• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 하계학술대회 논문집
• /
• pp.617-619
• /
• 2001

The effect of the superconducting film thickness on the substrate temperature has been investigated. Superconducting YBCO thin films have been grown on MgO substrates by pulsed laser deposition. The dependence of the orientation of YBCO film on thickness has been investigated by X-ray diffraction technique. X-ray diffraction indicated that the film orientation was changed by increasing the film thickness and by changing the substrate temperature.

• 한국초전도ㆍ저온공학회논문지
• /
• 제11권4호
• /
• pp.20-24
• /
• 2009

YBCO coated conductors (CC) on the $CeO_2$-buffered IBAD-MgO template were fabricated by metal-organic deposition (MOD) Process with Ba-trifluoroacetate and fluorine-free Y and Cu precursor materials. The precursor solution was coated on $CeO_2$-buffered IBAD MgO templates using the multiple dip-coating method, decomposed into inorganic precursors by pyrolysis up to $400^{\circ}C$ within 3 h, and finally fired at $740{\sim}800^{\circ}C$ in a reduced oxygen atmosphere. Microstructure, texture, and superconducting properties of YBCO films were found highly sensitive to both the firing temperature and time. The high critical current density ($J_C$) of $1.15\;MA/cm^2$ at 77.3K in the self-field could be obtained from $1\;{\mu}m$ thick YBCO CC, fired at $740^{\circ}C$ for 3.5 h, implying that high performance YBCO CC is producible on IBAD MgO template. Further enhancement of $J_C$ values is expected by improving the in-plane texture of $CeO_2$-buffer layer and avoiding the metal substrate contamination.

• 한국결정학회:학술대회논문집
• /
• 한국결정학회 2001년도 임시총회 및 추계학술대회연구발표회(한국결정학회)
• /
• pp.26-26
• /
• 2001

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2011년도 자성 및 자성재료 국제학술대회
• /
• pp.81-81
• /
• 2011

• 한국진공학회지
• /
• 제9권3호
• /
• pp.249-253
• /
• 2000

차세대 마이크로파 유전체 소자에 응용하기 위한 $MgTiO_3$ 박막을 펄스 레이저 증착법(PLD, pulsed laser deposition)을 이용하여 400-$500^{\circ}C$에서 비정질 상태로 실리콘 기판 위에 성장시킨 후 전기적 특성을 분석하였다. PLD로 증착된 $MgTiO_3$ 박막의 전기적 특성은 성장시 온도에 의존하였다. 즉, 증착 온도가 낮아짐에 따라 $MgTiO_3$ 박막 내부에 존재하는 이상정전하 결함 밀도가 증가하였으며, 이들 결함과 실리콘 기판과의 전하교환에 의하여 High Frequency(HF) C-V 곡선이 음의 방향으로 이동하는 현상이 관측된 것으로 사료된다. 또한, 증착 온도간 HF C-V 곡선 이동 폭 및 이상정전하 밀도는 ~l00$\AA$ 두께의 $SiO_2$ 중간층을 사용할 경우에 현저히 감소함을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
• /
• pp.150-153
• /
• 1999

The electrical and physical characteristics of MgO and Pt thin-films on Si wafers deposited by r.f magnetron sputtering, were analyzed with annealing condition(100$0^{\circ}C$, 120 min) by four point probe, SEM and XRD. Until annealing temperature of 100$0^{\circ}C$, MgO had the properties of improving Pt adhesion to SiO$_2$ and insulation without chemical reaction to Pt thin-films and the resistivity of Pt thin-films was improved. The thermal characteristics of Pt micro-heater were analyed with Pt-RTD integrated on the same substrate, In the analysis of properties of Pt-RTD, TCR value had 3927 ppm/$^{\circ}C$ and liner in the temperature range of 25~40$0^{\circ}C$ temperature of Pt micro-heater had up to 40$0^{\circ}C$ with 1.5 watts of the heating power.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
• /
• pp.157-160
• /
• 2004

