退火温度对铜铟镓硒薄膜电学性能的影响

使用磁控溅射铜铟镓硒(CuIn1-xGaxSe2,CIGS)四元陶瓷靶材制备沉积态预制膜,在240-550℃对预制膜进行退火处理,着重研究了退火温度对薄膜电学性能(载流子浓度及迁移率)的影响。结果表明:退火温度低于270℃时薄膜中存在CuSe低电阻相,CIGS薄膜的载流子浓度在1017-1019cm-3,迁移率在0.1 cm2·V-1·s-1左右,不适于作为太阳电池的吸收层;当退火温度高于410℃时薄膜中不存在CuSe相,薄膜具有10 cm2·V-1·s-1左右的较高迁移率,载流子浓度在1014-1017cm-3;退火温度高于410℃时,随着退火温度的升高薄膜晶粒长大,结晶性增强,此时薄膜内部缺陷减少,载流子浓度升高;对于用作太阳电池吸收层的CIGS,从载流子浓度及迁移率的角度评判,合适的退火温度区间为450-550℃。     

功率和退火对磁控溅射生长ZnO∶Ga薄膜的影响

采用射频磁控溅射法在玻璃衬底上制备了ZnO∶Ga透明导电薄膜(GZO)。通过X射线衍射(XRD)、四探针电导率测试、紫外可见分光光度等表征方法研究了溅射功率对薄膜结晶特性及光电性能的影响。结果表明:当溅射功率180W时制备的GZO薄膜光电性能最优,方块电阻为9.8Ω/sq,电阻率为8.6×10-4Ω·cm,霍尔迁移率为12.5cm2/V·s,载流子浓度为5.8×1020cm-3,可见光透过率超过92%。另外,研究了最优制备条件下的GZO薄膜的高温稳定性,在氩气、氧气和真空气氛下分别对薄膜进行退火处理。结果表明,氩气退火的薄膜电学性能显著提高,是显著改善GZO薄膜性能的有效方法之一;氧气退火不利于薄膜的导电性;真空退火介于两者之间。     

ZrO_2-12wt% Y_2O_3沉积薄膜退火后处理前后的相结构研究

在不同温度衬底上射频磁控溅射沉积ZrO2－12wt％Y2O3薄膜进行了不同方式的退火后处理。其一为1000℃大气气氛下的热退火处理，其二为高真空渗氧条件下的电子束退火处理。退火前后的相结构和显微形貌的研究表明，退火前的沉积膜相组成与沉积过程中衬底温度有关，退火后的沉积膜相组成与退火方式有关，其形貌特征经不同形式退火显示出明显的差别。     

非晶SrTiO3纳米薄膜退火处理方法的研究

用激光脉冲沉积技术(PLD),以N型(100)Si为基底在300℃下制备100nm非晶STO薄膜,分别用常规退火(CFA),快速退火(RTA)以及激光诱导晶化(LIC)处理将其转化多晶薄膜,用XRD测定薄膜相组分和结晶质量,用AFM观测薄膜表面微结构.比较不同工艺退火对薄膜结晶品质的影响并阐述了各自形核结晶的机理.     

低压MOCVD生长TiO2薄膜结构和电性能研究

采用低压MOCVD法沉积生长了TiO2薄膜，研究了Si衬底取向，退火温度，退火时间，退火气氛对其结构和电性能的影响，结果表明，500℃下沉积生长于Si(111)和Si(100)上的TiO2薄膜为锐钛矿相多晶膜，经过600℃以上退火处理后，均可转变为纯金红石相结构。其中，Si(111)上的TiO2薄膜更容易转变为金红石相结构，而Si(100)上的TiO2薄膜，需要更高的退火温度和更长的退火时间才能转变为金红石结构。结果还表明，退火气氛中氧分压的大小对TiO2薄膜的结构无明显的影响。     

真空退火对LiF和CaF2薄膜结晶性能的影响

研究了真空退火对玻璃衬底上热蒸发沉积的LiF和CaF2 薄膜的结晶性能的影响。X射线衍射分析结果表明 ,在4 2 0℃温度下 ,随着退火时间的增长 ,LiF薄膜的结晶状况明显改善 ;在 4 6 0℃温度下 ,随着退火时间的增长 ,CaF2 薄膜的结晶状况越来越好     

