• 한국레이저가공학회지
• /
• 제2권3호
• /
• pp.32-41
• /
• 1999

This study is about Jig used in wiring when we make Probecard and Large Scale Intergrated Electronic Circuit. The most universal wiring method is molding with Bond. Polymer film is punched down and adhesives is applied after wiring. Due to shrinkage and modification many problems still have happened in the process of molding. To solve these problems, ceramic plate was introduced in the study. Using Laser, an experiment of microhole treatment on ceramic plate was proceeded. Laser energy, assistance gas, and special features by purity degree were analyzed with the 35W low capacity YAG-Laser. In the condition of energy 0.08J, frequency 20Hz and interval time 200$mutextrm{s}$, about 70${\mu}{\textrm}{m}$ microhole was adequate for the Probecard Jig. In the purity experiment of ceramic materials, high purity ceramic met with good result for microhole. But the price is too high. The shape and size of holes machined combustion gas $O_2$ were better than those in $N_2$ and Ar, the inert gas.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
• /
• pp.1102-1103
• /
• 2006

The pretreatment for substrate was carried out in change of gun pressure of $0.5\sim3.5$ bar using wet blasting. The size of $Al_2O_3$ powder was about $50{\sim}150{\mu}m$. As the results, the surface roughness of cemented carbide substrate was improved with increment of gun pressure of wet blasting. A new surface layer was formed and Co particles were uniformly distributed over the entire surface after pretreatment. The adhesion of the pretreated substrate in same PVD-TiAlN film was improved and in approximately $Ra=90\sim120\;nm$ shown the best adhesion value.

• 한국전기전자재료학회논문지
• /
• 제11권8호
• /
• pp.628-636
• /
• 1998

LB layers L-$\alpha$-DLPC deposited by LB method were deposited onto n-type silicon wafer as Z-type film. Films made up of 8, 16 layers of lipid with long alkyl chain and the thickness of monolayer and multiayers was determined by ellipsometry. Ut was deposited Ag and Al onto LB layers and silicon wafer for electrode and small electrode exhibit high capacitiance and low lekage current. The C-V curves of the MLS capacitor shows very high saturation value of capacitance. And cross-sectional SEM image of MLD capacitor indicated the presence of pore with Al electrode and we found that the Ag is good for electrode metal.

• 한국결정성장학회지
• /
• 제13권4호
• /
• pp.172-175
• /
• 2003

We have investigated effects of the lattice mismatch between the LPE films and the substrates. We have grown $La_{2-x}Sr_{x}CuO_{4}$(x=0.1 to 0.15) single crystalline films on single crystalline substrates having different lattice parameter ratio c/a e.g., $La_{2-x}Sr_{x}Cu_{1-y}Zn_{y}O_{4},\;La_{2-x}Ba_{x}CuO_{4},\; LaSrAlO_{4}\;and\;La_{2-x}Sr_{x}Cu_{1-y}Al_{y}O_{4}$ etc., using the IR-LPE technique. The superconducting properties of the grown films were found to vary significantly depending on the lattice mismatch with different substrates.

• Bulletin of the Korean Chemical Society
• /
• 제31권1호
• /
• pp.112-115
• /
• 2010

Transparent conducting undoped and Al impurity doped ZnO films were deposited on glass substrate by spin coat technique using 24 days aged ZnO precursor solution with solution of ethanol and diethanolamine. The films were characterized by UV-Visible spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), electrical resistivity ($\rho$), carrier concentration (n), and hall mobility ($\mu$) measurements. XRD data show that the deposited film shows polycrystalline nature with hexagonal wurtzite structure with preferential orientation along (002) crystal plane. The SEM images show that surface morphology, porosity and grain sizes are affected by doping concentration. The Al doped samples show high transmittance and better resistivity. With increasing Al concentration only mild change in optical band gap is observed. Optical properties are not affected by aging of parent solution. A lowest resistivity ($8.5 \times 10^{-2}$ ohm cm) is observed at 2 atomic percent (at.%) Al. With further increase in Al concentration, the resistivity started to increase significantly. The decrease resistivity with increasing Al concentration can be attributed to increase in both carrier concentration and hall mobility.

• ETRI Journal
• /
• 제31권6호
• /
• pp.660-666
• /
• 2009

We investigate the effects of interfacial dielectric layers (IDLs) on the electrical properties of top-gate In-Ga-Zn-oxide (IGZO) thin film transistors (TFTs) fabricated at low temperatures below $200^{\circ}C$, using a target composition of In:Ga:Zn = 2:1:2 (atomic ratio). Using four types of TFT structures combined with such dielectric materials as $Si_3N_4$ and $Al_2O_3$, the electrical properties are analyzed. After post-annealing at $200^{\circ}C$ for 1 hour in an $O_2$ ambient, the sub-threshold swing is improved in all TFT types, which indicates a reduction of the interfacial trap sites. During negative-bias stress tests on TFTs with a $Si_3N_4$ IDL, the degradation sources are closely related to unstable bond states, such as Si-based broken bonds and hydrogen-based bonds. From constant-current stress tests of $I_d$ = 3 ${\mu}A$, an IGZO-TFT with heat-treated $Si_3N_4$ IDL shows a good stability performance, which is attributed to the compensation effect of the original charge-injection and electron-trapping behavior.

