이리듐 첨가에 의한 니켈모노실리사이드의 고온 안정화

윤기정,송오성,Yoon, Ki-Jeong,Song, Oh-Sung 한국재료학회 2006 한국재료학회지 Vol.16 No.9

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.

Pt와 Ir 첨가에 의한 니켈모노실리사이드의 고온 안정화

윤기정,송오성,Yoon, Ki-Jeong,Song, Oh-Sung 한국마이크로전자및패키징학회 2006 마이크로전자 및 패키징학회지 Vol.13 No.4

약 10%이하의 Pt 또는 Ir 첨가시켜 니켈모노실리싸이드를 고온에서 안정화 시키는 것이 가능한지 확인하기 위해서 활성화영역을 가정한 단결정 실리콘 웨이퍼와 게이트를 상정한 폴리 실리콘 웨이퍼 전면에 Ni, Pt, Ir을 열증착기로 성막하여 10 nm-Ni/l nm-Pt/(poly)Si, 10 nm-Ni/l nm-Ir/(poly)Si 구조를 만들었다. 준비된 시편을 쾌속 열처리기를 이용하여 40초간 실리사이드화 열처리 온도를 $300^{\circ}C{\sim}1200^{\circ}C$ 범위에서 변화시켜 두께 50nm의 실리사이드를 완성하였다. 완성된 Pt와 Ir이 첨가된 니켈실리사이드의 온도별 전기저항변화, 두께변화, 표면조도변화, 상변화, 성분변화를 각각 사점전기저항측정기와 광발산주사전자현미경, 주사탐침현미경, XRD와 Auger depth profiling으로 각각 확인하였다. Pt를 첨가한 결과 기판 종류에 관계없이 기존의 니켈실리사이드 공정에 의한 NiSi와 비교하여 $700^{\circ}C$ 이상의 NiSi 안정화 구역을 넓히는 효과는 없었고 면저항이 커지는 문제가 있었다. Ir을 삽입한 경우는 단결정 실리콘 기판에서는 $500^{\circ}C$ 이상에서의 NiSi와 동일하게 $1200^{\circ}C$까지 안정한 저저항을 보여서 Ir이 효과적으로 Ni(Ir)Si 형태로 $NiSi_{2}$로의 상변태를 적극적으로 억제하는 특성을 보이고 있었고, 다결정 기판에서는 $850^{\circ}C$까지 효과적으로 NiSi의 고온 안정성을 향상시킬 수 있었다. We fabricated thermally evaporated 10 nm-Ni/(poly)Si, 10 nm-Ni/l nm-Ir/(poly)Si and 10 nm-Ni/l nm-Pt/(poly)Si films to investigate the thermal stability of nickel monosilicides at the elevated temperatures by rapid annealing them at the temperatures of $300{\sim}1200^{\circ}C$ for 40 seconds. Silicides of 50 nm-thick were formed on top of both the single crystal silicon actives and the polycrystalline silicon gates. A four-point tester was used to examine sheet resistance. A scanning electron microscope and field ion beam were employed for thickness and microstructure evolution characterization. An X-ray diffractometer and an Auger depth profiler were used for phase and composition analysis, respectively. Nickel silicides with platinum have no effect on widening the NiSi stabilization temperature region. Nickel silicides with iridium farmed on single crystal silicon showed a low resistance up to $1200^{\circ}C$ while the ones formed on polycrystalline silicon substrate showed low resistance up to $850^{\circ}C$. The grain boundary diffusion and agglomeration of silicides lowered 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.

