• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.99-102
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• 1999

A mixture which was made from organic gel, glass powder and ceramic powder was masklessly etched for fabrication of barrier rib of PDP(Plasma Display Panel) by focused Ar$^{+}$ laser( λ =514 nm) and Nd:YAG(λ =532, 266 nm) laser irradiation at the atmosphere. The depth of the etched grooves increases with increasing a laser fluence and decreasing a scan speed. Using second harmonic of Nd:YAG laser, the threshold laser fluence was 6.5 mJ/$\textrm{cm}^2$ for the sample of PDP barrier rib softened at 12$0^{\circ}C$. The thickness of 130 ${\mu}{\textrm}{m}$ of the sample on the glass was clearly removed without any damage on the glass substrate by fluence of 19.5 J/$\textrm{cm}^2$....

• Journal of the Korean institute of surface engineering
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• v.29 no.5
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• pp.338-344
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• 1996

This study was an investigation of plasma-induced damages on silicon substrate in the semiconductor manufacturing technology. The plasma-induced damage level on silicon substrate was analyzed and compared in various plasma etching systems. The analysis methods were therma wave, life-time recovery, SCA (Surface Charge Analyzer) and TRXF (Total Reflection X-ray Fluorescence) measurements, and the measured values were compared for each systems. In the comparison of the values which were obtained by a system that had low life-time recovery, there was not any differences in DC parameters. However, the reflesh time distribution of device of that system had decreased about 10 to 20m sec compared to a system which had high life-time recovery.

• Korean Journal of Materials Research
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• v.3 no.4
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• pp.327-335
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• 1993

Using a RF cylindrical magnetron operated with two electromagnets having a Helmholz configuration, RF magnetron plasma properties and characteristics of reactive ion ething of Si were investigated as a function of applied magnetic field strengths using 3mTorr $CF_4/H_2$ and $CHF_3$. Also, I-V characteristics of Schottky diodes, which were made of silicons etched under different applied magnetic field strengths and gas environments, were measured to investigate the degree of radiation damage during the reactive ion etching. As the magnetic field strent;th increased, ion densities and radical densities of the plasmas were increased linearly, however, the dc self-bias voltages induced on the powered electrode, where the specimen are located, were decreased exponentially. Maximum etch rates, which were 5 times faster than that etched without applied magnetic filed, were obtained using near lOOGauss, and, under these conditions, little or no radiation damages on the etched silicons were found.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.10
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• pp.785-791
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• 2001

High dielectric (Ba, Sr) TiO$_3$ thin films were etched in an inductively coupled plasma (ICP) as a function of Cl$_2$/Ar mixing ration. Under Cl$_2$(20)/Ar(80), the maximum etch rate of the BST films was 400 $\AA$/mim and selectivities of BST to Pt and PR were obtained 0.4 and 0.2, respectively. Etching products were redeposited on the surface of BST and resulted in varying the nature of crystallinity. Therefore, we investigated the etched surface of BST by x-ray photoelectron spectroscopy (XPS) atomic force microscopy (AFM) and x-ray diffraction (XRD). From the result of XPS analysis, we found that residues of Ba-Cl and Ti-Cl bonds remained on the surface of the etched BST for high boiling point. The morphology of the etched surfact was analyzed by AFM. A smoothsurface(roughness ~2.8nm) ws observed under Cl$_2$(20)/Ar(80), rf power of 600 W, dc bias voltage of -250 V and pressure of 10 mTorr. This changed the nature of the crystallinity of BST. From the result of XRD analysis, the crystallinities of the etched BST film under Ar only and Cl$_2$(20)/Ar(80) were maintained as similar to as-deposited BST. However, intensity of BST(100) orientation under Cl$_2$ only plasma was abruptly decreased. This indicated that CI compounds were redeposited on the etched BST surface and resulted in changed of the crystallinity of BST during the etch process.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.2
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• pp.63-67
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• 2008

3D integration technology has been a major focus of the next generation of IC industries. In this study Si wafer ultra-thinning has been investigated especially for the effect of ultra-thinning on the silicon surface. Wafers were grinded down to $30{\mu}m\;or\;50{\mu}m$ thickness and then grinded only samples were compared with surface treated samples in terms of surface roughness, surface damages, and hardness. Dry polishing or wet etching treatment has been applied as a surface treatment. Surface treated samples definitely showed much less surface damages and better roughness. However, ultra-thinned Si samples have the almost same hardness as a bulk Si wafer.

