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The problem of pixel voltage shift for TFT-LCDs due to a gate-source capacitance coupling (Cgs) of a-Si TFT becomes more severe in high resolution LCDs. This problem can be moderated through diminishing Cgs using a self-alignment structure. The self-aligned a-Si TFT process can be simplified by using an ion-doping technique to form source/drain contact regions. The mobility of this ion-doped self-aligned a-Si TFT was 0.35 cm2/V·sec and the threshold voltage was 2.3V. The ON/OFF ratio was over 106 in the dark over 105 under 2000 lx light illumination. These characteristics were sufficiently stable under gate stress. The authors have developed 9-inch TFT-LCD panels with this new self-aligned a-Si TFTs. These LCDs show fairly good image. These data show that ion doping technology is very effective for improving 2-Si TFT-LCDs.

The x-ray and gamma-ray induced damage in BaLiF3 crystallites and its suppression by rare earth ion doping have been studied by electron spin resonance and thermally stimulated luminescence methods. It has been found that the x-ray irradiation damage is light and can be erased easily. This shows that the BaLiF3 crystallite is an ideal host for x-ray storage material. But the damage induced by gamma-ray has been found to be relatively hard to recover; however the gamma-ray irradiation hardness can be improved by rare earth (e.g., La3+, Yb3+) ion doping. So the BaLiF3 is also promising material for being used in detection of high-energy particles (e.g., gamma-ray).

The standard preparative route to [Pten2][Pten2Br2](ClO4)4 (PtBr, where en = H2NCH2CH2NH2) results in Cl− impurities in the product. A study of resonance Raman (RR) spectra of PtBr as a function of chloride ion doping illustrates that the 166 cm−1 component of the RR spectrum corresponds to the chain axis ν1 mode. Previously reported ν1 dispersion and fine structure and several other resonance enhanced defect vibrations are shown to result from chloride doping of the PtBr solid.

(and also of the smalldistortion undergone by the oxygen octahedron), can be obtainedfrom an analysis of experimental values of optical transitionsand EPR parameters through a parametrized crystal-field model.In essence such an analysis is founded on two main assumptions:(1) Electronic properties due to Cr

From $^{59}\mathrm{Co}$ and $^{23}\mathrm{Na}$ NMR, we demonstrate the impact of the ${\mathrm{Na}}^{+}$ vacancy ordering on the cobalt electronic states in ${\mathrm{Na}}_{0.75}{\mathrm{CoO}}_{2}$: at long time scales, there is neither a disproportionation into 75% ${\mathrm{Co}}^{3+}$ and 25% ${\mathrm{Co}}^{4+}$ states, nor a mixed-valence metal with a uniform ${\mathrm{Co}}^{3.25+}$ state. Instead, the system adopts an intermediate configuration in which 30% of the lattice sites form an ordered pattern of localized ${\mathrm{Co}}^{3+}$ states. Above 180 K, an anomalous mobility of specific ${\mathrm{Na}}^{+}$ sites is found to coexist with this electronic texture, suggesting that the formation of the latter may contribute to stabilizing the ${\mathrm{Na}}^{+}$ ordering. Control of the ion doping in these materials thus appears to be crucial for fine-tuning of their thermoelectric properties.

We propose a short channel gate overlapped lightly doped drain (GOLDD) poly-Si TFT employing 45° tilt implant for source and drain (S/D) regions without any additional ion doping or mask. Oblique-incident ELA activation is performed to activate both n+ S/D and n- LDD regions as well as cure junction defects. The proposed poly-Si TFT can suppress the anomalous leakage current, and exhibit the better reliability against the hot-carrier stress.

We proposed a new low temperature process for self-aligned gate overlapped LDD (GOLDD) poly-Si TFTs. The gate-overlapped LDD structure was self-aligned by side-etch of Al-Nd in Al-Nd/Mo gate electrode. A low temperature dopant activation was done by using H/sub 2/ ion doping after 450/spl deg/C annealing, in N/sub 2/ atmospheric. The characteristics of our GOLDD poly-Si TFT had high ON-current and low OFF-current.

