基底加热温度对ITO薄膜的性能影响研究

氧化铟锡(ITO)薄膜被广泛用作光电器件中的透明导电电极,其透光率、导电性、表面粗糙度、与基底的功函数匹配及其电流传输特性都会对光电器件的性能造成影响。本文采用射频(RF)磁控溅射方法制备ITO薄膜,系统研究了基底加热温度对其各方面性能的影响,并确认了最佳基底温度。实验采用锡掺氧化铟陶瓷为靶材,组分摩尔比为m(In₂O₃)∶m(SnO₂)=90∶10。采用XRD、SEM对所制备的薄膜进行表征,系统分析不同基底温度对ITO薄膜结晶性能、形貌的影响;采用紫外可见分光光度计、霍尔效应测试仪、紫外光电子谱仪(UPS)、电流电压曲线系统研究了基底温度对薄膜光电特性、载流子浓度、薄膜功函数以及电流传输特性的影响。研究结果表明,基底温度200 ℃为最佳,此时ITO薄膜结晶良好、表面平整、可见光波段平均透过率超过80%,导电性能和电流传输特性均较佳,且薄膜组分与靶材组分一致。

Effects of the Substrate Heating Temperature on Properties of ITO Films

Indium tin oxide (ITO) films have been widely used as transparent conductive electrodes for optoelectronic devices. Its light transmittance, electrical conductivity, surface roughness, work functions matching with substrates and carrier transferring performance at the interface all affect the performance of optoelectronic devices. In this paper, ITO films were prepared by RF magnetron sputtering. Influences of substrate heating temperature on properties of ITO films were systematically studied. The Sn doped indium oxide ceramic target was used, the composition molar is m(In₂O₃)∶m(SnO₂)=90∶10. The prepared films were characterized by XRD and SEM, and effects of different substrate temperatures on the crystallization and morphology properties of ITO films were studied respectively. The effects of substrate temperature on the photoelectric properties, carrier concentration, work function and carrier transferring properties of ITO films were studied by UV-Vis spectrophotometer, Hall effect tester, ultraviolet photoelectron spectrometer (UPS) and current-voltage curve, respectively. It is found that the comprehensive properties of the ITO film are the best when the substrate temperature is located at 200 ℃. At this time, the ITO film has good crystallinity, smooth surface, average transmittance over 80% in visible light band, excellent conductivity and current transmission characteristics, and the composition of the film is consistent with that of the target.