• Journal of the Microelectronics and Packaging Society
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• v.25 no.2
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• pp.49-53
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• 2018

Recently, technologies for integrating various devices such as a flexible device, a transparent device, and a MEMS device have been developed. The key processes of heterogeneous device manufacturing technology are chip or wafer-level bonding process, substrate grinding process, and thin substrate handling process. In this study, the effect of Si substrate grinding process on the electrical properties of tin oxide thin films applied as transparent thin film transistor or flexible electrode material was investigated. As the Si substrate thickness became thinner, the Si d-spacing decreased and strains occurred in the Si lattice. Also, as the Si substrate thickness became thinner, the electric conductivity of tin oxide thin film decreased due to the lower carrier concentration. In the case of the thinner tin oxide thin film, the electrical conductivity was lower than that of the thicker tin oxide thin film and did not change much by the thickness of Si substrate.

• Korean Journal of Optics and Photonics
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• v.31 no.6
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• pp.321-327
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• 2020

We investigated the light reflection from thin films coated on substrates. Using a prism with a high refractive index as the incident medium, the phenomena of the total internal reflection (TIR) of the prism/film/substrate system and the light coupling into the optical waveguide formed by the air/film/substrate system were comprehensively studied and compared. If the refractive index of the thin film is greater than that of the substrate, within the TIR region of the substrate, sharp reflection minima occur at specific angles where the waveguide modes are excited, that can be used to accurately measure the refractive index and thickness of a thin film. On the other hand, if the refractive index of the thin film is smaller than that of the substrate, such waveguide modes do not exist. In this case, although not so distinct as a bulk medium, the TIR effect of the thin film is still observable, accompanied by an interference pattern. In this study we analyzed the overall reflection phenomena occurring from prism/film/substrate structures, to investigate the possibility of measuring the refractive index of a thin film in both cases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.330-333
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• 2002

The substrate temperature is an important parameter in thin film deposition process. In this paper the effects of the substrate temperature on the properties of CuIn0.75Ga0.25Se2(CIGS) thin films are reported. Structure, surface morphology and optical properties of CIGS thin films deposited at various substrate temperatures have been investigated using a number of analysis techniques. X-ray diffraction (XRD) analysis shows that CIGS films exhibit a strong <112> preferred orientation. As expected, at higher substrate temperatures the films displayed a higher degree of crystallinity. The <112> peak was also enhanced and other CIGS peaks appeared simultaneously These results were supported by experimental work using Raman spectroscopy. The Raman spectra of the as-grown CIGS thin films show only the Al mode peak. The intensity of this peak was enhanced at higher deposition temperatures. Scanning electron microscopy (SEM) results revealed very small grains in films fabricated at 48$0^{\circ}C$ substrate temperature. When the substrate temperature was increased the average grain size also increased together with a reduction in the number and size of the voids. The deposition temperature also had a significant influence on the transmission spectra.

• Korean Journal of Materials Research
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• v.17 no.4
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• pp.232-235
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• 2007

Indium tin oxide (ITO) films were deposited on polycarbonate CR39 substrate using DC magnetron sputtering. ITO thin films were deposited at room temperature because glass-transition temperature of CR39 substrate is $130^{circ}C$ ITO thin films are used as bottom and top electrodes and for organic thin film transparent transistor (OTFT). The electrodes electrical properties of ITO thin films and their optical transparency properties in the visible wavelength range (300-800 nm) strongly depend on the volume of oxygen percent. The optimum resistivity and transparency of ITO thin film electrode was achieved with a 75 W plasma power, 10 % volume of oxygen and a 27 nm/min deposition rate. Above 85% transparency in the visible wavelength range (300-800 nm) was measured without post annealing process, and resistivity as low as $9.83{\times}^{TM}10^{-4}{\Omega}$ cm was measured at thickness of 300 nm.

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.46-50
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• 2016

In this study, we have investigated the effect of the substrate temperature and hydrogen flow rate on the characteristics of IGZO thin films for the TCO(transparent conducting oxide). For this purpose, IGZO thin films were deposited by RF magnetron sputtering at room temperature and $300^{\circ}C$ with various $H_2$ flow rate. In order to investigate the influences of the hydrogen, the flow rate of hydrogen in argon mixing gas has been changed from 0.1sccm to 1.0sccm. IGZO thin films deposited at room temperature show amorphous structure, whereas IGZO thin films deposited at $300^{\circ}C$ show crystalline structure having an (222) preferential orientation. The electrical resistivity of the amorphous-IGZO films deposited at R.T. was lower than that of the crystalline-IGZO thin films deposited at $300^{\circ}C$. The increase of electrical resistivity with increasing substrate temperature was interpreted in terms of the decrease of the charge carrier mobility. The transmittance of the IGZO films deposited at $300^{\circ}C$ was decreased deposited with hydrogen gas.

