Papers by Keyword: Substrate Bias Voltage

Abstract: The un-doped zinc oxide (ZnO) films on the polyethylene terephthalate (PET) substrate at a low temperature (<75°C) by using cathode vacuum arc deposition (CVAD) system with different negative substrate bias voltage applied between 0 and -100 V. The material, mechanical, optical and electrical properties were investigated and discussed. The results show that all ZnO thin films have (002) preferred orientation, an average transmittance was over than 70 % in the visible region. Calculated band gap values are all around 3.2 eV with the different substrate bias voltages. The ZnO thin films with resistivities as low as 10^-3 Ω*cm have been obtained by adjusting the substrate bias voltage on the plastic substrates.

Abstract: WS₂ soft coatings were deposited by medium-frequency magnetron sputtering, multi-arc ion plating and ion beam assisted deposition technique on the YT15 cemented carbide substrates. The influence of the substrate bias voltage on the coating properties has been studied. The coatings exhibited a dense and fine grained structure. WS₂ soft coatings with substrate bias voltage of -100 V revealed a better coating properties than other four samples, as the best crystallization of (002) preferred crystal orientation of Ⅱ texture, the most smooth and uniform microstructure of the coating, the largest critical load of 43.25 N and the largest coating thickness of 1.5 μm. But the microhardness of sample S1 was only 515.4 Hv. The critical load and the thickness of WS₂ coatings decreased firstly, then increased, and finally reduced with the increasement of substrate bias voltage. And the microhardness of the coatings decreased firstly, then increased, and decreased, finally increased with the increasement of substrate bias voltage.

Abstract: Ti containing hydrogenated diamond like carbon films (Ti-DLC) was deposited on Si substrates at room temperature by magnetron sputtering Ti-twin target in methane and argon mixture atmosphere via changing the substrate bias voltage. The Ti atomic concentration in the film is less than 0.57% and exists mainly in the form of metallic titanium rather than TiC, confirmed by XPS analysis. The internal compressive stress of the film decreases monotonically with the substrate bias voltage increase. However, the hardness values of the film keep at level (12 GPa) without almost any obvious change with the increase of the substrate bias voltage. Furthermore, Ti-containing DLC film prepared at -1600 V substrate bias voltage shows an extremely low wear rate (~10^-9 mm³/Nm) and low friction coefficient (0.09).

Abstract: Rutile TiO₂ films are normally used as biomaterial that synthesized on unheated stainless steel type 316L and glass slide substrates by dual cathode DC unbalanced magnetron sputtering. The influence of the substrate bias voltages (V_sb), from 0 V to-150V, on the structure of the as-deposited films was investigated. The crystal structure was characterized by grazing-incidence X-ray diffraction (GIXRD) technique, the films thickness and surface morphology was evaluated by atomic force microscopy (AFM) technique, respectively. The results show that the as-deposited films were transparent and have high transmittance in visible regions. The crystal structure of as-deposited films show the XRD patterns of rutile (110) with V_sb at 0V and shifted to rutile (101) with increasing V_sb. The films roughness (R_rms) and the thickness were 3.0 nm to 5.7 nm and 420 nm to 442 nm, respectively.

Abstract: Cr-Al-N coatings with the thickness of about 2 mm have been prepared in a magnetron sputtering system by reactive co-sputtering from a chromium target and an aluminum target in a mixed Ar/N₂ atmosphere. The effects of substrate negative bias voltage (VB) on the microstructure and critical failure load have been investigated by a scratch test as the VB varied from 0 to –150 V. The critical failure load reached the maximum value for the coating deposited under VB = –50 V, then decreased with VB further increasing. Re-sputter effect of The heavy bombardment of the ion to the substrate improve the critical failure load for the coating deposited under VB = –50 V. The decrease of the critical failure loads for the coatings deposited under –100V and –150 V probably resulted from the high microstrain in the crystal lattice.

Abstract: With the development of modern science and technology, the elements such as Al, Si, Mo, C, B will be doped into the TiN and CrN binary films to improve their properties. In this work, a series of Ti-X-N and Cr-X-N films were prepared under the various N2 partial pressures，bias voltages and substrate temperatures by reactive magnetron sputtering using the mosaic target and multi-targets systems. The composition, microstructure, mechanical properties and thermal stability of the films were investigated using EDS, XRD, XPS, AFM, nano-indentation, scratch and thermal stability test. The results indicated that the doping element content, microstructure and mechanical properties of the films can be easily regulated through the deposition parameters, such as the N2 partial pressure，bias voltages and so on. The superhard Ti-Si-N and Ti-Al-N films with the nanohardness of more than 40GPa can be achieved, especially when the lower N2 partial pressure is used.

Abstract: Cr-Al-N coatings with the thickness of about 2 μm have been prepared by a reactive magnetron sputtering method. The effects of substrate negative bias voltage (VB) on the microstructure and critical failure load have been investigated as the VB varied from 0 to –150 V. With VB increasing, grain size, lattice parameter and microstrain increase. (111) preferred orientation dominates in the coatings deposited under 0 and –50 V, while a (200) preferred orientation developed when VB further raised. The reasons for these variation caused by VB are discussed.

Abstract: c-BN film was synthesized using ME-ARE on Si substrate. The deposition process was optimized via the Taguchi method. The optimized conditions were as follows: substrate temperature, anode (plasma) current, Ar/N2 ratio, pulse frequency, duty frequency, bias voltage and deposition time were 500°C, 15A, 3, 1 kHz, 50%, -130V and 15 min, respectively. The crosssectional TEM observation revealed that the c-BN films with a thickness of 100nm ~300nm were composed of two layers, a columnar h-BN layer with a thickness of 30nm~40 nm normal to Si substrate and a c-BN structure.