Al/Ag/Al复合薄膜电极的抗氧化性和电性能研究

为开发大尺寸场发射显示器需要的能承受高温热处理的薄膜电极,以Al作为Ag层的保护层和与玻璃衬底的粘附层,采用直流磁控溅射制备了Al/Ag/Al复合薄膜及其电极.采用XRD、AFM、光学显微镜和电性能测试系统,研究不同温度热处理对复合薄膜和电极结构、表面形貌和电性能的影响.由于表面致密的Al2O3膜的保护,使得加热退火(<600℃)不会对Al/Ag/Al薄膜和电极造成明显的氧化,然而Al层与Ag层发生的界面扩散和固相反应增大了电极的电阻率(从5.0×10~(-8) Ω·m 上升至23.6×10~(-8) Ω·m).另外热处理温度足够高时(500℃、600℃),Ag原子向表面的扩散一定程度上降低了电极的化学稳定性.尽管如此,与Cr/Cu/Cr薄膜电极相比Al/Ag/Al薄膜电极仍然是一种能够承受高温热处理并且保持较低电阻率的新型电极.     

基于ZnO/Al2O3缓冲层制备耐高温SAW器件电极

为了声表面波(SAW)器件能在高温环境(不小于1 000 ℃)中工作,该文设计并在La3Ga5SiO14压电衬底上制作Pt/ZnO/Al2O3多层复合薄膜电极,利用ZnO/Al2O3组合缓冲层增强了Pt薄膜电极在极端高温条件下的导电稳定性。制备的SAW器件在经历3次1 000 ℃高温热处理后仍保持稳定的回波损耗系数S11。实验结果表明,ZnO/Al2O3组合缓冲层结构在提高SAW器件电极高温导电稳定性方面具有一定的潜在应用价值。     

VO2/Al2O3复合膜系制备及其相变特性

钒的氧化物具有对温度敏感的半导体-金属可逆相变特性.在多种钒氧化合物中,VO2的相变温度点约为68℃,适用于很多应用领域.VO2长期暴露在空气中时,会被氧化.研究了通过制备VO2/Al2O3复合膜系来保持氧化钒薄膜的稳定性的方法.采用TFCalc薄膜设计软件,设计了VO2/Al2O3复合膜系.依据材料的折射率和消光系数,优化了膜系各膜层的厚度,分析了复合膜系的相变特性.采用磁控溅射方式制备了氧化钒薄膜,再通过氧氩混合气氛热处理得到VO2占主要成分的氧化钒薄膜.在氧化钒薄膜上采用射频磁控溅射方法封装了120 nm厚的Al2O3膜.利用分光光度计测量分析了膜系的相变特性,Al2O3膜对VO2膜的相变性能影响很小.Al2O3膜适于VO2薄膜的封装.     

Cr薄膜电阻桥的湿法腐蚀工艺参数研究

采用直流磁控溅射法在Al2O3陶瓷基片上沉积了Cr薄膜,采用光刻–湿法腐蚀工艺对Cr薄膜图形化得到电阻桥。通过实验,详细研究了腐蚀液温度、pH值和硝酸铈铵[(NH4)2Ce(NO3)6]浓度对Cr薄膜电阻桥腐蚀效果的影响。实验结果表明,Cr薄膜电阻桥的最优腐蚀参数为:硝酸铈铵浓度1.16 mol/L,pH值4,30℃水浴恒温。采用该最佳工艺制备的Cr薄膜电阻桥的腐蚀速率为180 nm/min,侧蚀为400 nm,桥区边缘线条整齐,其在5A恒流作用下点火效果良好,点火时间约为27.4 ms。     

