• Journal of the Korean institute of surface engineering
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• v.51 no.2
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• pp.110-115
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• 2018

The Na low temperature gettering in $SiO_2/PSG/SiO_2/Al-1%Si$ and $SiO_2/TEOS/SiO_2/Al-1%Si$ multilevel thin films was investigated using dynamic SIMS(secondary ion mass spectrometry) analysis. DC magnetron sputter, APCVD and PECVD techniques were utilized for the deposition of Al-1%Si thin films, $SiO_2/PSG/SiO_2$ and $SiO_2/TEOS/SiO_2$ passivations, respectively. Heat treatment was carried out at $300^{\circ}C$ for 5 h in air. SIMS depth profiling was used to determine the distribution of Na, Al, Si and other elements throughout the $SiO_2/PSG/SiO_2/Al-1%Si$ and $SiO_2/TEOS/SiO_2/Al-1%Si$ multilevel thin films. XPS was used to analyze chemical states of Si and O elements in $SiO_2$ passivation layers. Na peaks were observed throughout the $PSG/SiO_2$ and $TEOS/SiO_2$ passivation layers on the Al-1%Si thin films and especially at the interfaces. Na low temperature gettering in $SiO_2/PSG/SiO_2/Al-1%Si$ and $SiO_2/TEOS/SiO_2/Al-1%Si$ multilevel thin films is considered to be caused by a segregation type of gettering.

• Journal of the Korean Chemical Society
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• v.38 no.1
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• pp.1-7
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• 1994

Semiempirical MNDO calculations are employed to study ionicity of OH groups and stability in $T_1-OH-T_2bridges(T_1$ = Al, B and $T_2$ = P, Si) such as found in aluminophosphate family($AlPO_4-5$, BAPO-5, and SAPO-5) molecular sieves. Dimeric model clusters of Al-OH-P, B-OH-P and Al-OH-Si bridges were considered. It is shown that the elongation of the T-O bond, upon replacement of Al by B, occurs preferentially by a local deformation of the Al-O-P bridge. But the elongation of the T-O bond occurs preferentially by a rotation of Al-O-Si bridge upon substitution P for Si. Also, the ionicity of OH groups and stability increase in order to B-OH-P < Al-OH-P < Al-OH-Si bridge.

• Journal of the Korean Ceramic Society
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• v.33 no.11
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• pp.1209-1216
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• 1996

MoSi2-Al2O3 composites were prepared by thermal explosion mode of self-propagating high temperature syn-thesis (SHS) using element powders of MoO3 Mo Si and Al. The combustion products of MoSi2 which have 10, 20, 30 and 40 wt% Al2O3 showed the molten state in the range of Mo to MoO3 6:1-9.5:1, 2:1-8:1, 1:1-5:1, and 1:1-3:1 (molar ratio) respectively. The combustion products which made least seperation the molten phase from the slag phase were in Mo/MoO3=9, 5:1, 8:1, 5:1 and 3:1 (molar ratio) respectively. Particles size of MoSi2 and Al2O3 in the combustion product were decreased as the molar ratio of Mo to MoO3 increase. By XRD analysis only MoSi2 and $\alpha$-Al2O3 peaks were identified in the combusion products, In case of MoSi2 containing 20wt% Al2O3 5.1wt% Al existed into MoSi2 grains and 30.7wt% Si and 7.7wt% Mo existed into Al2O3 grains. The relative density of MoSi2 containing 10, 20, 30 and 40 wt% Al2O3 were 82.7, 85.2, and 81.9% respectively. The fracture strength of MoSi2-Al2O3 composites increased with increasing Al2O3 and that of MoSi2-20wt% Al2O3 composite was 195 MPa.

• Journal of the Korean Vacuum Society
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• v.22 no.3
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• pp.126-130
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• 2013

The sodium (Na) and moisture ($H_2O$) gettering phenomena were measured and analyzed in PSG/$SiO_2$ passivated Al-1%Si thin film interconnections. PSG/$SiO_2$ passivation and Al-1%Si thin films were deposited by using APCVD (atmosphere pressure chemical vapor deposition) and DC magnetron sputter techniques, respectively. SIMS (secondary ion mass spectrometry) depth profiling analysis was used to determine the distribution of sodium and moisture throughout the PSG/$SiO_2$ passivated Al-1%Si thin film interconnections. Both sodium and moisture peaks were observed strongly at the interfaces between layers rather than within the Al-1%Si thin film interconnections. Sodium peaks were observed at the interface between PSG and $SiO_2$ passivations, while moisture peaks were not observed.

