A rich variety of optical centers with high energy local vibrational modes has been found in electron-irradiated 4H-SiC in both the as-irradiated and annealed states. These energies have been measured and the annealing dependence of the optical centers has been investigated by low-temperature... (Read more)

This paper deals with the positive identification by low-temperature photoluminescence microspectroscopy of the two spin states of the dicarbon antisites in 4H-SiC. The defects are created by high-dose electron irradiation at room temperature or by subsequent exposure to intense 325 nm radiation at... (Read more)

Through a combined application of two characterization methods, deep-level transient spectroscopy and lifetime spectroscopy, the lifetime-limiting defect level in intentionally aluminum-contaminated Czochralski silicon has been analyzed and a complete set of defect parameters could be obtained. This... (Read more)

The migration of monovacancies (V⁰) and self-interstitials (I) has been observed in ion-implanted low-doped float-zone silicon by variable-energy positron annihilation spectroscopy. V⁰ and I were created by the in situ implantation of ~20 keV... (Read more)

The asymmetry doping problem has severely hindered the potential applications of many wideband gap (WBG) materials. Here, we propose a possible approach to overcome this long-standing doping asymmetry problem for WBG semiconductors. Our approach is based on the reduction of the ionization energies... (Read more)

The authors have employed deep level transient spectroscopy to investigate the defects introduced in n-type Ge during 160 keV indium (In) ion implantation. Our results show that In implantation introduces three prominent electron traps with energy levels at... (Read more)

A 1.0 nm silicon nitride (SiN) layer can prevent reaction between HfO₂ and Si completely. In this case, the interface state spectra obtained from x-ray photoelectron spectroscopy measurements under bias have two peaks above and below the midgap, attributable to Si dangling bonds... (Read more)

Two occupied native defect bands are experimentally detected in pure HfO₂. The density of states of band one in the middle of the band gap reduces drastically with the Al addition, while that of band two slightly above the valence-band maximum remains rather unaffected. We attribute the... (Read more)

Only a few years ago, an account of degradation of silicon carbide high-voltage p-i-n diodes was presented at the European Conference on Silicon Carbide and Related Compounds (Kloster Banz, Germany, 2000). This report was followed by the intense effort of multiple groups... (Read more)

We present a detailed analysis of the fundamental atomic-scale processes that determine the surface smoothness of hydrogenated amorphous silicon (a-Si:H) thin films. The analysis is based on a synergistic combination of molecular-dynamics (MD) simulations of radical precursor migration on surfaces... (Read more)

Adsorption of gold atoms and clusters (N=6) on a graphite (0001) surface with defects has been studied using density functional theory. In addition to perfect graphite (0001), three types of surface defects have been considered: a surface vacancy (hole), a pyridinelike defect comprising three... (Read more)

Low temperature wavelength-modulated reflectivity measurements of isotopically engineered ZnO samples have yielded the dependence of their A, B, and C excitonic band gaps on the isotopic masses of Zn and O. The observed dependence is analyzed in terms of the band gap renormalization by zero-point... (Read more)

Based on first-principles calculations, we studied the generation behavior of P_b centers at SiO₂/Si interfaces, especially for P_b1 centers, under oxidation of Si(100) surfaces. P_b1 centers were found to be formed... (Read more)

First-principles calculations carried out in 3C- and 4H-SiC show that small metastable carbon clusters can be created in irradiated SiC. The metastable carbon clusters possess occupation levels in the p-type as well as in the n-type 4H-SiC. Depending on the... (Read more)

We propose a new method for calculating optical defect levels and thermodynamic charge-transition levels of point defects in semiconductors, which includes quasiparticle corrections to the Kohn-Sham eigenvalues of density-functional theory. Its applicability is demonstrated for anion vacancies at... (Read more)

Oxygen vacancy in cubic HfO₂ was investigated using first-principles calculation based on density functional theory and generalized gradient approximation. Five different charge states (V⁺⁺, V⁺, V⁰, V^–, and... (Read more)

Negative bias temperature instability has become an important reliability concern for ultra-scaled Silicon IC technology with significant implications for both analog and digital circuit design. In this paper, we construct a comprehensive model for NBTI phenomena within the framework of the standard reaction–diffusion model. We demonstrate how to solve the reaction–diffusion equations in a way that emphasizes the physical aspects of the degradation process and allows easy generalization of the existing work. We also augment this basic reaction–diffusion model by including the temperature and field-dependence of the NBTI phenomena so that reliability projections can be made under arbitrary circuit operating conditions. (Read more)