退火工艺对磁控溅射生长的Pt薄膜微观结构及电性能的影响

铂(Pt)是温度传感器常见的敏感材料。为了改善退火工艺提高Pt薄膜的电学特性,采用射频磁控溅射法在蓝宝石衬底上制备了以钽(Ta)为粘附层的Pt敏感薄膜,研究了不同退火温度、退火气氛和退火时间下的Pt薄膜结构以及电学性能方面的差异。结果表明:退火增强了薄膜的结晶化且使晶粒发生长大,从而有效降低了薄膜的电阻率。但过度退火,如退火温度超过1 000℃或过长的退火时间,会导致粘附层中的Ta元素向Pt薄膜中过度扩散,从而增加Pt薄膜的电阻率。在高纯N_2(99.999%)、超纯N_2(99.999 9%)及空气三种气氛中退火,结果发现在空气中退火的Pt薄膜电阻率最小,原因是空气中的氧元素在高温下穿过Pt薄膜扩散至Ta粘附层,形成了稳定的Ta_2O_5相,Ta元素向Pt薄膜的扩散减少。退火还提升了薄膜电阻随温度变化的线性度及其电阻温度系数(TCR),在空气中900℃退火1 h,Pt薄膜的TCR达到3.909×10~(-3)/℃,接近于块状Pt材料的值。此结果对提高Pt薄膜温度传感器的灵敏度具有重要意义。     

RF磁控溅射法制备ZnO薄膜的XRD分析

采用RF磁控溅射法，在玻璃村底上制备多晶ZnO薄膜，并对所制备的ZnO薄膜在空气气氛中进行了不同温度（350～600℃）的退火处理和600℃时N2气氛中的退火处理。利用X射线衍射分析了溅射参数如溅射功率、溅射氧分压、衬底温度以及退火处理对ZnO薄膜结晶性能的影响。结果表明，合适的衬底温度和退火处理能够提高ZnO薄膜的结晶质量。     

溅射Cu-Zn-Sn金属预制层后硫(硒)化法制备Cu2ZnSn(SxSe1-x)4薄膜及其光伏特性

采用溅射工艺制备Cu-Zn-Sn金属预制层并尝试在多种退火方案(硫化退火、硒化退火、不同温度下硫化后硒化)下对其进行退火处理,探索出一种只需采用金属预制层即可完成CZTSSe制备的退火工艺制度。通过扫描电镜对比研究了不同退火制度下Cu_2ZnSn(S_xSe_(1-x))_4薄膜的形貌差异,发现低温硫化后硒化工艺可以有效减少因硫化温度过高引起的薄膜中孔洞较多的问题,有利于薄膜的平整与致密化。在此基础上,采用X射线荧光光谱、扫描电镜、X射线衍射及拉曼光谱对不同硫化温度(200℃、300℃、400℃、500℃)下硫化后硒化工艺制备的Cu_2ZnSn(S_xSe_(1-x))_4薄膜的成分、形貌、物相结构及结晶性能进行了表征和分析。结果表明,300℃下硫化后硒化获得的Cu_2ZnSn(S_xSe_(1-x))_4较其他温度下硫化后硒化获得的产物有着更好的形貌及结晶性能,其器件的光电转换效率为2.09%,远高于500℃下硫化后硒化工艺所得薄膜器件的效率(0.94%)。     

温度对Cu_2S薄膜结构及光学特性的影响

以CuCl_2·2H_2O和(NH_2)_2CS为前驱体,三乙醇胺为络合剂,利用化学浴沉积法于25℃到60℃务件下反应30min在玻璃衬底上沉积Cu_2S薄膜。利用X射线衍射仪(XRD)、原子力显微镜(AFM)、X射线光电子能谱仪(XPS)及紫外可见近红外分光光度计对样品的结构和光学特性进行研究。XRD结果显示所制备的薄膜为单斜晶相的Cu_2S,且沉积温度为40℃时所得薄膜结晶度最好。与Cu_2S本体相比,所制备的Cu_2S薄膜带隙出现不同程度的蓝移。结果表明,沉积温度对薄膜的结晶度、表面形貌以及光学性质有很大的影响。     

退火处理对TiO2薄膜结构和透射的影响

在常温下,采用射频反应磁控溅射方法在不同溅射功率下于K9双面抛光玻璃基底上制备二氧化钛薄膜.将制备的样品进行450℃退火6h热处理.利用X射线衍射仪(XRD)对比分析了退火前后薄膜的微观结构,采用光栅光谱仪测试了退火前后薄膜样品的透射谱.实验结果表明,退火前薄膜样品是非晶态,退火后薄膜晶化为晶态,但不同溅射功率下制备的薄膜结晶取向有差异;退火热处理对薄膜的折射率有一定影响,表现为退火前后透射谱偏移.     