• Journal of Sensor Science and Technology
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• v.24 no.6
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• pp.373-378
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• 2015

The structure of the human ear is divided into the outer ear, the middle ear, and the inner ear. The inner ear includes the cochlea that plays a very important role in hearing. Recently, the development of an artificial cochlear device for the hearing impaired with cochlear damage has been actively researched. Research has been carried out on the biomimetic piezoelectric thin film ABM (Artificial Basilar Membrane) in particular. In an effort to improve the frequency separation performance of the existing piezoelectric thin film ABM, this paper presents the design, fabrication, and characterization of the production and performance of a partially etched-type ABM material. $O_2$ plasma etching equipment was used to partially etch a piezoelectric thin film ABM to make it more flexible. The mechanical-behavior characterization of the manufactured partially etched-type ABM showed that the overall separation frequency range shifted to a lower frequency range more suitable for audible frequency bandwidths and it displayed an improved frequency separation performance. In addition, the maximum magnitude of the vibration displacement at the first local resonant frequency was enhanced by three times from 38 nm to 112 nm. It is expected that the newly designed, partially etched-type ABM will improve the issue of cross-talk between nearby electrodes and that the manufactured partially etched-type ABM will be utilized for next-generation ABM research.

• Korean Journal of Materials Research
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• v.32 no.12
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• pp.522-527
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• 2022

Among efforts to improve techniques for the chemical vapor deposition of large-area and high-quality graphene films on transition metal substrates, being able to reliably transfer these atomistic membranes onto the desired substrate is a critical step for various practical uses, such as graphene-based electronic and photonic devices. However, the most used approach, the wet etching transfer process based on the complete etching of metal substrates, remains a great challenge. This is mainly due to the inevitable damage to the graphene, unintentional contamination of the graphene layer, and increased production cost and time. Here, we report the systematic study of an H₂ bubbling-assisted transfer technique for graphene films grown on Cu foils, which is nondestructive not only to the graphene film but also to the Cu substrate. Also, we demonstrate the origin of the graphene film tearing phenomenon induced by this H₂ bubbling-assisted transfer process. This study reveals that inherent features are produced by rolling Cu foil, which cause a saw-like corrugation in the poly(methyl methacrylate) (PMMA)/graphene stack when it is transferred onto the target substrate after the Cu foil is dissolved. During the PMMA removal stage, the graphene tearing mainly appears at the apexes of the corrugated PMMA/graphene stack, due to weak adhesion to the target substrate. To address this, we have developed a modified heat-press-assisted transfer technique that has much better control of both tearing and the formation of residues in the transferred graphene films.

• Membrane Journal
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• v.19 no.4
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• pp.317-323
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• 2009

In this study the nanofiltration (NF) membrane treatment of a nitric acid waste solutions containing $Pb^{+2}$ heavy metal ion discharging from the etching processes of an electronics and semiconductors industry has been studied for the purpose of recycling of nitric acid etching solutions. Three kinds of NF membranes (General Electric Co. Duraslick NF-4040 membrane, Dow Co. Filmtec LP-4040 membrane and Koch Co. SelRO MPS-34 4040 membrane) were tested for their separation efficiency (total rejection) of $Pb^{+2}$ ion and membrane stability in nitric acid solution. NF experiments were carried out with a dead-end membrane filtration laboratory system. The membrane permeate flux was increased with the increasing storage time in nitric acid solution and lowering pH of acid solution because of the enhancing of NF membrane damage by nitric acid. The membrane stability in nitric acid solution was more superior in the order of Filmtec LP-4040 < Duraslick NF-4040 < SelRO MPS-34 4040 membrane. The total rejection of Pb+2 ion was decreased with the increasing storage time in nitric acid solution and lowering the pH of acid solution. The total rejection of $Pb^{+2}$ ion after 4 months NF treatment was decreased from 95% initial value to 20% in the case of Duraslick NF-4040 membrane, from 85% initial value to 65% in the case of SelRO MPS-34 4040 membrane and from 90% initial value to 10% in the case of Filmtec LP-4040 membrane. These results showed that SelRO MPS-34 4040 NF membrane was more suitable for the treatment of an acidic etching waste solutions containing heavy metal ions.

