Study On The Morphology Control Of Graphitization Of Amorphous Carbon Thin Films And Its Performance Improvement Of RRAM

With the continuous progress of science and technology,we have entered a period of large-scale information industry,information technology has penetrated into all walks of life.RRAM devices are attractive to all people with simple structure,high storage density,low power,which has great potential in information storage,logic operation,neural protrusion simulation.RRAM has a metal-insulator-metal?MIM?sandwich structure,and the metal layers are the top electrode and the bottom electrode.The insulator is the resistive switch material located in the middle.At present,the generally accepted mechanism is the conductive filament model formed by metal cations and oxygen vacancies.However,due to the simple structure of RRAM,the location,size and microstructure of the formation and fracture of conductive filaments are great random.This directly affects the parameter reliability and stability of RRAM.The usual solution is to modify the traditional device structure model to make the distribution of internal electric field more localized,reduce the randomness of conductive filament growth and improve the stability of RRAM devices.Amorphous carbon?a-C?is an environmentally friendly material with adjustable internal structure,graphite microislands?GMs?films with good conductivity were prepared by graphitization of amorphous carbon and applied to the study of RRAM performance improvement.In this paper,we will explore the preparation of RRAM with high stability by means of graphitization of amorphous carbon.The main research contents are as follows:First,vacuum annealing was conducted on amorphous carbon with Cu and Ni as catalysts,achieving the transition from amorphous carbon to graphitization.The degree of graphitization of amorphous carbon can be controlled by controlling different annealing temperatures or carbon layer thickness.Through a series of data analysis,it is shown that Ni is an excellent catalyst for graphitization of amorphous carbon.Then the amorphous carbon was catalyzed by Ni to prepare GMs thin films with good conductivity,it provides material basis for later regulation of RRAM devices.Secondly,The effect of graphitization of amorphous carbon on the performance of RRAM was studied.GMs films obtained by graphitization of amorphous carbon are intercalated between the bottom electrode and the resistance layer as RRAM devices,and GMs can be used to localize the electric field,the RRAM stability improved.In order to verify the universality of this method,the GMs films were applied in carbon-based RRAM and metal oxide RRAM devices.We prepared RRAM devices of Cu/a-C/GMs/Ni and Au/Ta₂O₅/GMs/Ni,we also made Cu/a-C/Ni and Au/Ta₂O₅/Ni devices.Then they were tested for their electrical properties.After a comparative analysis of the test data,it is verified that the graphite with tip conduction of GMs can play the role of local electric field.It can effectively reduce the randomness of conductive filament growth in devices,and make RRAM show good stability and cyclicity in operation.It provides an effective method for improving the performance of RRAM.