• Journal of the Korean Vacuum Society
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• v.8 no.1
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• pp.31-35
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• 1999

In this paper, the lifetime dependence as a function of the line length of Al-1%Si thin film interconnections due to electromigration in semiconductor devices was studied. Al-1%Si thin film interconnections with a pattern of straight type were formed by using a standard photolithography process. The test patterns manufactured have line lengths in the range of 100 to 1600 $mu extrm{m}$. Al-1%Si thin film interconnections with Ti underlayers showed longer lifetime than those without Ti underlayers. Ti underlayers are believed to improve electromigration resistance resulting in a longer lifetime in Al-1%Si thin film interconnections. The dependence of lifetime on the line length in Al-1%Si/Ti thin film interconnections shows a saturation tendency near 800 $\mu\textrm{m}$ line length.

• Journal of the Korean institute of surface engineering
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• v.49 no.5
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• pp.467-471
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• 2016

In order to investigate the Na gettering, PSG/$SiO_2$/Al-1%Si multilevel thin films were fabricated. DC magnetron sputter techniques and APCVD (atmosphere pressure chemical vapor deposition) were utilized for the deposition of Al-1%Si thin films and PSG/$SiO_2$ passivations, respectively. Heat treatment was carried out at $300^{\circ}C$ for 5 h in air. SIMS (secondary ion mass spectrometry) depth profiling and XPS (X-ray Photoelectron Spectroscopy) analysis were used to determine the distribution and binding energies of Na, Al, Si, O, P and other elements throughout the PSG/$SiO_2$/Al-1%Si multilevel thin films. Na peaks were mainly observed at the the PSG/$SiO_2$ interface and at the $SiO_2$/Al-1%Si interfaces. Na impurity gettering in PSG/$SiO_2$/Al-1%Si multilevel thin films is considered to be caused by a segregation type of gettering. The chemical state of Si and O elements in PSG passivation appears to be $SiO_2$.

• Journal of the Korean institute of surface engineering
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• v.48 no.5
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• pp.233-237
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• 2015

In order to investigate the potassium (K) gettering, Al-1%Si/$SiO_2$/PSG multilevel thin films were fabricated. Al-1%Si thin films and $SiO_2$/PSG passivations were deposited by using DC magnetron sputter techniques and APCVD (atmosphere pressure chemical vapor deposition), respectively. Heat treatment was carried out at $300^{\circ}C$ for 5 h in air. SIMS (secondary ion mass spectrometry) depth profiling analysis was used to determine the distribution of K, Al, Si, P, and other elements throughout the $SiO_2$/PSG passivated Al-1%Si thin film interconnections. Potassium peaks were observed throughout the $SiO_2$/PSG passivation layers, and especially the interface gettering at the $SiO_2$/PSG and at the Al-1%Si/$SiO_2$ interfaces was observed. Potassium gettering in Al-1%Si/$SiO_2$/PSG multilevel thin films is considered to be caused by a segregation type of gettering.

• Journal of the Korean Ceramic Society
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• v.51 no.5
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• pp.392-398
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• 2014

$Al_2O_3$-SiC composites reinforced with SiC whisker ($SiC_w$) were fabricated using three different methods. In the first, $Al_2O_3-SiC_w$ starting materials were used. In the second, $Al_2O_3-SiC_w$-SiC particles ($SiC_p$) were used, which was intended to enhance the mechanical properties by $SiC_p$ reinforcement. In the third method, reaction-sintering was used with mullite-Al-C-$SiC_w$ starting materials. After hot-pressing at $1750^{\circ}C$ and 30 MPa for 1 h, the composites fabricated using $Al_2O_3-SiC_w$ and $Al_2O_3-SiC_w-SiC_p$ showed strong mechanical properties, by which the effects of reinforcement by $SiC_w$ and $SiC_p$ were confirmed. On the other hand, the mechanical properties of the composite fabricated by reaction-sintering were found to be inferior to those of the other $Al_2O_3$-SiC composites owing to its relatively lower density and the presence of ${\gamma}-Al_2O_3$ and ${\gamma}-Al_{2.67}O_4$. The greatest hardness and $K_{1C}$ were 20.37 GPa for the composite fabricated using $Al_2O_3-SiC_w$, and $4.9MPa{\cdot}m^{1/2}$ using $Al_2O_3-SiC_w-SiC_p$, respectively, which were much improved over those from the monolithic $Al_2O_3$.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.237.1-237.1
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• 2013

