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ABSTRACT: We have investigated the effects of fluoride residue on the thermal stability of a Cu/barrier metal(BM)/porous low-k film (k < 2.3) structure. We confirmed that the Cu agglomerated more on a BM/inter layer dielectric (ILD) with a fluoride residue. To consider the effect of fluoride residue on Cu agglomeration, the structural state at the Cu/BM interface was evaluated with a cross-section transmission electron microscope (TEM) and atomic force microscope (AFM). And the chemical bonding state at the Cu/BM interface was evaluated with the interface peeling-off method and X-ray photoelectron spectroscopy (XPS). Moreover, we confirmed the oxidation of Cu with fluoride in accelerated conditions to clarify the effect of fluoride on Cu. Our experiments suggested that the fluoride residue led to the formation of a metal fluoride, and this accelerated the Cu agglomeration accompanying an increase in Cu oxidation
Microelectronic Engineering 01/2011; 88:620. · 1.56 Impact Factor
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ABSTRACT: We clarified that interfacial barrier metal oxidation with inter layer dielectric (ILD) could be revealed by X-ray photoelectron spectroscopy (XPS) on the peeled-side of the barrier metal, and the barrier metal oxidation was promoted by fluorine contamination which adsorb to the ILD surface during etching. To consider the effect of fluorine contamination on barrier metal oxidation, hydrolysable property of fluorine contamination was evaluated by measuring the change of F 1s spectrum after dipping in boiling water. Moreover, fluoride ions and the acidity of water in which fluorine contamination was dipped were measured by Ion chromatography and pH measurement, respectively. According to our experiments, it was suggested that hydrofluoric acid (HF) acted as an oxidizing catalyst to promote barrier metal oxidation at the interface of barrier metal and ILD.
Microelectronic Engineering 03/2010; 87(3):370. · 1.56 Impact Factor
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H Kudo,
K Ishikawa,
M. Nakaishi,
A. Tsukune,
S Ozaki,
Y Nakata,
S Akiyama,
Y Mizushima,
M Hayashi,
Ade A. Akbar,
T Kouno,
H Iwata, Y Iba,
T Ohba,
T. Futatsugi,
T Nakamura,
T. Sugii
[show abstract]
[hide abstract]
ABSTRACT: Via cleaning using gas-phase organic acid has a high potential for improving the reduction capability of copper oxides (CuO), not degrading porous ultra-low-k dielectrics, and reducing processing cost. We applied our via cleaning technique to intermediate and semi-global levels consisting of homogeneous interlayer dielectric architectures based on the 45-nm technology node. The CuO reduction rate was by a factor of 10, which was much higher compared with that using hydrogen. This allowed us to achieve a 100% yield for a mega-scaled via chain. Via chains treated with gas-phase organic acid also showed greater resistance against stress-induced voiding. In addition, we substantially reduced the via cleaning process cost by a factor of 10 compared with the cost of conventional wet chemical cleaning. In addition, organic acid is preferable because it occurs naturally and is thus ecologically friendly.
Interconnect Technology Conference, 2008. IITC 2008. International; 07/2008
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H. Kudo,
H. Ochimizu,
A. Tsukune,
S. Okano,
K. Naitou,
M. Sakamoto,
S. Takesako,
T. Shirasu,
A. Asneil,
N. Idani, [......],
Y. Mizushima,
H. Matsuyama,
Y. Suzuki,
N. Shimizu,
K. Yanai,
M. Nakaishi,
T. Futatsugi,
I. Hanyu,
T. Nakamura,
T. Sugii
[show abstract]
[hide abstract]
ABSTRACT: According to the 45 nm BEOL technology node, we demonstrated that a homogeneous interlayer dielectric with dielectric constant of 2.25 has a substantial advantage in terms of RC delay reduction compared to other potential architectures such as hybrid and tri-level dielectrics. Combination of the homogeneous interlayer dielectric and ultra-thinned barrier metal lowered the RC delay to 86 % compared to that listed in the ITRS 2006 update.
