• Korean Journal of Materials Research
• /
• v.19 no.7
• /
• pp.349-355
• /
• 2009

Metal thin film patterns on a LTCC substrate, which was connected through inner via and metal paste for electrical signals, were formed by a screen printing process that used electric paste, such as silver and copper, in a conventional method. This method brought about many problems, such as non uniform thickness in printing, large line spaces, and non-clearance. As a result of these problems, it was very difficult to perform fine and high resolution for high frequency signals. In this study, the electric signal patterns were formed with the sputtered metal thin films (Ti, Cu) on an LTCC substrate that was coated with protective oxide layers, such as $TiO_2$ and $SiO_2$. These electric signal patterns' morphology, surface bonding strength, and effect on electro plating were also investigated. After putting a sold ball on the sputtered metal thin films, their adhesion strength on the LTCC substrate was also evaluated. The protective oxide layers were found to play important roles in creating a strong design for electric components and integrating circuit modules in high frequency ranges.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.29 no.6
• /
• pp.327-331
• /
• 2016

Resistive random access memory (ReRAM) of metallic conduction channel mechanism is based on the electrochemical control of metal in solid electrolyte thin film. Amorphous chalcogenide materials have the solid electrolyte characteristic and optical reactivity at the same time. The optical reactivity has been used to improve the memory switching characteristics of the amorphous $As_2Se_3$-based ReRAM. This study focuses on the formation of holographic lattices patterns in the amorphous $As_2Se_3$ thin film for straight conductive channel. The optical parameters of amorphous $As_2Se_3$ thin film which is a refractive index and extinction coefficient was taken by n&k thin film analyzer. He-Cd laser (wavelength: 325 nm) was selected based on these basic optical parameters. The straighten conduction channel was formed by holographic lithography method using He-Cd laser.$ Ag^+$ ions that photo-diffused periodically by holographic lithography method will be the role of straight channel patterns. The fabricated ReRAM operated more less voltage and indicated better reliability.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1119-1120
• /
• 2007

Nano-sized metal patterns were successfully fabricated on flexible PET substrate using nanoimprint lithography. 70nm line and space PMMA resist pattern was formed on PET substrate without residual layer by 'artial filling effect' and 20nm thin Cr metal layer was deposited by e-beam evaporation. Then, PMMA resist was selectively removed by acetone and 70nm narrow Cr pattern was formed.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2007.04a
• /
• pp.24-25
• /
• 2007

Nano-sized metal patterns were successfully fabricated on flexible PET substrate using nanoimprint lithography. 70nm line and space PMMA resist pattern was formed on PET substrate without residual layer by "partial filling effect' and 20nm thin Cr metal layer was deposited by e-beam evaporation. Then, PMMA resist was selectively removed by acetone and 70nm narrow Cr pattern was formed.

• Journal of the Korean Ceramic Society
• /
• v.45 no.3
• /
• pp.161-166
• /
• 2008

The multi-films of a metallic film and a transparent conducting oxide (TCO, indium-tin oxide, ITO) film were formed on the stainless steel 316 and 304 plates by a sputtering method and an E-beam method and then the external metallic region of the stainless steel bipolar plates was converted into the metal nitride films through an annealing process. The multi-film formed on the stainless steel bipolar plates showed the XRD patterns of the typical indium-tin oxide, the metallic phase and the metal substrate and the external nitride film. The XRD pattern of the thin film on the bipolar plates modified showed two metal nitride phases of CrN and $Cr_2N$ compound. Surface microstructural morphology of the multi-film deposited bipolar plates was observed by AFM and FE-SEM. The metal nitride film formed on the stainless steel bipolar plates represented a microstructural morphology of fine columnar grains with 10 nm diameter and 60nm length in FE-SEM images. The electrical resistivity of the stainless steel bipolar plates modified was evaluated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07a
• /
• pp.305-309
• /
• 2002

