Structural and resistance switching properties were investigated in the CoO resistance random access memory (RRAM) with the Ta electrode. The intermediate layer consisting of Co and Ta oxides was confirmed at the interface by the transmission electron microscopy and electron energy loss... (Read more)

We utilize a very sensitive electron spin resonance technique called spin-dependent tunneling to identify defect centers involved in the negative bias temperature instability in plasma-nitrided p-channel metal-oxide-silicon field-effect transistors. The defect's ²⁹Si hyperfine... (Read more)

The authors combine metal oxide semiconductor (MOS) gated diode measurements and very sensitive electrically detected electron spin resonance measurements to detect and identify negative bias temperature instability (NBTI) generated defect centers in fully processed HfO₂ pMOS field effect... (Read more)

The impact of a submonolayer of HfO₂ sandwiched between the SiON gate dielectric and the polycrystalline silicon layer on the low frequency noise of a n-channel metal oxide semiconductor field effect transistor is investigated. Fermi-level pinning at polycrystalline... (Read more)

The authors have used low energy electron-excited nanoscale-depth-resolved spectroscopy to probe the bulk and interface defect states of ultrathin Mo/HfO₂/Si with conventional process sequences. Multiple deep level emissions are evident below the 5.9 eV HfO₂ near band edge,... (Read more)

Electric-pulse induced resistance hysteresis switching loops for Pr_0.7Ca_0.3MnO₃ perovskite oxide films were found to exhibit an additional sharp “shuttle tail” peak around the negative pulse maximum for films deposited in an oxygen-deficient ambient. The... (Read more)

The Stark splitting of a single fourfold degenerate impurity located within the built-in potential of a metal-semiconductor contact is investigated using low temperature transport measurements. A model is developed and used to analyze transport as a function of temperature, bias voltage, and... (Read more)

The doping characteristics and carrier transport in a GaAs p-n junction were visualized with a ~10 nm spatial resolution, using light-modulated scanning tunneling spectroscopy. The dynamics of minority carriers under operating conditions, such as recombination, diffusion, and electric... (Read more)

In conventional Si/SiO₂-based metal oxide semiconductor devices, performance-limiting semiconductor/dielectric interface traps are localized precisely at the Si/SiO₂ boundary. The authors show that in high-quality SiC/SiO₂-based devices, this is not necessarily the... (Read more)

The authors have observed that for In_xGa_1−xN epitaxial layers grown on bulk GaN substrates exhibit slip on the basal plane, when in the presence of free surfaces that intercept the heterointerface and for indium compositions x0.07. This leads to... (Read more)

Under identical preparation conditions, Au/GaN Schottky contacts were prepared on two kinds of GaN epilayers with significantly different background electron concentrations and mobility as well as yellow emission intensities. Current-voltage (I-V) and variable-frequency... (Read more)

The authors report on the observation of electroluminescence (EL) in CuGaSe₂ solar cells using tapping-mode atomic force microscopy based on tuning-fork sensors. Individually injected current pulses are seen during intermittent contact driven by an external bias applied to the conducting... (Read more)

Fluorine (F) passivation in poly-Si/TaN/HfO₂/p-Si gate stacks through gate ion implantation has been studied. It has been found that when the TaN thickness was less than 15 nm, the mobility and subthreshold swing improved significantly in HfO₂ n-channel... (Read more)

Recombination centers in thin asymmetrical p-n junctions were analyzed in the context of capacitance transient experiments. The combined effect of the thin low-doped region of the junction and the nonzero value of the occupation factor of the recombination center in the depletion layer... (Read more)

In-grown stacking faults (IGSFs) are planar defects that do not propagate under either an applied optical or electrical bias; however, their effect upon the electrical characteristics of diodes is not well understood. We present evidence for a multilayered IGSF and discuss its electrical and optical... (Read more)

