• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.490-495
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• 1999

In 0.18 $\mu \textrm m$ LOGIC device, the etch rate of NMOS polysilicons is different from that of PMOS polysilicons due to the state of polysilicon to manufacture gate line. To control the etch profile, we tested the ratio of $Cl_2$/HBr gas and the total chamber pressure, and also we reduced Back He pressure to get the vertical profile. In the case of manufacturing the gate photoresist line, we used Bottom Anti-Reflective Coating (BARC) to protect refrection of light. As a result we found that $CF_4O_2$ gas is good to etch BARC, because of high selectivity and good photoresist line profile after etching BARC. in the results of the characterization of plasma damage to the antenna effect of gate oxide, NO type thin film(growing gate oxide in 0, ambient followed by an NO anneal) is better than wet type thin film(growing gate oxide in $0_2+H_2$ ambient).

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.237-242
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• 1998

A transparent and colorless $80SiO_2-20TiO_2$(mol%) thin films on soda-lime-silica slide glass and sapphire substrate were obtained by spin-coating technique using tetraethyl orthosilicate and titanium trichloride as starting materials. The prepared film annealed at $750^{\circ}C$ showed a high transmittance and a low reflectance. For the $SiO_2-TiO_2$ films on slide glasses, a strong interaction between the sodium ion and oxygens is properbly the origin of the good stability to the high temperature and the high humidity.

• Journal of the Korean Vacuum Society
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• v.21 no.1
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• pp.22-28
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• 2012

Transparent dye-sensitized solar cells have been widely investigated for the application to building integrated photovoltaic system. Thin film Si-based solar cells are emerging as a substitute for the dye-sensitized solar cells because their merits of well-established manufacturing processes. Since the selective transmitting layer transmits visible light and reflects infrared light, the solar cell efficiency increases with the introduction of the selective transmitting layer. In this work, AlTiO thin films were grown as the selective transmitting layer by cost-effective sputter deposition and their transmittances were improved by controlling deposition parameters.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.4
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• pp.281-286
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• 2019

Raman spectra of a-C:H thin films deposited with an unbalanced magnetron sputtering system showed that the G peak shifted to a higher wavenumber as the target power density increased and $I_D/I_G$ ratio increased from 0.902 to 1.012. Moreover, the transmittance of a-C:H films fabricated at 60 nm tended to decrease with increasing target power density; at 550 nm in the visible light region, the transmittance decreased from 69% to 58%. The rms surface roughness values of the a-C:H thin films decreased with increasing target power density, and varied from 1.11 nm to 0.71 nm. In order to achieve efficient light trapping, the light scattering at the rough interface must be enhanced. Consequently, the surface roughness of the thin film will decrease with the target power density. Further, the refractive index and reflectivity of the a-C:H thin films increased with increasing target power density; however, the Brewster angle decreased with the target power density. Hence, dye-sensitized solar cells using an a-C:H antireflective coating increased the CE, $V_{OC}$, and $J_{SC}$ by approximately 8.6%, 5.5%, and 4.5%, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.230-230
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• 2013

In amorphous or microcrystalline thin-film silicon solar cells, p-i-n structure is used instead of p/n junction structure as in wafer-based Si solar cells. Hence, these p-i-n structured solar cells inevitably consist of many interfaces and the cell efficiency critically depends on the effective control of these interfaces. In this study, in-situ plasma treatment process of the interfaces was developed to improve the efficiency of a-Si:H solar cell. The p-i-n cell was deposited using a single-chamber VHF-PECVD system, which was driven by a pulsed-RF generator at 80 MHz. In order to solve the cross-contamination problem of p-i layer, high RF power was applied without supplying SiH4 gas after p-layer deposition, which effectively cleaned B contamination inside chamber wall from p-layer deposition. In addition to the p-i interface control, various interface control techniques such as thin layer of TiO2 deposition to prevent H2 plasma reduction of FTO layer, multiple applications of thin i-layer deposition and H2 plasma treatment, H2 plasma treatment of i-layer prior to n-layer deposition, etc. were developed. In order to reduce the reflection at the air-glass interface, anti-reflective SiO2 coating was also adopted. The initial solar cell efficiency over 11% could be achieved for test cell area of 0.2 $cm^2$.

• Journal of Information Display
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• v.2 no.2
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• pp.52-60
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• 2001

The electrical and mechanical properties in indium-tin-oxide films deposited on polymer substrate were examined. The materials of substrates were polyethersulfone (PES) which have gas barrier layer and anti-glare coating for plastic-based devices. The experiments were performed by rf-magnetron sputtering using a special instrument and buffer layers. Therefore, we obtained a very flat polymer substrate deposited ITO film and investigated the effects of buffer layers, and the instrument. Moreover, the influences of an oxygen partial pressure and post-deposition annealing in ITO films deposited on polymer substrates were clarified. X-ray diffraction observation, measurement of electrical property, and optical microscope observation were performed for the investigation of micro-structure and electro-mechanical properties, and they indicated that as-deposited ITO thin films are amorphous and become quasi-crystalline after adjusting oxygen partial pressure and thermal annealing above $180^{\circ}C$. As a result, we obtained 20-25 ${\Omega}/sq$ of ITO films with good transmittance (above 80 %) of oxygen contents with under 0.2 % and vacuum annealing. Furthermore, using organic buffer layer, we obtained ITO films which have a rather high electrical resistance (40-45 ${\Omega}/sq$) but have improved optical (more than 85 %) and mechanical characteristics compared to the counterparts. Consequently, a prototype reflective color plastic film LCD was fabricated using the PES polymer substrates to confirm whether the ITO films could be realized in accordance with our experimental results.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.471-477
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• 2014

Purpose: We have analyzed the transmittance distribution of the ocular lens using local transmittance microscope to investigate the optical homogeneity of the lens. Methods: The transmittance of the laser which is focused on the surface of the ocular lens was measured by using the photo-detector and lock-in amplifier and analyzed. Multi-coated, uncoated, and progressive lenses were analyzed. Results: In the measurement of the progressive lens and a physical stimulated lens, local transmittance microscopy analysis showed a high degree of match with the measurement results through the optical microscope. In addition, the average value of the transmittance is reduced and the standard deviation was increased in the presence of optical defects. In unstimulated lens, there are a large impact on transmittance whether the anti-reflective coating is presence or absence in both the local transmittance microscopy and general transmittance analysis. Conclusions: The distribution of the transmittance measured by local transmission microscopy were changed when the various stimulus is applied to the lenses. These analyzes by local transmission microscopy can be utilized as a way to evaluate or determine the uniformity of the coating film or lens.

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.31-37
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• 2013

Lowering surface reflectance of Si wafers by texturization is one of the most important processes for improving the efficiency of Si solar cells. This paper presents the results on the effect of texturing using acidic solution mixtures containing the catalytic agents to moderate etching rates on the surface morphology of mc-Si wafer as well as on the performance parameters of solar cell. It was found that the treatment of contaminated crystalline silicon wafer with $HNO_3-H_2O_2-H_2O$ solution before the texturing helps the removal of organic contaminants due to its oxidizing properties and thereby allows the formation of nucleation centers for texturing. This treatment combined with the use of a catalytic agent such as phosphoric acid improved the effects of the texturing effects. This reduced the reflectance of the surface, thereby increased the short circuit current and the conversion efficiency of the solar cell. Employing this technique, we were able to fabricate mc-Si solar cell of 16.4% conversion efficiency with anti-reflective (AR) coating of silicon nitride film using plasma-enhanced chemical vapor deposition (PECVD) and Si wafers can be texturized in a short time.