International Interconnect Technology Conference, IEEE 2007; 07/2007
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[hide abstract]
ABSTRACT: A 56-year-old man had undergone ascending aorta and total arch replacement because of aortic dissection (Stanford type A) in 1997. He had onset of diplegia of the lower limb and vesicorectal disability. Computed tomography (CT) showed serpentine aneurysm in the descending aorta, it was seen between the left subclavian artery and diaphragm level. It was 80 mm of maximum diameter. Magnetic resonance imaging (MRI) was performed for identified Adamkiewicz artery, but we could not identify it. We performed a graft replacement. The 8th intercostal artery was reconstructed with a branch graft. The postoperative course was uneventful. We conclude that graft replacement for spinal ischemia can be effective.
Kyobu geka. The Japanese journal of thoracic surgery 04/2007; 60(3):207-11.
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ABSTRACT: A 60-year-old woman, who had undergone aortic root replacement with composite graft 5 months previously, suffered from anemia and slight fever. Transthoracic echocardiography showed pseudoaneurysm in the aortic root, and blood culture was positive. She was diagnosed with prosthetic valve endocarditis, and surgical intervention was planned. Intraoperatively necrotic tissue and dehiscence of the suture line in the aortic annulus were found. Re-aortic root replacement with Freestyle bioprosthesis and re-hemiarch graft replacement were performed with the omentopexy around the aortic root and the new graft. Antibiotics were administered intravenously for 6 weeks postoperatively. At 7 months after the operation, no prosthetic valve infection had recurred. Although the long-term results of Freestyle bioprosthesis have not been determined, it might be a valuable option for aortic root infection as an alternative to an aortic homograft. In addition, omentopexy might also be effective in the prevention of recurrent prosthetic valve infection.
Kyobu geka. The Japanese journal of thoracic surgery 08/2006; 59(7):531-5.
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M. Okuno,
K. Okabe,
T. Sakuma,
K. Suzuki,
T. Miyashita,
T. Yao,
H. Morioka,
M. Terahara,
Y. Kojima,
H. Watatani, [......],
M. Nakaishi,
S. Fukuyama,
A. Tsukune,
M. Yamabe,
I. Hanyuu,
M. Miyajima,
M. Kase,
K. Watanabe,
S. Satoh,
T. Sugii
[show abstract]
[hide abstract]
ABSTRACT: We describe the integration of a 45-nm node CMOS for low operation power (LOP) application. The SD extension profile along with a strain channel and a thin-gate-SiON were optimized to keep high drive current at the 45-nm node. A novel STI structure was developed to reduce the SRAM cell size. Nano-clustering silica (NCS) without a middle-etch stopper (MES) was also developed to decrease the wire capacitance. As a result, we achieved an excellent LOP device operation with conventional processing, and we produced a 50% smaller SRAM cell-size as compared to the 65-nm node
Electron Devices Meeting, 2005. IEDM Technical Digest. IEEE International; 01/2006
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I. Sugiura,
N. Misawa,
S. Otsuka,
N. Nishikawa, Y. Iba,
F. Sugimoto,
Y. Setta,
H. Sakai,
Y. Koura,
K. Nakano,
T. Suzuki,
H. Kitada,
N. Shimizu,
S. Nakai,
M. Nakaishi,
S. Fukuyama,
T. Nakamura,
E. Yano,
M. Miyajima,
K. Watanabe
[show abstract]
[hide abstract]
ABSTRACT: We developed a 65-nm CMOS technology that could successfully integrate a novel porous low-k material, NCS. Using our nano-clustering technique, we obtained that NCS had a high compatibility between a very low dielectric constant and high framework strength. We successfully fabricated 11-levels Cu interconnects using hybrid-NCS structure. These interconnects had a high tolerance to the etching process and produced a smooth surface on the bottom of the trenches, with no via-fences, and no low-k voiding. They did not require a pore-sealing process. These high-performance hybrid-NCS/Cu multilevel interconnects met the 65-nm node requirements for Back-End of the Line, while maintaining sufficient robustness to support CMP, wire-bonding, and packaging processes. Hybrid-NCS/Cu multilevel interconnects are suitable for mass production and show excellent reliability for 65-nm node device requirements.