The properties of semi-insulating GaN films with the lower part of the film doped with Fe are reported. The 300 K sheet resistivity of the films was 2×10¹⁰ /square with an activation energy of the dark conductivity of 0.5 eV. The Fermi level is also pinned at... (Read more)

The electronic, structural, and vibrational properties of small carbon interstitial and antisite clusters are investigated by ab initio methods in 3C- and 4H-SiC. The defects possess sizable dissociation energies and may be formed via condensation of carbon interstitials, e.g.,... (Read more)

Previous calculations on n-type doping of diamond by P and S predicted that S has a shallower level and a higher solubility than P. Our first-principles calculations show that the opposite is true: Phosphorus impurity in diamond gives rise to a shallower donor level, and has a higher bulk solid... (Read more)

The diffusion and reactions of hydrogenous species generated by single-pulsed F₂ laser photolysis of SiO-H bond in SiO₂ glass were studied in situ between 10 and 330 K. Experimental evidence indicates that atomic hydrogen (H⁰) becomes mobile even at temperatures as... (Read more)

Hydrogen is known to passivate Si dangling bonds at the Si-SiO ₂ interface, but the subsequent arrival of H ⁺ at the interface causes depassivation of Si-H bonds. Here we report first-principles density functional calculations, showing that, contrary to conventional... (Read more)

Band-gap states of tungsten in silicon carbide (polytypes 4H, 6H, and 15R) are investigated by deep-level transient spectroscopy (DLTS) and admittance spectroscopy on n-type SiC. Doping with W is done by ion implantation and annealing. To establish a definite chemical identification of band-gap... (Read more)

Hydrogen-related metastable defects (M3/M4) in n-GaAs were studied in relation to the EL2 center. We found that the M3/M4 defects were observed only in the crystals containing the EL2 center in the as-grown state after exposure to a hydrogen plasma. The EL3 level, which was tentatively assigned as... (Read more)

Recent deep level transient spectroscopy (DLTS), electron paramagnetic resonance (EPR) and infrared (IR) spectroscopy data on interactions of self-interstitial with carbon, aluminium, oxygen and hydrogen in silicon irradiated by light ions are reviewed. Self-interstitial behaviour in silicon was... (Read more)

Electron-paramagnetic-resonance (EPR) studies in radiation damaged diamond enriched to 5% ¹³C have resulted in the identification of the nearest-neighbor divacancy center. It is the isotopic enrichment, and consequent observation of ¹³C hyperfine lines, that has permitted the... (Read more)

The behavior of self-interstitials in silicon which was irradiated with light ions (protons and -particles) and electrons was explored by monitoring known impurity interstitial centers (C_i, Al_i, (Si-O)_i) with deep level transient spectroscopy (DLTS) and electron... (Read more)

I studied the effects of grown-in hydrogen on the lifetime of Czochralski-grown silicon crystals. It was found that grown-in hydrogen degraded the electrical properties of Czochralski-grown silicon crystals by enhancing the formation of recombination centers, which had a high thermal stability... (Read more)

Dislocation loops consisting of long and straight segments of 60? and screw parts were introduced in p-type Si by deformation under a high stress at a relatively low temperature. Electronic states associated with such dislocations were investigated by means of electric-dipole spin resonance, with... (Read more)

The B-H complex in Si can be aligned by stress and reorients with an activation energy of roughly 0.2 eV. We combine new measurements of the reorientation kinetics of the B-H complex made by the stress-induced dichroism technique with previous internal friction results to show that the reorientation... (Read more)

Deep levels in vanadium-doped n- and p-type silicon have been investigated using deep level transient spectroscopy (DLTS) and concentration profile measurements. The DLTS measurement reveals two electron traps of E_C−0.20 eV and... (Read more)

We have evaluated hydrogen and deuterium diffusivities in silicon below room temperature (220–270 K) by analyzing the kinetics of photoinduced dissociation of a chemical etching introduced hydrogen (deuterium)–carbon complex. Under sufficiently strong illumination, the annihilation rate... (Read more)

Tungsten deep levels are investigated to clarify energies, which are inconsistent among current research. Hole traps located at 0.41 eV above the top of the valence band are determined to be due to tungsten impurities. The concentration of hole traps is almost one-third of that of the tungsten... (Read more)

