Papers by Author: Jae Jong Lee

Paper TitlePage

Authors: Seung Woo Han, Ki Jeong Seo, Jae Jong Lee, Seung Woo Lee, Hak Joo Lee, Jung Yup Kim
Abstract: Nanoimprint lithography is a promising technology to produce sub-100 nm scale features on silicon chips. One of key issues in the nanoimprint lithography is how to make uniform contact between the stamp and the substrate on a large area. In this study a rubber membrane unit under substrate is introduced to resolve this problem. Two layers of membrane were designed to consider air flow in the middle of resist on a silicon wafer. The geometry design for accomplishing uniform contact was carried out using finite element analysis. The material modeling of hyperelastic properties of rubber is characterized by the Mooney-Rivlin strain energy functions. Material constants in the strain energy functions are able to be determined via the curve fitting of experimental stress-strain data. Simple tension and equi-biaxial tests were performed to determine the material constants. To evaluate the effects of a rubber membrane unit, nanoimprint lithography process with it was executed. We could confirm that a distinct improvement of uniform contact was shown and air flow problem was solved during the process.
Authors: Jae Jong Lee, Soo Yeon Park, Seung Woo Lee, In Deok Jeon
Abstract: The conducting polymer PAni is coated on Au electrode sample by spin coater on 500rpm and 3000rpm for 5sec and 30sec. Then, it was drying 10min at 180C. The layer thickness was 140~200nm. The electrodes were fabricated the resist pattern by electron beam writing machine which was performed on a Raith75 e-Line on the PMMA 950K, thickness 100nm. The electrodes were written at an electron does of 200uAs/cm2 and developed for 40sec in a 1:3 MIBK (methyl-isobutyl-ketone): IPA (isopropyl alcohol) solution. Metal lift-off of the PMMA in acetone was preceded by an e-beam evaporation consisting of 50Å Cr and 250Å Au. Electrical measurements were performed on low-noise commercial probe stations equipped. We measured distance between the electrodes ranges from a few tens of nanometer to hundreds nanometer by AFM (Atomic Force Microscopy) which was done with silicon tips in non-contact mode on a PSIA, XE-100.
Authors: Jae Jong Lee, Seung Woo Lee, Hyun Taek Cho, Gee Hong Kim, Kee Bong Choi
Abstract: The contact-based nanoimprinting lithography (NIL), such as thermal and/or UV nano-imprint, has been well known as one of the next generation lithography alternatives. Especially, the UV nanoimprinting lithography technology has the advantages in terms of process simplicity, low cost, high replication fidelity, and relatively high throughput. The UV nanoimprinting lithography tool is built with the characteristic functions like a self-alignment wafer stage, a nanoimprinting head unit, an alignment system for multi-layer process, stamp/wafer chucking units, releasing unit, and anti-vibration unit, etc. This UV-NIL tool is comprised of UV light source using mercury lamp, ultra-fine XY stage with nano-level positioning accuracy, and self-adjusting flexure stage. The self-adjusting stage has the capability to control 6- axes positions of wafer-holder. The UV-NIL tool can be used for fabrication of some functional nanostructure-patterns i.e. nanosensor electrodes, optical grating patterns and 70nm rectangle patterns.
Showing 1 to 3 of 3 Paper Titles