Uniformity and bias‐temperature instability of bottom‐gate zinc oxide thin‐film transistors (ZnO TFTs)

Abstract— Short‐range uniformity and bias‐temperature (BT) instability of ZnO TFTs with SiO^x/SiN^x stacked gate insulators which have different surface treatments have been investigated. The short‐range uniformity of ZnO TFTs was drastically improved by N²O plasma treatment of the gate insulator. The variation in the gate voltage where a drain current of 1‐nA flows (Vgs at an Ids of 1 nA) was dramatically reduced from ±1.73 V to ±0.07 V by N²O plasma treatment of the gate insulator. It was clarified that the variations in the subthreshold characteristics of the ZnO TFTs could be reduced by N²O plasma treatment of the gate insulator due to a decrease in the variation of trap densities in deep energy levels from 0.9–2.0 × 10¹⁷ to 1.2–1.3×10¹⁷ cm^?3‐eV^?1. From the BT stress tests, a positive shift of Vgs at an Ids of 1 nA could be reduced by N²O plasma treatment of the gate insulator due to a decrease in the charge traps in the gate insulator. When the gate‐bias stress increases, state creation occured in the ZnO TFTs in addition to the charge trapping in the gate insulator. However, N²O plasma treatment of the gate insulator has little effect on the suppression of the state creation in ZnO TFTs under BT stress. The surface treatment of the gate insulator strongly affects the short‐range uniformity and the BT instability of Vth in the ZnO TFTs.     

具有纳米结构的海胆形氧化锌的制备及其酒敏性能

以Zn(Ac)2.2H2O为原料,NH3.H2O为络合剂,在NaBH4辅助下140℃水热反应2 h制备出海胆形ZnO颗粒。采用X射线衍射仪和扫描电镜对产物进行表征。海胆形ZnO颗粒的直径约为3μm～17μm,它是由直径约为100 nm,长度约为500 nm～3μm的ZnO纳米棒自组装而成。研究了NaBH4物质的量,反应温度和时间对产物形貌的影响,结果表明,NaBH4在海胆形ZnO颗粒的形成过程中起着关键作用,提出了可能的生长机理。气敏测试结果表明,海胆形ZnO纳米颗粒在350℃对低浓度的乙醇气体具有快速敏感的传感性能。     

SiCl4锌还原异相反应机理的研究

通过MP2/6-311G（d,p）方法,计算并得到了SiCl4锌还原各反应通道上各驻点的几何构型、振动频率和能量.根据密度泛函理论,采用广义密度梯度近似和总体能量平面波赝势方法结合周期性平板模型,研究了反应驻点在Si（100）面上的吸附、解离及锌还原过程.结果表明,衬底硅参与SiCl4锌还原反应,SiCl4易在顶位吸附解离成SiCl3和Cl;当硅基表面有Cl自由基吸附时,Zn或ZnCl更倾向于与Cl结合,而不是还原SiCln（1～3）.     

镀锌板镀锌量检测分析仪的研制

介绍以Cygnal F005单片机作为智能部件,根据电解剥离原理研制出的镀锌板镀锌量检测分析仪,采用微分电位法解决了各层界面自动分层难题,对双电层电容充电电流引起的测量误差作了修正。该仪器既可提供本机显示和打印测量结果的功能,又能通过USB接口与上位机配合使用,具有小型轻便、检测数据精确和操作界面友好等特点。     

锌冶金废水综合治理实践

介绍某湿法炼锌企业废水综合治理情况,在治理过程中采用了先进的节水工艺技术、处理后废水回收利用以及废水处理工艺。运行情况表明,采用综合治理能够大幅度减少废水排放,并创造了良好的经济效益。     

电弧炉烟尘球团焙烧-洗涤脱卤制备低卤含量氧化锌的试验研究

针对电炉弧烟尘处理利用,进行了电弧炉烟尘球团焙烧-洗涤脱制备低卤含量氧化锌的试验研究,取得了满意的结果,在最佳球团焙烧工艺条件下,锌的挥发率>94%、铅的挥发率>90%,氟主要以难挥发的MnF2形式留在窑渣中,挥发氧化锌烟尘中难溶氟化物含量少,洗涤脱卤效果明显,洗涤后含锌62.14%,氟0.011%、氯0.20%,基本满足株冶氧化锌系统浸出原料的要求。     

Oxide engineering of ZnO thin‐film transistors for flexible electronics

Abstract— In this paper, we show that ZnO thin‐film transistors (TFTs) are potentially a higher performance alternative to organic and amorphous‐Si TFTs for macroelectronics on plastic substrates. Specifically, we fabricated nanocrystalline ZnO thin‐film transistors using low‐temperature processing, compatible with flexible electronics on plastic substrates. The ZnO semiconductor was rf magnetron sputtered, and the Al₂O₃ gate dielectric was deposited either by electron‐beam evaporation or atomic layer deposition. By controlling the partial pressure of oxygen pO₂) during ZnO sputtering, we could engineer the field‐effect mobility of ZnO transistors to be between 2 and 42 cm²/V‐sec, attractive for high‐performance electronic applications. We contend that pO₂ controls the oxygen‐vacancy content or stoichiometry of ZnO, and that allows control of transistor field‐effect mobility. Although most of the devices described here were fabricated on Si substrates, devices we made on a thin (50 μm thick) polyimide substrate had about equivalent performance, affirming the compatibility of our processes with plastic substrates. Finally, we show that properties of our nanocrystalline ZnO transistors can be explained by transport models that account for grain‐boundary trapping of mobile carriers.     

Preparation and study of thickness dependent electrical characteristics of zinc sulfide thin films

Zinc sulfide thin films have been deposited onto glass substrates by chemical bath deposition. The various deposition parameters such as volume of sulfide ion source, pH of bath, deposition time, temperature etc are optimized. Thin films of ZnS with different thicknesses of 76–332 nm were prepared by changing the deposition time from 6–20 h at 30° C temperature. The effect of film thickness on structural and electrical properties was studied. The electrical resistivity was decreased from 1.83 × 10⁵ Ω-cm to 0.363 × 10⁵ Ω-cm as film thickness decreased from 332 nm to 76 nm. The structural and activation energy studies support this decrease in the resistivity due to improvement in crystallinity of the films which would increase the charge carrier mobility and decrease in defect levels with increase in the thickness.