Research Of Electric Parameters Measurement System And Storing Performance Demo System For Phase Change Memory

Phase-Change memory(PCM),also called chalcogenide random access memory (CRAM),is considered to be one of the viable candidates for the next generation to replace conventional memory,because of its attractive advantages such as non-volatility,high speed,low power consumption,outstanding endurance,and CMOS compatibility etc.In order to promote the research of the CRAM,the electrics characteristics such as the threshold voltage,the voltage pulse parameters of SET and RESET operation,and the reliability become very important to understand its electrical model.This dissertation studies on the measurement methodology of device element as well as 1T1R device of PCM and the visual demonstration method on the data storage of the PCM cell array.Through the discussions about the principles of the phase change memory,including the device performances,cell structure,and electrical characteristics,a effective scheme was contrived on the base of present test method,which is the automated measurement system on the phase change memory.It included several modules of the relationship between current source and voltage,voltage source and current,resistance and voltage pulse width or height,fatigue characteristics.The whole system was made of hardware equipments and the according operation software;the hardware consisted of pulse signal generator,digital source meter,test platform,switch matrix,data acquisition card,and GPIB card;the virtual instrument operation interface was achieved to control the equipments to implement device test on the development enviornment VC++6.0.The principles of the hardware equipments and the software programming were introduced detailedly.As to acquire integrated pulse signal which is applied on the device, a match resistance is used in terminal,then the accurancy of pulse height,pulse width, pulse fall and the measured resistance are evaluated detailedly.a standard test process is put forward on basis of the conclusion of large number of test data,then according of which every test modules of the sysytem is testified.The test principle,test method,test parameters of 1T1R structure of PCM are expounded,then a automated test system is designed on the development environment of LabVIEW and now it works well on the research of 1T1R structure of PCM.In the end,an automated demonstration system for phase change memory cell arrays was presented.Its hardware consisted of row decoder circuit,read-out amplifier circuit, MCU and PLD circuit etc.which laid foundation for the phase change memory chip design and test.