The authors present a detailed investigation of defects generated during catastrophic optical damage (COD) in high-power 650 nm AlGaInP lasers using microphotoluminescence (µ-PL) mapping, focused ion beam (FIB) microscopy, and deep-etching techniques. High-resolution µ-PL... (Read more)

The effects of HfSiO nitridation on charge trapping and long-term dielectric reliability are investigated. A comparison between decoupled plasma nitridation, annealing in NH₃, and no nitridation is made. It was found that thinner HfSiO layers show less trapped charge. Decoupled plasma... (Read more)

Hydrogenation by high temperature rapid annealing of SiN_x:H is found to be very effective on the defects responsible for the carrier trapping effect in multicrystalline silicon. The passivation effect is reversible and is annihilated by a long thermal annealing. As for the... (Read more)

We have investigated by deep level transient spectroscopy the hole and electron trap defects introduced in n-type Ge during electron beam deposition (EBD) of Pd Schottky contacts. We have also compared the properties of these defects with those introduced in the same material during... (Read more)

Nickel-germanide Schottky barriers have been made on n-type germanium and evaluated by deep level transient spectroscopy in order to detect possible metal indiffusion during the 30 s rapid thermal annealing (RTA) employed for the germanidation. It is shown that while no electron traps have... (Read more)

An unusual appearance of a peak in the deep-level transient spectroscopy (DLTS) data for minority-carrier traps from an InGaN/GaN multiple-quantum-well (MQW) light-emitting diode, under a bias condition provided by a square pulse of varying height superimposed over the reverse-bias voltage, is newly... (Read more)

Based on theoretical calculations, we find that at p+ polycrystalline silicon (poly-Si)/HfO₂ gates, Si interstitials are easily migrated from the electrode, forming Hf–Si bonds with a charge transfer to the electrode, and the resulting interface dipole raises the Fermi level... (Read more)

The role of dimerization of atomic hydrogen to give molecular hydrogen in determining negative bias temperature instability (NBTI) kinetics is explored analytically. The time dependency of NBTI involving molecular hydrogen was found to obey a power law with a slope of 1/6, as opposed to the 1/4... (Read more)

RuO₂/4H–SiC Schottky diode structures based on n-type 4H–SiC (7×10¹⁷ cm^–3) with stoichiometric RuO₂ Schottky contacts were characterized by electrical capacitance-voltage and current voltage methods and deep-level transient... (Read more)

The transient properties of single grain–thin film transistors (SG-TFTs) with high electron mobility have been studied. Overshoot current induced by trap states has been observed in most of the devices. A method of ac measurements has been used to investigate the trap processes. Both transient... (Read more)

We investigate theoretically light- and bias-induced metastabilities in Cu(In,Ga)Se₂ (CIGS) based solar cells, suggesting the Se–Cu divacancy complex (V_Se-V_Cu) as the source of this hitherto puzzling phenomena. Due to its amphoteric nature, the... (Read more)

The influence of Hf-based dielectrics on the underlying SiO₂ interfacial layer (IL) in high-k gate stacks is investigated. An increase in the IL dielectric constant, which correlates to an increase of the positive fixed charge density in the IL, is found to depend on the starting,... (Read more)

The dislocation dependence of open circuit voltage is studied based on Donolato's model for the effect of dislocations on minority carrier effective diffusion length [J. Appl. Phys. 84, 2656 (1998)]. Experimental data measured on thin-film solar cells show a strong decrease of open circuit... (Read more)

Schottky contacts on p-type silicon, with embedded arrays of β-FeSi₂ nanocrystallites, were studied by current-voltage (I-V), deep level transient spectroscopy (DLTS), and low-frequency noise measurements. Forward I-V characteristics on logarithmic... (Read more)

The impact of TiN deposition on thin HfO₂ films formed on Si substrates was studied using x-ray photoelectron spectroscopy and a monoenergetic positron beam. For the predeposition sample, the positrons implanted into Si were found to diffuse toward the HfO₂/Si interface under... (Read more)

