• Nuclear Engineering and Technology
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• 제54권3호
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• pp.991-996
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• 2022

Microstructures of monolithic high purity SiC and SiC with sintering additives after neutron irradiation to a fluence of 2.0-2.5 × 10²⁴ n/m² (E > 0.1 MeV) at 333-363 K and after post-irradiation annealing up to 1673 K were observed using a transmission electron microscopy. Results showed that no black spot defects or dislocation loops in SiC grains were found after the neutron irradiation for all of the specimens owing to the moderate fluence at low irradiation temperature. Thus, it is confirmed that these specimens were swelled mostly by the formation of point defects. Black spots and small dislocation loops were discovered only after the annealing process in PureBeta-SiC and CVD-SiC, where the swelling almost diminished. Anomalous-shaped YAG grains were found in SiC ceramics containing sintering additives. These grains contained dense black spots defects and might lose crystallinity after the neutron irradiation, while these defects may annihilate by recrystallization during annealing up to 1673 K. Amorphous grain boundary phase was also presented in this ceramic, and a large part of it was crystallized through post-irradiation annealing and could affect their recovery behavior.

• 전기전자학회논문지
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• 제22권4호
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• pp.1230-1233
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• 2018

에어로졸 데포지션 (aerosol deposition)공정을 통해 $Al_2O_3$막을 4H-SiC 상에 50 nm 두께로 제조하였고, 후열처리 공정에 따른 전기적 특성을 분석하였다. 그 결과 $N_2$분위기 열처리 시 $Al_2O_3$와 SiC 계면의 고정전하량이 감소하였으나 산소공공 생성에 의한 누설전류의 증가를 확인하였다. 본 결과로부터 계면특성 향상과 누설전류의 감소를 위해서는 적절한 $N_2$와 $O_2$가스의 혼합이 중요함을 확인하였다.

• 한국전기전자재료학회논문지
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• 제24권5호
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• pp.392-397
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• 2011

The effect of various post-annealing temperature to sputtered Pb(Zr,Ti)$O_3$ (PZT) thin films was investigated. The crystallization process, surface morphology and the electrical characteristics strongly depends on the rapid thermal annealing (RTA). In radio frequency (RF) sputtering methods, there were many papers mostly forcing on the crystal forming and the surface variations with different elements distribution (Pb, Ti, Zr, O) on the surface of the PZT layer. In this experiment, the post-annealing treatment promoted the Pb volatilization in PZT thin film and affected the Ti diffused throughout the Pt layer into the PZT layer. Second ion mass spectroscopy (SIMS) analysis was employed to show that the Pb element in the PZT layer was decreased at the same time the Ti element mass was slight decreased than Pb with increasing RTA temperature. That result prove the content of Pb affect the PZT thin film property.

• 한국재료학회지
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• 제18권4호
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• pp.204-210
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• 2008

$1.5\;{\mu}m$-thick copper films deposited on silicon wafers were successfully bonded at $415^{\circ}C$/25 kN for 40 minutes in a thermo-compression bonding method that did not involve a pre-cleaning or pre-annealing process. The original copper bonding interface disappeared and showed a homogeneous microstructure with few voids at the original bonding interface. Quantitative interfacial adhesion energies were greater than $10.4\;J/m^2$ as measured via a four-point bending test. Post-bonding annealing at a temperature that was less than $300^{\circ}C$ had only a slight effect on the bonding energy, whereas an oxygen environment significantly deteriorated the bonding energy over $400^{\circ}C$. This was most likely due to the fast growth of brittle interfacial oxides. Therefore, the annealing environment and temperature conditions greatly affect the interfacial bonding energy and reliability in Cu-Cu bonded wafer stacks.

• 한국전기전자재료학회논문지
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• 제19권8호
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• pp.769-774
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• 2006

In this paper the ZnO thin films, which has used spotlight of next generation short wavelength LEDs and semiconductor laser were deposited based on RF magnetron sputtering is described. The temperature at substrate and work pressure, which has implemented in sputtering process of ZnO thin films were settle down at $100^{\circ}C$ and 15 mTorr respectively. The ZnO 5N has used target. The thickness of ZnO thin films was about $1.6{\mu}m$ which was measured by SEM analysis after the sputtering process. Structural properties of ZnO thin films by in-situ and atmosphere annealing were analyzed by XRD. Transformation of grain size and surface roughness were observed by AFM. XPS spectra showed that ZnO thin film had a peak positions corresponding to the $Zn_{2p}$ and the $O_{1s}$. As form above XPS, we confirmed that post-annealing condition changed the atom ratio of Zn/O and microstructure in ZnO thin films.

• 한국진공학회지
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• 제4권S2호
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• pp.115-130
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• 1995

In order to produce Cu nanocrystallite in silicon wafer, the implantation technique was used. The samples of silicon (100) wafers were implanted by $Cu^+$ ions at 100 keV and with varying the doses at room temperature. Post-annealing was performed at $800^{\circ}C$ with Ar environment. To investigate the formation of Cu nanocrystallite with ion doses and growth process by thermal annealing, SIMS and HRTEM(high resolution transmission electron microscopy)spectra were studied.

