• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.23 no.10
• /
• pp.752-758
• /
• 2010

The etching characteristics of indium tin oxide (ITO) thin films in an $O_2/BCl_3/Ar$ plasma were investigated. The etch rate of ITO thin films increased with increasing $O_2$ content from 0 to 2 sccm in $BCl_3$/Ar plasma, whereas that of ITO decreased with increasing $O_2$ content from 2 sccm to 6 sccm in $BCl_3$/Ar plasma. The maximum etch rate of 65.9 nm/m in for the ITO thin films was obtained at 2 sccm $O_2$ addition. The etch conditions were the RF power of 500 W, the bias power of 200 W, the process pressure of 15 mTorr, and the substrate temperature of $40^{\circ}C$. The analysis of x-ray photo electron spectroscopy (XPS) was carried out to investigate the chemical reactions between the surfaces of ITO thin films and etch species.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.340-343
• /
• 2000

ITO(Indium Tin Oxide) films for transparent electrodes of FPD(Flat Panel Display) were patterned in atmosphere using laser. A pulse type(repetition rate of 10 Hz) Q-switched Nd:YAG laser which can generate the fundamental wavelength at 1064 nm or its harmonics(532, 266 nm) was used for Patterning of the ITO film. In case of using the second harmonic(532 nm) of Nd:YAG laser, the ITO film(thickness of 20 nm) was removed clearly with a laser fluence of 5.2 J/$\textrm{cm}^2$ and a beam scan speed of 200${\mu}{\textrm}{m}$/s. But the glass substrate was damaged when the laser fluence was over 5.2 J/$\textrm{cm}^2$. We discussed the etching mechanism of the ITO film using Nd:YAG laser with observation of the etching characteristics including a depths and widths of ITO films as a function of laser fluence using SEM(Scanning Electron Microscopy) and surface profiler($\alpha$-step 500).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.04a
• /
• pp.49-51
• /
• 2006

OLEOs was fabricated by PLD method. Wet etching process and plasma treatment of ITO on the glass were performed to extend the lifetime of the OLED and increase its brightness. The NPB, $Alq_3$, Li-Benzoate and AI layers on ITO pattern on the glass were deposited by PLO method, sequentially. When the etched ITO was treated by $O_2$ plasma with RF power of 50W, the best result was obtained. The lifetime of the OLED treated by $O_2$ plasma was extended from 3,770sec to 12,586sec compared to that without the plasma treatment.

• Journal of Korean Vacuum Science & Technology
• /
• v.3 no.1
• /
• pp.79-84
• /
• 1999

the photolithographic patterning on an indium-tin oxide (ITO) glass and the electro-phoretic deposition were combined for preparing the screen of the full-color field emission display(FED). the patterns with a pixel of 400$\mu\textrm{m}$ on the ITO-glass were made by etching the ITO with well-prepared etchant consisting of HCL, H2O, and HNO3. Electrophoretic method was carried out in order to deposit each spherical red (R), green(G), and blue (B) phosphor on the patterned ITO-glass. The process parameters such as bias voltage, salt concentration, and deposition time were optimized to achieve clear boundaries. It was found that the etching process of ITO combined with electrophoretic method was cost-effective, provided distinct pattern, and even reduced process steps compared with conventional processes. The application of reverse bias to the dormant electrodes while depositing the phosphors on the stripe pattern was found to be very critical for preventing the cross-contamination of each phosphor in a pixel.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1999.07a
• /
• pp.99-99
• /
• 1999

투명전도막인 Ito(Indium Tin Oxide)는 flat panel display 와 solar cell 같은 optoelectronic 이나 microelectronic device에서 널리 이용되어 지고 있다. 현재 상용화되고 있는 거의 대부분의 ITO 박막은 sputtering법에 의해 제조되고 있으나 공정상의 이유로 15$0^{\circ}C$이상의 기판온도가 요구되어진다. 그런, 실제 display device 제조공정에서는 비정질 실리콘 박막이나 유기막 위에 ITO박막을 제작할 필요성이 증대되어 지고 있고, 또한 다른 전자소자에 있어서도 상온 ITO 박막 형성 공정에 대한 필요성이 증대되고 있다. 이러한 이유로 본 실험에서는 IBAE(Ion Beam Assisted Evsporation)을 이용하여 저온 ITO박막을 유기막 위에 증착하는 공정에 대한 연구를 수행하였다. 이렇게 증착된 ITO 박막의 결정성은 비정질이었다. 또한, 모든 display device 제작에는 식각공정이 필수인데 기존에 사용되고 있는 wet etching 법은 등방성 식각특성 때문에 미세 pattern 형성에 부적합？, 따라서 비등방성 식각에 용이한 plasma etching법을 사용하여 저온 증착된 ITO 박막의 식각특성을 알아보았다. 실험에 사용된 식각장비는 자장 강화된 유도결합형 플라즈마 식각장비(MEICP)를 사용하였으며, 13.56MHz의 RF power를 사용하였다. 식각조건으로 source power는 600W~1000W, 기판 bias boltage는 -100V~-250V를 가하였으며, Ar, CH4, O2, H2, BCl3의 식각 gases, 5mTorr~30mTorr의 working pressure 변화 그리고 기판 온도에 따른 식각특성을 관찰하였다. ITO 가 증착된 기판으로는 유기물 중 투명전도성 박막에 기판으로서 사용가능성이 클 것으로 기대되어지는 PET(polyethylene-terephtalate), PC(polycarbonate), 아크릴을 사용하여 기판 변화가 식각특성에 미치는 영향에 대해서 각각 관찰하였다. 식각속도의 측정은 stylus profiler를 이용하여 측정하였으며 식각후에 표면상태는 scanning electron spectroscopy(SEM)을 이용하여 관찰하였다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2000.01a
• /
• pp.85-87
• /
• 2000