In 1998, Donolato presented an analytical model describing the effect of dislocation density on minority carrier effective diffusion length [J. Appl. Phys. 84, 2656 (1998)]. While this analysis was derived for a "semi-infinite" specimen, our objective is the appropriate description... (Read more)

A rigorous method of obtaining the Cu diffusivities in various SiO₂-based dielectric materials is proposed. The diffusion profile of Cu ions in a dielectric material is first simulated and the resulting flatband voltage shift (V_FB) is compared with the experimental... (Read more)

In this paper, the impact of iron contamination on the conversion efficiency of single-crystalline p-type silicon solar cells is investigated by means of the combination of numerical simulations and experimental data, taking into account the more recent results about the properties of iron in... (Read more)

Electron energy-loss spectroscopy combined with high-angle annular dark-field (HAADF) imaging in scanning transmission electron microscopy was used to investigate the chemistry of interfacial layers in HfO₂ gate stacks capped with polycrystalline Si gate electrodes. To interpret the... (Read more)

The impact of threading dislocation density on Ni/n-GaN Schottky barrier diode characteristics is investigated using forward biased current-voltage-temperature (I-V-T) and internal photoemission (IPE) measurements. Nominally, identical metal-organic chemical vapor... (Read more)

Photoreflectance (PR) and contactless electroreflectance (CER) spectroscopies have been applied to study optical transitions in undoped and Si-doped AlGaN/GaN heterostructures at room temperature. Spectral features related to excitonic and band-to-band absorptions in GaN layer and band-to-band... (Read more)

Hydrogen was implanted into IrO₂ (200 nm)/Pb(Zr,Ti)O₃/Pt thin film capacitors at 26 keV with a flux of 2×10¹⁵ H⁺ ions/cm² and also implanted at 20 keV with a flux of 1×10¹⁵ H⁺ ions/cm² into... (Read more)

The pinholelike defects often observed in multistack InAs quantum dot structures on GaAs have been investigated comprehensively. Due to the high surface stress of InAs quantum dots, the overgrowth of GaAs and InGaAs capping layers on InAs quantum dots is far from conformal and leads to the formation... (Read more)

The influence of residual impurities in quaternary InAlGaN active layers on the emission efficiency of 350 nm band ultraviolet light-emitting diodes on GaN substrates has been investigated. Secondary ion mass spectrometry and capacitance-voltage measurements have revealed that a large amount of... (Read more)

The effects of x-ray irradiation on the transfer and noise characteristics of excimer-laser-annealed polycrystalline silicon (poly-Si) thin-film transistors (TFTs) have been examined at dose levels up to 1000 Gy. Parameters including mobility, threshold voltage, subthreshold swing, and leakage... (Read more)

In this paper, the formation and evolution of defects induced by ion irradiation with 1 MeV Si⁺ ions in Ni₂Si/4H–SiC Schottky diodes were studied and correlated with the electrical properties of the contacts. The current-voltage characteristics of the contacts... (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)

Both lowering the “reset” current of resistance random access memory (ReRAM) and raising the resistance in the low resistance state are crucial for practical use of ReRAM. These requirements have been satisfied by using a hetero junction structure consisting of transition metal oxides, NiO_y/TiO_x/Pt, combining direct contact with the NiO_y using a W-probe. It is considered that this configuration brought about extreme downsizing of the effective area of both the top and bottom electrodes for NiO_y and thus decreased the number of filaments formed in “forming” process. Reducing the number of filaments is essential to these issues. (Read more)

An overview of the evolution of transistor parameters under negative bias temperature instability stress conditions commonly observed in p-MOSFETs in recent technologies is presented. The physical mechanisms of the degradation as well as the different defects involved have been discussed according to a systematic set of experiments with different stress conditions. According to our findings, a physical model is proposed which could be used to more accurately predict the transistor degradation. Finally, based on our new present understanding, a new characterization methodology is proposed, which would open the way to a more accurate determination of parameter shifts and thus allowing implementing the degradation into design rules. (Read more)

