Research On Error Characteristics Of 3D NAND Flash Memory Of Its Application

NAND flash memory is a kind of non-volatile storage medium.Due to its excellent reading speed,good shock resistance,low power consumption and low noise,NAND flash memory quickly replaces traditional magnetic storage media and is widely used in storage solutions.in.With the rapid increase of the level of semiconductor technology,the storage density of NAND flash memory is rapidly increasing.Although the cost performance of NAND flash memory is greatly improved,the reliability of NAND flash memory is inevitably lowered,and the read performance is brought about.decline.Therefore,it is very meaningful to study and solve the reliability problem of NAND flash memory.Analyze the organizational structure,storage principle and basic operating mechanism of NAND flash.Based on the hardware test board,design software logic to implement a NAND flash test platform,and test for the retention error of flash memory reliability,analyze the threshold voltage distribution,physical block and physical page of the flash memory.Error rate and changes in read latency.Design and implement a solution that optimizes the read reference voltage to reduce the flash error rate.For the problem that the threshold voltage shift causes the flash error rate to rise,the method of fitting the threshold voltage distribution to a polynomial using the least squares method is used to optimize the read reference voltage.And through experiments,under different test conditions,before each physical page in the physical block is read,applying its optimized read reference voltage can reduce the error rate of the physical block.Design and implement a solution that reduces the read latency of physical blocks.Aiming at the problem that the physical block read latency is increased due to the increase of the physical page error rate in the physical block,and by reading the reference voltage of a shared page in the physical block according to the feature that the physical page read reference voltage gap is not large in the physical block,The method of reading the reference voltage of the entire physical block reduces the overall read latency of the physical block.And through experiments,this method can reduce the overall read latency of the physical block while reducing the error rate of the physical block.