• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.11
• /
• pp.1323-1328
• /
• 1988

Thermally grown $SiO_2$ films on silicon have been thermally nitrided in the $NH_3$ gas ambient and their properties have been investigated by analyzing the AES data and the results of the I-V and the C-V measurements. The Auger depth profile show that the nitrogen-rich layers are formed at the nitrided oxide film surface and near the $SiO_2$-Si interface. The higher the nitridation temperature is, the larger the refractive index of nitroxide film is. And the thinner the oxide film to be nitrided for the same nitridation temperature is, the larger the refractive index of nitroxide film is. When thin $SiO_2$ film is thermally nitrided, the I-V characteristics show the Fowler-Nordheim conduction fashion. Flatband voltages of $SiO_2$ films are shifted by nitridation, due to the fixed charge formation.

• Korean Journal of Materials Research
• /
• v.16 no.9
• /
• pp.571-577
• /
• 2006

We fabricated thermal evaporated 10 nm-Ni/(poly)Si and 10 nm-Ni/1 nm-Ir/(poly)Si films to investigate the thermal stability of nickel monosilicide at the elevated temperatures by rapid annealing them at the temperatures of $300{\sim}1200^{\circ}C$ for 40 seconds. Silicides for salicide process was formed on top of both the single crystal silicon actives and the polycrystalline silicon gates. A four-point tester is used for sheet resistance. Scanning electron microscope and field ion beam were employed for thickness and microstructure evolution characterization. An x-ray diffractometer and an auger depth profile scope were used for phase and composition analysis, respectively. Nickel silicides with iridium on single crystal silicon actives and polycrystalline silicon gates showed low resistance up to $1200^{\circ}C$ and $800^{\circ}C$, respectively, while the conventional nickel monosilicide showed low resistance below $700^{\circ}C$. The grain boundary diffusion and agglomeration of silicides led to lower the NiSi stable temperature with polycrystalline silicon substrates. Our result implies that our newly proposed Ir added NiSi process may widen the thermal process window for nano CMOS process.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1999.07a
• /
• pp.113-113
• /
• 1999

최근의 고품질 III-N 화합물 반도체 박막성장과 더불어 청색계열의 LED 및 LD의 성공적인 실현은 본 연구분야에 대한 새롭고 헌신적인 상업적, 학문적/ 기술적 투자환경을 유도해 나가고 있다. 특히, c-축 배향 단결정 사파이어를 기판재료로 사용하고 얇은 GaN buffer의 사용은 고온에서 그 위에 성장되는 성장박막의 특성을 크게 향상시키는 것으로 알려져 있다. 그러나 절연체를 기판으로 사용함에 따른 소자구조 및 제작공정의 복잡성과 기판과 GaN 박막사이의 큰 격자 부정합에 따른 결함센터 등은 소자의 전기, 광학적, 구조적 특성에 부정적인 영향을 미치고 있다. 이러한 문제점을 해결하고 양질의 박막을 성장하기 위한 GaN 혹은 그 대체 기판의 개발에 많은 연구투자가 이루어지고 있는 현실 속에서 Si을 기판으로 이용한 GaN 성장의 가능성이 조심스럽게 점쳐지고 있다. 현재까지의 연구결과를 참조할 때 대체로 복잡한 interlayer를 사용하여 박막성장이 일부 이루어졌으나 그 재현성이나 성장의 중요인자에 대한 해석은 아직 분명하게 밝혀져 있지 않다. 본 연구에서는 원자적 관점에서 Si의 표면에 일부 변화를 유도하고, MOCVD 방법으로 그 위에 성장되는 GaN 박막의 광학적 및 표면 morphology 등에 미치는 영향을 분석하여 핵심적인 성장인자를 추출하고자 시도하였다. 성장된 GaN/Si 박막의 물성은 SEM(AFM), PL, XRD, Auger depth profile 장비등을 이용하여 조사하였으며 사파이어 기판 위에 성장된 GaN 박막의 특성들과 비교 검토하였다.

