磁控溅射制备增透ITO薄膜及其性能研究

Study on the preparation and properties of antireflective ITO thin films by magnetron sputtering

用射频磁控溅射法在低温下制备了光电性能优良的ITO(In2O3:SnO2=1:1)薄膜。质量流量计调节氩气压强PAr为0.2～3.0Pa,氧流量fO2为0～10sccm,并详细探讨了溅射时PAr和fO2变化对ITO薄膜光学性能的影响。结果表明:fO2的改变引起薄膜中氧空位浓度变化而影响ITO薄膜折射率n;fO2对ITO靶材表面的溅射阀值和对Ar+散射而改变溅射速率。衬底表面粗糙度对ITO薄膜的折射率测量准确性有较大影响。PAr为0.8Pa,fO2为2.4sccm,薄膜厚度为241.5nm时,nmin=1.97,最大透过率为89.4%(包括玻璃基体),方阻为75.9?/□,电阻率为8.8×10-4?·cm。AFM分析表明薄膜表面针刺很少,表面平整(RMS=3.04nm)。

Highly transparent and conductive ITO （indium-tin oxide） films were deposited on glass substrate at room temperature （R.T.） by magnetron sputtering, and the target was indium-tin oxide （In2O3： SnO2=1：1） made by sintered. The Ar gas pressure （PAr） varies from 0.2～3.0Pa and the oxygen flux （fO2） varies in range of 0～10sccm controlled by gas mass flowmeter. Furthermore the detailed investigation was carried out for the effects of PAr and fO2 on ITO films. It is concluded that fO2 value not only affects refractive index （n） due to carrier concentration variation in ITO films but also affects the deposition rate because of sputtering threshold and free length Ar^＋. Substrate surface roughness has an important influence on the refractive index, the minimum refractive index is 1.97 which approaches the optical matching when PAr=0. 8Pa and fO2=2.4sccm. The maximal transmittance of ITO film is 89.4% in visible light spectrum, the square resistance Rs=75.9Ω/□, resistivity ρ=8.8×10^-4Ω·cm when the thickness of ITO film is 241.5nm. AFM analysis show that the spikes and needles on thin film are few and ITO film surface is smooth.