Research On Phase Change Memory With Nano-Current-Channel

With the advent of the information age,memory has occupied an increasingly important position in life.The current research on memory is mainly developing in the direction of high speed,low power consumption,and high stability.Among all novel memories,phase change memory(PCRAM)has huge potential.Phase change memory has the advantages of high read and write speed,high storage density,and compatibility with traditional CMOS technology.However,the main factor restricting the development of phase change memory is the excessive power consumption of erasing and writing,so reducing the power consumption of phase change memory is of great significance to its development.In this paper,from the perspective of device structure,we add a nano-current-channel layer between the bottom electrode of the phase change memory and the phase change layer.The nano-current-channel layer is an insulating layer with metal nanocrystalline grains which penetrate the nano-current-channel layer.The small contact area between the phase change layer and the electrode layer increases the local current density and heat generation efficiency.At the same time,the insulating material in the nano-current-channel layer can prevent heat from dissipating from the phase change layer to the electrode layer,which has a thermal resistance effect.Therefore,the phase change memory can reduce the writing power consumption without reducing the cell size and improving the preparation process.In this thesis,we use VASP calculation software to calculate the Formation Energy,Mean Square Displacement,Diffusion Coefficient,and Pair Correlation Function of the selected atoms in the insulating material to screen materials suitable for growth and aggregation in the insulating material,and through the finite element simulation method,we analyze the advantages of the phase change unit structure containing the nano-current-channel layer compared with the traditional unit structure.The result shows that the nano-current-channel can effectively improve the heat utilization of the unit,and the phase change unit structure containing the nano-current-channel layer can reach a higher temperature under the same pulse excitation.In this thesis,we also studied the preparation process of phase change memory cell and nano-current-channel layer,and we successfully prepared a nano-current-channel layer with metal crystal grains under this preparation process.Later,we also studied the V-R relationship,phase change speed,and cycle performance of the phase change unit structure which containing the nano-current-channel layer.The result shows that the power consumption of the phase change unit structure which containing the nano-current-channel layer during the RESET process is lower than that of the traditional structure,and its phase change speed is much higher than the traditional phase change unit.And the existence of the-nano-currentchannel layer does not affect the cycle performance of the device.