The Research On The Property Of Variable Resistance Memory

With the advancement and application of science and technology, manufacturing processes andresearch has improved continuously, and the information industry is rapidly developing all over the world.The information storage has also been an unprecedented development. The improving memory has higherintegration. more sophisticated appearance, lighter weight, faster access speed and higher storage capacity.It can not meet the need of the information developing. It’s important to find novel nonvolatile memorieswith high-density, high-speed and low power consume. To overcome the limitations of conventionalsemiconductor devices based on charge storage，various new nonvolatile-memory(NVM) devices suchas，ferroelectric, Polymer，phase change memory and resistance random access memories(RRAM) havebeen investigated. Especially, resistance random access memory (RRAM) is a reliable and achievablealternative among many substitutes due to its low power consumption, simple fabrication process fastswitching speed, excellent size scalability and the potential to be scaled down to sub-100nm scale. Withthe ongoing study, we found that the resistance switching a lot of new interesting phenomena: Unipolarresistive switching and bipolar resistance switching can be transformed into each other, the I-V curve’sclockwise rotation and counterclockwise rotation of the resistance switching’s electrical properties isimpacted by electrical formation process. In the study of resistance switch, we found the presence ofnonpolar resistive switching and unconventional bipolar resistance switching, at the same time weconcluded that unconventional bipolar resistance switching under appropriate conditions can betransformed into a conventional bipolar resistance switching. The discovery of these phenomena canprovide good help on a more comprehensive understanding of the formation mechanism of the resistanceswitch for the researchers. In the paper we prepared thin-film resistor switch by Pulsed Laser Deposition(PLD), and studied the mechanism of resistance switching by changing substrate conditions and theintroduction of light. In addition, I have some new ideas and research findings on the resistance switchingin the gate. The paper covers the following aspects:First, SrTiO3(STO) thin film was deposited on P（tPt/TiO2/SiO2/Si）substrate by pulsed laser deposition(PLD). The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM). The resistive switching characteristic of the device with Au/STO/Ptsandwich structure was studied, The devices have a good resistive switching performance, including lowthreshold voltage for turning on and off the device, good endurance and retention properties. The reasons ofthe formation of the Au/STO/Pt thin-film bipolar Resistive switching was explained，In addition,according to the features and advantages of the bipolar resistance switching, the appropriate encodingmethod was constructed, using a simple resistance change memory to implement logic gates constructedwith a different memory technology to achieve new resistance-change memory technology, and resistivememory transistor memory for a simple comparison, the chip functions, the role of pin, how to achievestorage were introduced.Secondly, the Au/Nb:STO/Pt and Au/Nb:STO/FTO sandwich structure resistance switching devicewas prepared, a variety of characterization techniques was applyed to analyze the similarities anddifferences between the two kinds of memory structures, they have different I-V curves because of thedifferent substrates, this is because the Schottky barrier played an important role IN resistive switchingdevice was irradiated by LED array light, the of two different device acted common features。Differentcompliance current caused different electroforming process. After that process bipolar or unipolar resistiveswitching behaviour was produced by different compliance current. More important, the conversionbetween bipolar and unipolar modes was reversible. Our analysis shows that different resistive switchingbehaviour was caused by different variation in the film at different compliance current and they followeddifferent conduction mechanisms.