X-ray absorption spectroscopy study of thermally annealed Cu–Al–O thin films

Cu–Al–O thin films are deposited on (0001) sapphire substrates by radio-frequency sputtering using an Al–Cu mosaic target. The Cu/Al atomic ratio of as-deposited Cu–Al–O films is measured to be 1.1. After deposition, the Cu–Al–O films are annealed at 600, 800, and 1000 °C, respectively, for 1 h in a N₂ atmosphere. The film crystal structure, electronic structure, valence band, and electrical properties are studied. The as-deposited films are amorphous and films annealed at 600 °C contain the crystallized CuO phase; the structure becomes crystallized CuAlO₂ after annealing at 800 °C and 1000 °C. The 800 °C annealed film grows along the (00l) plane. The crystallization decreases with the growth of the (012) and (018) planes for films annealed at 1000 °C. The resistivity values of the 800 °C and 1000 °C annealed films were measured as 1.07 Ω-cm and 864.01 Ω-cm, respectively. The lower resistivity of the 800 °C annealed film is attributed to preferred (00l) growth orientation and a reduction of the energy band gap.     

Preparation and characterization of sputtered Cu films containing insoluble Nb

Copper films containing various amounts of insoluble Nb (up to 24.7 at.%) were prepared by r.f. magnetron sputtering. The crystallography and microstructure of the films were investigated for as-deposited and annealed Cu(Nb) thin films. Cu(Nb) thin films are found to consist of non-equilibrium supersaturated solid solution of Nb in Cu with a nanocrystalline microstructure. X-ray diffraction and scanning electron microscope analyses revealed a reduction in the grain sizes of the films with increasing Nb content in the films leading to a grain refinement. The electrical resistivity of as-deposited and annealed Cu(Nb) thin films is found to be low for an Nb content 2.7 at.%. Significant drops in the resistivity were observed for the high Nb contents after annealing at 530 °C which may be due to grain growth and formation of Nb-bearing phase in the film. Microhardness of the films was found to increase with the Nb concentration due to the combined effects of grain refinement and the solute strengthening of Nb.     

Chemical structure and electrical properties of sputtered HfO2 films on Si substrates annealed by rapid thermal annealing

The chemical structure and electrical properties of HfO₂ thin film grown by rf reactive magnetron sputtering after rapid thermal annealing (RTA) were investigated. The chemical composition of HfO₂ films and interfacial chemical structure of HfO₂/Si in relation to the RTA process were examined by X-ray photoelectron spectroscopy. Hf 4f and O 1s core level spectra suggest that the as-deposited HfO₂ film is nonstoichiometric and the peaks shift towards lower binding energy after RTA. The Hf-Si bonds at the HfO₂/Si interface can be broken after RTA to form Hf-Si-O bonds. The electrical characteristics of HfO₂ films were determined by capacitance-voltage (C-V) and current density-voltage (J-V) measurements. The results showed that the density of fixed charge and leakage current density of HfO₂ film were decreased after the RTA process in N₂ atmosphere.     

Opto-electronic properties of sputter-deposited Cu2O films treated with rapid thermal annealing

Cu₂O thin films were first deposited using magnetron sputtering at 200 °C. The samples produced were then annealed by a rapid thermal annealing (RTA) system at 550 °C in a protective atmosphere with or without the addition of oxygen. After annealing, various Cu₂O and CuO films were formed. These films were characterized, as a function of oxygen concentration in RTA, using UV-VIS photometer, four-point probe, and Hall measurement system. The results show that these Cu₂O thin films annealed at 550 °C with more than 1.2% oxygen added in the protective argon atmosphere would transform into the CuO phase. Apparently, the results of RTA are sensitive to the amount of oxygen added in the protective atmosphere. The resistivity of these Cu₂O thin films decreases with the increase in the oxygen amount in the annealing atmosphere, most likely due to the increase in carrier mobility. In addition, Cu₂O/ZnO (doped with AlSc) junctions were produced at 200 °C and annealed. The rectifying effect of P-N junction disappeared after annealing, probably due to the damage of p-n interface, which directly causes current leakage at the junction.     

The influences of rapid-thermal annealing on the characteristics of Sr0.6Ba0.4Nb2O6 thin film

The Sr0.6Ba0.4Nb2O6 (SBN) thin films were successfully prepared on Pt/Ti/Si and SiO2/Si/Al substrates and crystallized subsequently using rapid thermal annealing (RTA) process in ambient atmosphere for 1 min. The surface morphologies and thicknesses of as-deposited and annealed SBN thin films were characterized by field emission scanning electron microscopy, and the thickness was about 246 nm. As compared with the as-deposited SBN thin films, the RTA-treated process had improved the crystalline structures and also had large influence on the crystalline orientation. When the annealing temperatures increased from 700 degrees C to 900 degrees C, the diffraction intensities of (410) and (001) peaks apparently increased. Annealed at 900 degrees C, the (001) peak had the maximum texture coefficient and SBN thin films showed a highly c-axis (001) orientation. The influences of different RTA-treated temperatures on the polarization-applied electric field (P-E) curves and the capacitance-voltage (C-V) curves were also investigated.     