In this study, high-density plasma etching characteristics of ITO(indium tin oxide) films used for transparent electrodes in display devices have been investigated. The etch characteristics of ITO as a function of $Ar/CH_4$ gas mixtures were analyzed using QMS(quadrupole mass spectrometry), OES(optical emission spectroscopy), and ESP(electrostatic probe). ITO etch rates were increased with the addition of moderate amount of $CH_4$ to Ar due to the increased chemical reaction between $CH_3$ or H and ITO in addition to the physical sputtering of ITO by Ar ion bombardment. However, the addition of excess amount of $CH_4$ decreased the ITO etch rates possibly due to the increased polymer formation on the ITO surface. Also, the measurement data obtained by QMS and OES suggested that $CH_3$ radicals are more activity involved in the etching of ITO compared to H radicals.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.345-346
• /
• 2013

InGaN material is being studied increasingly as a prospective material for solar cells. One of the merits for solar cell applications is that the band gap energy can be engineered from 0.7 eV for InN to 3.4 eV for GaN by varying of indium composition, which covers almost of solar spectrum from UV to IR. It is essential for better cell efficiency to improve not only the crystalline quality of the epitaxial layers but also fabrication of the solar cells. Fabrication includes transparent top electrodes and surface texturing which will improve the carrier extraction. Surface texturing is one of the most employed methods to enhance the extraction efficiency in LED fabrication and can be formed on a p-GaN surface, on an N-face of GaN, and even on an indium tin oxide (ITO) layer. Surface texturing method has also been adopted in InGaN-based solar cells and proved to enhance the efficiency. Since the texturing by direct etching of p-GaN, however, was known to induce the damage and result in degraded electrical properties, texturing has been studied widely on ITO layers. However, it is important to optimize the ITO thickness in Solar Cells applications since the reflectance is fluctuated by ITO thickness variation resulting in reduced light extraction at target wavelength. ITO texturing made by wet etching or dry etching was also revealed to increased series resistance in ITO film. In this work, we report a new way of texturing by deposition of thickness-optimized ITO films on ITO nano dots, which can further reduce the reflectance as well as electrical degradation originated from the ITO etching process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.05a
• /
• pp.597-600
• /
• 1999

A solar cell conversion efficiency was degraded by grain boundary effect in polycrystalline silicon To reduce grain boundary effect, we performed a preferential grain boundary etching, POC$_3$ n-type emitter doping, and then ITO film growth on poly- Si. Among the various preferential etchants, Schimmel etch solution exhibited the best result having grain boundary etch depth higher than 10 ${\mu}{\textrm}{m}$. RF magnetron sputter grown ITO films showed a low resistivity of 10$^{-4}$ $\Omega$ -cm and high transmittance of 85 %. With well fabricated poly-Si solar cells, we were able to achieve as high as 15 % conversion efficiency at the input power of 20 mW/$\textrm{cm}^2$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.5
• /
• pp.377-380
• /
• 2012

Laser direct patterning of indium tin oxide(ITO) is one of new methods of direct etching process to replace the conventional photolithography. A diode pumped Q-switched Nd:$YVO_4$ (${\lambda}$= 1,064 nm) laser was used to produce ITO electrode on various transparent oxide semiconductor films such as zinc oxide(ZnO). The laser direct etched ITO patterns on ZnO were compared with those on glass substrate and were considered in terms of the overlapping rate of laser beam. In case of the laser etching on double-layer, it was possible to obtain the higher overlapping rate of laser beam.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.222-225
• /
• 2008

We proposed the dry etching process recipe for the fabrication of In-Ga-Zn-O (IGZO)-based oxide TFTs, in which the etching behaviors of IGZO films were systematically investigated when the etching gas mixtures and their mixing ratios were varied. Good device characteristics of the fabricated TFT were successfully confirmed.