10 nm 두께의 니켈 코발트 합금 박막으로부터 제조된 니켈코발트 복합실리사이드의 미세구조 분석

송오성,김상엽,김종률,Song, Oh-Sung,Kim, Sang-Yeob,Kim, Jong-Ryul 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.4

We fabricated thermally-evaporated 10 nm-Ni/(poly)Si and 10 nm-$Ni_{0.5}Co_{0.5}$/(Poly)Si structures to investigate the microstructure of nickel silicides at the elevated temperatures required lot annealing. Silicides underwent rapid annealing at the temperatures of $600{\sim}1100^{\circ}C$ for 40 seconds. Silicides suitable for the salicide process formed on top of both the single crystal silicon actives and the polycrystalline silicon gates. A four-point tester was used to investigate the sheet resistances. A transmission electron microscope and an Auger depth profilescope were employed for the determination of vortical microstructure and thickness. Nickel silicides with cobalt on single crystal silicon actives and polycrystalline silicon gates showed low resistance up to $1100^{\circ}C$ and $900^{\circ}C$, respectively, while the conventional nickle monosilicide showed low resistance below $700^{\circ}C$. Through TEM analysis, we confirmed that a uniform, $10{\sim}15 nm$-thick silicide layer formed on the single-crystal silicon substrate for the Co-alloyed case while a non-uniform, agglomerated layer was observed for the conventional nickel silicide. On the polycrystalline silicon substrate, we confirmed that the conventional nickel silicide showed a unique silicon-silicide mixing at the high silicidation temperature of $1000^{\circ}C$. Auger depth profile analysis also supports the presence of this mixed microstructure. Our result implies that our newly proposed NiCo-alloy composite silicide process may widen the thermal process window for the salicide process and be suitable for nano-thick silicides.

Si₃N₄/SiC 복합 세라믹의 온도에 따른 크랙 힐링 관찰과 확산거동

송오성,안도 코토지,다카하시 코지,나가오 와타루,류지호,Song, Oh-Sung,Ando, Kotoji,Takahashi, Koji,Nakao, Wataru,Ryu, Ji-Ho 한국재료학회 2005 한국재료학회지 Vol.15 No.12

To investigate the microcrack healing behavior of $Si_3N_4-20wt\%SiC-8wt\%Y_2O_3$ composite ceramics(SNCY8), we observe the crack length evolution a! the time of 20, 40, 60 minutes with in-situ optical microscopy by varying healing temperature of $800\~1200^{\circ}C$. Crack healing obviously occurred as heating temperature and time increased. We proposed a simple model of effective diffusion based on the crack length evolution with healing condition, and determined the effective diffusion coefficient as Our result implies that we may predict the healing ability quantitatively with temperature and time in structural ceramics through the effective diffusion coefficient model.

코발트 니켈 합금 구조에서 생성된 실리사이드의 마이크로 핀홀의 발생

송오성,김상엽,전장배,김문제,Song, Oh-Sung,Kim, Sang-Yeob,Jeon, Jang-Bae,Kim, M.J. 한국재료학회 2006 한국재료학회지 Vol.16 No.10

We fabricated thermal evaporated 10 nm-$Ni_xCo_{1-x}$ (x=0.2, 0.5 and 0.8) /(poly)Si films to form nanothick cobalt nickel composite silicides by a rapid thermal annealing at $700{\sim}1100^{\circ}C$ for 40 seconds. A field emission scanning electron microscope and a micro-Raman spectrometer were employed for microstructure and silicon residual stress characterization, respectively. We observed self-aligned micro-pinholes on single crystal silicon substrates silicidized at $1100^{\circ}C$. Raman silicon peak shift indicates that the residual tensile strain of $10^{-3}$ in single crystal silicon substrates existed after the silicide process. We propose thermal stress from silicide exothermic reaction and high temperature silicidation annealing may cause the pinholes. Those pinholes are expected to be avoided by lowering the silicidation temperature. Our results imply that we may use our newly proposed composite silicides to induce the appropriate strained layer in silicion substrates.