Microelectronic Engineering 12/2005; 82(3-4):380. · 1.56 Impact Factor
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I. Sugiura,
Y. Nakata,
N. Misawa,
S. Otsuka,
N. Nishikawa, Y. Iba,
F. Sugimoto,
Y. Setta,
H. Sakai,
Y. Mizushima, [......],
H. Watatani,
M. Sato,
S. Nakai,
M. Nakaishi,
N. Shimizu,
S. Fukuyama,
M. Miyajima,
T. Nakamura,
E. Yano,
K. Watanabe
[show abstract]
[hide abstract]
ABSTRACT: 45 nm-node multilevel Cu interconnects with porous-ultra-low-k have successfully been integrated. Key features to realize 45 nm-node interconnects are as follows: 1) porous ultra-low-k material NCS (nano-clustering silica) has been applied to both wire-level and via-level dielectrics (what we call full-NCS structure), and its sufficient robustness has been demonstrated; 2) 70-nm vias have been formed by high-NA 193 nm lithography with fine-tuned model-based OPC and multi-hard-mask dual-damascene process - more than 90% yields of 1 M via chains have been obtained; 3) good TDDB (time-dependent dielectric breakdown) characteristics of 70 nm wire spacing filled with NCS has been achieved. Because it is considered that the applied-voltage (Vdd) of a 45 nm-node technology will be almost the same as that of the previous technology, the dielectrics have to endure the high electrical field. NCS in Cu wiring has excellent insulating properties without any pore sealing materials which cause either the k<sub>eff</sub> value or actual wire width to be worse.
Interconnect Technology Conference, 2005. Proceedings of the IEEE 2005 International; 07/2005
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S. Nakai,
M. Kojima,
N. Misawa,
M. Miyajima,
S. Asai,
S. Inagaki, Y. Iba,
T. Ohba,
M. Kase,
H. Kitada, [......],
N. Horiguchi,
H. Matsuyama,
T. Minami,
M. Minamizawa,
H. Morioka,
E. Yano,
A. Yamaguchi,
K. Watanabe,
T. Nakamura,
T. Sugii
[show abstract]
[hide abstract]
ABSTRACT: This paper presents a 65 nm CMOS technology for mobile multimedia applications. The reduction of interconnect capacitance is essential for high-speed data transmission and small power consumption for mobile core chips. We have chosen a hybrid ULK structure which consists of NCS (nano-clustering silica; k=2.25) at the wire level and SiOC (k=2.9) at the via level. Although NCS is a porous material, the NCS/SiOC structure has sufficient mechanical strength to endure CMP pressure and wire bonding. Successfully fabricated 200 nm-pitch hybrid-ULK/Cu interconnects and a high-performance and low-leakage transistors meet the electrical targets from the circuit requirements. Moreover, an embedded 6T-SRAM with a 0.55 μm<sup>2</sup> small cell size has been achieved.
Electron Devices Meeting, 2003. IEDM '03 Technical Digest. IEEE International; 01/2004
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M. Ikeda,
J. Nakahira, Y. Iba,
H. Kitada,
N. Nishikawa,
M. Miyajima,
S. Fukuyama,
N. Shimizu,
K. Ikeda,
T. Ohba,
I. Sugiura,
K. Suzuki,
Y. Nakata,
S. Doi,
N. Awaji,
E. Yano
[show abstract]
[hide abstract]
ABSTRACT: A highly reliable nano-clustering silica (NCS) with low dielectric constant(k<2.3) and high elastic modulus (E=10 Gpa) for copper damascene process has been developed by controlling the size and distribution of pores in the NCS precursor. Using this material in a process compatible with the 90 nm technology node, we successfully demonstrated Cu wiring in NCS dielectrics.
