A REVIEW OF LAST DEVELOPMENTS IN THIN FILMS PARAMETERS OF DIRECT CURRENT SPUTTERING FOR OPTICAL AND BIOMEDICAL APPLICATIONS

Nano thin films and nano coating have been applied in different fields in health care system because of their higher antiviral properties. Additionally, as the world have suffered since December 2019 from Covid-19 situation, different scientists and industrials people have tried to apply nano antiviral films and coatings in our daily life. In this short review, nano thin film coating procedure by DC sputtering technique has been reviewed, investigated, and evaluated by using different materials and device parameters in recent years. This report focuses on device factors that affect the thickness of nano-thin films for optical and optic-electric applications. These parameters including time, temperature, power, pressure, and flow rate of gases. The review provides more understanding meaning of the coating procedure by DC sputtering process.

THE EFFECT OF RATIO OF GAS MIXTURE FOR MECHANICAL PROPERTIES AND CRYSTAL STRUCTURES ON 316L STAINLESS STEEL BIOMATERIAL USING DC SPUTTERING TECHNIQUE

316L stainless steel is widely used as an orthopedic implant due to its high corrosion resistance and biocompatibility, but the weakness of these materials is low hardness and high wear. The surface must be modified to improve the material. For the purpose, a titanium nitride (TiN) thin film was deposited on the surface of SS 316L using DC sputtering technique. The sputtering process was carried out for various of a gas mixture of argon (Ar) and nitrogen (N2) such as 90 Ar: 10N2, 80 Ar: 20 N2, 70 Ar: N2, and 60 Ar: 40 N2, while the other parameters kept constant. The objective of the gas mixture variation is to find out the optimum condition of ratio Ar: N2 gas mixture with the highest hardness and lowest wear resistance. From experiment done it’s found that the highest hardness in order of 232.02 VHN, while before being coated the hardness is 133.61 VHN, or there is an increasing hardness by factor 1.73, while the wear resistance reduces from 11.6 × 10-8 mm2/kg to 1.17 × 10-8 mm2/kg or there is reducing in wear resistance by factor 9.9. The optimum conditions were achieved at Ar: N2 ratio = 70:30. From XRD analysis, it can be concluded that the crystal structure of TiN thin film is cubic with the peaks (111), (200), (202), (311) and (222). From cross-section microstructure analysis using Scanning Microscope Electron (SEM), it’s found the thickness of the thin film is 744 nm.

Utilization and Measurements of Ferric Oxide thin films as a Nitride Dioxide gas sensor

In this work, we investigate and revealed a (NO2) gas sensing properties of Ferric oxide (Fe2O3) thin films prepared using magnetron DC- sputtering technique, using different thicknesses concurring various deposition times. Each film tested with different sample temperature (200, 250 and 300) oC in order to enhance gas sensitivity. The results reveal that the sensitivity increase as the film thickness decrease (lower grain size) the film gas sensitivity increases, and the gas sensitivity increase also with increasing the operating temperature.

Temperature Dependent Current-Voltage Characteristics of Pt/MoS2 Schottky Junction

Molybdenum disulphide (MoS2) is one of the transition metal dichalcogenide (TMD) materials which has attracted attention due to its various interesting properties. MoS2 is very promising for electronic and optoelectronic devices due to its indirect band gap (∼1.2 eV) for few layer and direct band gap (∼1.8 eV) for monolayer MoS2. In MoS2 based Schottky devices, Schottky barrier height depends on the thickness of MoS2 because of its tunable electronic properties. Here, we have used DC sputtering technique to fabricate metal-semiconductor junction of MoS2 with platinum (Pt) metal contacts. In this work, MoS2 thin film (∼10 nm) was deposited on p-Silicon (111) using DC sputtering technique at optimized parameters. Schottky metallization of Pt metal (contact area ∼ 0.785x10-2 cm2) was also done using DC sputtering. Current-voltage (I-V) characteristics of the Pt/MoS2 Schottky junction have been investigated in the temperature range 80-350K. Forward I-V characteristics of Pt/MoS2 junction are analysed to calculate different Schottky parameters. Schottky barrier height increases and ideality factor decreases on increasing the temperature from 80-350K. The I-V-T measurements suggest the presence of local inhomogeneities at the Pt/MoS2 junction. Schottky barrier inhomogeneities occur in case of rough interface. In such cases, the Schottky barrier height does not remain constant and vary locally. Current transport through the Schottky junction is a thermally activated process. As temperature increases, more and more electrons overcome the spatially inhomogeneous barrier height. As a result, the ideality factor becomes close to unity and apparent barrier height increases due to increase in temperature.