아몰퍼스실리콘의 결정화에 따른 복합티타늄실리사이드의 물성변화

송오성,김상엽,Song Oh-Sung,Kim Sang-Yeob 한국마이크로전자및패키징학회 2006 마이크로전자 및 패키징학회지 Vol.13 No.1

반도체 메모리 소자의 스피드 향상을 위해 저저항 배선층을 채용하는 방안으로 70 nm-두께의 아몰퍼스실리콘과 폴리실리콘 기판부에 $TiSi_2$ 타켓으로 각각 80 nm 두께의 TiSix 복합실리콘을 스퍼터링으로 증착한 후 RTA $800^{\circ}C$-20sec 조건으로 실리사이드화 처리하고 사진식각법으로 선폭 $0.5{\mu}m$의 배선층을 만들었다. 배선층에 대해 다시 각각 $750^{\circ}C-3hr,\;850^{\circ}C-3hr$의 부가적인 안정화 열처리를 실시하였으며, 이때의 면저항의 변화는 four-point probe로 실리사이드층의 미세구조와 수직단면 두께 변화를 주사전자현미경과 투과전자현미경으로 관찰하였다. 아몰퍼스실리콘 기판인 경우 후속열처리에 따른 결정화 진행과 함께 급격한 면저항의 증가가 확인되었고, 이 원인은 결정화 과정에서 실리콘과 복합티타늄실리사이드 층과의 상호확산으로 표면 공공(void)을 형성한 것으로 미세구조 관찰에서 확인되었다. 따라서 복합티타늄실리사이드의 하지층의 종류와 열처리 조건을 바꾸어 저저항 또는 고저항 실리사이드를 조절하여 제작하는 것이 가능하여 복합 $TiSi_2$를 저저항 배선층 재료로 채용할 수 있음을 확인하였다. We prepared 80 nm-thick TiSix on each 70 nm-thick amorphous silicon and polysilicon substrate using an RF sputtering with $TiSi_2$ target. TiSix composite silicide layers were stabilized by rapid thermal annealing(RTA) of $800^{\circ}C$ for 20 seconds. Line width of $0.5{\mu}m$ patterns were embodied by photolithography and dry etching process, then each additional annealing process at $750^{\circ}C\;and\;850^{\circ}C$ for 3 hours was executed. We investigated the change of sheet resistance with a four-point probe, and cross sectional microstructure with a field emission scanning electron microscope(FE-SEM) and transmission electron microscope(TEM), respectively. We observe an abrupt change of resistivity and voids at the silicide surface due to interdiffusion of silicide and composite titanium silicide in the amorphous substrates with additional $850^{\circ}C$ annealing. Our result implies that the electrical resistance of composite titanium silicide may be tunned by employing appropriate substrates and annealing condition.

복합 코발트 실리사이드 공정에 따른 게이트 산화막의 특성변화

송오성,정성희,이상돈,이기영,류지호,Song, Oh-sung,Cheong, Seong-hwee,Yi, Sang-don,Lee, Ki-yung,Ryu, Ji-ho 한국재료학회 2003 한국재료학회지 Vol.13 No.11

Gate length, height, and silicide thickness have all been shrinking linearly as device density has progressively increased over the years. We investigated the effect of the cobalt diffusion during the silicide formation process on the 60$\AA$-thick gate oxide lying underneath the Ti/Co and Co/Ti bilayers. We prepared four different cobalt silicides, which have similar sheet resistance, made from the film structure of Co/Ti(interlayer), and Ti(capping layer)/Co, and peformed the current-voltage, time-to-break down, and capacitance-voltage measurements. Our result revealed that the cobalt silicide process without the Ti capping layer allowed cobalt atoms to diffuse into the upper interface of gate oxides. We propose that 100$\AA$-thick titanium interlayer may lessen the diffusion of cobalt to gate oxides in 1500-$\AA$ height polysilicon gates.

