3D NAND Flash Word Line Control Research And Improvement

With the rapid development of information technology,the development trend of 5G,AI,IOT,digital office and many other fields is gradually changing our society.No matter in technology,military,economy or life,data is closely related to storage,which is promoting the continuous growth of memory demand.At the same time,the vast majority of data is generated by devices rather than humans themselves,so memory will become an important part of solving these big data problems.The 3D NAND flash memory in nonvolatile memory is the key component to realize this mode transformation.Its development is of great significance: as one of the most advanced technologies in the field of nonvolatile memory,the success of its localized R & D,design and manufacturing will directly affect the development of the whole semiconductor industry in China,and whether can catch up with the advanced semiconductor technology in foreign countries,break the monopoly of other countries and deal with all kinds of disguised sanctions.This paper takes 3D NAND Flash word-line control and improvement as the research direction.Focusing on the program operation of 3D NAND Flash memory,an improvement scheme which can effectively reduce the establishment time of programming word line and improve the program speed is proposed.The main work is as follows:1.Research background and basic aspects: introduce and explain the types and background of memory,the development history,application fields,differences,advantages and disadvantages of NAND Flash memory and NOR Flash memory,mainly explain the principle and physical structure of NAND Flash memory cell,and briefly describe the 3D NAND Flash array and physical architecture,introduces the current typical 3D NAND Flash manufacturing process.2.Basic aspects of word-line control: introduce the function module,basic operation of 3D NAND Flash memory,some important technical parameters,behavior level modeling of word-line set-up process in one complete program operation,the importance and significance of improving the program speed of 3D NAND Flash memory,the WL capacitance model of 3D NAND Flash selected word line building,put forward the principle and scheme of improving program speed.3.The implementation and verification of the improved scheme: build a 3D NAND Flash word-line module simulation platform,Fine Sim simulation,calculating the program time improvement ratio according to the simulation data and waveform results,and evaluate the performance and effectiveness of the improved scheme.After using the improved scheme,the set-up time of the word-line in the program operation is obviously shortened.By selecting the different Boost voltage and the Boost time,the best program time improvement ratio is 18.6%,compared with one program operation time.The simulation environment is: HV₂5C_TT,0.18?m SMIC In CMOS process,it is proved that the improved scheme proposed in this paper is basically effective to reduce the word-line set-up time in program operation.