention.
Industrial Standard
JEDEC standard JESD22-A117 indicates that over-stressing a NAND Flash product during reliability evaluation will impact the data retention
after Program/Erase cycling.
Refers to KIOXIA/WD reliability tests for BiCS technology to implement SP Industrial SSD Data Retention
Reliability test result of Data Retention( reference: KIOXIA/WD NAND Flash Reliability report)
Data retention is determined by three main parameters:
- System Field Temperature (Program/Erase Cycling and Data Storage)
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- 40 degree Celsius is common assumption
- Total number of Program/Erase Cycles
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- 300 PE cycles (10%)
- 3,000PE cycles (100%)
- Cycling Interval Time:
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- 3K PE cycles over 3 years at 40 degree Celsius, Average Interval time= 3 yearsx365x24x3600=31,536 seconds
These factors can significantly impact the retention lifetime after Program/Erase cycling. To ensure that the reliability design of the product is suitable for a particular customer application, a good understanding of these parameters is essential.
Arrhenius equation
Temperature is a significant modifier for endurance and data retention. Most of the time, a continuous high or low temperature is not typical for most applications. There is always a distribution of use at different temperatures. However, an average use temperature can be calculated from a complex temperature profile through the Arrhenius equation.
Higher temperatures increase the impact to the average field temperature. Lower storage temperatures can increase retention lifetime.
Data Retention of SP Industrial Flash products
SP Industrial flash products implemented with high quality NAND Flash chips to make sure to meet data retention specifications.
- Data Retention: 10 Years @ Life Begin / 1 Year @ Life End at 40 degree Celsius
During the NPI process SP Industrial flash products are implemented with Data Retention test under 85 degree Celsius 83 hours condition and verify data integrity via H2 program without any error to make sure to meet specification
Used case for special application requirement
Customer would like to request special application requirement as below:
- Data Retention: 1 Year @ 10% PE cycles at 70 degree Celsius
Based on the Arrhenius equation, the test condition will be changed to 125 degrees Celsius for 83 hours to make sure if it meets the requirement or not.
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