Structural Design And Simulation Of Back-to-back Phase Change Memory

Since the era of big data,the explosive growth of information has posed great challenges to the storage and processing of data,prompting people to seek for low-cost,high reliability and high-speed storage solutions.Phase change memory(PCM)is considered to be the next generation of memory devices with the most potential applications because of its outstanding performance in power consumption,writing speed and reliability.Phase change memory has been used in two ways: 3D stack and in-memory computing to solve the memory wall problem that impedes computer performance.Phase change memory uses the huge difference in resistance between crystalline and amorphous phase change materials for storage.The principle is that different pulses act on the element to generate heat,so that phase change materials can be converted reversibly between crystalline and amorphous states.In practice,people generally pay close attention to making devices at high or low resistance state by pulse operation,the actual internal changes in the device during the operation process is less talked about.In this paper,the temperature field distribution of the cell after partial reset pulse action is simulated by ANSYS,the multi-pulse modulated superposition of the cell resistance is discussed,and the direct representation of the amorphous region distribution of the cell in the phase transition layer after each pulse operation is given.It can be deduced that under the action of partial reset pulse sequence,the distribution of amorphous region in the phase transition layer varies with the number of pulses.Combined with the traditional pulse operation method,a more reliable operation method is presentedIn this thesis,a back-to-back phase-change storage cell structure is also proposed.Compared with the traditional structure,this structure consists of two phase-change layers,which can be operated by pulse independently.Using ANSYS simulation,the design of back-to-back cell structure is discussed,and its possible application of inmemory computing is discussed.