不同气氛保护下退火制备的CuO/SiO2复合薄膜微观结构分析

采用射频磁控共溅射法在Si(111)衬底上沉积Cu/SiO2复合薄膜.然后在N2和NH3保护下高温退火,再于空气中自然冷却氧化,制备出CuO结构,并对其微观结构进行分析.N2保护下退火温度为1100℃时样品中主晶相为立方晶系的CuO(200)晶面,薄膜样品表面出现纳米线状结构,表面组分主要包括Cu,O元素,冷却氧化形成CuO/SiO2复合薄膜.NH3气氛保护下退火,随着退火温度的升高,CuO由单斜晶相逐渐转变为立方晶相,CuO薄膜结晶质量提高.样品于900℃和1100℃退火后,形成有序散落的微米级颗粒,前者由粒状团簇组成,颗粒表面比较粗糙;后者由片融状小颗粒融合而成,颗粒表面比较光滑.     

不同气氛保护下退火制备的CuO/SiO2复合薄膜微观结构分析

采用射频磁控共溅射法在Si (111)衬底上沉积Cu/SiO2 复合薄膜,然后在N2和NH3保护下高温退火,再于空气中自然冷却氧化,制备出CuO结构,并对其微观结构进行分析. N2保护下退火温度为1100℃时样品中主晶相为立方晶系的CuO (200）晶面,薄膜样品表面出现纳米线状结构,表面组分主要包括Cu,O元素,冷却氧化形成CuO/SiO2复合薄膜. NH3气氛保护下退火,随着退火温度的升高,CuO由单斜晶相逐渐转变为立方晶相,CuO薄膜结晶质量提高. 样品于900℃和1100℃退火后,形成有序散落的微米级颗粒,前者由粒状团簇组成,颗粒表面比较粗糙;后者由片融状小颗粒融合而成,颗粒表面比较光滑.     

复合氮化铝压电薄膜研制及其应用

采用中频(MF,40 kHz)双S枪磁控反应溅射制备出了氮化铝(AlN)压电薄膜;采用直流磁控溅射法制作了Mo电极薄膜;采用脉冲DC磁控溅射Au、Cr、Al靶分别制作Au/Cr底电极薄膜及Al/Cr顶电极薄膜。通过对AlN压电薄膜、Mo及Au电极薄膜进行了X线衍射(XRD)分析,结果表明,复合AlN压电薄膜(002)面、Mo薄膜(110)面及Au薄膜(111)面择优取向优良,说明选用Al/Cr/AlN/Au/Cr/YAG复合结构压电薄膜能研制出Ku波段及K波段声体波微波延迟线(BAWDL), 其Ku及K波段BAWDL器件插入损耗分别低至43.7 dB、54.6 dB。     

YSZ/Al_2O_3复合薄膜高温绝缘层的研究

采用电子束蒸发、射频磁控溅射、等离子喷涂等方法,在镍基高温合金基底上制备YSZ(质量分数12%Y2O3稳定的Zr O2)、Al2O3复合薄膜结构绝缘层,并研究了复合薄膜结构绝缘层在室温到800℃范围内的绝缘特性,以及高温对复合薄膜晶体结构和表面形貌的影响。结果表明:晶态YSZ/非晶态YSZ/Al2O3结构绝缘层在室温下的绝缘电阻大于1.2 GΩ,在800℃大气环境下有150 kΩ左右的绝缘电阻。在室温到800℃范围内,随温度升高其绝缘电阻呈近指数下降的变化规律。经过在800℃大气环境中热处理8 h,YSZ的立方相结构未发生改变,Al2O3表面十分致密,表明该复合结构绝缘层薄膜具有良好的高温绝缘性能和稳定性。     