This paper presentsseries efforts to lower resistance of bakelite electrode plate to improve the RPC capability under high rate working condition. New bakelite material with alkali metallic ion doping has been manufactured and tested. This bakelite is found unstable under large charge flux and need further investigation. Alternatively, a new structure of carbon-embedded bakelite RPC has been developed, which can reduce the effective resistance of electrode by a factor of 10. The prototype of the carbon-embedded chamber could function well under gamma radiation source at event rate higher than 10 kHz/cm2. The preliminary tests show that this kind of new structure performs as efficiently as traditional RPCs.

We investigated the Layer-by-Layer method to obtain thin μc-Si films. Good quality μc-Si films can be obtained at a thickness of 600 Å Ion-doping of phosphor to i-type μc-Si was investigated to realize the top-gate, self-aligned μc-Si TFT. High conductivity, more than 1 ohm-cm, can be obtained. Using the combination of Layer-by-Layer deposition method and ion-doping method, we fabricated top gate self-aligned μc-Si TFTs. The mobility of TFTs with 600Å-thick μc-Si channel layer is 1.5 cm2/Vs, which is about three times that of a-Si TFT's mobility. The top gate self-aligned μc-Si TFT is very promising technology for large LCD with high mobility.

We have performed a neutron diffraction experiment on Pr-doped Ce0.5Pr0.1La0.4B6, in which an antiferromagnetic octupole order with q = ( 1/2, 1/2, 1/2 ) could be anticipated by analogy with Ce0.7La0.3B6. Contrary to this natural expectation, we detected an unambiguous magnetic peak at q = ( 1/4, 1/4, 1/2 ), which is the same q-vector frequently realized in the magnetic ordered phases of RB6 (R=rare earth) compounds. No significant signal was observed at q = (1/2, 1/2, 1/2 ) at zero magnetic field. This result shows that the normal antiferromagnetic dipole moment is also one of the competing multipole order parameters in the CexLa1－xB6 system. The relevant order parameters are close in energy and can be tuned by a weak perturbation., This work was supported by Grants-in-Aid for Scientific Research (Nos. 21204456, 21102515, and 2430087) from JSPS and MEXT.

Carbyne is one of the allotropes of sp-carbon with a one-dimensional chain, but its physicochemical properties have not yet been clarified. We produced a carbyne-like carbon (carbon containing sp b...

Ion doping technology using a bucket-type ion source to fabricate low temperature poly-Si TFTs is presented. Low energy and high ion density conditions are applied to realize the short doping time and resist mask doping for large area glass substrates. A novel CMOS doping technology with one resist mask process is proposed using compensation and inversion of the shollow doped layer. In combination with excimer laser crystallization and activation below 450°C, high performance CMOS TFTs are produced.

Development of ion doping and hydrogenation equipment using plasma ion implantation (PII) is being studied. It is shown that low energy, high throughput operation could eliminate problems associated with etching, charging, cooling, and contamination. The applications of a new plasma source and neural network implementation optimization are also reported.

0.1 and 30 keV Si2+ focused ion beams (FIB) were implanted in two types of GaAs, one of which is semi-insulating (s.i.) GaAs, while the other is grown by molecular beam epitaxy (MBE). Successive regrowth over the implanted surface was performed using MBE-FIB combined system, and the resistance was measured. It was found that for 100 eV Si2+ FIB implantation, the sample was nonconductive without a post annealing at 800°C. After the post annealing, however, the sample became conductive, and the resistance was the same order in magnitude as the sample fabricated using 30 keV Si + FIB irradiation. This suggests a potential of selective formation of Si δ-like doped layers in GaAs and GaAs/AlGaAs using a low-energy FIB.

The active matrix liquid-crystal-display (AM-LCD) has been actively developed in the field of the flat panel displays, and the ion implantation technique is hopeful for the fabrication of the thin film transistor (TFT) in the element of AM-LCD. The new equipment, called Ion Doping Equipment, for ion implantation into large glass substrates has been developed in which the ions are implanted without mass-separation.

