Sang-Gab Kim

Effects of the n+ etching process in TFT-LCD fabrication for Mo/Al/Mo data lines

The n+ etching process is investigated for the fabrication of TFT-LCD (thin film transistor liquid crystal display) deposited with low resistance data lines of Mo/Al/Mo. Problems of consumption of the upper Mo layer and contamination of the channel area can be resolved using a PR mask. With a PR mask, either HCl or Cl2 can be selected as a main etchant gas, and either SF6 or CF4 can be selected as an additive. Plasma treatment after the n+ etching process can reduce the high off-current problem which occurs when the Mo data line is in contact with the n+a-Si layer.

Characteristics of Ag Etching using Inductively Coupled Cl2-based Plasmas

In this study, Ag thin films deposited on glass were etched using inductively coupled Cl2-based plasmas and the effects of various Cl2-based gas mixtures on the formation of reactive byproducts affecting Ag etching were investigated. When Cl2-based gas mixtures were used with Ar and O2, due to the very low vapor pressure of the etch products, thick etch products remaining on the substrate could be observed after the etching. However, these etch products were easily removed during the photoresist stripping by a photoresist stripper. In particular, when O2 was added to Cl2, higher Ag removal rates during the photoresist stripping than those by pure Cl2 or O2 could be obtained. These results are interpreted as the formations of more porous and reactive etch reaction products when O2 was added to Cl2. The Ag removal rates by Cl2/O2/50%N2 estimated after the photoresist stripping were higher than those by Cl2/O2/50%Ar and the use of Cl2/O2/50%Ar resulted in higher Ag etch rates than those by Cl2/50%Ar. Therefore, the physical and chemical properties of the etch products formed by the specific gas mixture appear to be important in removing Ag for Cl2-based plasmas.

An optimized frequency of dielectric barrier discharge analyzed by difference of voltage and current

Summary form only given. In this paper, we configured the open type DBD (dielectric barrier discharge) system. Discharge character was remained as a stable feature and its properties were successfully investigated. Power absorption was measured as product of voltage and current as a function of frequency under open-air atmosphere. We observed the existence of an optimum frequency for power absorption. It is suggested that the optimum frequency occurs because the phase difference between voltage and current decreases as frequency increases. Helium addition to O/sub 2/-discharge under open-air condition shows OES intensity changes as He flow rate. This means that generation rate of radical may change according to the gas species although inert gas is added. Physical meaning of the area of current and voltage trajectory on 1-V plain is supposed to reactive part. To increase the power efficiency, we should reduce the area, i.e. the phase difference of voltage and current. Contact angle is measured on PR (photoresist) surface after some treatment conditions. Helium addition on the main O/sub 2/-discharge results in the increase of contact angle. It means that the He addition changes the radicals generated from oxygen and affects the surface of PR.