Interconnect Technology Conference, 2003. Proceedings of the IEEE 2003 International; 07/2003
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[hide abstract]
ABSTRACT: Percutaneous transluminal coronary stenting is a proven nonoperative method of direct myocardial revascularization. We encountered a case of iatrogenic significant subacute left main coronary artery stenosis in a patient who had undergone prior percutaneous transluminal coronary artery stenting of the left anterior descending (LAD) artery. Coronary artery bypass grafting was performed. To our knowledge, this is the first report of a surgical case of left main coronary artery stenosis worsened by changes secondary to earlier coronary stenting in the mid portion of left descending coronary artery in Japan.
The Journal of cardiovascular surgery 03/2002; 43(1):55-8. · 1.56 Impact Factor
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[hide abstract]
ABSTRACT: Gemella morbillorum (G. morbillorum) is part of the commensal flora of the oropharynx and intestinal tract, and on rare occasions causes infective endocarditis. A 55-year-old man with massive aortic regurgitation caused by recurrent infective endocarditis with G. morbillorum had a history of prior endocarditis caused by alpha-hemolytic streptococcus and multiple antibiotic allergies 5 years prior, and was successfully treated by aortic valve replacement. Almost all the reported cases of endocarditis caused by G. morbillorum have been bacteriologically cured with antibiotics and this is the first reported case of recurrent endocarditis caused by G. morbillorum in which the initial infection was bacteriologically cured by antibiotics and the secondary infection treated with valve replacement. This organism can be one of the causes of infective endocarditis and prompt surgical repair is mandatory if the infection is refractory or there is progression of congestive heart failure under antibiotic cover.
Japanese Circulation Journal 12/2001; 65(11):997-1000.
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ABSTRACT: A 66-year-old woman who received maintenance hemodialysis for the last 14 years was referred to our hospital due to the sudden onset of ischemic stroke and systemic emboli. Transthoracic echocardiography before surgery showed large protruding masses measuring 2 cm which projected into the lumen of the aortic root. The plaque originated on a wide base of the posterior aspect of the ascending aorta at its junction with the sinus of Valsalva. The mobile plaque was surgically removed by endarterectomy from the posterior wall of sino-tubular junction under cardiopulmonary bypass. Pathologic examination of the masses removed at the time of surgery showed that they were atherosclerotic plaque with superimposed thrombi. During operation, transesophageal echocardiography appears to be useful for the rapid detection of a protruding aortic atheroma especially in the initial period of cardiopulmonary bypass until aortic cross clamp.
Kyobu geka. The Japanese journal of thoracic surgery 12/2001; 54(12):1059-61.
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[show abstract]
[hide abstract]
ABSTRACT: Graft replacement for arch aneurysms and concomitant coronary artery bypass grafting (CABG) were performed in four consecutive patients over a three-year period between March 1995 and October 1998. The etiology of the aneurysms was atherosclerosis in all the patients. One early death as a result of a cerebellar infarction occurred on the 74th postoperative day. In all cases, respiratory failure frequently occurred after surgery. In a recent case, the internal mammary artery was used as a graft conduit to the left anterior descending artery (LAD). Both artery and vein grafts were anastomosed to coronary arteries during the initial core cooling. Selective cerebral perfusion was carried out during the reconstruction of the transverse aortic arch and its branches. The left subclavian artery was anastomosed first to secure perfusion to the LAD. To achieve sufficient myocardial protection and obtain good postoperative hemodynamics, CABG was simultaneously performed at the time of aortic aneurysm repair in cases complicated with coronary artery disease.
Kyobu geka. The Japanese journal of thoracic surgery 06/2001; 54(5):408-10.
