Stoichiometry control mechanisms for bias-sputtered zinc-oxide thin films

1985 ◽  
Vol 63 (6) ◽  
pp. 819-825 ◽  
Author(s):  
M. J. Brett ◽  
R. R. Parsons
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Rf Discharge ◽  
Control Mechanisms ◽  
Transparent Conducting ◽  
Self Bias ◽  
Planar Magnetron ◽  
Stoichiometry Control ◽  
Excess Zinc ◽  
Reactive Gas

We have deposited transparent, conducting ZnO thin films of resistivity 3 × 10−3 Ω∙cm by the technique of DC planar-magnetron sputtering in a reactive Ar–O2 atmosphere, incorporating a reactive gas baffle and substrate RF discharge. The substrate discharge was found to increase the oxygen content of the growing film. Films at low values of the RF-induced substrate self-bias voltage were characterized by a brown colour, resistivities of about 4 × 10−2 Ω∙cm, and composition ZnO0.8. Films at higher bias voltages of −80 V were clear with resistivities of 3 × 10−3 Ω∙cm and a composition approaching stoichiometric ZnO. The oxidation of the films by the RF discharge was shown to occur through preferential resputtering and re-evaporation of excess zinc and by activation and ion-plating of oxygen species. Resputtering and re-evaporation rates were found to be enhanced above that expected for bulk Zn, owing to the loosely bound nature of surface adatoms during film growth.

Tailored electric and optical properties of Nd doped ZnO: from transparent conducting oxide to photon down-shifting thin films

RSC Advances ◽  
2016 ◽  
Vol 6 (47) ◽  
pp. 41465-41472 ◽  
Author(s):  
M. Nistor ◽  
L. Mihut ◽  
E. Millon ◽  
C. Cachoncinlle ◽  
C. Hebert ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Film Growth ◽  
Transparent Conducting Oxide ◽  
Transparent Conducting ◽  
Tunable Properties ◽  
Doped Zno

Tunable properties from transparent conducting to photon down-shifting are obtained with slight change in O2 pressure during Nd:ZnO film growth.

The Origin of Stress in Co-Cr Alloy Thin Films Deposited by Magnetron Sputtering

1991 ◽  
Vol 239 ◽  
Author(s):  
Zhi-Feng Zhou ◽  
Yu-Dian Fan
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Growth Process ◽  
Film Growth ◽  
Perpendicular Magnetic Recording ◽  
Glass Substrates ◽  
Planar Magnetron ◽  
Film Substrate ◽  
Defect Elimination ◽  
Deposition Conditions

ABSTRACTCo-Cr alloy thin films are considered as an applicable perpendicular magnetic recording medium, and their mechanical properties such as internal stress can not be neglected. In this experiment, Co-Cr films are deposited on glass substrates by D. C planar magnetron sputtering, and the effects of film thickness, Ni-Fe underlayer as well as substrate temperature on the stress are studied respectively. The stresses are all tensile in all cases, and the stress existing at the film-substrate interface is very small. According to the above experimental results and the structure analysis of the films, the atomic peening effect produced by the rebounded working gas atoms can be negligible, and the stress is thought to originate from the film growth process but not from the inter-facial effect. Therefore, the structural defect elimination model is proposed (here the defects mainly include vacancies and grain boundaries). With this model, the origin of the tensile stress as well as the relations between the stress and the deposition conditions are explained qualitatively.

Preparation of Planview TEM Samples of Yba2Cu307−x Films Grown on BaF2(001)

1991 ◽  
Vol 254 ◽  
Author(s):  
Yang Li ◽  
Zhang Jinlong ◽  
Fan Chenggao ◽  
Zhang Yuheng
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Magnetron Sputtering ◽  
Transmission Electron Microscope ◽  
Film Growth ◽  
Ybco Thin Film ◽  
Transmission Electron ◽  
Planar Magnetron ◽  
Fringe Patterns

AbstractA method for the preparation of planview transmission electron microscope (TEM) specimens of expitaxial Yba2Cu3O7−x (YBCO) thin films deposited on BaF2 by a dc modified planar magnetron sputtering technique is reported. The films are granular with their grains size ranging from a few hundred to a few thousand nanometers. The epitactic nature of the film growth is shown by analyses of moiré fringe patterns and by selected area diffraction methods. It is demonstrated that the YBCO thin film obtained is highly c-axis oriented, with misorientation corresponding to rotations of 9.2° and 90° about the c-axis. Additionally, the film's a or b axes form a 45° angle with that of the substrate.

scholarly journals Epitaxial Growth and Stoichiometry Control of Ultrawide Bandgap ZnGa2O4 Films by Pulsed Laser Deposition

