• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.12
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• pp.1091-1098
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• 1998

Thermal stability of the electroless deposited Cu thin film was investigated. Cu/TaN/Si multilayer was fabricated by electroless-depositing Cu thin layer on TaN diffusion barrier layer which was deposited by MOCVD on the Si substrate, and was annealed in $H_2$ ambient to investigate the microstructure of Cu film with a post heat-treatment. Cu thin film with good adhesion was successfully deposited on the surface of the TaN film by electroless deposition with a proper activation treatment and solution control. Microstructural property of the electroless-deposited Cu layer was improved by a post-annealing in the reduced atmosphere of $H_2$ gas up to $600^{\circ}C$. Thermal stability of Cu/TaN/Si system was maintained up to $600^{\circ}C$ annealing temperature, but the intermediate compounds of Cu-Si were formed above $650^{\circ}C$ because Cu element passed through the TaN layer. On the other hand, thermal stability of the Cu/TaN/Si system in Ar ambient was maintained below $550^{\circ}C$ annealing temperature due to the minimal impurity of $O_2$ in Ar gas.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.3
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• pp.149-154
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• 2000

Bi-layer Mo films were deposited on soda-lime glass substrates using DC magnetron supttering. Increasing gas pressure, the resistivity varied from $1\times10^{-5}\; to\; 8.3\times10^{-3}\; \Omega.cm$. Furthermore, stress direction yielded compressive-to-tensile transition stress curves. The micro-structure of the compressively-stressed film which had poor adhesion consists of tightly packed columns, but of the tensile-stressed films had less dense structure. Under all gas pressure conditions, Mo films exhibited distinctly increasing optical reflection with decreasing gas pressure. The expansion of (110) peak width with the gas pressure meant the worse crystalline growth. The impurity levels in the Mo film exhibited highly concentrated Na, Se and O elements due to less dense micro-structure. The degree of Na diffusion depends on the type of the glass substrate used and the nature of the Mo film.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.3
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• pp.60-65
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• 1984

In this paper, we have used symmetrical GaAs/(Ga, Al) As DH-LED as a model for the optimization of frequency response which is the most important design parameter of the optical communication-LED. And optimum design parameters have been chosen to improve performance factors of the DH-LED by computer simulation. This is for the purpose of systematic consideration of the interrelation of the physical parameters such as impurity concentration of the active layer, thickness of the active layer, minority carrier lifetime, space charge capacitance and injected current density.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.2
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• pp.54-57
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• 2005

Photoreflectance (PR) has been measured to investigate the characterization of the Si$_{3}$N$_{4}$Al$_{0.21}$ Ga$_{0.79}$As/GaAs and Al$_{0.21}$Ga$_{0.79}$As/GaAs heterostructures. In the PR spectrum, the caplayer thickness was 170 nm and Si$_{3}$N$_{4}$ was utilized as the capping material. The C peak is confirmed as the carbon defect with residual impurity originating from the growth process. After annealing, in the presence of the Si$_{2}$N$_{4}$ cap layer, band gap energy was low shifted. This result indicates that the Si$_{3}$N$_{4}$ cap layer controlled evaporation of the As atom.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.1
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• pp.74-78
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• 1999

For a high efficient field emission display (FED), the specific vacuum conditions below 10-7 Torr should be required. However, because the FED has the geometrical restriction due to its micro size, the thin film getters can be proposed for chemical pumping as a way to reduce impurity gases in the panel. The thin film getters, developed by employing the coating of new materials such as NI or Pt on getter surface, can be used without any activation process and show the enhanced sorption characteristics. Especially, using the Zr (1${\mu}{\textrm}{m}$) thin film getters with the Pt surface layer, the significant gettering for various active gases could be achieved from 9$\times$10-5 Torr to 1$\times$10-6 Torr or below. this good sorption properties is mainly contributed to the surface coating layer which shows the catalytic effect for gas dissociation and protects the getter materials against oxidation.