Ti 와 Al 은 금속간의 화합물이 내산화성에 우수한 성질을 가지고 있으며 낮은 밀도와 고온에도 큰 변화가 없는 성질을 가지고 있다. 그리하여 내식 및 부식 관련 연구나 고온재료를 필요로 하는 우주, 엔진 제품 등에 많은 연구가 진행되고 있다. 또한 Ti-Al-N 박막은 경도가 우수하여 고속 공구 부품에 널리 사용되고 있으며 최근 Ti-Al-N 에 Si 첨가로 인하여 40 GPa 이상의 고경도와 1,000도 이상의 산화온도를 지닌 나노 혼합물 코팅을 형성 시키는 것으로 알려져 있다. 본 연구에서는 Ti, Al, Si 원분말을 PBM (Planetary Ball Milling) 방법을 사용하여 Ti-Al-Si 혼합분말로 제조하고, 제조된 분말들은 SPS (Spark Plasma Sintering) 공정을 통하여 Ti-Al-Si 합금타겟을 제작하였다. 제작된 Ti-Al-Si 합급타겟을 사용한 Sputtering 공정을 수행하여 Ti-Al-Si 3원계 박막을 증착하였다. 그 결과 기존 Ti (82 ${\mu}m$), Al (32 ${\mu}m$), Si (16 ${\mu}m$) 크기의 원분말들이 PBM (Planetary Ball Milling) 공정 후 Ti-Al-Si (18 ${\mu}m$) 로 입도가 작아진 것을 확인 할 수 있었고, 소결 후 타겟이 99% 이상의 높은 밀도를 가졌으며 원분말의 조성과 동일한 조성을 가진 타겟이 제작되었음을 확인하였다. Ti-Al-Si 타겟의 경도는 약 1,000 Hv 이상의 값을 보였으며, Ti-Al-Si-N 박막의 경우 타겟의 조성과 동일하였고 경도는 약 35 GPa 로 높은 경도 값을 가지는 것을 확인하였다. 내산화 테스트 결과 Ti-Al-Si-N 박막은 1,000도 에서도 박막의 손상이 가지 않았다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.130-130
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• 2018

산업 발전으로 특수합금들이 발달함에 따라 가공할 수 있는 새로운 절삭공구소재들이 개발되어지고 있다. 또한 공구소재보다 코팅개발이 상대적으로 더욱 효과적이기 때문에 코팅 기술 개발이 활발히 진행되고 있다. 일본에서는 새로운 코팅층 물질 개발보다는 기존의 코팅물질을 조합하거나 개량하여 성능을 향상시키는 추세이다. TiAlSiN 박막은 스퍼터링과 음극 아크 소스를 이용한 hybrid 공정을 이용하여 코팅 후 특성을 평가하였다. Ti-50at.%Al의 조성을 갖는 TiAl 합금 타겟은 음극 아크 소스를 이용하여 코팅하였다. 공정 가스는 Ar과 N2의 혼합 가스를 사용하였으며 공정 압력은 $1.0{\times}10^{-2}Torr$이었다. 음극 아크 소스에 인가된 전류는 70 A이었다. TiAlSiN 박막의 Si 함량을 조절하기 위해서 Si은 스퍼터링으로 코팅하였으며 스퍼터링 소스에 인가되는 전력의 세기를 0.29 kW ~ 1.05 kW까지 변화시켰다. 코팅 공정에 사용된 Si 타겟의 순도는 4N이다. TiAlSiN 박막의 Si 함량은 스퍼터링 전력에 따라 3.4 ~ 14.4at%까지 변화하는 것을 확인하였다. TiAlSiN 코팅층의 경도는 초미소 경도계를 이용하여 측정하였으며, Si 함량이 증가하면 TiAlSiN 박막의 경도도 증가하는 것을 확인할 수 있다. TiAlSiN 박막의 Si 함량이 9.2at.%일 때 3000 Hv 이상의 경도를 보였다. TiAlSiN 코팅층의 Si 함량이 14.4at%로 높아지면 경도가 낮아지는 현상을 보였다. TiAlSiN 박막의 Si 함량이 증가하면 내산화성이 향상되는 현상을 확인할 수 있었다.