Ferroelectric $(Ba_xSr_{1-x})TiO_3$ (BST) thin films have been deposited on (001) MgO single crystals by a pulsed laser deposition (PLD) method. The structure of deposited BST thin films were investigated by an x-ray diffractometer. Calculated c-axis lattice parameters of the BST films exhibit a strong lattice distortion, which was not observed in ceramic BST at room temperature. This lattice distortion of BST has been attributed to strains caused by lattice constant difference between film and substrate, oxygen vacancies in BST film, and thermal expansion difference between film and substrate. Ferroelectric properties at 10 GHz have been measured using a HP 8510C vector network analyzer. Dielectric properties, capacitance tunability and quality factor, of the interdigitaed capacitors fabricated on BST films were calculated from the measured s-parameters. Two distinct behaviors in structural, opitical, and microwave properties of BST films were observed; below and above 200 mTorr of oxygen pressure in the deposition chmber.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
• /
• pp.77-77
• /
• 2011

These days, a growing demand for memory device is filled up with the flash memory and the dynamic random access memory (DRAM). Although DRAM is a reasonable solution for current demand, the universal novel memory with high density, high speed and nonvolatility, needs to be developed. Among various new memories, the magnetic random access memory (MRAM) device is considered as one of good candidate memories because of excellent features including high density, high speed, low operating power and nonvolatility. The etching of MTJ stack which is composed of magnetic materials and insulator such as MgO is one of the vital process for MRAM. Recently, MgO has attracted great interest in the MTJ stack as tunneling barrier layer for its high tunneling magnetoresistance values. For the successful realization of high density MRAM, the etching process of MgO thin films should be investigated. Until now, there were some works devoted to the investigations on etch characteristics of MgO thin films. Initially, ion milling was applied to the etching of MgO thin films. However, ion milling has many disadvantages such as sidewall redeposition and etching damage. High density plasma etching containing the magnetically enhanced reactive ion etching and high density reactive ion etching have been employed for the improvement of etching process. In this work, inductively coupled plasma reactive ion etching (ICPRIE) system was adopted for the improvement of etching process using MgO thin films and etching gas mixes of $CH_4$/Ar and $CH_4$/$O_2$/Ar have been employed. The etch rates are measured by a surface profilometer and etch profiles are observed using field emission scanning emission microscopy (FESEM). The effects of gas concentration and etch parameters such as coil rf power, dc-bias voltage to substrate, and gas pressure on etch characteristics will be systematically explored.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 E
• /
• pp.2236-2238
• /
• 1999

This paper deals with the surface glow discharge characteristics and some physical properties of MgO thin films prepared by RF unbalanced magnetron sputtering(UBMS) in surface discharge type AC PDP. The minimum discharge voltage is obtained for the sample of substrate holder bias voltage -10V. The main factors that improves the discharge characteristics by applied bias voltage is considered to be due to the morphology changes or crystal structure of the MgO thin film by ion bombardment during deposition process Moreover, the anti-sputtering characteristics of MgO thin film by UBMS is more excellent than that of balanced magnetron sputtering(BMS) and E-beam evaporation method.

• 한국결정성장학회지
• /
• 제7권2호
• /
• pp.235-243
• /
• 1997

$YBa_2Cu_3O_x$ 고온 초전도체 상을 MgO 단결정위에 증착시키기 위하여 액상의 에어로 졸 입자를 저온 플라즈마의 화학증기 증착로안에 유입하였다. 플라즈마의 분포를 조절하기 위한 반응로의 설계에 따라 초전도체상의 미세구조가 변화하는 양상을 관찰하였으며, 이때 증착 기판 위에서 관찰되는 입자들의 생성원인에 대하여 고찰하였다. 입자생성의 주된 원인으로는 불안정한 플라즈마의 분포와 출발원료의 낮은 기화속도에 기인하는 것으로 나타났다. 또한 증착속도는 출발원료가 기화되는 곳으로부터 멀어질수록 급격히 감소하는 것으로 밝혀졌다.