• The korean journal of orthodontics
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• v.29 no.4 s.75
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• pp.445-456
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• 1999

As a result of increased education and communication, the field of orthodontics has recently been expanded to include a greater number of adult treatment procedures. With this increased demand for adult orthodontic treatment, a problem that frequently arises is the placement of appliances on teeth restored with porcelain. But conventional acid-etching is ineffective in the preparation of porcelain surface for mechanical retention of orthodontic attachments. Also, it is possible to damage on porcelain. The purpose of this study was to evaluate the effect of composite bonding materials and the porcelain surface treatment methods on shear bond strength, and to observe the porcelain fracture rates. To accomplish this purpose, this study was carried out with feldsphatic porcelain, Ceram II. Porcelain surface treatment methods were divided into intact glazed porcelain which had not treatment and surface roughening. Surface roughening by etching with Hydroluoric acid(HF), sandblasting with Microetcher II and compound treatment with etching and sandblasting. Bonding materials were Ortho-two and Transbond. All porcelain specimens were applicated with porcelain primer. 1. In comparision according to porcelain surface treatment, surface roughening groups by HF etching and sandblasting had higher shear bond than intact group. No significant difference was found in Transbond group. 2. Ortho-two group had the higher shear bond strength than that of Transbond group in B:.u etching and sandblasting. 3. E(Transbond. Intact)group had the lowest shear bond strength in all experimental group. The bond strength was higher than clinically successful bond strength. 4. Non-treated group had very higher porcelain rates than treated group. 5. This study indicates that porcelain surface-roughening may not be necessary to attachment of orthodontic brackets to porcelain surfaces.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.523-523
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• 2012

As the wafer geometric requirements continuously complicated and minutes in tens of nanometers, the expectation of real-time add-on sensors for in-situ plasma process monitoring is rapidly increasing. Various industry applications, utilizing plasma impedance monitor (PIM) and optical emission spectroscopy (OES), on etch end point detection, etch chemistry investigation, health monitoring, fault detection and classification, and advanced process control are good examples. However, process monitoring in semiconductor manufacturing industry requires non-invasiveness. The hypothesis behind the optical monitoring of plasma induced ion current is for the monitoring of plasma induced charging damage in non-invasive optical way. In plasma dielectric via etching, the bombardment of reactive ions on exposed conductor patterns may induce electrical current. Induced electrical charge can further flow down to device level, and accumulated charges in the consecutive plasma processes during back-end metallization can create plasma induced charging damage to shift the threshold voltage of device. As a preliminary research for the hypothesis, we performed two phases experiment to measure the plasma induced current in etch environmental condition. We fabricated electrical test circuits to convert induced current to flickering frequency of LED output, and the flickering frequency was measured by high speed optical plasma monitoring system (OPMS) in 10 kHz. Current-frequency calibration was done in offline by applying stepwise current increase while LED flickering was measured. Once the performance of the test circuits was evaluated, a metal pad for collecting ion bombardment during plasma etch condition was placed inside etch chamber, and the LED output frequency was measured in real-time. It was successful to acquire high speed optical emission data acquisition in 10 kHz. Offline measurement with the test circuitry was satisfactory, and we are continuously investigating the potential of real-time in-situ plasma induce current measurement via OPMS.