• Journal of the Korean Physical Society
• /
• v.73 no.11
• /
• pp.1675-1678
• /
• 2018

Methylammonium lead halide ($MAPbI_3$) perovskites are considered as promising materials owing to their excellent optical and electrical properties. However, perovskite materials suffer from degradation in air, which limits their practical applications. Here, we demonstrate successful passivation of the $MAPbI_3$ photodetectors through monochloro-para-xylylene (Parylene-C) deposition. The time-dependent photocurrent characteristics were systematically investigated, and we achieved significantly improved device performance and stability with Parylene-C passivation. Based on the excitation-power-dependent photoluminescence (PL) data, we confirmed that Parylene-C can reduce the carrier losses in $MAPbI_3$, leading to the enhancement of photocurrent and PL in $MAPbI_3$ photodetectors.

• Journal of the Microelectronics and Packaging Society
• /
• v.24 no.3
• /
• pp.19-26
• /
• 2017

Stretchable deformation-resistance characteristics of Au, Pt, and Cu films were measured for the stretchable packaging structure where a parylene F was used as an intermediate layer between a PDMS substrate and a metal thin film. The 150 nm-thick Au and Pt films, sputtered on the parylene F-coated PDMS substrate, exhibited the initial resistances of $1.56{\Omega}$ and $5.53{\Omega}$, respectively. The resistance increase ratios at 30% tensile strain were measured as 7 and 18 for Au film and Pt film, respectively. The 150 nm-thick Cu film, sputtered on the parylene F-coated PDMS substrate, exhibited a very poor stretchability compared to Au and Pt films. Its resistance was initially $18.71{\Omega}$, rapidly increased with applying tensile deformation, and finally became open at 5% tensile strain.

• Applied Chemistry for Engineering
• /
• v.34 no.4
• /
• pp.383-387
• /
• 2023

The quartz crystal microbalance (QCM), commonly used in high vacuum deposition, becomes difficult to use when a thick film is deposited on the quartz, affecting the crystal's inherent vibration. In this study, a non-destructive optical measurement method was developed to measure the film's deposition rate during the in-situ film deposition process. By measuring the scattered laser intensity caused by the dimer in the parylene gas passing through the gas flow path, it was successfully confirmed that the ratio of the dimer in the parylene gas increases as the pyrolysis temperature decreases. Additionally, it was noted that the film's thickness and haze increase as the pyrolysis temperature decreases by confirming the characteristics of the visible parylene films. Through the research results, we aim to utilize the stable in-situ film deposition rate measurement system to control the precise film deposition rate of parylene films.

• Proceedings of the Korean Ceranic Society Conference
• /
• 2003.04a
• /
• pp.35.2-35
• /
• 2003

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2018.06a
• /
• pp.126-126
• /
• 2018

최근 차세대 디스플레이인 flexible 하고 transparent 한 디스플레이 개발이 진행 중 이며, 이러한 디스플레이가 개발 되기 위해 백 플레인으로 사용되는 Thin Film Transistor (TFT) 또한 차세대 디스플레이 못지 않게 연구가 진행 되고 있다. 기존의 무기물을 기반으로 하고 Rigid한 TFT는 현재 많은 곳에 적용이 되어 사람들이 사용 하고 있다. 하지만 이미 시장은 포화상태이며 차세대 디스플레이 컨셉인 flexible 하고 투명한 것과 맞지 않는다. 그래서 유연하며 투명한 특성을 가진 TFT에 대한 연구가 활발히 진행 되고 있으며 많은 성과를 이루었다. 이러한 소자를 이용하여 훗날 Electronic-skin(e-skin)이라 부르는 전자 피부를 활용하여 실시간 모니터링 할 수 있는 헬스 케어 분야 등에 활용 가치 또한 높다. 현재 유연하며 투명한 기판 및 물질 개발에 많은 연구 개발이 진행 되고 있다. 하지만 유연한 기판을 사용하여 TFT를 제작한 후 stress나 bending에 대한 내구성과 안정성, 신뢰성 등이 무기물을 기반으로 한 TFT에 비해 좋지 않은 실정이다. 따라서 유연하며 투명한 기판을 사용한 TFT에 대한 안정성, 신뢰성 등을 확보하여야 한다. 본 연구 에서는 유연한 기판을 사용하여 TFT를 제작 한 후, TFT특성과 안정성을 확보하는 것을 목표로 실험을 진행하였다. 우리는 Mo전극과 Parylene 기판을 사용하여 유연한 TFT소자를 탑 게이트 구조로 제작 하였고 Rigid한 Glass기판 위에 Floating Process를 진행하기 위해 PVA층을 코팅 후 그 위에 Parylene을 CVD로 증착 하고 IGZO를 Sputter를 사용해 증착했다. Parylene은 DI Water 70도에서 Floating 공정을 통해 Rigid 기판에서 탈착 시켰다. 유연한 기판 위에 TFT를 제작 후 bending에 대한 특성 변화 및 안정성에 대한 측정을 실시하였다. Bending에 대한 특성 변화는 우수한 결과가 나왔지만 안정성 측정 중 Negative Bias Stress(NBS) 상에서 비정상적인 On Current Drop 현상이 발생 되었다. Parylene과 Channel층 사이 interface roughness로 인해 charge trap이 되고 이로 인해 On Current Drop 이라는 현상으로 나타났다. 그래서 우리는 Parylene 기판과 Channel 층간의 surface roughness를 개선하기 위한 방법으로 UV Treatment를 사용하였고 시간을 다르게 하여 surface 개선을 진행했다. Treatment 시간을 증가 시킴에 따라 Surface roughness가 많이 좋아 졌으며, Surface를 개선하고자 비정상적인 On Current Drop 현상이 없어졌으며 위 실험으로 Polymer의 surface roughness에 따라 TFT에 대한 안정성에 대한 신뢰성이 확보 될 수 있는 것을 확인 하였다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.669-672
• /
• 2004