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 782
Author(s):  
Liu Wang ◽  
Wenrui Zhang ◽  
Ningtao Liu ◽  
Tan Zhang ◽  
Zilong Wang ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Pulsed Laser Deposition ◽  
High Performance ◽  
Film Growth ◽  
Growth Parameters ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Stoichiometry Control ◽  
Ultraviolet Photodetectors

ZnGa2O4 is a promising semiconductor for developing high-performance deep-ultraviolet photodetectors owing to a number of advantageous fundamental characteristics. However, Zn volatilization during the ZnGa2O4 growth is a widely recognized problem that seriously degrades the film quality and the device performance. In this study, we report the synthesis of epitaxial ZnGa2O4 thin films by pulsed laser deposition using a non-stoichiometric Zn1+xGa2O4 target. It is found that supplementing excessive Zn concentration from the target is highly effective to stabilize stochiometric ZnGa2O4 thin films during the PLD growth. The influence of various growth parameters on the phase formation, crystallinity and surface morphology is systematically investigated. The film growth behavior further impacts the resulting optical absorption and thermal conductivity. The optimized epitaxial ZnGa2O4 film exhibits a full width at half maximum value of 0.6 degree for a 120 nm thickness, a surface roughness of 0.223 nm, a band gap of 4.79 eV and a room-temperature thermal conductivity of 40.137 W/(m⋅K). This study provides insights into synthesizing epitaxial ZnGa2O4 films for high performance optoelectronic devices.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

Quantitative Image Analysis of Fractal-like Thin Films of Organic Semiconductors

2018 ◽  
Author(s):  
Weikun Zhu ◽  
Erfan Mohammadi ◽  
Ying Diao
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Image Analysis ◽  
Fractal Dimension ◽  
Organic Semiconductors ◽  
Film Growth ◽  
Electronic Device ◽  
Significant Control ◽  
Semiconductor Thin Films ◽  
Two Parameters

Morphology modulation offers significant control over organic electronic device performance. However, morphology quantification has been rarely carried out via image analysis. In this work, we designed a MATLAB program to evaluate two key parameters describing morphology of small molecule semiconductor thin films: fractal dimension and film coverage. We then employ this program in a case study of meniscus-guided coating of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C<sub>8</sub>-BTBT) under various conditions to analyze a diverse and complex morphology set. The evolution of morphology in terms of fractal dimension and film coverage was studied as a function of coating speed. We discovered that combined fractal dimension and film coverage can quantitatively capture the key characteristics of C<sub>8</sub>-BTBT thin film morphology; change of these two parameters further inform morphology transition. Furthermore, fractal dimension could potentially shed light on thin film growth mechanisms.

scholarly journals Stoichiometry control and electronic and transport properties of pyrochlore Bi2Ir2O7 thin films

2018 ◽  
Vol 2 (11) ◽  
Author(s):  
W. C. Yang ◽  
Y. T. Xie ◽  
X. Sun ◽  
X. H. Zhang ◽  
K. Park ◽  
...  
Keyword(s):  
Thin Films ◽  
Transport Properties ◽  
Stoichiometry Control

scholarly journals Influence of Substrate Materials on Nucleation and Properties of Iridium Thin Films Grown by ALD

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 173
Author(s):  
Paul Schmitt ◽  
Vivek Beladiya ◽  
Nadja Felde ◽  
Pallabi Paul ◽  
Felix Otto ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Bulk Material ◽  
Atomic Layer ◽  
Substrate Material ◽  
Fused Silica ◽  
Silicon Wafers ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Influence Of Substrate

Ultra-thin metallic films are widely applied in optics and microelectronics. However, their properties differ significantly from the bulk material and depend on the substrate material. The nucleation, film growth, and layer properties of atomic layer deposited (ALD) iridium thin films are evaluated on silicon wafers, BK7, fused silica, SiO2, TiO2, Ta2O5, Al2O3, HfO2, Ru, Cr, Mo, and graphite to understand the influence of various substrate materials. This comprehensive study was carried out using scanning electron and atomic force microscopy, X-ray reflectivity and diffraction, four-point probe resistivity and contact angle measurements, tape tests, and Auger electron spectroscopy. Within few ALD cycles, iridium islands occur on all substrates. Nevertheless, their size, shape, and distribution depend on the substrate. Ultra-thin (almost) closed Ir layers grow on a Ta2O5 seed layer after 100 cycles corresponding to about 5 nm film thickness. In contrast, the growth on Al2O3 and HfO2 is strongly inhibited. The iridium growth on silicon wafers is overall linear. On BK7, fused silica, SiO2, TiO2, Ta2O5, Ru, Cr, and graphite, three different growth regimes are distinguishable. The surface free energy of the substrates correlates with their iridium nucleation delay. Our work, therefore, demonstrates that substrates can significantly tailor the properties of ultra-thin films.

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