We have successfully fabricated a Metal-Ferroelectric-Insulator-Semiconductor (MFIS) structure using Bi$\sub$4-x/La$\sub$x/Ti$_3$O$\sub$12/ (BLT) ferroelectric thin film and SiO$_2$/Nitride/SiO$_2$ (ONO) stacked buffer layers for single transistor type ferroelectric nonvolatile memory applications. BLT films were deposited on 15 nm-thick ONO buffer layer by sol-gel spin-coating. The dielectric constant and the leakage current density of prepared ONO film were measured to be 5.6 and 1.0 x 10$\^$-8/ A/$\textrm{cm}^2$ at 2MV/cm, respectively, It was interesting to note that the crystallographic orientations of BLT thin films were strongly effected by pre-bake temperatures. X-ray diffraction patterns showed that (117) crystallites were mainly detected in the BLT film if pre-baked below 400$^{\circ}C$. Whereas, for the films pre-baked above 500$^{\circ}C$, the crystallites with preferred c-axis orientation were mainly detected. From the C-V measurement of the MFIS capacitor with c-axis oriented BLT films, the memory window of 0.6 V was obtained at a voltage sweep of ${\pm}$8 V, which evidently reflects the ferroelectric memory effect of a BLT/ONO/Si structure.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.907-912
• /
• 2005

Micro-patterns of $Pb(Zr_{0.53}Ti_{0.47})O_3$, PZT, thin films with a MPB composition were deposited on $Pt/Ti/SiO_2/Si$ substrate from molecular-designed PZT precursor solution by using self-assembledmonolayer(SAM) as a template. This method includes deposition of SAM followed by the optical etching by exposing the SAM to the UV-light, leading to the patterned SAM as a selective deposition template. The pattern of SAM was formed by irradiating UV-light to the SAM on a substrate and/or patterned PZT thin film through a metal mask for the selective deposition of patterned PZT or lanthanum nickel oxide (LNO) precursor films from alkoxide-based precursor solutions. As a result, patterned ferroelectric PZT and PZT/LNO thin film capacitors with good electrical properties in micrometer size could be successfully deposited.

• Korean Journal of Materials Research
• /
• v.9 no.2
• /
• pp.124-131
• /
• 1999

Copper film, which is expected to be used as interconnection material for 1 giga DRAM integrated circuits was deposited on hole and trench patterns by Metal Organic Chemical Vapor Deposition(MOCVD) method. After a reflow process, contact and L/S patterns were filled by copper and the characteristics of the Cu reflow process were investigated. When deposited Cu films were reflowed, grain growth and agglomeration of Cu have occurred in surfaces and inner parts of patterns as well as complete filling in patterns. Also Cu thin oxide layers were formed on the surface of Cu films reflowed in $O_2$ambient. Agglomeration and oxidation of Cu had bad influence on the electrical properties of Cu films especially, therefore, their removal and prevention were studied simultaneously. As a pattern size is decreased, preferential reflow takes place inside the patterns and this makes advantages in filling patterns of deep submicron size completely. With Cu reflow process, we could fill the patterns with the size of deep sub-micron and it is expected that Cu reflow process could meet the conditions of excellent interconnection for 1 giga DRAM device when it is combined with Cu MOCVD and CMP process.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.646-648
• /
• 2008

The multi-films of a metallic film and a transparent conducting oxide (TCO, indium-tin oxide, ITO) film were formed on the stainless steel 316 and 304 plates by a sputtering method and an E-beam method and then the external metallic region of the stainless steel bipolar plates was converted into the metal nitride films through an annealing process. The multi-film formed on the stainless steel bipolar plates showed the XRD patterns of the typical indium-tin oxide, the metallic phase and the metal substrate and the external nitride film. The XRD pattern of the thin film on the bipolar plates modified showed two metal nitride phases of CrN and $Cr_2N$ compound. Surface microstructural morphology of the multi-film deposited bipolar plates was observed by AFM and FE-SEM. The electrical resistivity of the stainless steel bipolar plates modified was evaluated.

• Journal of the Korean Vacuum Society
• /
• v.11 no.4
• /
• pp.194-200
• /
• 2002

MOCVD(metal-organic chemical vapor deposition) copper thin film was annealed at various conditions and the eletrical properties and micro-structures were investigated to find the optimal annealing condition and its effect. Cu thin film annealed at Ar 1 torr, $400^{\circ}C$ had the most improved resistivity of 1.98 $\mu\Omega$cm, and texture; the ratio of $I_{(111)}/I_{(200)}$ was varied from 2.03 to 3.11, and Cu thin film annealed at Ar 1 torr, $450^{\circ}C$ had the largest grain size and uniformity. After the annealing, the EM(electromigration) test was followed to ensure the improved properties by annealing. Compare to other conditions, Cu patterns annealed at Ar 1 torr, $400 ^{\circ}C$ had the most improved properties when it came to the EM resistance, which was due to the low resistivity, the preferential evolution of texture to (111) plane, and the reduction of surface roughness of annealed copper film.