Research And Strategy On Error Characteristics Of 3D TLC NAND Flash

NAND flash memory is a widely used storage medium today,and the applied process technology is gradually mature.Traditional 2D NAND flash memory is still scaled down in the X and Y directions of the 2D plane.In order to increase the capacity of flash memory,the number of data bits stored in each flash memory cell need to be increased as well.In addition,the cost of 2D process technology has become higher and higher,and it has encountered bottlenecks in the development of technology nodes in endurance and performance.Further reducing the cost per bit is no longer competitive with HDD.Therefore,3D NAND flash memory came into being.Compared with 2D NAND flash memory,3D NAND flash memory uses advanced etching tools to increase the number of layers in the Z direction in the 3D space to achieve lower costs and similar technical specifications to 2D MLC NAND.Therefore,research on the error characteristics of 3D NAND flash memory has also become an important research topic.This paper focuses on studying the error characteristics of 3D TLC NAND,reflecting the current life of the flash memory through the current number of error bits in the flash memory,and proposing corresponding error mitigation strategies through the error characteristic research data.This article is mainly composed of four parts:I.The first part starts with 3D TLC NAND flash memory storage unit to explain the basics of the flash memory,mainly involving the structure and working principle of the flash memory unit,and introduces the physical characteristics of flash memory block and flash memory chip architecture from the storage unit.II.The second part introduces the research experiment platform composed of hardware,firmware and software.III.The third part studies the impact of P/E cycle errors,program errors,write disturb,read disturb,and data retention errors on the 3D TLC NAND performance in detail,and draws specific conclusions.IV.The fourth part proposes corresponding mitigation strategies through the conclusions of the above five error characteristics and summarizes them.The research on the error characteristics of 3D TLC NAND flash memory is based on considerations of practical use.For flash memory,errors are inevitable,so it is essential to correct and mitigate them through mitigation strategies.The error mitigation strategy proposed in this article has dramatically improved the performance and lifespan of flash memory,correcting 74% of the error bits in 3D TLC NAND flash memory,increasing the lifespan of 3D TLC NAND flash memory,enabling it to perform more erasing and writing times.