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[hide abstract]
ABSTRACT: A patient with a thrombosed mechanical valve underwent valve re-replacement during which a tumor of the left ventricular outflow tract with the typical macroscopic and microscopic characteristics of a papillary fibroelastoma was successfully removed surgically. The 60-year-old woman had undergone isolated mitral valve replacement with a St Jude Medical 29-mm valve for mitral regurgitation 15 years ago. The present admission was for investigation of dyspnea on exertion. Two-dimensional transthoracic echocardiography demonstrated a posteroseptal, pedunculated mass, measuring 1.3x1.0 cm, in the outflow tract of the left ventricle, mild mitral regurgitation and slight aortic stenosis.
Japanese Circulation Journal 11/2000; 64(10):797-9.
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Y. Iba,
T. Taguchi,
F. Kumasaka,
T. Iizuka,
Y. Sanbonsugi,
K. Deguchi,
H. Aoyama,
M. Fukuda,
M. Oda,
H. Morita,
T. Matsuda,
K. Horiuchi,
Y. Matsui
[show abstract]
[hide abstract]
ABSTRACT: Proximity X-ray lithography (PXL) is a promising technology for
fabricating ultra-large-scale integrated (ULSI) devices smaller than 100
nm because it offers high-resolution capabilities and dimensional
control with high throughput. We used PXL at five levels (mark,
isolation, gate, contact, wiring) and fabricated 100-nm complicated
dense patterns and sub-100-nm channel length MOSFETs. In this paper, we
discuss lithographic performance and the performance of the MOSFET
device
Microprocesses and Nanotechnology Conference, 2000 International; 08/2000
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[show abstract]
[hide abstract]
ABSTRACT: A 57-year-old man was admitted to hospital for acute myocardial infarction associated with mild aortic regurgitation, which was successfully treated by intracoronary thrombolysis. Twenty-four days later, he suffered from another chest pain attack without any electrocardiographic ST-T changes. The coronary angiogram did not show any significant lesions, but the aortic root angiogram showed massive aortic regurgitation. Surgery revealed a bicuspid aortic valve with a conjoined cusp that had a fenestrated raphe torn away from the aortic wall and prolapsing into the left ventricle. The aortic valve was successfully replaced with a St Jude Medical mechanical valve prosthesis. The pathological significance of the intact raphal cord and the rupture remains an unsolved problem. This is the first reported case in which an increase of aortic regurgitation due to a ruptured raphal cord supporting the conjoined cusp was confirmed by a serial root angiogram.
Japanese Circulation Journal 07/2000; 64(6):477-80.
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I. Sugiura,
N. Misawa,
S. Otsuka,
N. Nishikawa, Y. Iba,
F. Sugimoto,
Y. Setta,
H. Sakai,
Y. Koura,
K. Nakano, [......],
T. Suzuki,
H. Kitada,
N. Shimizu,
S. Nakai,
M. Nakaishi,
S. Fukuyama,
T. Nakamura,
E. Yano,
M. Miyajima,
K. Watanabe
[show abstract]
[hide abstract]
ABSTRACT: We developed a 65-nm CMOS technology that could successfully integrate a novel porous low-k material, NCS. Using our nano-clustering technique, we obtained that NCS had a high compatibility between a very low dielectric constant and high framework strength. We successfully fabricated 11-levels Cu interconnects using hybrid-NCS structure. These interconnects had a high tolerance to the etching process and produced a smooth surface on the bottom of the trenches, with no via-fences, and no low-k voiding. They did not require a pore-sealing process. These high-performance hybrid-NCS/Cu multilevel interconnects met the 65-nm node requirements for Back-End of the Line, while maintaining sufficient robustness to support CMP, wire-bonding, and packaging processes. Hybrid-NCS/Cu multilevel interconnects are suitable for mass production and show excellent reliability for 65-nm node device requirements.
Microelectronic Engineering.
