• Proceedings of the Korean Vacuum Society Conference
• /
• 2007.08a
• /
• pp.77-77
• /
• 2007

• Journal of the Korean institute of surface engineering
• /
• v.39 no.3
• /
• pp.137-141
• /
• 2006

Process window for infinite etch selectivity of silicon nitride $(Si_3N_4)$ layers to ArF photoresist (PR) was investigated in dual frequency superimposed capacitive coupled plasma (DFS-CCP) by varying the process parameters such as low frequency power $(P_{LF})$, $CH_2F_2$ and $H_2$ flow rate in $CH_2F_2/H_2/Ar$ plasma. It was found that infinite etch selectivities of $Si_3N_4$ layers to the ArF PR on both blanket and patterned wafers can be obtained for certain gas flow conditions. The etch selectivity was increased to the infinite values as the $CH_2F_2$ flow rate increases, while it was decreased from the infinite etch selectivity as the $H_2$ flow rate increased. The preferential chemical reaction of the hydrogen with the carbon in the polymer film and the nitrogen on the $Si_3N_4$ surface leading to the formation of HCN etch by-products results in a thinner steady-state polymer and, in turn, to continuous $Si_3N_4$ etching, due to enhanced $SiF_4$ formation, while the polymer was deposited on the ArF photoresist surface.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.5
• /
• pp.672-679
• /
• 2022

Microbial lipases are used widely in the synthesis of various compounds due to their substrate specificity and position specificity. 4-Ethyl malate (4-EM) made from diethyl malate (DEM) is an important starting material used to make argon fluoride (ArF) photoresist. We tested several microbial lipases and found that Photobacterium lipolyticum M37 lipase position-specifically hydrolyzed DEM to produce 4-EM. We purified the reaction product through silica gel chromatography and confirmed that it was 4-EM through nuclear magnetic resonance analysis. To mass-produce 4-EM, DEM hydrolysis reaction was performed using an enzyme reactor system that could automatically control the temperature and pH. Effects of temperature and pH on the reaction process were investigated. As a result, 50℃ and pH 4.0 were confirmed as optimal reaction conditions, meaning that M37 was specifically an acid lipase. When the substrate concentration was increased to 6% corresponding to 0.32 M, the reaction yield reached almost 100%. When the substrate concentration was further increased to 12%, the reaction yield was 81%. This enzyme reactor system and position-specific M37 lipase can be used to mass-produce 4-EM, which is required to synthesize ArF photoresist.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.3
• /
• pp.183-187
• /
• 2000

In this study the SrBi$_2$Ta$_2$$O_{9}$ (SBT) thin films were etched by using magnetically enhanced inductively coupled Ar/CHF$_3$plasma as function of CHF$_3$/(Ar+CHF$_3$)gas mixing ratio. Maximum etch rate of SBT thin films was 1650 $\AA$/min and the selectivities of SBT to Pt and photoresist(PR) were 1.35 and 0.94 respectively under CHF$_3$/(Ar+CHF$_3$) of 0.1 For study on etching mechanism of SBT thin film X-ray photoelectron spectroscopy (XPS) surface analyses and secondary ion mass spectrometry (SIMS) mass analysis of etched SBT surfaces were performed. Among the elements of SBT thin film. M(Sr, Bi, Ta)-O bonds are broken by Ar ion bombardment and form SrF and TaF$_2$by chemical reaction with F. SrF and TaF$_2$are removed more easily by Ar ion bombardment. Scanning electron microscopy(SEM) was used for the profile examination of etched SBT film and the cross-sectional SEM profile of etched SBT film under CHF$_3$(Ar+CHF$_3$) of 0.1 was about 85$^{\circ}$X>.

• Journal of the Korean Vacuum Society
• /
• v.5 no.3
• /
• pp.263-267
• /
• 1996

Reactive ion etching of Pt thinfilm was studied using $CCl_2F_2$, Ar, and $O_2$ . Etch rate of the Pt increased as the total pressure decreases and the RF power increased, while the flow rate of $CCl_2F_2$ had little effect on the Pt etch rate. Addition of $O_2$ had no effect on Pt etch rate up to 20% $O_2$ Selectivity between Pt and photoresist increased as the pressure decreased and the RF power increased, making it possible to pattern a thicker Pt layer with a thinner photoresist. A maximum etch rate of 300$\AA$/min was obtained at $CCl_2F_2$ flow rate of 20 sccm. RF power of 400 W, and the total pressure of 60mTorr.

• Journal of the Speleological Society of Korea
• /
• no.82
• /
• pp.1-4
• /
• 2007

In this paper, the etching of Au films using photoresist masks on Si substrates was investigated using a capacitively coupled plasma etch reactor. The advantages of plasma etch techniques over current methods for Au metalization include the ability to simplify the metalization process flow with respect to resist lift-off schemes, and the ability to cleanly remove etched material without sidewall redeposition, as is seen in ion milling. The etch properties were measured for different gas mixing ratios of CF4/Ar, and chamber pressures while the other conditions were fixed. According to statistical design of experiment (DOE), etching process of Au films was characterized and also 20 samples were fabricated followed by measuring etch rate, selectivity and etch profile. There is a chemical reaction between CF4 and Au. Au- F is hard to remove from the surface because of its high melting point. The etching products can be sputtered by Ar ion bombardment.

• Korean Chemical Engineering Research
• /
• v.43 no.4
• /
• pp.531-536
• /
• 2005

Inductively coupled plasma reactive ion etching of CoTb and CoZrNb magnetic materials with the photoresist mask was performed using $Cl_2/Ar$ and $C_2F_6/Ar$ gas mixtures and characterized in terms of etch rate and etch profile. As the concentrations of $Cl_2$ and $C_2F_6$ gases increased, the etch rates of magnetic films decreased and the etch slopes became slanted. The $Cl_2/Ar$ gas was more effective in obtaining fast etch rate and steep sidewall slope than the $C_2F_6/Ar$ gas. As the coil rf power and dc bias increased, fast etch rate and steep etch slope were obtained but the redeposition on the sidewall was observed. This is due to the increase of ion and radical densities in plasma with increasing the coil rf power and the increase of incident ion energy to the substrate with increasing the dc bias voltage. By applying high density reactive ion etching to magnetic tunnel junction stack containing various magnetic films and metal oxide, steep etch slope and clean etch profile without redeposition were obtained.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.8
• /
• pp.806-811
• /
• 2004

1-Hydroxy-4-(2-naphthalenesulfonyloxy) cyclohexane(1), 1,4-di-(2-naphthalenesulfonyloxy) cyclohexane(2), 1-hydroxy-4-(2-thiophenesulfonyloxy) cyclohexane(3), 1,4-di-(2-thiophenesulfonyloxy) cyclohexane(4) were synthesized and evaluated for their performance as novel acid amplifiers for 193 nm photoresists. These acid amplifiers(1-4) showed reasonable thermal stability at the usual resist-processing temperature, 9$0^{\circ}C$-12$0^{\circ}C$. And estimated by the sensitivity curve, (1)-(4) enhanced the sensitivity of poly(tert-butyl methacrylate) film by 1.2-1.4 times, compared to poly(tert-butyl methacrylate) film whithout acid amplifiers, in the presence of a photoacid generator.