P型透明导电Cu-Al-0薄膜的直流共溅射法制备

采用Cu靶和Al靶直流共溅射法制备了P型透明导电Cu—Al—O薄膜。用原子力显微镜（AFM）、X射线衍射（XRD）仪、四探针测量仪、紫外-可见分光光度计对样品进行了表征。结果表明,对所制备的P型透明导电Cu—Al—O薄膜经高温退火后,其结晶质量和导电性能均有一定提高,薄膜在可见光区的平均透过率接近70％,禁带宽度约为3．75eV。     

n型CuInS2薄膜的制备及特性

将高纯Cu,In和S粉末按1:0.1:1.2(原子个数比)配比混合均匀,热蒸发沉积CuInS2薄膜,再将薄膜进行热处理。研究热处理工艺对薄膜性能和导电类型转换的影响。本研究制备的薄膜经360℃,30 min的热处理,得到n型、黄铜矿结构的CuInS2薄膜,平均晶粒尺寸29.43 nm。经370℃,20 min热处理的CuInS2薄膜也呈n型,平均晶粒尺寸38.23 nm。霍尔效应测试显示上述两种n型CuInS2薄膜的导电性良好,迁移率分别为1.071 cm2/V·s和53.82 cm2/V·s。能谱分析给出,CuInS2薄膜(360℃)体内原子个数比Cu:In:S=1:1.2:1.6,S元素损失较多。CuInS2薄膜(370℃,20 min)的原子个数比为1:0.8:1.4,S和In元素的含量较少;扫描电子显微镜给出薄膜表面呈颗粒状,随热处理温度增加,薄膜表面的致密性变好但粗糙度增大,370℃,30 min热处理后CuInS2的晶相结构不变,导电类型转为p型,迁移率为1.071 cm2/V·s。     

Effect of thermal treatment on the properties of YBa2Cu3O7-x thin films with multilayer Al/Cr/Yb metals as ohmic contact electrodes

Detailed studies were conducted on YBa₂Cu₃O_7-x thin films with multilayer Al/Cr/Yb metals as ohmic contact electrodes. Ytterbium not only provided an excellent ohmic contact to YBa₂Cu₃O_7-x thin films, but also improved the zero resistance temperature after thermal treatment of the contacts. Superconducting thin films with zero resistance temperature of around 90 K with extremely sharp resistivity transitions, contact current density greater than 1.3 x 10³A/cm², and specific contact resistivity as low as 10^-9 ohm · cm² at 77 K were achieved on yttrium stabilized ZrO₂ substrates. This occurred after contact deposition and thermal treatment at 450° C in pure oxygen for 20 min.     

All‐Solution‐Processed Indium‐Free Transparent Composite Electrodes based on Ag Nanowire and Metal Oxide for Thin‐Film Solar Cells

Fully solution‐processed Al‐doped ZnO/silver nanowire (AgNW)/Al‐doped ZnO/ZnO multi‐stacked composite electrodes are introduced as a transparent, conductive window layer for thin‐film solar cells. Unlike conventional sol–gel synthetic pathways, a newly developed combustion reaction‐based sol–gel chemical approach allows dense and uniform composite electrodes at temperatures as low as 200 °C. The resulting composite layer exhibits high transmittance (93.4% at 550 nm) and low sheet resistance (11.3 Ω sq^‐1), which are far superior to those of other solution‐processed transparent electrodes and are comparable to their sputtered counterparts. Conductive atomic force microscopy reveals that the multi‐stacked metal‐oxide layers embedded with the AgNWs enhance the photocarrier collection efficiency by broadening the lateral conduction range. This as‐developed composite electrode is successfully applied in Cu(In_1‐x,Ga_x)S₂ (CIGS) thin‐film solar cells and exhibits a power conversion efficiency of 11.03%. The fully solution‐processed indium‐free composite films demonstrate not only good performance as transparent electrodes but also the potential for applications in various optoelectronic and photovoltaic devices as a cost‐effective and sustainable alternative electrode.     

Cu/Ta/SiO2/Si薄膜在纳米压痕下的分层现象研究

采用磁控溅射技术在热氧化单晶硅衬底上先后淀积了厚度分别为50nm的Ta膜和400 nm的Cu膜.使用纳米压入仪在样品表面进行压入测试,在薄膜表面制造出残留压痕.使用扫描电镜(SEM)、聚焦离子束(FIB)、透射电镜(TEM)和X射线能谱仪(EDX)对残留压痕形貌、剖面上的分层现象进行观察,确定分层所在的位置.发现在69 mN的最大载荷作用后,在TA/SiO2界面处发生分层.分层的原因主要归结为在应力作用下,多层膜中各种材料的应变、弹性恢复能力不同.     