We investigate transport in phosphorus-doped buried-channel metal-oxide-semiconductor field-effect transistors at temperatures between 10 and 295 K. We focus on transistors with phosphorus donor concentrations higher than those previously studied, where we expect conduction to rely on donor... (Read more)

We report on the static magnetic field dependence of the random telegraph signal in a submicrometer silicon n-metal-oxide-semiconductor field-effect transistor. Using intense magnetic fields and low temperatures, we find that the characteristic time ratio changes by three orders of magnitude... (Read more)

An electron spin resonance (ESR) method is applied to a pentacene field-effect device to investigate gate-induced hole carriers in such devices. Clear field-induced ESR signals are observed, demonstrating that all of the field-injected carriers have S=1/2 spins. Anisotropic ESR signals due to... (Read more)

We report Stark shift measurements for ¹²¹Sb donor electron spins in silicon using pulsed electron spin resonance. Interdigitated metal gates on a Sb-implanted ²⁸Si epilayer are used to apply the electric fields. Two quadratic Stark effects are resolved: a decrease of the... (Read more)

The resistivity change due to electron spin resonance (ESR) absorption is investigated in a high-mobility two-dimensional electron system formed in a Si/SiGe heterostructure. Results for a specific Landau level configuration demonstrate that the primary cause of the ESR signal is a reduction of the... (Read more)

We utilize a very sensitive electron paramagnetic resonance technique called spin-dependent recombination to observe and identify defect centers generated by modest negative bias and moderately elevated temperatures in fully processed p-channel metal-oxide-silicon field-effect transistors.... (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)

Interface defects related to negative-bias temperature instability (NBTI) in an ultrathin plasma-nitrided SiON/ Si<100> system were characterized by using conductance–frequency measurements, electron-spin resonance measure- ments, and synchrotron radiation X-ray photoelectron spectroscopy. It was confirmed that NBTI is reduced by using D₂-annealing instead of the usual H₂-annealing. Interfacial Si dangling bonds (P_b1 and P_b0 centers) were detected in a sample subjected to negative-bias temperature stress (NBTS). Although we suggest that NBTS also generates non-Pb defects, it does not seem to generate nitrogen dangling bonds. These results show that NBTI of the plasma-nitrided SiON/Si system is predominantly due to P_b depassivation. Plasma nitridation was also found to increase the P_b1/P_b0 density ratio, modify the P_b1 defect structure, and increase the latent interface trap density by generating Si suboxides at the interface. These changes are likely to be the causes of NBTI in ultrathin plasma-nitrided SiON/Si systems. (Read more)

We utilize spin-dependent recombination (SDR) to observe deep level trap defects at or very near the interface of 6H silicon carbide and the SiO₂ gate dielectric in SiC metal-oxide-semiconductor field effect transistors. The SDR response is strongly correlated to SiC/SiO₂... (Read more)

Epitaxial 4H-SiC n-type layers implanted at room temperature with a low fluence of mega-electron-volt protons have been measured by deep level transient spectroscopy (DLTS). The proton fluence of 1×10¹² cm^–2 creates an estimated initial concentration of... (Read more)

Process-induced defects are a serious issue for modern sub-micron Si LSIs. To characterize such defects, two different techniques are useful: electrically detected magnetic resonance (EDMR) and transmission electron microscope (TEM), which can detect small (point) and extended defects, respectively. We applied EDMR and TEM to the issue of defect-induced leakage currents in dynamic-random-access memory (DRAM) cells. For our DRAM samples (a 0.25- μm-rule series), although TEM showed no extended defects, EDMR successfully detected two types of point defects: V₂+O x (Si divacancy-oxygen complexes) and larger Si vacancies (at least larger than V₆). We confirmed that these defects are the source of DRAM leakage currents. The observed defects were formed by ion implantation processes, but were more thermally stable than those in bulk Si crystals. The origins of this enhanced stability are attributed to the presence of oxygen atoms and a strong mechanical strain in LSIs. To clarify the origin of the complicated strain in LSI structures, we can directly measure the local-strain distribution in DRAM samples by means of convergent-beam electron diffraction (CBED) using TEM, which provides us with a valuable hint for understanding the formation mechanism of process-induced defects. (Read more)

