• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.170-170
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• 2000

Synthetic polymers such as polyimide, polycarbonate, and poly(methyl methacrylate) are long chain molecules which consist of carbon, hydrogen, and heteroatom linked together chemically. Recently, polymer surface can be modified by using a high energy ion beam process. High energy ions are introduced into polymer structure with high velocity and provide a high degree of chemical bonding between molecular chains. In high energy beam process the modified polymers have the highly crosslinked three-dimensionally connected rigid network structure and they showed significant improvements in electrical conductivity, in hardness and in resistance to wear and chemicals. Polyimide films (Kapton, types HN) with thickness of 50~100${\mu}{\textrm}{m}$ were used for investigations. They were treated with two different surface modification techniques: Plasma Source Ion Implantation (PSII) and conventional Ion Implantation. Polyimide films were implanted with different ion species such as Ar+, N+, C+, He+, and O+ with dose from 1 x 1015 to 1 x 1017 ions/cm2. Ion energy was varied from 10keV to 60keV for PSII experiment. Polyimide samples were also implanted with 1 MeV hydrogen, oxygen, nitrogen ions with a dose of 1x1015ions/cm2. This work provides the possibility for inducing conductivity in polyimide films by ion beam bombardment in the keloelectronvolt to megaelectronvolt energy range. The electrical properties of implanted polyimide were determined by four-point probe measurement. Depending on ion energy, doses, and ion type, the surface resistivity of the film is reduced by several orders of magnitude. Ion bombarded layers were characterized by Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS), XPS, and SEM.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.344-346
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• 2016

본 논문에서는 3-stream model에 기반한 Dopant diffusion simulator를 사용하여 실리콘 기판 내부의 As이온의 확산을 시뮬레이션한 결과와 Dual-Pearson Analytic model에 기반하여 Ion implantation을 1-D doping simulation한 결과를 토대로 여러 공정 설계에서 diffusion simulator의 사용가능함을 확인하였다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.165-166
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• 2002

Hydrogen free diamond like carbon (DLC) films were prepared on steel substrates by using a single ion beam in a configuration that allowed sputtering of a graphite target and at the same time allowed to impact the substrate at a grazing angle. The DLC films so prepared have improved properties with increased disorder and with modest hardness that is slightly higher than previously reported values. We have studied the effects of $N_2^+$ ions implantation on such films. It is found that the implantations of nitrogen ions into DLC films lead to chemical modifications that allowed N atoms to be incorporated into the carbon network to produce a nitrogenated DLC. Nano-indentation experiments indicated that the nitrogenated films have consistently higher hardnesses ranging from 30 to 45GPa, which represents a considerable increase in surface hardness, compared with non-nitrogenated precursor films. The investigations by XPS and Raman spectroscopy suggests that the $N_2^+$ implanted DLCs had undergone both chemical and structural modifications through the incorporation of N atoms and the increased ratio of $sp^3/sp^2$ type bonding. The observed high hardness was therefore attributable to these structural and chemical modifications. This result has implication for the preparation of super hard wear resistant films required for tribological functions in devices.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.2
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• pp.162-168
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• 2011

In this research, nitrogen plasma source ion implantation(PSII) of non-coated tungsten carbide endmill tools was conducted with low heat treatment for increasing wear resistance. After the low heat treatment of PSIIed tools to give a homogeneity of wear resistance, the surface modification of tools was analyzed by hardness test, surface roughness and cutting forces. As for the resultant cutting forces, low heat treatment in temperature of $400^{\circ}C$ and $500^{\circ}C$ is stable because of low cutting resistance. The 20-minutes heat treated tool at spindle speed 25000rpm has superiority of surface roughness, Ra of $0.420{\mu}m$ and was found to have good wear resistance. The higher hardness value was obtained by increasing temperature from $300^{\circ}C$ to $600^{\circ}C$ for PSIIed tools with low heat treatment. As the PSIIed tools under 10minutes at temperature of $600^{\circ}C$ have the highest hardness as Hv of 2349.8, It was analyzed that temperature processing give much influences on hardness.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.180-180
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• 2000

