Cu 기판위에 성장한 MgO, MgAl₂O₄와 MgAl₂O₄/MgO 박막의 집속이온빔을 이용한 스퍼터링수율 측정과 이차전자방출계수 측정

정강원(K. W. Jung),이혜정(H. J. Lee),정원희(W. H. Jung),오현주(H. J. Oh),박철우(C. W. Park),최은하(E. H. Choi),서윤호(Y. H. Seo),강승언(S. O. Kang) 한국진공학회(ASCT) 2006 Applied Science and Convergence Technology Vol.15 No.4

MgAl₂O₄ 막은 MgO 보호막 보다 단단하며 수분 흡착 오염문제에 상당히 강한 특성을 가진다. 본 연구에서 AC-PDP의 유전체보호막으로 사용되는 MgO 보호막의 특성을 개선하기 위해 MgAl₂O₄/MgO 이중층 보호막을 제작하여 특성을 조사하였다. 전자빔 증착기를 사용하여 Cu 기판에 MgO와 MgAl₂O₄을 각각 1000 Å 두께로 증착, MgAl₂O₄/MgO을 200/800 Å 두께로 적층 증착 후, 이온빔에 의한 충전현상을 제거하기 위해 Al을 1000 Å 두께로 증착하였다. 집속 이온빔(focused ion beam ; FIB)장치를 이용하여 10 ㎸에서 14 ㎸까지 이온빔 에너지에 따라 MgO는 0.364 ~ 0.449 값의 스퍼터링 수율에서 MgAl₂O₄/MgO을 적층함으로 24 ~ 30 % 낮아진 0.244 ~ 0.357 값의 스퍼터링 수율이 측정되었으며, MgAl₂O₄는 가장 낮은 0.088 ~ 0.109 값의 스퍼터링 수율이 측정되었다. g-집속이온빔(g-FIB)장치를 이용하여 Ne? 이온 에너지를 50 V에서 200 V까지 변화 시켜 MgAl₂O₄/MgO와 MgO는 0.09 ~ 0.12의 비슷한 이차전자방출 계수를 측정 하였다. AC-PDP셀의 72시간 열화실험 후 SEM 및 AFM으로 열화된 보호막의 표면을 관찰하여 기존의 단일 MgO 보호막과 MgAl₂O₄/MgO의 적층보호막의 열화특성을 살펴보았다. It is known that MgAl₂O₄ has higher resistance to moisture than MgO, in humid ambient MgO is chemically unstable. It reacts very easily with moisture in the air. In this study, the characteristic of MgAl₂O₄ and MgAl₂O₄/MgO layers as dielectric protection layers for AC-PDP (Plasma Display Panel) have been investigated and analysed in comparison for conventional MgO layers. MgO and MgAl₂O₄ films both with a thickness of 1000 Å and MgAl₂O₄/MgO film with a thickness of 200/800 Å were grown on the Cu substrates using the electron beam evaporation. 1000 Å thick aluminium layers were deposited on the protective layes in order to avoid the charging effect of Ga? ion beam while the focused ion beam(FIB)is being used. We obtained sputtering yieds for the MgO, MgAl₂O₄ and MgAl₂O₄/MgO films using the FIB system. MgAl₂O₄/MgO protective layers have been found th show 24 ~ 30% lower sputtering yield values from 0.244 up to 0.357 than MgO layers with the values from 0.364 up to 0.449 for irradiated Ga? ion beam with energies ranged from 10 ㎸ to 14 ㎸. And MgAl₂O₄ layers have been found to show lowest sputtering yield values from 0.88 up to 0.109. Secondary electron emission coefficient(g) using the γ-FIB. MgAl₂O₄/MgO and MgO have been found to have similar g values from 0.09 up to 0.12 for indicated Ne+ ion with energies ranged from 50 V to 200 V. Observed images for the surfaces of MgO and MgAl₂O₄/MgO protective layers, after discharge degradation process for 72 hours by SEM and AFM. It is found that MgAl₂O₄/MgO protective layer has superior hardness and degradation resistance properties to MgO protective layer.

