| In order to meet the requirements of IC memory for lower power consumption, higherdensity and higher speed，RRAM has become one of the most competitive candidates of thenext generation non-volatile memory due to its simple structure, low operation voltage andcompatibility with the CMOS process. So far, among the researches in RRAM, the selectionand optimization of materials is still one important part. The MIT characteristic of VOxwasinvestigated widely, but it was seldom used for RRAM induced by electric.In this thesis, we take VOxas the key RRAM material and obtained many samples underdifferent condition. These samples are tested and analyzed by AFM, XRD, XPS, SPA and soon. At last, several samples with different bottom electrode and the different thickness offunction layer were fabricated based on the research ahead, and these samples wereselectively analyzed by SPA for its electrical characteristics, and we preliminarily studied themechanism of the resistance switching, the primary research content and conclusion are asfollows:(1)Comparison of the fabrication process: this thesis used four methods to prepare thefilms:①DC-reactive sputtering②RF-reactive sputtering③RF-sputtering④pure V filmoxidized in oxygen. Through the analysis comparison of these data of the films, we concludedthat: The films’deposition rate of DC-sputtering is 2.4 times of RF- sputtering; thecomponent of DC-sputtering is more complicated than RF-sputtering from XRD analysis; thefilms has a higher density by RF-sputtering than DC-sputtering from AFM analysis; InRF-sputtering and DC-sputtering the films’O: V rate were 2.7:1 and 3.47:1.(2)The electrical characteristics of the films deposited by RF-reactive sputtering of pure Vtarget was emphatically analyzed, and a conclusion was got that the characteristics of thefilms deposited at the condition of 100W(RT) and 10% O2rate were better with 3.79 VForming voltage, 1.45 V and 0.53 V Set/Reset voltage, 13.2 mA reset current.(3)Through the analysis of the devices’switching characteristics with different bottomelectrodes, the switching mechanism was primarily discussed. The resistance switching withPt as the bottom electrode exhibited one volatile switching characteristic. The devices with Albottom electrode show the similar phenomenon with the device with Pt bottom electrode.However the devices with Cu bottom electrode which can easily diffuse into the insulatorexhibited steady non-volatile characteristics. This phenomenon may be due to the paths’construction and rupture formed by Cu atom in the insulator.(4)Though the analysis of the devices’electrical characteristics with different thicknessfunction layer based on Cu bottom electrode, the influence of thickness to switchingcharacteristics was discussed. We found that when the thickness increased the FormingVoltage increase too，but the Set/Reset electrical characteristics didn’t changed much. This thesis made an investigation of VOxfilm prepare method and the influence of thebottom electrode and the thickness of function layer to its characteristic. At last, we analyzedthe switching mechanism of VOx. Wish these work can provide some support for the researchof RRAM. |
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