• International Journal of Precision Engineering and Manufacturing
• /
• v.7 no.4
• /
• pp.47-50
• /
• 2006

SCM415 alloy was implanted with nitrogen ions using plasma source ion implantation (PSII), at a dose range of $1{\times}10^{17}\;to\;6{\times}10^{17}\;N^+cm^{-2}$ Auger electron spectrometry (AES) was used to investigate the depth profile of the implanted layer. Friction and wear tests were carried out on a block-on-ring wear tester. Scanning electron microscopy (SEM) was used to observe the micro-morphology of the worn surface. The results revealed that after being implanted with nitrogen ions, the frictional coefficient of the surface layer decreased, and the wear resistance increased with the nitrogen dose. The tribological mechanism was mainly adhesive, and the adhesive wear tended to become weaker oxidative wear with the increase in the nitrogen dose. The effects were mainly attributed to the formation of a hard nitride precipitate and a supersaturated solid solution of nitrogen in the surface layer.

• Journal of the Korean Solar Energy Society
• /
• v.35 no.4
• /
• pp.9-15
• /
• 2015

Black cobalt solar selective coatings were prepared by using an electroplating method. The changes in the optical properties of the black cobalt selective coating due to thermal degradation were analyzed by using the Auger electron spectroscopy (AES) and spectrophotometer. The black cobalt selective coating was prepared on a copper substrate by using a synthesized electrolyte with $CoCl_2$ and KSCN at a current density of ${\sim}0.5A/dm^2$ for 45s ~ 60s. Its optical properties were a solar absorptance (${\alpha}$) of the order of 0.80 ~ 0.84 and a thermal emittance (${\epsilon}$) of 0.01. From the AES depth profile analysis of heated sample, thermal degradation of the black cobalt selective coating heated for 33 hours at temperature of $350^{\circ}C$ occurred primarily due to interdiffusion at interface of cobalt and copper substrate. This results were predictable that the ${\alpha}$ decreases due to the thermal oxidation and diffusion.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.12
• /
• pp.1649-1655
• /
• 1988

Thermally growon SiO2 films were thermally nitrided in a hot-wall furnace and in a RF-heated cold-wall reactor and their characteristics were investigated by the AES and the C-V dmeasurements. The Auger depth profile show that 200\ulcornerSiO2 film nitrided at 1200\ulcorner, for 2hrs by the hot-wall process has a nitrogen-rich layer near the SiOxNy-Si interface. However the nitrogen-ri h layer is not observed in the case of cold-wall process. The maximum flat-band voltage for the SiO2 films nitrided by the hot-wall process is higher than by the cold-wall process, and the peak value of flat-band voltage for the hot-wall process appears the longer nitridation time than that for the cold-wall process. The SiOxNy-Si interface shift toward the Si substrate for the case of the hot-wall process is larger than that for the cold-wall process.

• Tribology and Lubricants
• /
• v.4 no.2
• /
• pp.36-43
• /
• 1988

Titanium carbide(TiC) and titanium nitride(TiN) flims were deposited on $Si_3N_4$-TiC composite cutting tools by chemical vapor deposition(CVD) using $TiCl_4-CH_4-H_2$ and $TiCl_4-H_2-N_2$ gas mixtures, respectively. The nonmetal to metal ratio of deposit increases with increasing $m_{C/Ti}$(mole ratio of CH$_4$ to TiCl$_4$ in the input) for TiC coatings and $m_{N/Ti}$(mole ratio of N$_2$ to TiCl$_4$ in the input) for TiN coatings. The nearly stoiahiometric films could be obtained under the deposition condition of $m_{C/Ti}$ between 1.15 and 1.61 for TiC, and that of $m_{N/Ti}$ between 25 and 28 for TiN. Also maximum microhardness of the coatings can be obtained in these ranges. The interfacial region of TiC coatings on $Si_3N_4$-TiC ceramics is wider than that of TiN coatings according to Auger depth profile analysis, which indicates good interfacial bonding for TiC. Experimental results show that TiC coatings have an randomly equiaxed structure and Columnar structure with(220) preferred orientation can be obtained for TiN coatings. And, multilayer coatings have a dense and equiaxed structure.