RF-O₂ Plasma 처리한 MgO 박막의 스퍼터링 수율 측정

정원희(W. H .Jeoung),정강원(K. W. Jeong),임연찬(Y. C. Lim),오현주(H. J. Oh),박철우(C. W. Park),최은하(E. H. Choi),서윤호(Y. H. Seo),김윤기(Y. K. Kim),강승언(S. O. Kang) 한국진공학회(ASCT) 2006 Applied Science and Convergence Technology Vol.15 No.3

RF-O₂ plasma 처리한 MgO 박막의 스퍼터링 수율을 집속이온빔 장치를 이용하여 측정하였다. 가속 전압 10 ㎸의 Ga 이온빔을 주사했을 때 plasma 처리하지 않은 MgO 박막의 스퍼터링 수율은 0.33 atoms/ion, RF-O₂ plasma 처리한 MgO 박막의 스퍼터링 수율은 0.20 atoms/ion 으로 RF-O₂ plasma 처리한 경우 스퍼터링 수율이 낮아졌다. 또한 XPS, AFM을 통해 plasma 처리로 인한 MgO 표면의 변화를 관찰하였다. MgO 박막에 RF-O₂ plasma 처리 한 후 XPS O 1s spectra의 binding energy와 FWHM 값이 각각 2.36 eV와 0.6167 eV 작아졌고 표면거칠기의 RMS 값 또한 0.32 ㎚ 작아졌다. We measured sputtering yield of RF O₂-plasma treated MgO protective layer for AC-PDP(plasma display panel) using a Focused Ion Beam System(FIB). A 10 ㎸ acceleration voltage was applied. The sputtering yield of the untreated sample and the treated sample were 0.33 atoms/ion and 0.20 atoms/ion, respectively. The influence of the plasma-treatment of MgO thin film was characterized by XPS and AFM analysis. We observed that the binding energy of the O 1s spectra, the FWHM of O 1s spectra and the RMS(root-mean-square) of surface roughness decreased to 2.36 eV, 0.6167 eV and 0.32 ㎚, respectively.

CHF₃ / C₂F6 플라즈마에 의한 실리콘 표면 잔류막의 특성

권광호(K.-H. Kwon),박형호(H.-H. Park),이수민(S. M. Lee),강성준(S. J. Kang),권오준(O.-J. Kwon),김보우(B.W. Kim),성영권(Y.-K. Sung) 한국진공학회(ASCT) 1992 Applied Science and Convergence Technology Vol.1 No.1

실리콘을 CHF₃/C₂F_6 가스 플라즈마를 이용하여 식각하면 실리콘위에 탄소, 불소 및 산소로 이루어진 잔류막이 형성된다. 이 잔류막을 XPS로 분석한 결과 탄소는 C-Si, C-Si, C-C/H, C-CF_x(x≤3), C-F, C-F₂, C-F₃ 결합을 하고 있으며, 불소는 F-Si, F-C 및 F-O 결합으로 이루어져 있음을 알았다. 한편 산소는 O-Si 및 O-F 결합으로, 실리콘은 Si-Si, Si-C 및 Si-O 결합상태를 나타낸다. 잔류막의 수직분포 연구를 통하여 Si-O 및 Si-C 결합이 탄소와 불소의 결합층 아래에 존재하고, 잔류막의 표면부에 F-O 결합이 분포함을 알았다. 또한 건식식각 변수가 잔류막 형성에 미치는 영향이 조사되었으며 CHF₃/C₂F_6 가스 유량비, RF power 벚 압력 등이 잔류막의 두께, 조성비 및 잔류막의 결합상태에 영향을 미침을 알 수 있었다. Si surfaces exposed to CHF₃/C₂F_6 gas plasmas in reactive ion etching (RIE) have been characterized by X-ray photoelectron spectroscopy (XPS). CHF₃/C₂F_6 gas plasma exposure of Si surface leads to the deposition of residual film containing carbon and fluorine. The narrow scan spectra of C 1s show various bonding states of carbon as C-Si, C-Si, C-C/H, C-CF_x(x≤3), C-F, C-F₂, and C-F₃. The chemical bonding states of fluorine are described with F-Si, F-C, and F-O. And the oxygen and silicon are also detected. The effects of parameters for reactive ion etching as CHF₃/C₂F_6 gas ratio, RF power, and pressure are investigated.

A conserved splicing silencer dynamically regulates O-GlcNAc transferase intron retention and O-GlcNAc homeostasis

Sung-Kyun Park,Xiaorong Zhou,Kathryn E. Pendleton,Olga V. Hunter,Jennifer J. Kohler,Kathryn A. O’Donnell,Nicholas K. Conrad 한국당과학회 2018 한국당과학회 학술대회 Vol.2018 No.01

Modification of nucleocytoplasmic proteins with O-GlcNAc regulates a wide variety of cellular processes and has been linked to human diseases. The enzymes O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) add and remove O-GlcNAc, but the mechanisms regulating their expression remain unclear. Here, we demonstrate that retention of the fourth intron of OGT is regulated in response to O-GlcNAc levels. We further define a conserved intronic splicing silencer (ISS) that is necessary for OGT intron retention. Deletion of the ISS in colon cancer cells leads to increases in OGT, but O-GlcNAc homeostasis is maintained by concomitant increases in OGA protein. However, the ISS-deleted cells are hypersensitive to OGA inhibition in culture and in soft agar. Moreover, growth of xenograft tumors from ISS-deleted cells is compromised in mice treated with an OGA inhibitor. Thus, ISS-mediated regulation of OGT intron retention is a key component in OGT expression and maintaining O-GlcNAc homeostasis.

