氧氩流量比对高介电薄膜Ta_2O_5电学性能的影响

Effects of O_2/Ar flow volume ration on the electrical properties of Ta_2O_5 films

利用反应溅射的方法沉积Ta2O5高介电薄膜,研究了溅射过程中氧气与氩气的体积流量比Ψ(O2:Ar)对薄膜电学性能的影响。结果表明,制备的薄膜退火后为多晶态四方结构的β-Ta2O5。随着Ψ(O2:Ar)的增大,薄膜的沉积速率逐渐减小,积累电容逐渐增大,等效氧化层厚度逐渐减小,平带电容增大,氧化层中可动离子电荷密度逐渐减小。当Ψ(O2:Ar)=6:5时,所沉积Ta2O5薄膜的相对介电常数r最大,为38.32;当Ψ(O2:Ar)=2:5时,漏电流密度最小,仅为7.7×10–7A/cm2。

The Ta2O5 films were deposited by reactive sputtering,the effects of volume flow ratio Ψ（O2：Ar） on the electrical properties of Ta2O5 films were studied.The results show that the prepared films are polycrystal with tetragonal structure of β-Ta2O5 after annealing.With the increase of Ψ（O2：Ar） value,the deposited rate,the equivalent oxide thickness and the moving ionic charge density decrease,while the accumulation capacitance and the flatband capacitance increase.The deposited Ta2O5 films possess the highest dielectric constant of 38.32 when Ψ（O2：Ar） = 6：5.When Ψ（O2：Ar）=2：5,the leakage current density is minimum,only 7.7×10-7 A/cm2.