• Transactions on Electrical and Electronic Materials
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• v.5 no.5
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• pp.173-179
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• 2004

The influence of heavily Si impurity doping in the GaN barrier of InGaN/GaN multi-quantum well structures of blue light emitting diodes were investigated by growing samples in metal-organic chemical vapor deposition. The delta-doped sample was compared to the sample with the undoped barrier. The delta-doped sample shows the tunneling behavior and forms the energy level of 0.32 eV for tunneling and the photoemission of the 450-nm band. The photo-luminescence shows the blue-shifted broad band of the radiative transition due to the inclusion of Si delta-doped layer indicating that the delta doping effect acts to form the higher energy level than that of quantum well. The dislocation may provide the carrier tunneling channel and plays as a source of acceptor. During the tunneling of hot carrier, there was no light emission.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.571-573
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• 2007

It is known that the main source of the area image sticking is the ion charge adsorption on the alignment layer. We found out that the adsorption of the ion charge of the liquid crystal in the cell was physisorption, which takes place between all molecules on any surface providing the adsorption force is small.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.3
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• pp.139-143
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• 2017

N-type crystalline silicon solar cells have high metal impurity tolerance and higher minority carrier lifetime that increases conversion efficiency. However, junction quality between the boron diffused layer and the n-type substrate is more important for increased efficiency. In this paper, the current status and prospects for boron diffused layers in N-type crystalline silicon solar cell applications are described. Boron diffused layer formation methods (thermal diffusion and co-diffusion using $a-SiO_X:B$), boron rich layer (BRL) and boron silicate glass (BSG) reactions, and analysis of the effects to improve junction characteristics are discussed. In-situ oxidation is performed to remove the boron rich layer. The oxidation process after diffusion shows a lower B-O peak than before the Oxidation process was changed into $SiO_2$ phase by FTIR and BRL. The $a-SiO_X:B$ layer is deposited by PECVD using $SiH_4$, $B_2H_6$, $H_2$, $CO_2$ gases in N-type wafer and annealed by thermal tube furnace for performing the P+ layer. MCLT (minority carrier lifetime) is improved by increasing $SiH_4$ and $B_2H_6$. When $a-SiO_X:B$ is removed, the Si-O peak decreases and the B-H peak declines a little, but MCLT is improved by hydrogen passivated inactive boron atoms. In this paper, we focused on the boron emitter for N-type crystalline solar cells.

• Journal of the Korean Vacuum Society
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• v.16 no.3
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• pp.205-209
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• 2007

ZnO thin films were deposited on a Si wafer and a soda lime glass using atomic layer deposition(ALD). The substrate temperature were between $130^{\circ}C{\sim}150^{\circ}C$. The deposition rate of the ZnO film was measured to be $2.72{\AA}$ per cycle. The films were analyzed using field emission scanning electron microscopy(FESEM), X-ray diffractometer(XRD), and Auger electron spectroscopy(AES). Impurity-free ZnO thin films were obtained and the crystallinity was found to be dependant upon the substrate temperature.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.3
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• pp.126-134
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• 1996

Tungsten silicide films were deposited on the phosphorus-doped poly-Si/SiO$_{2}$/Si-substrates by LPCVD (low pressue chemical vapor deposition). The formation and various properties of tungsten silicide processed by furnace annealing in N$_{2}$ ambient were evaluated by using XRD. AFM, 4-point probe and SEM. And the redistribution of phosphorus atoms has been observed by SIMS. The crystal structure of the as-deposited tungsten silicide films were transformed from the hexagonal to the tetragonal structure upon annealing at 550.deg. C. The surface roughness of tungsten polycide films were found to very smoothly upon annelaing at 850.deg. C and low phosphorus concentration in polysilicon layer. The sheet resistance of tungsten polycide low phosphorus concentration in polysilicon layer. The sheet resistance of tungsten polycide films are measured to be 2.4 .ohm./ㅁafter furnace annealing at 1100.deg. C, 30min. It was found that the sheet resistance of tungsten polycide films upon annealing above 1050.deg. C were independant on the phosphorus concentration of polysilicon layer and furnace annealing times. An out-diffusion of phosphorus impurity through tungsten silicide film after annealing in $O_{2}$ ambient revealed a remarkably low content of dopant by oxide capping.