氧压对VO_(x)薄膜阈值开关性能的影响

Effect of oxygen pressures deposition on the performance of VO_(x) thin film threshold switches

结合脉冲激光沉积(Pulsed Laser Deposition,PLD)和直流(DC)磁控溅射方法成功制备了Pt/VO_(x)/Pt/SiO_(2)/Si阈值开关器件(TS),VO_(x)薄膜厚度约为300 nm.为了研究器件沉积时氧压对器件性能的影响,本文制备了四个不同沉积气压的VO_(x)薄膜器件(0.5 Pa、1.2 Pa、2.4 Pa和3.0 Pa),利用XRD、SEM、XPS手段对VO_(x)薄膜器件进行晶体结构、形貌、厚度和元素价态表征,同时还对四个器件进行TS性能测试以及研究了不同沉积气压对器件阻变机制的影响.结果表明,随着沉积气压从0.5 Pa增加到2.4 Pa,VO_(x)薄膜中的氧空位含量减少,器件的开关电流比(I_(ON)/I_(OFF))和阈值电压(V_(th))增大,且循环稳定性增强;但是当氧压增加到3.0 Pa后,器件性能略有降低.这表明O空位的含量对VO_(x)薄膜的TS性能有显著的影响,并且可以通过调控薄膜的O空位含量来实现对器件性能的改性.

Pulsed laser deposition(PLD)and direct current(DC)magnetron sputtering have been used to prepare Pt/VO_(x)/Pt/SiO_(2)/Si threshold switch devices(TS)successfully.The thickness of VO_(x) thin films is about 300 nm.In order to study the effect of oxygen pressure on the device performance,four VO_(x) thin film devices with different deposition pressures(0.5 Pa,1.2 Pa,2.4 Pa and 3.0 Pa)were prepared.The crystal structure,morphology,thickness and element valence of VO_(x) thin films devices were characterized by XRD,SEM and XPS.The TS performance of the four devices was tested and the influence of different deposition pressure on the resistance mechanism of the devices was analyzed.The results show that with the increase of deposition pressure from 0.5 Pa to 2.4 Pa,the oxygen vacancy content in VO_(x) thin films decreases,the switching current ratio(I_(ON)/I_(OFF))and threshold voltage(V^(th))of the devices increase,and the cycle stability is enhanced.However,when the oxygen pressure increases to 3.0 Pa,the device performance decreases slightly.This indicates that oxygen vacancy content has a significant effect on the TS performance of VO_(x) thin films,and the device performance can be modified by adjusting the oxygen vacancy content of the thin films.