• Bulletin of the Korean Chemical Society
• /
• 제35권10호
• /
• pp.3041-3046
• /
• 2014

Blue emitting materials, 9,10-bis-biphenyl-4-yl-anthracene (AC-P), 9,10-bis-[1,1';4',1"]terphenyl-4-yl-anthracene (AC-DP), and 9,10-bis[3",5"-deiphenyltriphenyl-4'-yl]anthracene (AC-TP) were synthesized through boration and Suzuki aryl-aryl coupling reaction. EL performance of blue light-emitters was optimized and improved by varying the chemical structures of the side groups. In the thin film state, the three materials exhibit $PL_{max}$ values in the range of 442-456 nm. EL device with the synthesized compounds in the following configuration was fabricated: ITO/4,4',4"-tris(N-(2-naphthyl)-N-phenylamino)triphenylamine (2-TNATA) 60nm/N,N'-bis (naphthalene-1-yl)-N,N'-bis(phenyl)benzidine (NPB) 15nm/synthesized blue emitting materials (30nm)/1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (TPBi) 20nm/LiF 1nm/Al 200nm. The current efficiency and C.I.E. value of AC-TP were 3.87 cd/A and (0.15, 0.12). A bulky and non-planar side group helps to prevent ${\pi}-{\pi}^*$ stacking interaction, which should lead to the formation of more reliable amorphous film. This is expected to have a positive effect on the high efficiency of the operating OLED device.

• 한국안광학회지
• /
• 제5권2호
• /
• pp.187-192
• /
• 2000

본 연구에서는 물 유리의 경제성을 바탕으로 광학적 및 기계적인 특성을 조사하여 투명하고 높은 경도를 가진 표면 보호막의 기능을 검토하기 위하여 $SiO_2-Na_2O-R_mO_n$계 박막을 제조하였다. 물 유리에 CaO와 $Al_2O_3$를 소량의 1 N HCl 1N $NH_4OH$와 함께 각각 첨가하여 코팅용 졸을 준비하였다. Stainless steel. Si wafer. soda-lime-silica glass등 다양한 기판 위에 spin-coating 한 후 질소 분위기 하에서 500, 750 및 $900^{\circ}C$로 최종 열처리를 행했다. 제조된 막은 Knoop 경도계로 micro-hardness를 측정하였다. 막의 표면 질소 함유량을 알아보기 위하여 EDX 분석을 행하였다. 그리고 Field Emission Scanning Electron Microscope(FE-SEM)을 이용하여 막의 표면구조를 관찰하였으며, UV-VIS 스펙트라 측정을 통하여 막의 두께와 반사 특성을 조사하였다.

• 센서학회지
• /
• 제13권2호
• /
• pp.157-167
• /
• 2004

A stoichiometric mixture of evaporating materials for $CuAlSe_{2}$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $CuAlSe_{2}$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were $680^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $CuAlSe_{2}$ single crystal thin films measured with Hall effect by van der Pauw method are $9.24{\times}10^{16}cm^{-3}$ and $295cm^{2}/V{\codt}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $CuAlSe_{2}$ obtained from the absorption spectra was well described by the Varshni's relation, $E_{g}(T)$ = 2.8382 eV - ($8.68{\circ}10^{-4}$ eV/K)$T^{2}$/(T + 155 K). The crystal field and the spin-orbit splitting energies for the valence band of the $CuAlSe_{2}$ have been estimated to be 0.2026 eV and 0.2165 eV at 10 K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_{5}$ states of the valence band of the $CuAlSe_{2}$. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1-}$, $B_{1-}$, and $C_{1-}$ exciton peaks for n = 1.

• 한국재료학회지
• /
• 제21권10호
• /
• pp.573-579
• /
• 2011

Highly textured Ag, Al and Al:Si back reflectors for flexible n-i-p silicon thin-film solar cells were prepared on 100-${\mu}m$-thick stainless steel substrates by DC magnetron sputtering and the influence of their surface textures on the light-scattering properties were investigated. The surface texture of the metal back reflectors was influenced by the increased grain size and by the bimodal distribution that arose due to the abnormal grain growth at elevated deposition temperatures. This can be explained by the structure zone model (SZM). With an increase in the deposition temperatures from room temperature to $500^{\circ}C$, the surface roughness of the Al:Si films increased from 11 nm to 95 nm, whereas that of the pure Ag films increased from 6 nm to 47 nm at the same deposition temperature. Although Al:Si back reflectors with larger surface feature dimensions than pure Ag can be fabricated at lower deposition temperatures due to the lower melting point and the Si impurity drag effect, they show poor total and diffuse reflectance, resulting from the low reflectivity and reflection loss on the textured surface. For a further improvement of the light-trapping efficiency in solar cells, a new type of back reflector consisting of Ag/Al:Si bilayer is suggested. The surface morphology and reflectance of this reflector are closely dependent on the Al:Si bottom layer and the Ag top layer. The relationship between the surface topography and the light-scattering properties of the bilayer back reflectors is also reported in this paper.