• Journal of the Speleological Society of Korea
• /
• no.77
• /
• pp.21-30
• /
• 2007

Photo-lithography lies in the middle of the wafer fabrication process. It is often considered as the most critical step in the IC process. We use a mask in exposure steps of the photo-lithography. Typically, 20 to 25 different levels of masks are required to complete an IC device. That means, if a photo process can be developed with the use of only one photo mask, we can reduce more process cost. To satisfy this, we plan to develop an alternative photo mask. For this reason, we chose to use a LCD. We expect to develop a LCD panel that can be changed by electrical control. This is the main idea about the adjustive photo mask. The Photo mask made of LCD panel will replace the former one.

• Korean Journal of Optics and Photonics
• /
• v.8 no.4
• /
• pp.345-352
• /
• 1997

Recently, in designing optical mask such as 4GDRAM, the scattering effect of electromagnetic wave must be considered. For this reason we claculated directly the mask function using the finite difference time domain(FDTD) method. The modification of image theory with this new mask function could explain clearly the scattering effect at the etched side wall of the submicron optical mask. The characteristics of the various type of alternating PSM were investigated. According to the simulation, the dual wet etch process was the most useful fabrication technique to overcoe the light scattering off at the shifted opening.

• Journal of the Semiconductor & Display Technology
• /
• v.3 no.2
• /
• pp.5-9
• /
• 2004

Microcircuit fabrication requires precise control of impurities in tiny regions of the silicon. These regions must be interconnected to create components and VLSI circuits. The patterns to define such regions are created by lithographic processes. In order to image features smaller than 70 nm, it is necessary to employ non-optical technology (or next generation lithography: NGL). One such NGL is extreme ultra-violet lithography (EUVL). EUVL transmits the pattern on the wafer surface after reflecting ultra-violet through mask pattern. If particles exist on the blank mask, it can't transmit the accurate pattern on the wafer and decrease the reflectivity. It is important to care the blank mask. We removed the particles on the wafer using focused ion beam (FIB). During removal, FIB beam caused damage the multi layer mask and it decreased the reflectivity. The relationship between particle removal and reflectivity is examined: i) transmission electron microscope (TEM) observation after particle removal, ii) reflectivity simulation. It is found that the image mode of FIB is more effective for particle removal than spot and bar mode.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.364-365
• /
• 2006

One of the promising routes for producing highly ordered nanostructures is a template method using the porous alumina membrane (PAM). Because the PAM is mechanically, chemically, thermally stabile with highly ordered structure, many researchers have studied under various experimental conditions to fabricate nanostructures. We present the information on the fabrication of about 300 nm nano-mask which have important applications for various patterned nanostructures.

• Korean Journal of Materials Research
• /
• v.16 no.3
• /
• pp.151-156
• /
• 2006

A method for fabrication of nano-scale GaN structure by inductively coupled plasma etching is proposed, exploiting a thermal dewetting of Pt thin film as an etch mask. The nano-scale Pt metal islands were formed by the dewetting of 2-dimensional film on $SiO_2$ dielectric materials during rapid thermal annealing process. For the case of 30 nm thick Pt films, pattern formation and dewetting was initiated at temperatures greater $600^{\circ}C$. Controlling the annealing temperature and time as well as the thickness of the Pt metal film affected the size and density of Pt islands. The activation energy for the formation of Pt metal island was calculated to be 23.2 KJ/mole. The islands show good resistance to dry etching by a $CF_4$ based plasma for dielectric etching indicating that the metal islands produced by dewetting are suitable for use as an etch mask in the fabrication of nano-scale structures.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.05a
• /
• pp.535-536
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.633-634
• /
• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.215-216
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.659-660
• /
• 2011

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.948-951
• /
• 2005

New technology that reduces photolithography process steps from 4 to 3 in fabrication of TFT LCD is introduced. The core technology for 3mask-TFTs is the lift-off process [1], by which the PAS and PXL layer are formed simultaneously. To evaluate the stability of this lift-off process, outgases from photo resist on a substrate during ITO deposition and the quality of ITO film were analyzed and the conventional photo resist stripper machine which operates lift-off process was examined to see its ability to reduce particle problems of the machine. Through the development of total process and design for TFTs using this 3mask technology, panels in TN and IPS modes which exhibit same performances of a display using a conventional process were achieved. In addition, this process was already verified in the mass production line and now some products are being produced by the 3mask technology.