The thin-film passivation technology using the poly-para-xylylene (parylene) was applied to polymer electroluminescent devices. The fabricated device shows a good luminescent characteristic of maximum 11640 cd/$m^2$. The measured lifetime was reached up to 28 hours, which means the effectiveness of the passivation. Applying the parylene thin-film passivation technique, 10${\times}$10 passive matrix display system was implemented and obtained some still images.

• Transactions on Electrical and Electronic Materials
• /
• v.9 no.4
• /
• pp.156-162
• /
• 2008

We report results on a study of inductively coupled plasma (ICP) etching of Parylene-C (poly-monochloro-para-xylylene) films using an $O_2$ gas. Effects of process parameters on etch rates were investigated and are discussed in this article from the standpoint of plasma parameter measurements, performed using a Langmuir probe and modeling calculation. Process parameters of interest include ICP source power and pressure. It was shown that major etching agent of polymer films was oxygen atoms O($^3P$). At the same time it was proposed that positive ions were not effective etchant, but ions played an important role as effective channel of energy transfer from plasma towards the polymer.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.4
• /
• pp.721-726
• /
• 2017

We fabricated stretchable thin-film transistors(TFTs) on a polydimethylsiloxane substrate with patterned polyimide island structures by using an amorphous InGaZnO semiconductor and parylene gate insulator. The TFTs exhibited a field- effect mobility of $5cm^2V^{-1}s^{-1}$ and a current on/off ratio of $10^5$ at a relatively low operating voltage. Furthermore, the fabricated transistors showed no noticeable changes in their electrical performance for large strains of up to 50 %.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.357-358
• /
• 2011

Dichloro-(2,2)-paracyclophane을 출발 물질로 하여 화학기상증착법(CVD)을 이용해 우수한 투명성과 수분 투과성을 갖는 poly(p-xylylene) 코팅 막을 얻었다. 상기 코팅 막을 얻기 위한 최적의 공정 조건은 Deposition Pressure 0.02~0.04Torr, Vaporization temperature $110{\sim}150^{\circ}C$으로 확인 되었다. 이러한 공정 조건으로 500 mm*500 mm size의 PET bare film을 코팅 기재로 사용하여 $10{\mu}m$, $20{\mu}m$의 parylene 코팅 막을 얻었고 이를 특성 분석해 보았다. 상기 코팅 막은 전체적으로 ${\pm}1{\mu}m$의 thickness uniformity가 관찰 되었고 투과율은 90% 이상을 보였으며 수분 투과율은 기재 대비 상대적으로 40%의 향상이 기대 되었다. 또한 우수한 내식성, 내염기성, 내용제성을 갖고 있었으며 PET 기재에 대해 우수한 부착력을 가지고 있었다. surface morphology는 AFM을 통해 분석하였으며 Ra가 15.123, Rq가 22.859로 측정 되었다.

• Journal of the Korean institute of surface engineering
• /
• v.55 no.6
• /
• pp.390-397
• /
• 2022

Parylene-C which was mainly used for industries such as electronics, machinery and semiconductors has recently been in the spotlight in the medical field due to its properties such as corrosion resistance and biocompatibility. In this study we intend to derive a plan to improve the bonding strength of Parylene-C coating with the SUS304 base material for medical use which can be applied to various medical fields such as needles, micro needles and in vitro diagnostic device sensors. Through plasma pretreatment the bonding strength between Parylene-C and metal materials was improved. It was confirmed that the coated surface was hydrophobic by measuring the contact angle and the improvement of the surface roughness of the sample manufactured through CNC machining was confirmed by measuring the surface roughness with SEM. Through the above results, it is thought that it will be effective in increasing usability and reducing pain in patients by minimizing friction when inserting medical devices and in contact with skin. In addition it can be applied to various application fields such as human implantable stents and catheters, and is expected to improve the performance and lifespan of medical parts.