Papers - TERAUCHI Mamoru
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Suppression of the Floating-Body Effects in SOI MOSFETs by Bandgap Engineering Reviewed
Mamoru Terauchi, Makoto Yoshimi, Atsushi Murakoshi, Yukihiro Ushiku
Digest of Technical Papers, 1995 Symposium on VLSI Technology 35 - 36 1995.6
Joint Work
Authorship：Lead author
The floating-body effects, which are regarded as the most critical issues in applying Silicon-On-Insulator (SOI) devices to actual LSIs, can be suppressed by the reduction in bandgap energy in the source region. In addition to an increase in the drain breakdown voltage, the suppression of both kinks in I/sub d/-V/sub d/ characteristics and threshold voltage shift with an increase in drain voltage are achieved in sub-quarter micron Nch thin-film SOI MOSFETs.
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Technology Trends of Silicon-On-Insulator -Its Advantages and Problems to be Solved- Reviewed
Yoshimi, Terauchi, Murakoshi, Koh, Matsuzawa, Shigyo, Ushiku
Digest of Technical Papers, 1994 IEEE Electron Devices Meeting 429 - 432 1994.12
Joint Work
Recent progress in SOI technology is reviewed and problems which need be solved are discussed. Emphasis is placed on the substrate floating effect, for which the bandgap engineering method is proposed for the first time. It is demonstrated that Si-Ge formation in the source region can improve the drain breakdown voltage significantly.
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A Surrounding Gate Transistor (SGT) Gain Cell for Ultra High Density DRAMs Reviewed
Mamoru Terauchi, Akihiro Nitayama, Fumio Horiguchi, Fujio Masuoka
Digest of Technical Papers, 1993 Symposium on VLSI Technology 21 - 22 1993.6
Joint Work
Authorship：Lead author
Conventionally, it is necessary to obtain enough (eg. 30fF per one cell) storage capacitance in as small a area as possible. In order to realize high density DRAMs, this leads to the employment of very deep trench- or complicated stacked-capacitors, which elongates fabrication processes. On the other hand, read-out voltage in a conventional DRAM cell is so small that the folded bit-line (BL) scheme must be utilized. In order to reduce noise voltage due to the so-called array-noise, the minimum cell size in this scheme is 8F^2 (F: feature size), which Is larger than that (6F^2) in the open BL scheme. Both the elongated fabrication processes and the 1arge cell size may augment the fabrication cost to be an intolerable amount as F is going to be scaled down to lower sub-micron dimension.
In order to overcome these cost-related problems, the authors propose an easy-to-make, and extremely small, new gain cell structure based on Surrounding Gate Transistor (SGT) [1-3]. Since it operates as a gain cell, it ls possible to read out sufficient amount of signal charge regardless of the stored amount. Thus the storage capacitance needed to realize enough retention time can be much smaller than that required for the conventional trench/stacked DRAM cells. Therefore the open BL scheme can be used for this SGT gain cell because there ls no noise-related problem. In addition, Its cell size is reduced to be 4F.- since It can be arranged to have the cross-point-type configuration. It ls much smaller than other gain cells such as SEA cell [4] or CG cell [5]. Therefore this gain cell ls a promising candidate cell structure for 1G bit/4G bit DRAMs. -
Primary Processes in Sensory Rhodopsin and Retinochrome Reviewed
Kobayashi, Ohtani, Tsuda, Ogasawara, Koshihara, Ichimura, Hara, Terauchi
Plenum Photobiological Science: Its Application 561 - 570 1991.4
Joint Work
hotochemistry of two chromoproteins with retinal have been studied. One is a photoreceptor for the phototaxis of Halobacterium halobium and the other is a photosensitive pigment contained in cephalopod visual cells. The behaviors of the intermediates in their photocycles were clarified with picosecond and nanosecond timeresolved absorption spectroscopy apparatuses.