성장홀몬과 내분비계 질환

박창윤,최규옥,김기황,허갑범,유경자,이혜리,손희영 대한핵의학회 1979 핵의학 분자영상 Vol.13 No.1

1976년 1월부터 1979년 3월까지 연세대학교 부속 세브란스병원에 내원하여 뇌하수체 기능부전이 의심되어 성장홀몬의 분비능을 관찰하기 위해 L-Dopa 자극시험을 실행했던 35명과 L-Dopa 자극시험과 포도당 부가반응을 관찰하였던 4예의 달단비대증 환자를 연구 검토하여 다음과 같은 결과를 얻었다. 1) 각종 질환에서 성장홀몬의 기저치는 Sheehan씨 증후군에서는 평균치는 대조군보다 낮으나 통계적으로 유의한 차이는 없었고 당뇨병 환자에서도 평균치는 높으나 통계적으로 유의한 차이는 아니었다. 말단비대증 환자 4예 모두 대조군보다 현저한 증가를 보여주었다. 2) 당뇨병 환자 13명종 9명은 당뇨병성 망막증이 합병되었던 환자였고 이중 6명에서 L-Dopa 자극에 성장홀몬의 분비항진을 보여주었다. 망막증이 없었던 4명 중 1명에서만 분비 항진을 보여주었다. 3) Sheehan씨 증후군 10예중 L-Dopa에 분비항진을 보여준 경우는 2예였다. 4) 뇌하수체 혐염기성선종 8예중 L-Dopa 자극반응에 분비항진을 관찰한 수 있었던 것은 1예였다. 5) 4명의 말단비대증 환자중 3명은 호산성 선공이였고 1명은 혐염기성 선종이였다. 이중 3명에서 L-Dopa 자극시험을 행하였는데 1명은 그 측정치가 80 ng/ml 이상이어 반응 판정이 불가능했고 2명은 L-Dopa에 paradoxical response를 보여주었다. 포도당 부가검사를 시행한 2명 모두에서 포도당 투여후 억제반응을 보여주었다. 6) 두개인두종 2예중 1예에서 L-Dopa 자극반응을 보여주었 저신장(short statas)는 2예중 1예에서 L-Dopa 자극후 분비 항진을 보여주었다. This is an analysis of 39 patients studied at the Yonsei Medical Center from January, 1976 to March 1979. Of these 35 patient were suspected of having hypothalamic insufficiency and subjected to the L-Dopa stimulation test to observe growth hormone sceretory function while four acromegaly patient received the glucose loading test and L-Dopa stimulation test. The results are as follows: 1) The basal level of GH in the various disease was as follows: a) The basal level was lower than the control level but was not statisfically significant b) In diabetes the mean value tended to higher than the control level but was not significant statistically c) In all four acromegaly patients the GH level was significantly higher than the control level 2) Of 13 patients with diabetes, nine had diabetic retinopathy, and of those nine, six showed increased L-Dopa response. However, of the four non retinopathic DM patients, onl one showed increased response to L-Dopa. 3) Two patients out of ten with Sheehan's syndrome responded to L-Dopa stimulation. 4) One Patient of eight prith pituitary chromophobe adenoma responded to L-Dopa stimulation. 5) Four acromegaly patients revealed 3 acidophilic adenoma and one chromophobe adenoma histologically. Of patients receiving the L-Dopa stimulation test. Two showed a paradoxical response. Two patients who received the glucose loading test showed supressed response. 6) Of two craniopharyngioma patients, one showed increased GH response after L-Dopa stimulation. Increased response of GH after L-Dopa stimulation was seen in one two craniopharyngioma patients and also in one of two patients with short statasture.