An Ag 2.6 Sc 1.8 Nb 0.2 (PO 4 ) 3 solid, highly conductive to Ag + ions and with a three-dimensional Na + superionic conductor Na 1+x Zr 2 P 3-x Si x O 12 (NASICON)-type structure, was developed by introducing pentavalent Nb 5+ ions into NASICON-type AgSc(PO 4 ) 3 . Because Nb 5+ ion doping of the NASICON-type solid reduced the interaction between Ag + and the surrounding O 2- ions, the highest Ag + ion conductivity among the NASICON-type Ag + ion conducting solids was obtained.

A technical challenging issue in rare-earth ion doping in ZnO nanocrystals has been tackled in this communication by a novel isocrystalline core-shell protocol, and the fabricated ZnO:Tb(3+)/ZnO core/shell nanocrystals showed efficient doping and excellent optical properties.

A new self-aligned a-Si TFT has been developed. Ion doping and chromium silicide (CrSix) formation technique was used to fabricate source and drain, which are self-aligned to the gate electrode, instead of using the previously reported lift-off process. The fabricated TFT mobility is about 0.5cm2/V' sec and threshold voltage is about 3V. The ON/OFF ratio is over 106. The actions of as short as 2μm channel TFT have been confirmed, using a large area TFT process. These results show that this technique can be applicable to manufacturing high quality TFT-LCDs in a large area.

Molecular-beam epitaxy (MBE) has become a well established technique for single-crystal Si film growth. However, almost all of the dopants commonly used in bulk Si present problems when co-evaporated with Si during MBE. For example, the incorporation probabilities σ of thermal Sb(1), Ga(2), In(3), and As(4) dopant beams range from ~ 10–4 to < 10–8at typical MBE Si growth temperatures Ts. Moreover, σ decreases exponentially with increasing Ts making control of dopant concentrations difficult. These problems arise due to strong segregation of dopant atoms to the growth front and/or rapid desorption of dopant atoms.(5) Dopant accumulation on the surface leads to highly distorted doping profiles with segregation-induced broadening as large as ~ 300 nm.(6) High dopant surface coverages during growth also limit the maximum concentrations Cmax obtainable (e.g. Cmax is ≤ 1018 cm-3 for thermal Sb) without degrading electronic properties due to introduction of structural defects.

Incomplete annealing of the ion doping damage near the source/drain junctions of the excimer-laser-annealed polycrystalline silicon thin-film transistor has been observed by transmission electron microscopy. The degree ofthe incomplete annealing was increased with increasing gate thickness due to the laser beam diffraction at the gate electrode edge. Simulation of the laser beam diffraction showed that the laser intensity decreased considerably near the junctions and the width of reduced laser intensity region increased with increasing gate thickness. The incompletely annealed ion doping damage decreases the field-effect mobility considerably and increases the leakage current.

The differential specific heats of the La2−xMxCuO4−δ (M=Sr and Ba) and La1.85Sr0.15Cu1−yCoyO4−δ polycrystalline samples are measured. For La2−xSrxCuO4−δ samples, the superconducting transition temperature Tc and the specific heat anomalies Δ C (Tc) all present maximum at x=0.15, while they disappear near x=0.14 for the La2−xBaxCuO4−δ samples. The magnitude of the specific heat anomaly is reduced quickly when the concentration x deviate from the optimal value, which are 0.15 for LSCO and 0.10 and 0.22 for LBCO. The Tc is lowered and the specific heat anomaly is smeared out with foreign ion doping at Cu site.

The Raman spectra of Sr1-xBaxNb2O6(SBN) and (K1-yNay)z(Sr1-xBax)l-zNb2O6(KNSBN) crystals have been obtained and discussed based on the space group theory and lattice dynamics. It provides scientific basic for an improvement on SBN and KNSBN by ion doping.

Source/drain formation by ion doping using self-activation technique without thermal anneal on polysilicon thin film transistors (TFT's) have been investigated. Phosphorus ions and protons were simultaneously implanted into polysilicon films. At total ion doses over 8×1015 ions/cm2, resistivities of self-activated films have been found equal to those of the ones annealed after the implantation. This self-activation technique enabled us to fabricate self-aligned TFT's having low-resistance Al gates and, at the same time, to hydrogenate active layers. With the case of self-activation technique, field-effect mobilities as high as 58 and 49 cm2/(V·s) were achieved in n-channel and p-channel TFT's, respectively, fabricated on glass substrates.