Interfacial defect structures of NO-nitride oxide on Si(100) were characterized by electron spin resonance spectroscopy. We confirmed that the effective g values of the P_b1 center are affected by interfacial nitridation even at a small nitrogen concentration of 5 at. %, while those of the P_b0 center proved to be unchanged. We observed that the shifted P_b1 line appeared gradually with interfacial nitrogen concentration, which suggests that the nitrogen-induced modified structure substitutes for the original P_b1 structure. Angular variations of the shifted P_b1 lines were also significantly different from those of pure oxide. Based on our analysis, we attributed the g value shift of the P_b1 center to dangling bond tilting, caused by the displacement of nearest-neighbor Si atoms. (Read more)

There is a current upsurge in research on nonvolatile two-terminal resistance random access memory (RRAM) for next generation electronic applications. The RRAM is composed of a simple sandwich of a semiconductor with two metal electrodes. We introduce here an initial model for RRAM with the... (Read more)

The mechanism of hydrogen release from the anode Si/SiO₂ interface that triggers defect generation and finally the dielectric breakdown of the oxide in metal-oxide-semiconductor structures is investigated. Extensive experimental charge-to-breakdown statistics are used to derive the defect... (Read more)

An unexpected physical phenomenon—dynamic recovery of negative bias temperature instability (NBTI)—is reported. NBTI degradation in p-type metal–oxide–semiconductor field-effect transistors is significantly (by ~40%) reduced after stress interruption. NBTI recovery... (Read more)

Interface defects generated by negative-bias temperature stress (NBTS) in an ultrathin plasma- nitrided SiON/Si(100) system were characterized by using D₂ annealing, conductance-frequency measurements, and electron-spin resonance measurements. D₂ annealing was shown to lower... (Read more)

The influence of nitrogen concentration at a nitrided oxide/silicon interface on the activation energies of both near-interface fixed-charge trapping and interface state generation caused by negative bias temperature instability stress has been studied quantitatively. It is observed that the charge... (Read more)

We used electrically detected magnetic resonance to study the microscopic structure of ion-implantation-induced point defects that remained in large-scale Si integrated circuits (Si LSIs). Two types of defects were detected in the source/drain (n⁺-type) region of... (Read more)

We present an overview of negative bias temperature instability (NBTI) commonly observed in p-channel metal–oxide–semiconductor field-effect transistors when stressed with negative gate voltages at elevated temperatures. We discuss the results of such stress on device and circuit... (Read more)

The thermal stability and annealing kinetics of a bistable defect, recently reported by Martin (Master Thesis, KTH/ELE/FTE/2003-1) employing deep level transient spectroscopy and labelled the M-centre, has been studied using n-type epitaxially grown 4H-SiC layers implanted with 2.5 MeV protons to a... (Read more)

Poly-Si/SiO₂/Si diodes in which oxides were grown thermally under wet oxidation conditions and subsequently treated by a post-oxidation anneal (POA) have been characterized electrically and chemically before and after applying negative-bias-temperature stress (NBTS). It was confirmed that... (Read more)

We used a density functional method to investigate the mechanism of negative-bias temperature instability (NBTI) and resultant structural changes of Si/SiO₂ and Si/SiO_xN_y interfaces. The reaction energies for the water- and hydrogen-originated... (Read more)

We report electron spin resonance (ESR) observation of interface defects at the HfO₂/(111)Si boundary for HfO₂ films deposited via atomic layer chemical vapor deposition using Hf(NO₃)₄ as a precursor. We observe several signals, dominated by one due to a... (Read more)