表面无小丘Al双层栅电极结构研究

利用ＤＳＣ方法研究了纯铝薄膜中的小丘现象,同时制备了Ａｌ双层栅电极Ｔａ／Ａｌ、Ｃｒ／Ａｌ和Ｍｏ／Ａｌ薄膜,并在不同温度下进行了退火处理,研究了双层结构中上层金属Ｔａ、Ｃｒ和Ｍｏ）厚度对Ａｌ薄膜中小丘的抑制作用。实验结果表明,上层Ｔａ膜厚度在８０￣９０ｎｍ左右（在本实验条件下）时,可得到表面无小丘的Ｔａ／Ａｌ薄膜栅材料。实验制备的表面无小丘Ｔａ／Ａｌ、Ｃｒ／Ａｌ和Ｍｏ／Ａｌ等栅电极材料的电阻率均在７     

The incubation time for hole formation due to electromigration in Al and Al/Cu/Al thin films

Transmission electron microscope observations of hole formation in Al and Al/Cu/Al thin film conductors carrying high current densities have revealed the presence of an incubation period for hole growth. The temperature dependence of this incubation period for pure aluminum conductors has been determined and found to follow an Arrhenius relationship with an activation energy of 0.55 ev ± 0.1 ev.     

金属基NiCr-NiSi薄膜热电偶的制备及性能研究

采用电子束蒸发和磁控溅射法在Ni基超合金基片上制备NiCr-NiSi薄膜热电偶,薄膜热电偶依次由Ni基超合金基片、NiCrAlY过渡层、Al2O3热氧化层、氧化铝绝缘层、NiCr-NiSi薄膜热电偶层以及氧化铝保护层构成。对此薄膜热电偶样品的静态标定结果表明,所制备的金属基NiCr-NiSi薄膜热电偶在25～600℃内具有良好的线性度,Seebeck(塞贝克)系数达到37.5μV/K,略低于K型标准热电偶的塞贝克系数40.0μV/K。     

AA6061铝基材上激光熔覆Cu／Cr合金层的研究

在易氧化的纯AI表面制备Cu/Ar合金熔覆层,因二者的熔点温度差别大且容易结合过渡区产生脆性裂纹而有一定难度。本文通过扫描电镜（SEM）分析研究了激光工艺参数对Cu/Ar熔覆层过渡区裂纹倾向的影响。实验结果表明,以1．06μm波长的Nd:YAG激光器的聚焦光束为热源,通过选择合适的激光工艺参数,可获得理想的Cu/Ar合金熔覆层,这对于改进铝材表面的物理、化学性能并进一步开发其作为电接触材料具有应用价值。     

Enhancement of electrical properties in pentacene-based thin-film transistors using a lithium fluoride modification layer

We investigated the electrical performances of pentacene-based thin-film transistors with a thin LiF film as a modification layer between the source/drain electrodes and the active layer. Au, Pt, and Pd were employed as the source/drain (S/D) electrodes of the organic thin-film transistors (OTFTs). The thickness of the LiF layer was varied to optimize the electrical performances of the OTFTs. We found that the electrical performances of the devices with LiF layer are better than those without inserting the LiF layer, regardless of which one metal used for the S/D electrodes. The electrical performances of the devices in terms of drain current, on resistance, threshold voltage, on/off current ratio and mobility have been optimized when the thickness of the LiF buffer layer was at 1.0 nm. These improvements are attributed to work function of S/D contact materials were modified by the dipole of the inserted LiF layer and an ultrathin LiF layer provides the tunneling condition to enhance the carrier injection efficiently. Additionally, LiF layer with optimal thickness (1.0 nm) can modify surface roughness of pentacene film and partly enhance the carrier injection.