The EPR linewidths of Gd3+ ion doping single crystals of YbxY1–xCl3 · 6 H2O for x = 0.75, 0.50, 0.25 are measured from room temperature down to liquid helium temperature in order to study the spin-lattice relaxation times of the Yb3+ ion. It is found that for all samples there are three distinct regions in which the plots are linear: T > 180 K, 180 K > T > 30 K, and T < 30 K; the Debye temperatures of these samples are about 180 K and the Yb3+ ions solely populate the lowest lying Kramer's doublet below about 30 K. It is concluded that Gd3+ cannot be used as a probe to measure the spin-lattice relaxation times of host Yb3+ ions at temperatures below 180 K. La largeur des lignes RPE d'ion Gd3+ dopant des monocristaux de YbxY1–xCl3 · 6 H2O pour x = 0,75; 0,50; 0,25 est mesuree de la temperature de la chambre a la temperature de l'helium liquide afin d'etudier les periodes de relaxation d'ion Yb3+. Il y a clairement trois regions pour tous les echantillons ou les schemas sont lineaires: T > 180 K, 180 K > T > 30 K, et T < 30 K; la temperature Debye de ces echantillons est de pres de 180 K, et les ions Yb3+ occupent les niveau des doublets de Kramer qui se trouvent le plus bas aux temperatures inferieurs a 30 K. On conclut que Gd3+ ne peut ětre utilise comme indicateur pour mesurer les periodes de relaxation entre les ions hǒtes Yb3+ et le reseau aux temperatures inferieurs a 180 K.

An expression is derived for the intensity operator which can be used for a quick, accurate and rigorous computation of the intensities of EPR lines at any temperature. As an illustrative example, the intensities of X-band EPR lines for the Gd3+ ion doping a SmCl3.6H2O crystal are computed. A step-by-step procedure for the use of the intensity operator to evaluate the spin Hamiltonian parameters from the resonance data, in a rigorous least-squares fitting procedure, valid at all temperatures, is also presented.

Fundamental ion-solid interactions which affect ion implantation in III–V compound semiconductors will be discussed. It is shown that certain species will produce a significant reduction in the electrical activity of the primary ion species, e.g. a Si ion beam contaminated with N2 ions during the implantation of GaAs. The origin of these trace contaminant ions and their detection is analyzed and shown to be explicable in terms of basic ion-gas interactions in the production and transport of the ions in the implanter. Other factors which determine the uniformity of ion doping will be presented. Assuring the uniformity of electrostatic scanning is discussed in detail. A simple method is shown to be available for determining the reliability of the ion scan system. The implications of data obtained with GaAs and GaAlAs ion implantations, but applicable to other materials, are examined.

This paper reviews recent advances in silicon molecular beam epitaxy. Discussion includes the following topics: Innovations in the apparatus for increased substrate size, control, uniformity, and versatility; a comparison of work on substrate preparation techniques, such as flash annealing, ion sputtering, and laser irradiation; ion doping experiments; growth, both on and of metals and insulators; device structures; and patterned epitaxy.