• Journal of the Semiconductor & Display Technology
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• v.15 no.1
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• pp.1-5
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• 2016

In this study, we have investigated the effect of the substrate temperature on the characteristics of IGZO thin films for the TCO(transparent conducting oxide). For this purpose, IGZO thin films were deposited by RF magnetron sputtering at various substrate temperature (room temperature ${\sim}400^{\circ}C$). IGZO thin films deposited at room temperature show amorphous structure, whereas IGZO thin films deposited at $250^{\circ}C$ or more show crystalline structure having an (222) preferential orientation. The electrical resistivity of IGZO film increased with increasing temperature. The change of electrical resistivity with increasing temperature was mainly interpreted in terms of the charge carrier concentration rather than the charge carrier mobility. The electrical resistivity of the amorphous-IGZO films deposited at R.T. was lower than that of the crystalline-IGZO thin films deposited at $300^{\circ}C$. The transmittance of the IGZO films deposited at $300^{\circ}C$ was decreased deposited with hydrogen gas.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.422-426
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• 2003

Cu thin films of $6000{\AA}$ thickness were deposited by Electron Beam Evaporation(EBE) method on the glass. The resistivity properties and adhesion of Cu thin films were investigated by various annealing and substrate temperature. Cu thin films were annealed in the air and vacuum condition for 10 min after the deposition. The resistivity and adhesion(the force required to separate films from substrates) was measured by 4-point probe and scratch testing. The resistivity of non-annealing Cu thin films was distinguished more substrate temperature loot than substrate temperature R.T, $200^{\circ}C$. In the case of air condition annealing, as heating temperature was increased, the resistivity was decreased. In the case of vacuum condition annealing, the resistivity was increased at heating temperature $200^{\circ}C$. The best resistivity($1.72\;{\mu}{\Omega}{\cdot}cm$) of Cu thin films was obtained by the air condition heating temperature $200^{\circ}C$ at the substrate heating temperature $100^{\circ}C$. As a result of scratch testing, adhesion was increased by annealing. And maximum adhesion had 600 gf.

• Journal of the Korean Vacuum Society
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• v.8 no.3A
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• pp.194-200
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• 1999

In this paper studied was the piezoelectric properties of the $\beta$-PVDF organic thin films prepared by physical vapour deposition method. The molecular orientation of organic thin films was controlled by the application of an electric field and variation of substrate temperature during the evaporation process. Optimum conditions of manufacturing $\beta$-PVDF organic thin film by physical vapor deposition method is to keep at the substrate temperature of $80^{\circ}C$, at the applied electric field of 142.8 kV/cm. The voltage output coefficient increased from 1.39 to 7.04V increasing the force moment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.347-350
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• 2001

A typical Mold method is to form a gate electrode, a gate oxide, and emitter tip after fabrication of mold shape using wet-etching of Si substrate. In this study, however, new Mold method using a side wall space structure is used in order to make sharper emitter tip with a gate electrode. Using LPCVD(low pressure chemical vapor deposition), a gate oxide and electrode layer are formed on a Si substrate, and then BPSG(Boro phospher silicate glass) thin film is deposited. After, the BPSG thin film is flowed into a mold as high temperature in order to form a sharp mold structure. Next TiN thin film is deposited as a emitter tip substance. The unfinished device with a glass substrate is bonded by anodic bonding techniques to transfer the emitters to a glass substrate, and Si substrate is etched using KOH-deionized water solution. Finally, we made sharp field emitter array with gate electrode on the glass substrate.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.218.2-218.2
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• 2013

In this study, CdS thin films were deposited onto glass substrates by radio frequency magnetron sputtering. The films were grown at various substrate temperatures in the range of 100 to $250^{\circ}C$. The effects of substrate temperatures on the structural and optical properties were examined. The XRD analysis revealed that CdS films were polycrystalline and retained the mixed structure of hexagonal wurtzite and cubic phase. The percentages of hexagonal structured crystallites in the films were seen to be increased by increasing substrate temperatures. The film grown at $250^{\circ}C$ showed a relatively high transmittance of 80% in the visible region, with an energy band gap of 2.45 eV. The transmittance date analysis indicated that the optical band gap was closely related to the substrate temperatures.