Effects of post-rapid thermal annealing on structural, electrical and optical properties of hydrogenated aluminum doped zinc oxide thin films

In this study, hydrogenated aluminum doped zinc oxide (HAZO) thin films were prepared by DC magnetron sputtering in different H₂/(Ar+H₂) volume ratio atmosphere. The effects of post-rapid thermal annealing (RTA) in Ar+8 % H₂ atmosphere on the structural, optical, and electrical properties of the thin films were investigated systematically. Results showed that the RTA treatment effectively improved the electrical conductivity of the HAZO thin films with small hydrogen content, due to the increase of the Hall mobility and the carrier concentration. The lowest resistivity of the HAZO thin film deposited in 8 % H₂ ratio atmosphere reached 6.3 × 10^?4 Ω cm after RTA. The improved electrical properties of the RTA-treated HAZO films were ascribed to the activation of Al dopants, the increase of oxygen vacancies and the desorption of negative charged oxygen species at the grain. These results implied that RTA process might be useful to fabricate high quality HAZO films with a low thermal budget.     

Optoelectronic properties of sputter-deposited Cu2O-Ag-Cu2O treated with rapid thermal annealing

Cu₂O and two types of Cu₂O-Ag-Cu₂O (CAC) multilayered thin films were deposited on glass substrates using DC-magnetron sputtering. For CAC films, the mass thickness of Ag layer was controlled at 3 nm. After deposition, some of these films were annealed using a rapid thermal annealing (RTA) system at 650 °C, in order to create embedded Ag particles. AC films were used to study the clustering effect of Ag in Ar atmosphere, as well as for forming the 2nd type of CAC film by covering another Cu₂O layer on the annealed AC structure. A UV-VIS-NIR photometer, a Hall measurement system, and a I-V measurement system were used to characterize the optical and electrical properties of these films with and without RTA. The results show that 2-dimensional Ag layer can transform into many individual particles due to its high surface tension at annealing temperature, no matter when the annealing was carried out. For CAC films, without annealing, the optical transmission and the resistivity are decreased with the inserted Ag layer. After annealing, both the transmission and resistivity are increased, possibly due to the clustering effect of Ag layer. Most importantly, it is found that the embedded Ag particles can increase the light absorption in the NIR-IR region, which can increase photo-induced current.     

射频磁控溅射 Ba0.6Sr0.4TiO3薄膜表层的XPS研究

用射频磁控溅射在Pt／Ti／SiO2／Si基体上沉积Ba0．6Sr0．4TiO3（BST）薄膜，用X射线光电子能谱（XPS）研究BST薄膜表层在常规晶化和快速晶化条件下的结构特征．结果表明，常规晶化时，BST薄膜表层约3-5nm厚度内含有非钙钛矿结构的BST，随着温度的升高该厚度增加；快速晶化时，该厚度减薄至1nm内，随着温度的升高没有明显增加．元素的化学态分析结果表明，非钙钛矿结构的BST并非来自薄膜表面吸附的CO和CO2等污染物，而与表面吸附的其他元素（如吸附氧）对表层结构的影响有关．GXRD和AFM表明，致密的表面结构能有效的阻止表面吸附元素在BST膜体中的扩散，从而减薄含非钙钛矿结构层的厚度．     

Depth dependent properties of ITO thin films grown by pulsed DC sputtering

A systematically prepared set of ITO layers for solar cell applications has been analyzed by spectroscopic variable angle ellipsometry in order to trace the dependence of free carriers’ distribution along the film depth as a function of film thickness as well as its change upon annealing. Samples were deposited on silicon substrates with various thicknesses in steps of approximately 10–20 nm. This set was duplicated and these samples were annealed, so that for each thickness an as-deposited and an annealed sample is available. Conventionally measured electrical conductivity and morphological properties (AFM measurements) of the films have been compared with the optical constants’ inhomogeneity, i.e. material properties along the film thickness modelled by variable-angle spectroscopic ellipsometry. The obtained results show that the optical as well as electrical properties of thin ITO films prepared by pulsed DC sputtering are depth dependent. For the deposition conditions used a well-determined reproducible non-uniform distribution of free carriers within the film thickness was determined. In particular it has been found that the majority of free carriers in as-deposited ultra-thin ITO films is concentrated at sample half-depth, while their distribution becomes asymmetric for the thicker films, with a maximum located at approximately 40 nm depth. The distribution of free carriers in annealed samples is qualitatively different from that of as-deposited layers.