Research On Electronic Synapse Simulation Of Edge Contact Phase Change Memory Cell

In recent years,artificial intelligence has been widely used in various fields.The computing power of computers based on the traditional Feng Neumann architecture has not met the needs of artificial intelligence development.The construction of artificial neural networks of humanoids is crucial to the development of artificial intelligence.The synapse is the key to constructing artificial neural network of human brain.Phase change memory has both nano-integrable characteristics and storage function.It is an important way to realize electronic synapse.Therefore,the simulation study of electronic synapse of phase change memory unit is of great significance.Based on the working principle of phase change memory cells,this paper uses the finite element method to establish a mathematical and physical model of the three-dimensional structure of edge contact phase change memory cells.Under the MATLAB platform,by controlling the size and pulse parameters of the unit,the electrical,thermal performance,and phase change process simulations of the phase change memory cell are performed to obtain the temperature,phase distribution,and resistance change of the phase change memory cell.First,by changing the structure size of the phase change memory cell,the Reset threshold voltage and Reset current of the electronic synapse of the phase change memory cell are studied.Secondly,by changing the structure size and pulse parameters of phase change memory cells,the symmetry of long-term depression(LTD)and long-term potentiation(LTP)process were studied.The simulation results show that:(1)Changing the size of edge heating electrode and the phase-change layer has a regulating effect on the Reset threshold voltage;reducing the width and thickness of the edge heating electrode can reduce the Reset current and reducing the thickness of the phase change layer will increase the Reset current.Decreasing the area of the phase change layer will reduce the Reset current.Increasing the thickness and width of the edge contact electrode will increase the effect of the voltage on the Reset current.Changing the thickness of the phase change layer will not change the effect of the voltage on the Reset current.Increasing the area of the phase change layer will increase the effect of voltage on Reset current.(2)As the thickness of the edge heating electrode increases,the symmetry of the LTD and LTP process becomes better.As the width of the edge heating electrode increases,the symmetry of the LTD and LTP process becomes better and then worsens.As the area of the phase change layer increases,the symmetry between LTD and LTP process becomes better and then worsens.As the thickness of the phase change layer increases,the symmetry of the LTD and LTP process becomes better and then worsens.Increasing the pulse amplitude and pulse width of LTP process,the symmetry of the LTD and LTP process becomes better and then worsens.