• 한국세라믹학회지
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• 제31권2호
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• pp.171-176
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• 1994

The spin-casted PLZT(9/65/35) thin films through polymeric sol-gel process were prepared on Pt substrate. The crack-free, uniform and dense films were obtained by post-annealing at the temperature between 35$0^{\circ}C$ and $700^{\circ}C$. The composite structure mixed together with large grains called "rosette" and surrounding small grains were observed on the films annealed over $600^{\circ}C$. Pyrochlore phase was completely changed to perovskite phase above $600^{\circ}C$ with the increase of annealing temperature. Dielectric constant (k) was larger with the increase of film thickness and annealing temperature. from the measurements of dielectric constant as a function of measuring temperature, it was also observed that Curie temperature was shifted to higher temperature with the increase of film thickness and annealing temperature. The pyroelectric coefficient(P) of 10 times coated film annealed at $700^{\circ}C$ was 65 $\mu$C/$\textrm{cm}^2$.K.$.K.

• 한국진공학회지
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• 제9권2호
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• pp.155-161
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• 2000

이온빔보조증착법을 이용하여 c-BN(70%)/h-BN(30%) 혼합막을 합성하였으며, 이를 후속 열처리로 안정화 시켰다. 보론은 e-beam evaporator로, 질소는 end-hall type 이온 건으로 공급하였으며, 기판에는 -400과 -500V의 DC 바이어스를 각각 인가하였고, $700^{\circ}C$로 가열하였다. 보론의 기화속도는 1.2 $\AA$/sec였고, 질소이온의 에너지는 약 100 eV였다. 막 합성 후같은 진공에서 후속열처리를 $700^{\circ}C$ 및 $800^{\circ}C$에서 1시간동안 각각 행하였다. 후속열처리를 하지 않은 경우에는 공기 중에 노출된 직후에 막이 기판에서 박리된 반면, $800^{\circ}C$에서 후속 열처리를 한 경우에는 안정하였다. 후속 열처리에 의하여 막 전체의 응력은 4.9 GPa에서 3.4 GPa로 감소하였으나, c-BN상의 응력은 변화하지 않았다. 이러한 결과는 c-BN상의 응력 해소를 주요 안정화 기구로 보고한 기존의 결과와 다른 것으로, 후속 열처리 동안에, 비정질이나 결함이 많은 h-BN상의 구조적, 화학적 relaxation에 의하여 막의 안정화가 진행될 수 있음을 의미한다. c-BN상의 분율이 작은 혼합막의 경우 비 c-BN상의 안정화가 막 전체의 안정화에 매우 중요할 것으로 판단된다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.127.1-127.1
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• 2011

In this paper, ZnO:Al thin films with c-axis preferred orientation were prepared on Soda lime glass substrates by RF magnetron sputtering technique. AZO thin film were prepared in order to clarify optimum conditions for growth of the thin film depending upon process, and then by changing a number of deposition conditions and substrate temperature conditions variously, structural and electrical characteristics were measured. For the manufacture of the AZO were vapor-deposited in the named order. It is well-known that post-annealing is an important method to improve crystal quality. For the annealing process, the dislocation nd other defects arise in the material and adsorption/decomposition occurs. The XRD patterns of the AZO films deposited with grey theory prediction design, annealed in a vacuum ambient($2.0{\times}10-3$Torr)at temperatures of 200, 300, 400 and $500^{\circ}C$ for a period of 30min. The diffraction patterns of all the films show the AZO films had a hexagonal wurtzite structure with a preferential orientation along the c-axis perpendicular to the substrate surface. As can be seen, the (002)peak intensities of the AZO films became more intense and sharper when the annealing temperature increased. On the other hand, When the annealing temperature was $500^{\circ}C$ the peak intensity decreased. The surface morphologies and surface toughness of films were examined by atomic force microscopy(AFM, XE-100, PSIA). Electrical resistivity, Gall mobility and carrier concentration were measured by Hall effect measuring system (HL5500PC, Accent optical Technology, USA). The optical absorption spectra of films in the ultraviolet-visibleinfrared( UV-Vis-IR) region were recorder by the UV spectrophotometer(U-3501, Hitachi, Japan). The resistivity, carrier concentration, and Hall mobility of ZnS deposited on glass substrate as a function of post-annealing.

• 한국결정성장학회지
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• 제29권6호
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• pp.245-250
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• 2019

라디오주파수 분말 스퍼터링 방법으로 sapphire (0001) 기판 위에 Sn을 함유한 β-Ga₂O₃(β-Ga₂O₃ : Sn) 나노와이어를 증착하였다. 후열처리 공정의 가스 분위기가 나노와이어 형상의 변화에 미치는 영향을 연구하였다. 800℃에서 진공 중 열처리 과정에서, as-grown 나노와이어는 다공성 구조로 전이하였다. 비화학양론 Ga₂O_3-x는 화학양론 Ga₂O₃로 바뀌고, Sn원자는 응집하여 나노클러스터를 형성한다. Sn 나노클러스터는 증발하여 Sn 원자의 함량은 1.31에서 0.27 at%로 감소하였다. Sn원자의 증발로 인하여 나노와이어 표면에 다수의 기공이 형성되고, 이는 β-Ga₂O₃ : Sn 나노와이어의 체적대비 표면적 비율을 증가시킨다.