나노급 두께 니켈실리사이드의 적외선 흡수 특성

윤기정,한정조,송오성,Yoon, Ki-Jeong,Han, Jeung-Jo,Song, Oh-Sung 한국재료학회 2007 한국재료학회지 Vol.17 No.6

We fabricated thermaly evaporated 10 nmNi/(poly)Si films to investigate the energy saving property of silicides formed by rapid thermal annealing (RTA) at the temperature of $300{\sim}1200^{\circ}C$ for 40 seconds. Moreover, we fabricated $10{\sim}50$ nm-thick ITO/Si films with a rf-sputter as reference films. A four-point tester was used to investigate the sheet resistance. A transmission electron microscope (TEM) and an X-ray diffractometer were used for the determination of cross sectional microstructure and phase changes. A UV-VISNIR and FT-IR (Fourier transform infrared rays spectroscopy) were employed for near-IR and middle-IR absorbance. Through TEM analysis, we confirmed $20{\sim}70nm-thick$ silicide layers formed on the single and polycrystalline silicon substrates. Nickel silicides and ITO films on the single silicon substrates showed almost similar absorbance in near-IR region, while nickel silicides on polycrystalline silicon substrate showed superior absorbance above 850 nm near-IR region to ITO films. Nickel silicide on polycrystalline substrate also showed better absorbance in middle IR region than ITO. Our result implies that nano-thick nickel silicides may have exellent absorbing capacity in near-IR and middle-IR region.

나노급 Au층 삽입 니켈실리사이드의 미세구조 변화

윤기정,송오성,Yoon, Ki-Jeong,Song, Oh-Sung 한국재료학회 2008 한국재료학회지 Vol.18 No.1

Thermally evaporated 10 nm-Ni/1 nm-Au/(30 nm-poly)Si structures were fabricated in order to investigate the thermal stability of Au-inserted nickel silicide. The silicide samples underwent rapid thermal annealing at $300{\sim}1100^{\circ}C$ for 40 seconds. The sheet resistance was measured using a four-point probe. A scanning electron microscope and a transmission electron microscope were used to determine the cross-sectional structure and surface image. High-resolution X-ray diffraction and a scanning probe microscope were employed for the phase and surface roughness. According to sheet resistance and XRD analyses, nickel silicide with Au had no effect on widening the NiSi stabilization temperature region. Au-inserted nickel silicide on a single crystal silicon substrate showed nano-dots due to the preferred growth and a self-arranged agglomerate nano phase due to agglomeration. It was possible to tune the characteristic size of the agglomerate phase with silicidation temperatures. The nano-thick Au-insertion was shown to lead to self-arranged microstructures of nickel silicide.

논문 : 이리듐이 첨가된 니켈실리사이드의 적외선 흡수 특성

윤기정 ( Ki Jeong Yoon ),송오성 ( Oh Sung Song ),한정조 ( Jeung Jo Han ) 대한금속재료학회 ( 구 대한금속학회 ) 2008 대한금속·재료학회지 Vol.46 No.11

We fabricated thermally evaporated 10 nm-Ni/1 nm-Ir/(poly)Si films to investigate the energy saving property of silicides formed by rapid thermal annealing (RTA) at the temperature range of 300~1,200℃ for 40 seconds. Moreover, we fabricated 100 nm-thick ITO/(poly)Si films with an rf-sputter as references. A transmission electron microscope (TEM) and an X-ray diffractometer were used to determine cross-sectional microstructure and phase changes. A UV-VIS-NIR and FT-IR (Fourier transform infrared spectroscopy) were employed for near-IR and middle-IR absorbance. Through TEM analysis, we confirmed 20~65 nm-thick silicide layers formed on the single and polycrystalline silicon substrates. Ir-inserted nickel silicide on single crystalline substrate showed almost the same absorbance in near IR region as well as ITO, but Ir-inserted nickel silicide on polycrystalline substrate, which had the uniform absorbance in specific region, showed better absorbance in near IR region than ITO. The Ir-inserted nickel silicide on polycrystalline substrate particularly showed better absorbance in middle IR region than ITO. The results imply that nano-thick Ir-inserted nickel silicides may have excellent absorbing capacity in near-IR and middle-IR region.

