【作者】 董建华；

【导师】 黄佳木；

【作者基本信息】 重庆大学 ， 材料学， 2002， 硕士

【摘要】 透明导电氧化物薄膜材料具有大的载流子浓度和光学禁带宽度，因而表现出优良的光电特性，如低的电阻率和高的可见光透过率等。目前此类材料体系包括：In2O3、SnO2、ZnO及其掺杂体系In2O3:Sn(ITO)、SnO2:Sb、SnO2:F、ZnO:Al(ZAO)等。其中SnO2(TO)和In2O3:Sn(ITO)薄膜作为透明电极在液晶显示和太阳能电池等领域得到实际应用。ZnO:Al(ZAO)薄膜具有优良的光电特性而成为ITO薄膜的潜在替代材料，而且具有原材料来源丰富、成本低廉、无毒以及在氢等离子体中具有较好的稳定性等优点。多种工艺可以用来制备透明导电薄膜，如磁控溅射、真空反应蒸发、化学气相沉积，溶胶-凝胶法以及脉冲激光沉积等。其中磁控溅射工艺具有沉积速率高、均匀性好等优点而成为一种广泛应用的成膜方法。本研究课题以氧化铟锡靶和氧化锌铝靶为靶材，采用射频磁控溅射工艺在纯氩气氛中沉积ITO和ZAO薄膜，靶材中SnO2和Al2O3的掺杂比例分别为10%和3%，成膜过程中研究了各工艺参数对其结构和光电特性的影响。另外采用了在氩和氧的混合气氛中共溅射锌靶和铝靶的方法来制备铝掺杂氧化锌薄膜，铝的掺杂量由施加在铝靶上的功率大小决定。研究表明：在基底温度为300℃时，ITO薄膜具有(222)晶面的择优取向，由于Sn4+对In3+的置换而出现晶格收缩现象，薄膜的最小电阻率和可见光范围透过率分别为6.8×10-4Ωcm和80%。ZAO薄膜在低温下沉积时，由于薄膜内存在残余应力使衍射峰位置与体材相比向低角度方向移动；高温沉积的ZAO薄膜经热处理后具有c轴择优取向的六角纤锌矿多晶结构，晶粒垂直于衬底柱状生长，薄膜的最小电阻率和可见光透过率分别为7.5×10-4Ωcm和85%。双靶共溅沉积ZAO薄膜时，氧流量和基片温度是影响薄膜特性的重要因素，随着铝靶射频功率增加，由于铝的掺杂使薄膜表面方块电阻降低，当功率为120W时，沉积的薄膜具有最小的电阻值。当功率大于120W时，功率进一步增加，薄膜的导电性变差。更多还原

【Abstract】 Due to big carrier concentration and optical band gap，transparent conductive oxide thin films exhibit outstanding optical and electrical properties，such as low resistivity and high transmittance in the visible range etc．At present，this kind of material system include In2O3，SnO2，ZnO and dopant system In2O3:Sn(ITO)，SnO2:Sb，SnO2:F，ZnO:Al(ZAO) etc．Among them，SnO2(TO) and In2O3:Sn(ITO) films have been widely used in liquid crystal display and solar cell as transparent electrode．Al-doped ZnO films show good electrical and optical properties and emerge as a potential alternative candidate for ITO films．Furthermore，they offer a number of advantages compared to the predominant ITO films nowadays：(i) cheap and abundant raw materials；(ii) nontoxicity；(iii) good stability in hydrogen plasma，which is of significance for applications related to amorphous silicon solar cell．Many processes are used to prepare transparent conductive films such as magnetron sputtering，vacuum reactive evaporation，chemical vapor deposition，sol-gel，laser-pulsed deposition．Among these methods，magnetron sputtering is the most widely used technique for preparing thin films owing to its high deposition rate and good uniformity etc．ITO and ZAO films were prepared by RF magnetron sputtering in pure argon gas atmosphere using In2O3 and ZnO target mixed with SnO2(10wt%) and Al2O3 (3wt%) respectively，and the effect of process parameters on the structural，electrical and optical properties of ITO and ZAO films werestudied．In addition，ZAO films were deposited by reactive magnetron co-sputtering from two separate metallic targets of Zn(DC) and Al(RF) in Argon and oxygen atmosphere． During deposition，Al concentration was determined by the RF power of Al target．ITO thin films deposited at the substrate temperature of 300℃ have preferred orientation of (222)，the lattice shrinkage is ascribed to the replacement of Sn4+ for In3+，the visible transmittance of 80% and the minimum specific resistance of 6.8×10-4Ωcm were obtained．The peak position of ZAO films prepared at low temperature shifts to the lower angle comparable to that of bulk ZnO due to the residual stress；as-deposited post-annealed ZAO films was polycrystalline with the hexagonal crystal structure and had a strongly preferred orientation of c axis perpendicular to<WP=6>the substrate surface，the minimum resistivity and average transmittance to the visible light are 7.5×10-4Ωcm and 85% respectively。During deposition of ZAO films，oxygen and substrate temperature have great influence on the optical and electrical properties．The surface sheet resistance decreases with increasing RF power of Al target，ZAO thin films show minimum resistivity at the power of 120W．The conductivity get worse with further increase in RF power．更多还原