나노급 Ir 삽입 니켈실리사이드의 미세구조 분석

송오성,윤기정,이태헌,김문제,Song, Oh-Sung,Yoon, Ki-Jeong,Lee, Tae-Hyun,Kim, Moon-Je 한국재료학회 2007 한국재료학회지 Vol.17 No.4

We fabricated thermally-evaporated 10 -Ni/(poly)Si and 10 -Ni/1 -Ir/(poly)Si structures to investigate the microstructure of nickel monosilicide at the elevated temperatures required for annealing. Silicides underwent rapid at the temperatures of 300-1200 for 40 seconds. Silicides suitable for the salicide process formed on top of both the single crystal silicon actives and the polycrystalline silicon gates. A four-point tester was used to investigate the sheet resistances. A transmission electron microscope(TEM) and an Auger depth profile scope were employed for the determination of vertical section structure and thickness. Nickel silicides with iridium on single crystal silicon actives and polycrystalline silicon gates shoed low resistance up to 1000 and 800, respectively, while the conventional nickle monosilicide showed low resistance below 700. Through TEM analysis, we confirmed that a uniform, 20 -thick silicide layer formed on the single-crystal silicon substrate for the Ir-inserted case while a non-uniform, agglomerated layer was observed for the conventional nickel silicide. On the polycrystalline silicon substrate, we confirmed that the conventional nickel silicide showed a unique silicon-silicide mixing at the high silicidation temperature of 1000. Auger depth profile analysis also supports the presence of thismixed microstructure. Our result implies that our newly proposed iridium-added NiSi process may widen the thermal process window for the salicide process and be suitable for nano-thick silicides.

급속 응고법으로 제조된 Cu90Fe10 합금 리본의 자기적 특성과 미세구조

송오성 ( Oh Sung Song ),김종률 ( Jong Ryul Kim ) 서울시립대학교 산업기술연구소 2006 산업기술연구소논문집 Vol.14 No.-

By employing a rapidly solidified method and atmospheric annealing at 450℃-1hr, which is economical process, the granular ribbons of Cu90Fe10 with thickness of 20㎛were manufactured successfully. The magnetic property and microstructure evolution with annealing have been investigated. Saturation magnetization increased as annealing time increased, but no magnetoresistance effect observed at the applied field of 5000 O e. The surface oxidation layer of the ribbons increased as annealing time increased. TEM revealed that 30 nm Fe-rich cluster were foamed with 30 nm-pitch, which lessens the spin exchange interaction. Our result implies that more Fe contents and preventing surface oxidation be required to realize the granular magnetoresistance effect in CuFe ribbons.

도금된 Cop/구리 와이어의 GMI 효과

송오성 ( Oh Sung Song ),윤기정 ( Ki Jeong Yoon ) 서울시립대학교 산업기술연구소 2006 산업기술연구소논문집 Vol.14 No.-

We fabricated the electroplated 20 ㎛-thick CoP on 150 ㎛-diameter copper wires by varying the concentration of H3PO3 by 0~50 g/l for the application of giant magneto-impedance (GMI) sensors of the micro-devices. We investigated the M-H loops and impedance at 250 Oe with 4.5 and 10.7 MHz of the CoP/Cu wires. We reveal that a maximum GMI ratio larger than 200% is achieved by the electroplating condition with H3PO3 30 g/l. Our result implies that our proposed electroplated CoP/Cu may show a superior GMI ratio over the conventional rapidly solidified ribbons and films.

나노급 두께의 Ni50Co50 복합 실리사이드의 적외선 흡수 특성 연구

송오성 ( Oh Sung Song ),김종률 ( Jong Ryul Kim ),최용윤 ( Young Youn Choi ) 대한금속ᆞ재료학회 2008 대한금속·재료학회지 Vol.46 No.2

블루사파이어와 루비의 고온산소 화염처리에 의한 색향상

송오성(Oh Sung Song),김상엽(Sang Yeob Kim) 한국표면공학회 2005 한국표면공학회지 Vol.38 No.2

We enhanced the color of blue sapphires and rubies successfully by using a oxygen-propane torch flame annealing, which had not been employed so far. We confirmed that about 1 ㎜-thick de-coloring of the corundum samples were available with 60 minutes flame annealing through eye evaluation, color coordination characterization, and methylene iodide immersion observation. We also suggest that the color centers such as [Fe<SUP>Al</SUP>˙], [Cr<SUP>Al</SUP>˙] may transform into transparent [FeAl<SUP>x</SUP>], [Cr<SUP>Al</SUP>x] sites with [V<SUP>o</SUP><SUP>"</SUP>] generation at the elevated temperature in oxygen-rich atmosphere by diffusion mechanism. Our results implied that the longer diffusion time and the higher oxygen partial pressure might lead to the better de-coloring enhancement in corundum gem stones.