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Femtosecond Spectroscopy of Acidified Bacteriorhodopsin Reviewed
Takayoshi Kobayashi, Mamoru Terauchi, Masayuki Yoshizawa, Makoto Taiji, Tsutomu Kouyama
Proceedings of 1990 International Quantum Electronics Conference 182 - 182 1990.6
Joint Work
Bacteriorhodopsin (bR) is a ligh t-harvesting energy-transducing pigment so far found only in Halobacterium halobium, prokaryotes that occur in natural brines where the NaCl concentration is at or near saturation.1 Its chromophore, retinal (vitamin A aldehyde), is bound via protonated Schiff base linkage to the E group of a lysine-216 residue in the 26,000-mol wt. protein.2 At neutral pH, bR exhibits a purple color and becomes blue in the acidic environment.1
Because the acidic form of bR (bR605) is an ~40:60 mixture of 13-cis bR605 and all-trans bR605 and neither 13-cis bR605 nor all-trans bR605 can be isolated from each other, there are few papers concerning the photocycles of bR605 including our early picosecond experiment.3
The primary photoprocesses of bR605 studied for the first time, we believe, by femtosecond absorption spectroscopy are described. It has been found that the lowest excited singlet states of 13-cis and all-trans bR605 have different lifetimes (1.5 ± 0.2 ps for 13-cis bR605 and 8.6 ± 0.9 ps for all-trans bR605) from each other and that the red shifted ground state intermediate so far reported in the nanosecond time scale Kacid is directly formed from the lowest excited singlet states of bR605; i.e., there is no species that corresponds to J625, which is the first red shifted ground state intermediate in the photocycle of light adapted bacteriorhodopsin at neutral pH (bR568) in the photocycle of bR605. It has also been found that, because there was no clear oscillatory behavior in the transient gain or absorption associated with the transition from the lowest excited singlet states of bR605, the isomerization around C13=C14 of the retinal molecule in the lowest excited singlet states in both 13-cis bR605 and all-trans bR605 has an overdamped nature; i.e., the isomerization angle varies only monotonously in the lowest excited singlet states of both 13-cis bR605 and all-trans bR605. -
Femtosecond Spectroscopy of Acidified and Neutral Bacteriorhodopsin Reviewed
Takayoshi Kobayashi, Mamoru Terauchi, Tsutomu Kouyama, Masayuki Yoshizawa, Makoto Taiji
SPIE Laser Applications in Life Science 1403 407 - 416 1990.5
Joint Work
Femtosecond time-resolved spectroscopic measurements were performed over a wide spectral range of 450-900 nm for the acidic state (bR605) and neutral state (bR568) of bacteriorhodopsin, and their initial photoprocesses were compared. In the neutral state, the induced emission at 860 nm and the excited-state absorption at 480 nm decayed simultaneously with a time constant of 500 fs. This result supports the previous report that the transient absorption species at 460 nm corresponds to the S1 state of bR568. In the acidic state, the decay of induced emission at 860 nm and excited-state absorption at 480 nm were described by two time constants of 1.5 ± 0.2 ps and 8.6 ± 0.9 ps. These two components are estimated to be due to two isomers present in the acidic state. In the acidic state, no time-dependent vibrational structure was observed in the induced emission or excited-state absorption. From these experimental results, it is evident that the isomerization around the C13-C14 bond of the retinal molecule in the S1 state can be described by overdamped vibration. In other words, in the S1 state, the isomerization angle changes monotonically.
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Primary Photoprocesses in Bacteriorhodopsin and Octopus Rhodopsin by Time-Resolved Spectroscopy
Mamoru Terauchi
Doctor's thesis 1990.3
Single Work
Femtosecond time-resolved spectroscopic measurements were performed over a wide spectral range of 450-900 nm for the acidic state (bR605) and neutral state (bR568) of bacteriorhodopsin, the light-sensitive protein of the halophilic archaeon Halobacterium halobium. The results showed that the transient absorption species correspond to the S1 state of bR568 for the neutral state. For the acidic state, a two-component transient response was observed, which is estimated to be due to two isomers present in the acidic state. Additionally, it was revealed that the isomerization angle around the carbon backbone C13-C14 of the retinal molecule in the S1 state changes monotonically with time.