The elastic energy loss between 60 and 300 K was measured in SiB_xH_y at frequencies between 2.4 and 32 kHz. A single-time relaxation process appears in the neighborhood of 130 K, which is due to the stress-induced jumps of H around B, with a relaxation time... (Read more)

The electron-nuclear double-resonance spectra of interstitial ⁴⁷Ti⁺ and ⁴⁹Ti⁺ in silicon have been measured at 4.2 K. Spin Hamiltonians for these systems were determined and had to include hyperfine contributions of the type S³I and... (Read more)

The motion of hydrogen in the B-H complex in silicon has been studied. An applied stress is used to produce a preferential alignment of the B-H complex at temperatures sufficiently high for the H to move within the complex (above ∼60 K). This alignment of the complexes is detected by comparing the... (Read more)

The band-gap energy distribution of P_b centers on oxidized (100) Si wafers has been determined and compared with interface electrical trap density D_it. Two different P_b centers are observed on (100) Si: P_b0,... (Read more)

The Si-NL29 EPR spectrum, which is associated with the positive charge state of interstitial titanium in silicon, was investigated by electron-nuclear double resonance. Hyperfine-interaction parameters of 17 shells of silicon neighbors, comprised of 214 atoms, could be determined. These parameters... (Read more)

We find that two paramagnetic ``trivalent silicon'' centers appear to be primarily responsible for radiation damage in metal-oxide-silicon structures. Applied Physics Letters is copyrighted by The American Institute of Physics. ... (Read more)

Energy distribution of P_b centers (·SiSi₃) and electronic traps (D_it) at the Si/SiO₂ interface in metal-oxide-silicon (MOS) structures was examined by electric-field-controlled electron paramagnetic resonance (EPR)... (Read more)

A review is given on the diffusion, solubility and electrical activity of 3d transition metals in silicon. Transition elements (especially, Cr, Mn, Fe, Co, Ni, and Cu) diffuse interstitially and stay in the interstitial site in thermal equilibrium at the diffusion temperature. The parameters of the liquidus curves are identical for the Si:Ti — Si:Ni melts, indicating comparable silicon-metal interaction for all these elements. Only Cr, Mn, and Fe could be identified in undisturbed interstitial sites after quenching, the others precipitated or formed complexes. The 3d elements can be divided into two groups according to the respective enthalpy of formation of the solid solution. The distinction can arise from different charge states of these impurities at the diffusion temperature. For the interstitial 3d atoms remaining after quenching, reliable energy levels are established from the literature and compared with recent calculations. (Read more)

On unannealed, thermally oxidized silicon, electron spin resonance reveals an oriented interface defect which is termed the P_b center and identified as the trivalent silicon defect. Deep level transient spectroscopy (DLTS) reveals two broad characteristic peaks in the... (Read more)

Using deep level transient spectroscopy (DLTS) the defects introduced into silicon by plastic deformation are investigated with respect to their capture and emission characteristics. In agreement with what has been found by electron spin resonance (EPR), kind and density of the detected localized... (Read more)

EPR studies of silicon irradiated at 20.4 K and 4.2 K by 1.5 MeV and 46 MeV electrons are described. In 46 MeV irradiations the dominant defects formed appear to be divavancies and other multiple defect aggregates which liberate vacancies throughout the anneal to room temperature as they reorder, recombine, etc. For 1.5 MeV irradiations group III atoms play a vital role in p- and n-type materials in trapping interstitials and stabilizing damage. Carbon and oxygen are not effective interstitial traps at these temperatures. Evidence of limited vacancy migration during irradiation is also cited. Two distinct excited configurations of vacancy-oxygen pairs are identified as precursors to A-centre formation in n-type silicon. The kinetics for their conversion to A-centres depends strongly upon the Fermi level as does the isolated vacancy migration energy whhich is measured to be 0.18 ± 0.02 eV for the V^＝ charge state. The vacancy has four charge states, V^＋, V⁰, V^－ and V^＝. Kinetics for hole release from V^＋ reveals an activation barrier of 0.057 eV. The concentration of V^＋ at 20.4 K in boron-doped material indicates the corresponding donor level even closer to the band edge, approximately E_V ＋ 0.039 eV. Jahn-Teller energies for V⁰, V^＋, and V^－ are estimated from stress-alignment studies and confirmed to be large. Kinetics studies for reorientation from one Jahn-Teller distortion to another are also described for each charge state.