Plasma source ion implantation is a new doping technique for the formation of shallow junction with the merits of high dose rate, low-cost and minimal wafer charging damage. In plasma source ion implantation process, the wafer is placed directly in the plasma of the appropriate dopant ions. Negative pulse bias is applied to the wafer, causing the dopant ions to be accelerated toward the wafer and implanted below the surface. In this work, inductively couples plasma was generated by anodized Al antenna that was located inside the vacuum chamber. The outside wall of Al chamber was surrounded by Nd-Fe-B permanent magnets to confine the plasma and to enhance the uniformity. Before implantation, the wafer was pre-sputtered using DC bias of 300B in Ar plasma in order to eliminate the native oxide. After cleaning, B2H6 (5%)/H2 plasma and negative pulse bias of -1kV to 5 kV were used to form shallow p+/n junction at the boron dose of 1$\times$1015 to 5$\times$1016 #/cm2. The as-implanted samples were annealed at 90$0^{\circ}C$, 95$0^{\circ}C$ and 100$0^{\circ}C$during various annealing time with rapid thermal process. After annealing, the sheet resistance and the junction depth were measured with four point probe and secondary ion mass spectroscopy, respectively. The doping uniformity was also investigated. In addition, the electrical characteristics were measured for Schottky diode with a current-voltage meter.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.351-355
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• 1999

BN films with a high content of cubic phase has been deposited by a variety of techniques. It is well known that c-BN films grow with a unique microstructure consisting of $sp^2$ and $sp^{3-}$ bonded layers. Because of existence of the initially grown $sp^{2-}$ /bonded layer, BN films are not adhesive to the substrates. In this study, post-N$^{+ }$ / implantation was applied to improve the adhesion of the films. A Monte Carlo program TAMIX was used to simulate this modification process. The simulation showed nitrogen concentration profile at $1200\AA$ in depth in case of 50keV -implantation energy. FTIR spectra of the $N^{+}$ implanted specimens demonstrated a strong change of absorption band at 1380 cm$^{ -1 }$The films were also investigated by HRTEM. From these results, it is concluded that the post ion implantation could be an effective technique which improves the adhesion between BN film and substrate.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.6
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• pp.1107-1113
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• 2011

In this paper, ion beam technology was investigated through the published papers. Ion beam technology is mainly used by the focused ion beams. There are two different types of application methods. One method is to remove the material from the substrate, the other one is to deposit the materials on the surface of the substrate or specimen. Based on the literature review there are 1.5 times more published research papers related to the deposition than those of the removal.

• The Magazine of the IEIE
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• v.28 no.8
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• pp.57-62
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• 2001

• Journal of Korean Vacuum Science & Technology
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• v.6 no.2
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• pp.62-66
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• 2002

Hydraulic pumps are used to control the landing wheels of aircrafts, and their proper operation is vital to plane safety It is well hewn that adhesive wear failure is a major cause of pump failure. A dual nitrogen plasma immersion ion implantation process calling for the implantation of nitrogen at two different energies and doses has been developed to enhance the surface properties of the disks in the pumps. The procedures meet the strict temperature requirement of <200$^{\circ}C$, and after the treatment, the working lifetime of the pumps increases by more than a factor of two. This experimental protocol has been adopted by the hydraulic pump factory as a standard manufacturing procedure.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.3
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• pp.251-263
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• 2008

In this paper, we report an analytical modeling and 2-D Synopsys Sentaurus TCAD simulation of ion implanted silicon carbide MESFETs. The model has been developed to obtain the threshold voltage, drain-source current, intrinsic parameters such as, gate capacitance, drain-source resistance and transconductance considering different fabrication parameters such as ion dose, ion energy, ion range and annealing effect parameters. The model is useful in determining the ion implantation fabrication parameters from the optimization of the active implanted channel thickness for different ion doses resulting in the desired pinch off voltage needed for high drain current and high breakdown voltage. The drain current of approximately 10 A obtained from the analytical model agrees well with that of the Synopsys Sentaurus TCAD simulation and the breakdown voltage approximately 85 V obtained from the TCAD simulation agrees well with published experimental results. The gate-to-source capacitance and gate-to-drain capacitance, drain-source resistance and trans-conductance were studied to understand the device frequency response. Cut off and maximum frequencies of approximately 10 GHz and 29 GHz respectively were obtained from Sentaurus TCAD and verified by the Smith's chart.