X-band EPR measurements on a single crystal of Cu2+-doped magnesium acetate tetrahydrate, Mg(CH3COO)2 · 4H2O, are made at 295, 77, and 4.2 K. The Cu2+ spin-Hamiltonian parameters are evaluated, at all these temperatures, from the EPR line positions by means of a rigorous leastsquares fitting method. The principal values of the g2 and A2 tensors indicate that the local symmetry of the Cu2+ ion, in the host lattice of Mg(CH3COO)2 · 4H2O crystal, is tetragonal. The room-temperature optical-absorption spectrum, recorded in the 190 to 820 nm wavelength range, is exploited to study the crystal-field and charge-transfer transitions of the Cu2+ ion. On the other hand, both the room-temperature optical-absorption and EPR data are used to estimate the core polarization contribution (K) and the molecular-orbital coefficients for the Cu2+ ion doping Mg(CH3COO)2 · 4H2O. On a mesure le RPE a bande-X sur un monocristal de Mg(CH3COO)2 · 4H2O, dope par l'ion Cu2+ a 295, a 77 et a 4,2 K. Les parametres du spin hamiltonian du Cu2+ ont ete evalues, a toutes ces temperatures, par une methode rigoureuse d'adatation aux moindres carres, utilisant les positions des raies RPE. Les valeurs principales des tenseurs g2 et A2 indiquent que la symetrie locale de l'ion Cu2+, dans le reseau-hǒte du cristal de Mg(CH3COO)2 · 4H2O, est tetragonal. Le spectre d'absorption optique, a la temperature ambinate, enregistre dans l'intervalle de longueur d'onde 190 a 820 nm, a ete exploite afin d'etudier les transitions du champ cristallin, ainsi que celles du transfert de charge. D'un autre cote, a la fois les donees d'absorption optique et les donnees de RPE, a la temperature ambiante, ont ete utilisees, afin d'estimer la contribution de la polarisation du core et des coefficients de l'orbite moleculaire pour l'ion Cu2+ dopant Mg(CH3COO)2 · 4H2O.

Electromagnetic isotope separators serve a dual scientific purpose. The large production machines continue to provide the only practicable source of many stable isotopes, while the smaller laboratory separators have proved to be versatile research instruments in a variety of fields. The use of experimental separators in nuclear spectroscopy is now well established, and they have also been successfully employed in the study of ion-solid interactions. More recently they have proved particularly useful in the ion doping of semiconductors. The use of the separator for hyperfine interaction studies combines the stringent but largely disparate requirements of the nuclear and the ion implantation applications. The advantages and the limitations of this method of sample preparation are considered in some detail and briefly compared with other possible techniques.

The control of rare-earth ion doping profiles is a key challenge for several photonic applications and quantum technologies that require spatially localized emitters. In this work, we propose to use atomic layer deposition (ALD) followed by an annealing post-treatment to localize europium emitters close to the surface of a Y2O3film or a Y2SiO5single crystal by exploiting in-diffusion. Indeed, ALD is a conformal method that can provide in-depth nanometer-scale positioning accuracy on a large scale. However, the post-thermal annealing required to achieve higher crystalline quality and activate diffusion needs to be precisely controlled to maximize our ability to localize ions. In this paper, we evaluate europium ion diffusion in an ALD-grown Eu2O3/Y2O3/Si stack using Rutherford backscattering spectroscopy (RBS) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). We then extend this approach to investigate diffusion from a Eu2O3ALD film into a single-crystalline substrate of Y2SiO5(YSO), a technologically relevant material system for quantum applications. We determine the Eu3+diffusion coefficients in both cases and show that diffusion starts at 950 °C in the polycrystalline Y2O3ALD submicron film, whereas it becomes significant only above 1200 °C in single-crystal YSO. Finally, spectral hole burning of such in-diffused emitters revealed homogeneous lines as narrow as 2 MHz. This study indicates that appropriate annealing of ALD-grown rare-earth oxide films can be harnessed to create localized dopants that preserve their outstanding optical properties, a prerequisite for their integration into photonic and quantum devices.

Arbitrary doping profiles with abrupt transitions have been produced in Si MBE films by means of Sb ion doping. The ion doping could control the doping level in the films over the range 1016–1020 cm-3. The accuracy of controlling the doped layer thickness was within a couple of 100 Å. The doping levels of the doped Sb determined by neutron activation analysis, backscattering measurement, and four point probe technique were all in good agreement. It was also found from the doping profiles determined by the three measurements that the Sb atoms doped by the ion doping did not segregate to the surface of the epitaxial film.

Titania nanotube arrays are an exceptionally adaptable material for various applications ranging from energy conversion to biomedicine. Besides electronic properties, structural morphology on nanom...

Ion implantation is conventionally associated with the controlled modification of the physical or chemical properties of the surface of a solid target. This note describes the extension of the process to the ion beam treatment of materials in powder form. It briefly outlines the special experimental techniques which have been found to be necessary and it identifies some quite general features which distinguish the ion doping of continuous solid surfaces and discrete particles.