• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 추계학술대회 논문집
• /
• pp.498-501
• /
• 2005

Photonic crystals, periodic structure with a high refractive index contrast modulation, have recently become very interesting platform for manipulation of light. The existence of a photonic bandgap, a frequency range in which propagation of light is prevented in all direction, makes photonic crystal very useful in application where spatial localization of light is required for waveguide, beam splitter, and cavity. But fabrication of 3 dimensional photonic crystal is still difficult process. a concept that has recently attracted a lot of attention is a planar photonic crystal based on a dielectric membrane, suspended in the air, and perforated with 2 dimensional lattice of hole. We show that the polymer slabs suspended in air with triangular lattice of air hole can exhibit the in-plane photonic bandgap for TE-like modes. The fabrication of Si master with pillar structure using hot embossing process was investigated for 2 dimensional low-index-contrast photonic crystal waveguide.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2007년도 추계학술발표대회 및
• /
• pp.138.2-138.2
• /
• 2007

• 한국전기전자재료학회논문지
• /
• 제32권5호
• /
• pp.357-360
• /
• 2019

We demonstrate an alignment technology using an imprinting process on an inorganic NiOx film. The aligned nanopattern was fabricated on a silicon wafer by laser interference lithography. The aligned nano pattern was then imprinted onto the sol-gel driven NiOx film using an imprinting process at an annealing temperature of $150^{\circ}C$. After the imprinting process, parallel grooves had been formed on the NiOx film. Atomic force microscopy and water contact angle measurements were performed to confirm the parallel groove on the NiOx film. The grooves caused liquid crystal alignment through geometric restriction, similar to grooves formed by the rubbing process on polyimide. The liquid crystal cell exhibited a pretilt angle of $0.2^{\circ}$, which demonstrated homogeneous alignment.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
• /
• pp.534-537
• /
• 2007

To promote liquid crystal application of nanoimprint lithography, a polymer with new concept is proposed. The material consists of a polyamic acid for good LC alignment and an epoxy resin for good imprinting. The result of sum-frequency generation (SFG) vibrational spectroscopy proves that this material is a functionally gradient material. This material shows excellent capability as a nanoimprinting material as well as an LC alignment layer.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회A
• /
• pp.1934-1938
• /
• 2008

Formation of air bubble is the one of common defects in UV nano imprint lithography. Location of dispensing and volume of droplets are among the most important parameters in the process. ]n this study, UV curable resin droplets with different volumes were dispensed at different locations and pressed to investigate air bubble formation. By varying volume of droplet and dispensing location, process conditions were found for minimum air bubble area.

• Macromolecular Research
• /
• 제13권5호
• /
• pp.435-440
• /
• 2005

This study describes a method where the match of two different length scales, i.e., the patterns from self-assembled block copolymer (<50 nm) and electron beam writing (>50 nm), allow the nanometer scale pattern mask. The method is based on using block copolymers containing a poly(methyl methacrylate) (PMMA) block, which is subject to be decomposed under an electron beam, as a pattern resist for electron beam lithography. Electron beam on self assembled block copolymer thin film selectively etches PMMA microdomains, giving rise to a polymeric nano-pattern mask on which subsequent evaporation of chromium produces the arrays of Cr nanoparticles followed by lifting off the mask. Furthermore, electron beam lithography was performed on the micropatterned block copolymer film fabricated by micro-imprinting, leading to a hierarchical self assembled pattern where a broad range of length scales was effectively assembled, ranging from several tens of nanometers, through submicrons, to a few microns.

• 한국진공학회지
• /
• 제13권1호
• /
• pp.39-45
• /
• 2004

UV-나노임프린팅 (Ultraviolet-Nanoimprinting Lithography:UV-NIL) 공정 기술은 수십 나노에서 수 나노미터 크기의 구조물을 적은 비용으로 대량생산 할 수 있다는 장점을 가지고 있는 기술로 최근 전세계적으로 연구가 활발히 진행되고 있다. 본 연구에서는 반도체 공정 중 마스크 제작 공정을 이용하여 나노패턴을 가진 5${\times}$5${\times}$0.09 인치 크기의 수정스탬프(quartz stamp)를 제작하였고, 임프린팅 (imprinting)시에 레지스트(resist)와 스탬프(stamp) 사이에서 발생하는 점착현상(adhesion)을 방지하고자 그 표면에 Fluoroalkanesilane(FAS) 표면처리를 하였다. 웨이퍼의 평탄도를 개선하고 친수(hydrophilic) 상태의 표면을 만들기 위해 그 표면에 평탄화층을 스핀코팅하였고, 1 nl의 분해능을 가진 디스펜서(dispenser)를 이용하여 레지스트 액적을 도포하였다. 스템프 상의 패턴과 레지스트에 임프린트된 패턴은 SEM, AFM 등을 이용하여 측정하였으며, EVG620-NIL 장비를 이용한 임프린팅 실험에서 370 nm - 1 um 크기의 다양한 패턴을 가진 스탬프의 패턴들이 정확하게 레지스트에 전사됨을 확인하였다.

• 한국정밀공학회지
• /
• 제21권6호
• /
• pp.153-159
• /
• 2004

In this study, a new process to pattern directly on a thin metal layer using improved nano replication printing (nRP) process is suggested to evaluate the possibilities of fabricating a stamp for nano-imprinting. In the nRP process, any figure can be replicated from a bitmap figure file in the range of several micrometers with nano-scaled details. In the process, liquid-state resins are polymerized by two-photon absorption which is induced by femto-second laser. A thin gold layer was sputtered on a glass plate and then, designed patterns or figures were developed on the gold layer by newly developed top-down building approach. Generally, stamps fur nano-imprinting have been fabricated by using the costly electron-beam lithography process combined with a reactive ion-etching process. Through this study, the effectiveness of the improved nRP process is evaluated to make a stamp with the resolution of around 200nm with reduced cost.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2007년도 추계학술발표대회 및
• /
• pp.26.2-26.2
• /
• 2007

• 반도체디스플레이기술학회지
• /
• 제9권4호
• /
• pp.19-23
• /
• 2010

Nanoimprint lithography (NIL) is one of the most versatile and promising technology for micro/nano-patterning due to its simplicity, high throughput and low cost. Recently, one of the major trends of NIL is large-area patterning. Especially, the research of the application of NIL to TFT-LCD field has been increasing. Technical difficulties to keep the uniformity of the residual layer, however, become severer as the imprinting area increases. In this paper we performed a numerical study for a large area NIL (the $2^nd$ generation TFT-LCD glass substrate ($370{\times}470$ mm)) by using finite element method. First, a simple model considering the surrounding wall was established in order to simulate effectively and reduce the computing time. Then, the volume of fluid (VOF) and grid deformation method were utilized to calculate the free surfaces of the resist flow based on an Eulerian grid system. From the simulation, the velocity fields and the imprinting pressure during the filling process in the NIL were analyzed, and the effect of the surrounding wall and the uniformity of residual layer were investigated.