• Korean Journal of Materials Research
• /
• v.31 no.2
• /
• pp.97-100
• /
• 2021

We report the effect of Standard Clean-1 (SC-1) cleaning to remove residual Ti layers after silicidation to prevent Al diffusion into Si wafer for Ti Schottky barrier diodes (Ti-SBD). Regardless of SC-1 cleaning, the presence of oxygen atoms is confirmed by Auger electron spectroscopy (AES) depth profile analysis between Al and Ti-silicide layers. Al atoms at the interface of Ti-silicide and Si wafer are detected, when the SC-1 cleaning is not conducted after rapid thermal annealing. On the other hand, Al atoms are not found at the interface of Ti-SBD after executing SC-1 cleaning. Al diffusion into the interface between Ti-silicide and Si wafer may be caused by thermal stress at the Ti-silicide layer. The difference of the thermal expansion coefficients of Ti and Ti-silicide gives rise to thermal stress at the interface during the Al layer deposition and sintering processes. Although a longer sintering time is conducted for Ti-SBD, the Al atoms do not diffuse into the surface of the Si wafer. Therefore, the removal of the Ti layer by the SC-1 cleaning can prevent Al diffusion for Ti-SBD.

• Korean Journal of Materials Research
• /
• v.9 no.9
• /
• pp.878-882
• /
• 1999

Structural properties of $Al_xGa_1-_xN$ epilayers grown on (0001) sapphire substrate by plasma induced molecular beam epitaxy are investigated in the range of AlN molar fraction from 0.16 to 0.76. The AlN molar fraction estimated by X-ray diffraction agrees well with that of Rutherford backscattering spectroscopy, showing a good linear relationship. The uniform Auger electron microscopy depth profile and linear dependence of average atomic concentration of all the constituents of AlGaN epilayers on AlN molar fraction imply that the epitaxial growth of $Al_xGa_1-_xN$ layers with variation of AlN molar fraction is well controlled without the compositional fluctuation in depth of the epilayer. It is observed by atomic force microscopy that the surface grain shape of $Al_xGa_1-_xN$ epilayer changes from roundish to coalesced one with increasing AlN molar fraction.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.31A no.8
• /
• pp.80-90
• /
• 1994

The ultra shallow junction was formed by 2-step RTP. Phosphorus solid source(P$_{2}O_{5}$) was transfered on wafer surface during RTG(Rapid Thermal Glass Transfer) of which process condition was 80$0^{\circ}C$ and 60sec. The process temperature and time of the RTD(Rapid Thermal Diffusion) were 950~105$0^{\circ}C$ during 5~15sec respectively sheet resistances were measured as 175~320$\Omega$/m and junction depth and dopth and dopant surface concentration were measured as 0.075~0.18$\mu$m and 5${\times}10^{19}cm^{4}$ respectively. Ti-silicide was formed by 2-step RTA after 300$\AA$ Titanium was deposited. The 1st RTA (2nd RTA) was carried out at the temperature of $600^{\circ}C$(700~80$0^{\circ}C$) for 30 seconds (10~60 seconds) under N$_2$ ambient. Sheet resistances after 2nd RTA were measured as 46~63$\Omega$/D. Si/Ti component ratio was evaulated as 1.6~1.9 from Auger depth profile. Ti-Silicided n-p junction diode (pattern size : 400$\times$400$\mu$m) was fabricated under the RTD(the process was carried out at the temperature of 100$0^{\circ}C$ for 10seconds) and 2nd RTA(theprocess was carried out at the temperature of 750$^{\circ}C$ for 60 seconds). Leakage current was measured 1.8${\times}10^{7}A/mm^{2}$ at 5V reverse voltage. Whent the RTD process condition is at the temperature of 100$0^{\circ}C$ for 10seconds and the 2nd RTA process condition is at the temperature of 75$0^{\circ}C$ for 60 seconds leakage current was 29.15${\times}10^{9}A$(at 5V).