루테늄 삽입층에 의한 니켈모노실리사이드의 안정화

윤기정 ( Ki Jeong Yoon ),송오성 ( Oh Sung Song ) 대한금속재료학회 2008 대한금속·재료학회지 Vol.46 No.3

Pd 삽입 니켈모노실리사이드의 물성과 미세구조 변화

윤기정 ( Ki Jeong Yoon ),송오성 ( Oh Sung Song ) 대한금속ᆞ재료학회 2008 대한금속·재료학회지 Vol.46 No.2

계자권선 절환에 의한 직류전동기의 고효율 추종 운전

윤기정(Ki-Jeong Yoon),김광헌(Kwang-Heon Kim) 대한전기학회 1997 대한전기학회 학술대회 논문집 Vol.1997 No.11

Ir과 Co를 첨가한 니켈모노실리사이드의 고온 안정화 연구

윤기정(Yoon, Ki-Jeong),송오성(Song Ohsung) 한국산학기술학회 2006 한국산학기술학회논문지 Vol.7 No.6

10 ㎚-Ni/1 ㎚-Ir/(poly)Si과 10 ㎚-Ni₅₀Co₅₀/(poly)Si 구조의 박막을 열증착기로 준비하고 쾌속열처리기로 40초 간 300-1200℃ 온도 범위에서 실리사이드화 시켰다. 이들의 실리사이드 온도에 따른 면저항, 미세구조와 두께, 생성상, 화학조성과 표면조도의 변화를 사점면저항 측정기와 이온빔현미경,x선 회절기, 오제이 분석기, 주사탐침현미경을 써서 확인하였다. Ir과 Co의 혼입에 따라 기존의 700℃에 한정된 NiSi에 비해 단결정, 다결정 실리콘 기판에서의 저 저항 안정 구간이 각각 1000℃, 850℃로 향상되었다. 이때의 실리사이드층의 두께도 20-50 ㎚로 나노급 공정에 적합 하였다. Ir과 Co의 첨가는 단결정 기판에서의 니켈실리사이드의 고저항 NiSi₂로의 변태를 방지하였고, 다결정 기판에서 고온에서의 고저항은 고저항 상의 출현과 실리콘층과의 혼합과 도치현상이 발생한 것이 이유였다. Ir의 첨가는 특히 최종 실리사이드 표면온도를 3 ㎚ 이내로 유지시키는 장점이 있었다. Ir과 Co를 첨가한 니켈실리사이드는 기존의 니켈실리사이드의 열적 안정성을 향상시켰고 나노급 디바이스에 적합한 물성을 가짐을 확인하였다. Thermal evaporated 10 ㎚-Ni/1 ㎚-Ir/(or polycrystalline)p-Si(100) and 10 ㎚-Ni₅₀Co₅₀/(or polycrystalline)p-Si(100) films were thermally annealed using rapid thermal annealing for 40 sec at 300~1200℃. The annealed bilayer structure developed into Ni(Ir or Co)Si and resulting changes in sheet resistance, microstructure, phase and composition were investigated using a four-point probe, a scanning electron microscopy, a field ion beam, an X-ray diffractometer and an Auger electron spectroscope. The final thickness of Ir- and Co-inserted nickel silicides on single crystal silicon was approximately 20-40 ㎚ and maintained its sheet resistance below 20 Ω/sq. after the silicidation annealing at 1000 ℃. The ones on polysilicon had thickness of 20~55 ㎚ and remained low resistance up to 850℃. A possible reason for the improved thermal stability of the silicides formed on single crystal silicon substrate is the role of Ir and Co in preventing NiSi₂ transformation. Ir and Co also improved thermal stability of silicides formed on polysilicon substrate, but this enhancement was lessened due to the formation of high resistant phases and also a result of silicon mixing during high temperature diffusion. Ir-inserted nickel silicides showed surface roughness below 3 ㎚, which is appropriate for nano process. In conclusion, the proposed Ir- and Co- inserted nickel silicides may be superior over the conventional nickel monosilicides due to improved thermal stability.

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.