Furthermore, nanosecond time-resolved spectroscopy of halorhodopsin was conducted, and the temperature dependence of its light-induced initial process reverse reaction was investigated to determine in which reaction process the conformational change of rhodopsin is maximized. -
Picosecond Absorption Spectra of a Reaction Center from a Novel Thermophilic Photosynthetic Bacterium 'Chromatium tepidum' Reviewed
Nozawa, Terauchi, Kobayashi, Hatano
Springer Series in Chemical Physics 48 606 - 609 1988.10
Joint Work
Picosecond transient absorption spectroscopy has been applied to a new reaction center purified from a novel thermophilic photosynthetic bacterium Chromatium tepidum. Although the ground state spectrum of the reaction center shows significant differences from that of a mesophilic purple bacterium (Rhodobacter sphaeroides R-26), the primary charge separation kinetics in the reaction center of C. tepidum were essentially the same as those of R. sphaeroides R-26. The significant differences in the ground state spectra are reflected in the profile of the transient absorption spectra. Futhermore electronic transition assignments were discussed.
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Nosaka, Miyama, Terauchi, Kobayashi
Journal of Physical Chemistry 92 255 - 256 1988.10
Joint Work
Study of semiconductor particles is attractive because of possible applications for the direct conversion of solar energy into chemical energy.1 Therefore, it seems important to investigate the processes such as interfacial electron transfer and electron-hole recombination occurring at illuminated semiconductor colloidal particles. For that purpose, time-resolved laser spectroscopy for transparent colloidal semiconductor solution is very useful.1 2 Serpone and co-workers3 first reported picosecond absorption spectra of reduced methylvlologen (MV*+) on illuminated colloidal CdS and claimed that the photoinduced electron transfer from CdS to methylviologen (MV2+) occurred at the rate of 109 s™1. Rossetti and Brus4 reported that the rise time of MV’+ radical is between 5 ns and 20 ps from a picosecond resonance Raman scattering study. Recently, Ramsden5 6has reported that MV2+ is not adsorbed on colloidal CdS stabilized with sodium hexametaphosphate (HMP) from the analysis of nanosecond laser flash photolysis.
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Picosecond Absorption Spectra of a Reaction Center from a Novel Thermophilic Photosynthetic Bacterium 'Chromatium tepidum' Reviewed
Nozawa, Hatano, Terauchi, Kobayashi, Trost, Blankenship
Proceedings of 1988 International Conference on Ultrafast Phenomena 172 - 173 1988.8
Joint Work
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Mamoru Terauchi, Takayoshi Kobayashi
Chemical Physics Letters 137 319 - 323 1987.10
Joint Work
Authorship：Lead author
Laser tuning spectra, nanosecond gain spectra, and picosecond gain and absorption spectra of 1-[p-(N,N-dimethyl-amino)phenyl]-4-(p-nitrophenyl)-1,3-butadiene (DMANPB) are reported. Its permanent dipole moment is found to be larger than 30 D in the lowest excited singlet state. The tuning ranges are 690–725, 695–745, and 705–755 nm in dioxane-acetone mixed solution with volume ratios of 1:0, 5:1, and 4:1, respectively.
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Takayoshi Kobayashi, Hiroyuki Ohtani, Kenji Kurokawa, Mamoru Terauchi
Proceedings of 1987 International Quantum Electronics Conference 114 - 115 1987.10
Joint Work
Stilbene derivatives with electron-donative group(s) attached to one benzene ring and electron-acceptive group(s) to the other are interesting molecules with respect to their large nonlinear optical properties associated with their giant permanent dipole moments, especially in the excited singlet states. One such molecule is 4-dimethyla- mino-4'-nitrostilbene (DMANS), which is reported to have a very large dipole moment (32 D) in the lowest excited singlet state.1 We have proposed the possibility of the application of such molecular systems as DMANS and its diethyl derivative, 4-diethylamino-4'-nitrostilbene (DEANS), which has higher solubility than DMANS in various solvents, to the optically bistable devices utilizing their large third-order nonlinear susceptibility induced by the large dipole moments.2,3
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Lasing Properties and Gain Spectrum of 4-Diethylamino-4'-Nitrostilbene with a Giant Permanent Dipole Reviewed
Takayoshi Kobayashi, Mamoru Terauchi, Hisao Uchiki
Chemical Physics Letters 126 143 - 148 1986.10
Joint Work
Lasing properties are reported for 4-diethylamino-4'-nitrostilbene (DEANS), which has a giant permanent dipole moment in the lowest excited singlet state. Tuning ranges are 612–650 nm, 647–705 nm, 653–708 nm, and 680–705 nm in benzene-acetone mixed solution with volume ratios of 1:0, 5:1, 4:1, and 3:1, respectively. Nanosecond gain and laser spectra measured for DEANS in benzene are also reported.