We clarified the generation of process-induced dislocations around a shallow trench isolation (STI) by using convergent-beam electron diffraction. Comparing the resolved shear strain (RSS) of 12 slip systems, we found that at the trench bottom corner the RSS on slip systems (1 –1 1)[0 1 1] and... (Read more)

The electronic properties of the (100) Si/SiO₂ interfacial defect called P_b1 are quite controversial. We present electron spin resonance measurements that demonstrate: (1) that the P_b1 defects have levels in the silicon band gap, (2) that... (Read more)

Optical injection of electron-hole pairs in 3–5 nm thick layers of SiO₂, Al₂O₃, ZrO₂ and their stacks on (100)Si is found to result in positive oxide charging, suggesting trapping of holes. In thin layers of the high-permittivity metal oxides... (Read more)

The local lattice strain around the channel in metal–oxide–semiconductor (MOS) field-effect transistors of 0.1 µm gate length was measured by using convergent-beam electron diffraction. It was found that the normal strain along the gate-length direction is compressive beneath the... (Read more)

We recently published a letter in which we utilized spin-dependent recombination (SDR) measurements to demonstrate that P_b1 centers, silicon dangling-bond defects at the (001) Si/SiO₂ interface, have electronic levels in the silicon band gap.¹ In their comment on our... (Read more)

We have characterized the leakage current paths of ultra-thin gate dielectrics using spin-dependent tunneling (SDT) spectroscopy. A spin-dependent current was detected in metal-oxide-semiconductor diodes with chemical-vapor-deposition SiN gate films with thickness less than 3 nm. We examined the nature of the trap sites in terms of g-value, bias-dependent signal intensity, and magnetic-field orientation dependence. The main feature of the observed spectrum is attributed to a paramagnetic Si site in the SiN films. By using a quantitative model of electron spin-polarization, we were able to estimate the ratio of trap-assisted current to the total leakage current. (Read more)

We show that Cat-CVD silicon nitride films contain more than 1019 cm−3 nitrogen-bonded Si dangling bonds, similarly to the case for conventional CVD films. However, the charge-trapping behavior of the Cat-CVD films is found to be quite different, in spite of the same origin for the dominant... (Read more)

The electronic properties of the (001) Si/SiO₂ P_b1 defect are the subject of considerable controversy. We present spin-dependent recombination results which indicate most strongly that the P_b1 centers have levels in the Si band gap. Our... (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)

Hydrogen-related defects in oxygen-deficient silica, representing the material of a thermal gate oxide, are analyzed using first-principles calculations. Energetics and charge-state levels of oxygen vacancies, hydrogen, and their complexes in the silica framework are mapped out. The neutral hydrogen... (Read more)

Electron paramagnetic resonance (EPR) measurements of Si/SiO₂ systems began over 30 years ago. Most EPR studies of Si/SiO₂ systems have dealt with two families of defects: P_b centers and E centers. Several variants from each group have... (Read more)

Atomic hydrogen is found to simultaneously passivate and depassivate silicon dangling bonds at the Si(111)/SiO₂ interface at room temperature via the reactions P_b+H⁰" align="bottom">P_bH and... (Read more)

Hot electrons in the gate dielectric (SiO₂) of field effect transistors create defects at the Si/SiO₂ interface. Using electrically detected magnetic resonance, we have identified a major component of these interface defects as the well-known P_b0 center. We... (Read more)

We demonstrate the drift of a donor-passivating hydrogen species under the action of the electric field in the depletion region of a reverse-biased Au/n-Si Schottky diode hydrogenated by exposure to a low-frequency discharge. The redistribution is explained by the unidirectional drift of a... (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)

It is demonstrated that hydrogen can migrate in silicon as a negatively charged species (H^-). The evidence is the combined observation of a strong electric-field dependence in the rate of removal of PH complexes during bias-temperature stress of hydrogenated Schottky-barrier diodes and... (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)

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)