Study Of Thermal Crosstalk Test Of Phase Change Memory Array

In such an era that information technology develops rapidly,the traditional memories have had trouble to meet the growing demand for information storage.As one of the new generation of the non-volatile memories,phase change memory has the advantages of fast speed of reading and writing,being compatible with CMOS,anti-radiation quality and so on.However,reducing the cell size,which is the primary means of increasing memory density,is hampered by thermal crosstalk between neighboring phase change memory cells.So it is necessary to study the thermal crosstalk of phase change memory.In this paper,the thermal crosstalk of phase change memory array is studied.Firstly,the phase change memory array with three layers was fabricated by photolithography and sputtering.Then by using ANSYS,the finite element analysis software,the phase change memory arrays with three layers structure which is mentioned above was simulated.Then through the thermocouple simulation conducted by using the SOLID227 model,the heat distribution of phase change arrays with single cell and cells with the space between their neighboring cells of 90 nm,100nm,130 nm,and 160 nm were analyzed.In conclusion,if the space between neighboring cells is more than 130 nm,the thermal crosstalk effect to the neighboring cell could be ignored.Then,by analyzing the test requirements for phase change memory array's thermal crosstalk,the thermal crosstalk test system of phase change memory array is built.This system consists of three modules,which are phase change memory array selection module,the center cell stimulation module,and the neighboring cell test module.According to the severity of the thermal crosstalk's effect,the test process is divided into two steps.When the effect of thermal crosstalk is serious enough to influence the resistance of the neighboring cell,it is necessary to test the resistance of the neighboring cell in time when the stimulation is applied to the center cell.However,when the thermal crosstalk is only a transient effect on the neighboring cell,the state of the neighboring cell should be monitored in the meantime to achieve the purpose of testing.