Research On Transparent Resistive Random Memory Based On Metal Oxide

Under the background of the vigorous development of semiconductor memory technology and brain-like bionic chips,resistive random access memory devices have been widely used by people for their high integration,simple structure,good tolerance,and compatibility with current manufacturing processes.The fully transparent resistive random access memory devices based on metal oxides studied in this article have more excellent optical performance on the basis of the above advantages,and have more extensive applications in wearable devices,photoelectric conversion devices,optical chips and other fields.And due to the low production cost of metal oxide materials and their high adaptability to the current process,they have greater application potential.The performance of the ITO/La AlO₃/ITO fully transparent resistive random access memory prepared after LaO_x doping is explored and its conduction mechanism is analyzed.Next,the fabrication process of the resistive switching layer and the annealing process conditions after the preparation are explored.The optical and electrical performance has been improved,and the main research conclusions are as follows:1.ITO/Al₂O₃/ITO RRAM devices were used as a control group,we studied the effect of inserting LaO_x layer in the resistive switching layer fabrication cycle using ALD equipment.The electrical characteristics such as the operating voltage,resistance distribution,resistance switching cycle characteristics,and retention characteristics of multiple sets of devices prepared in the same batch are statistically analyzed.Finally,the conduction mechanism of the devices are analyzed combined with changes in temperature and device area.The result shows that the device fabricated by inserting LaO_xin the cycle of preparing alumina materials using ALD equipment has more stable resistance characteristics.The average value and standard deviation of the operating voltage have been reduced and the number of resistive switching cycles of the transparent device is increased from 60 to 100.While the performance of the device is improved,the average light transmittance of the device is maintained at 78%.By exploring the relationship between the resistance of the device and the area and temperature of the device and analyzing its I-V characteristic curve,it is confirmed that the conductive mechanism of the device is dominated by the oxygen vacancy conductive filament,which belongs to the valence-changing resistance change mechanism.2.By changing the temperature of the ALD equipment during the preparation process,the performance of the device is improved.Four control groups are set at 220°C,250°C,280°C,and 300°C under the condition that all other process steps are the same.Studies have shown that the temperature of the cavity during the preparation of the resistive switching layer can significantly improve the reliability of the device by increasing the content of amorphous oxygen in the resistive layer under the premise that it hardly affects the light transmittance characteristics of the device.In addition,the research also found that when the temperature of the cavity is too low,it contains more impurities and defects,the conduction mechanism is transformed into the trap-controlled SCLC conduction mechanism.3.In order to further improve the light transmittance and electrical properties of the transparent device,the device was treated with a rapid thermal annealing process.Two conditions were set for annealing at 350°C for 20 minutes and annealing at 400°C for 20minutes in a nitrogen annealing atmosphere and a comparison was made with unannealed devices.The research results show that the annealing process effectively increased the light transmittance characteristics of the device.After annealed at 350°C and 400°C,the average light transmittance of the device in the visible light range has increased from 78%to about92%and 93%respectively.The maximum light transmittance increased from 87.6%to91.1%after annealing.The annealing process improves the crystalline state of the ITO material prepared at room temperature.At the same time,the oxide layer formed at the interface plays a role of partial pressure,which improves the optical characteristics and makes the current of the transparent RRAM device more stable and has a more uniform resistance distribution.