MgAl₂O₄ 스피넬 내화물의 합성과 응용

이윤복,권상오,장윤식,박상희,오기동 부산대학교 1995 生産技術硏究所論文集 Vol.48 No.-

MgO-Al₂O₃계에서 MgO첨가량에 따른 스피넬의 생성과 소결성을 조사하였다. 아울러 스피넬 내화물과 시멘트를 구성하는 주성분인 CaO의 반응성에 대하여 검토하였다. 가열된 시편의 상은 대부분의 스피넬, 페리클레이스 및 코런덤으로 동정되었고 과잉의 MgO를 함유한 시편의 경우 1750℃에서는 잔류 코런덤은 확인되지 않았다. MgO 함량이 감소함에 따라 스피넬내에 Al₂O₃의 고용에 기인된 스피넬의 생산량은 증가하는 경향을 나타내었다. 과잉의 MgO를 함유한 시편은 1600℃에서 치밀화가 촉진되어 1750℃, 5시간 유지한 시편의 경우 최종 소결밀도는 3.51g/㎤였다. 1750℃, 5시간 유지한 시편을 회전침식시험한 결과, 과잉의 MgO를 함유한 시편의 경우 침식깊이가 8.2mm, 침식면적이 225㎟로 다른 시편에 비교하여 가동면에서 CaO에 대한 침식저항성이 우수하였다. Effects of MgO content in spinel formation and sintering behavior of MgO-Al₂O₃ system were investigated. The reactivity of CaO in spinel refractories was also studied. From phase analyse, the refractories composed of mainaly two phase as like periclase and spinel, and residual corundom. However, the residual corundum was almost disappeared as it was fired at 1750℃ with excess of MgO. As the amount of MgO was reduced, the formation of spinel increased due to solid solubility of Al₂O₃ in spinel. The sample with excess of MgO markedly promoted the densification of spinel at 1600℃. The density of sample fired at 1750℃ for 5h was 3.51g/㎤. In rotary corrosion test, the sample with excess of MgO content, which had 8.2mm in the corrosion depth and 225㎟ in the corrosion area showed excellent corrosion resistance against the reactivity of CaO on the surface of spinel refractories.

Scalable CGeSbTe-based phase change memory devices employing U-shaped cells

Park, J.H.,Kim, J.H.,Ko, D.-H.,Wu, Z.,Ahn, D.H.,Park, S.O.,Hwang, K.H. Elsevier S.A. 2017 Thin Solid Films Vol.634 No.-

<P><B>Abstract</B></P> <P>Phase change memory (PCM) that is operated on resistance changes caused by joule heating has been suggested as the next-generation memory for scaling since its programming current scales linearly. We propose a U-shaped cell design to further reduce the reset current in PCM devices, which enables easier and more efficient scaling than conventional PCMs. Simulation studies of heat transfer demonstrated that our U-shaped design with a dashed heater has a higher thermal efficiency of 4.97K/μA compared to 3.36K/μA in a lance cell with a ring heater for the same storage node. The reset current can be better scaled proportionate to k<SUP>2.0</SUP> in which the exponent is higher than the lance cell of k<SUP>1.5</SUP> in non-isotropic scaling. This better scalability is attributed to the small programming volume of the U-shaped cell, which was verified by transmission electron microscopy analysis. Furthermore, the cyclic endurance of the U-shaped cell was enhanced by 1 order of magnitude compared to a lance cell and the thinner CGeSbTe films reduced the reset current further. Our results show that a U-shaped cell is a highly promising design to scale reset current in next-generation PCM devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> U-shaped cell is a promising cell design to scale phase change memory. </LI> <LI> U-shaped cell with dashed heater is more thermally efficient than lance cell with ring heater. </LI> <LI> Thinner CGeSbTe layer can reduce the reset current further. </LI> </UL> </P>

Ethylene Glycol 을 이용한 유리화 동결시 배 발달단계별 생쥐배의 생존성

박충생,곽대오,공일근,정기화,박준규 경상대학교 축산진흥연구소 1993 畜産振興硏究所報 Vol.20 No.1

고온가스정제공정의 후류 연료가스를 이용한 SO₂의 직접환원에 관한 연구

박노국,김봉석,이종대,전진혁,류시옥,이태진 한국공업화학회 2003 응용화학 Vol.7 No.2

The catalytic reactivity for the direct sulfur recovery from the produced SO₂in the regeneration process to element sulfur with the slip-stream fuel gas of hot gas desulfurization process as reductant was studied. The the catalyst for directly sulfur recovery process was used Ce_(0.8)Zr_(0.2)O₂, and the SO₂conversion and the element sulfur yield were investigated with the change of a reaction conditions, such as the amount of H₂O(2-10vol%), the reaction temperatures(400-600℃) and the mole ratio of reactants([reductant]/[SO₂]〓 1.0-3.0). The SO₂conversion and the element sulfur yield decreased by increasing the amount of H₂O in the slip-stream fuel gas using as reductant and increased by increasing the reaction temperature and the mole ratio of reactants. From TPR experiment result, reason that the SO₂conversion and the element sulfur yield becomes low by H₂O was confirmed because that the water-gas shift reaction(CO + H₂O → CO₂+ H₂). Specially, the element sulfur yield was fallen due to that created hydrogen to the water-gas shift reaction is converted to H₂S reacting with element sulfur.

腦炎發生豫測에 對한 病毒學的 昆蟲學的 調査硏究(1972)

申鶴均,李漢一,朴基德,洪漢基,鄭義範,金薄榮,李溫永,金慶浩 國立保健硏究院 1974 국립보건연구원보 Vol.11 No.-