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Silicon Carbide JFETs with low on-state resistance are suitable for a number of high power applications. The static, dynamic and short circuit characterization of 600 V SiC Trench JFETs are reported in this paper. Typical JFETs fabricated with a 1.2 μm cell pitch had an on-resistance value around 40 mΩ and blocking voltages of ~600 V across the wafer. JFETs were successfully switched with a dc link voltage of 300 V, a current of 15 A and operating temperature of 125 °C. These JFETs were subjected to a short circuit condition with duration ranging from 10 μs to 45 μs at a dc link voltage of ~300 V, and operating temperatures of 25 °C and 125 °C. The device could withstand subsequent short circuit successfully without any failure at both 25 °C and 125 °C. The short circuit current showed consistent dependency on the applied gate voltage, when it was varied from 0 V to 15 V.

Accurate detection of semiconductor defects is crucial to ensure reliability of operation and to improve yield by understanding and eradicating yield detractors. Recent advances in computer vision driven by Deep Convolutional Neural Networks (DCNN) and transfer learning have enabled novel techniques for defect detection and classification [1–7]. However, training neural networks requires very large datasets, even with transfer learning. This paper addresses this shortcoming by introducing for the first time the active learning approach for semiconductor devices. The proposed neural network can accurately identify defective dies with modest efforts in terms of annotating the image set. Finally, the feature maps of the DCNN are used to generate an unsupervised taxonomy of the semiconductor die defects, supporting further investigations to address yield detractors

The fast and accessible verification of nonclassical resources is an indispensable step towards a broad utilization of continuous-variable quantum technologies. Here, we use machine learning methods for the identification of nonclassicality of quantum states of light by processing experimental data obtained via homodyne detection. For this purpose, we train an artificial neural network to classify classical and nonclassical states from their quadrature-measurement distributions. We demonstrate that the network is able to correctly identify classical and nonclassical features from real experimental quadrature data for different states of light. Furthermore, we show that nonclassicality of some states that were not used in the training phase is also recognized. Circumventing the requirement of the large sample sizes needed to perform homodyne tomography, our approach presents a promising alternative for the identification of nonclassicality for small sample sizes, indicating applicability for fast sorting or direct monitoring of experimental data., Comment: 8 pages, 7 figures

Despite the recent progress in SiC power MOSFET technology and its commercialization, the defective MOS interface still hampers the exploitation of the full potential of these devices. We present results using our high-k gate stack technology that shows significantly reduced density of interface states (D it ) along with superior threshold voltage (V TH ) stability for low voltage SiC power MOSFETs. The findings indicate virtually no V TH -shift during static characterization as function of the starting gate voltage and its ramp. Furthermore, dynamic switching results show virtually no threshold voltage shift for $V_{GS,start} \gt -12$V.

In medical radiation dosimetry , the use of small photon fields is almost a prerequisite for high precision localized dose delivery to delineated target volumes. The accurate measurement of standard dosimetric quantities in such situations depends on the size of the detector with respect to the field dimensions. Polycrystalline diamond devices with 3-dimensional structures are produced by using laser pulses to create graphitic paths in the diamond bulk. By fabricating very narrow and close-by columnar electrodes perpendicular to the detector surface, it is possible to create arrays of 3-D cells (pixels) with a very small sensitive volume. In order to present a solution to the problem of the detector size for small field dosimetry the 3-D technology aims to a new highly segmented larger polycrystalline diamond dosimeter to obtain field profiles in a single measurement, reducing the uncertainty of the delivered dose. To this purpose a 3D all carbon detector with an array of 9 3-D pixels has been produced. Due to the heterogeneous structure of the polycrystalline diamond substrate, it was necessary to study the response of each pixel under a standard field photon beam (10 x 10 cm 2 ). For 6 pixels of the array was demonstrated that they present different sensitivities to the radiation beam , but the response is linear and stable hence different calibration factors can be applied to obtain an overall detector response and reduce the uncertainty of the delivered dose.

Diamond sensors provide a promising radiation hard solution to the challenges posed by the future experiments at hadron machines. A 3D geometry with thin columnar resistive electrodes orthogonal to the diamond surface, obtained by laser nanofabrication, is expected to provide significantly better time resolution with respect to the extensively studied planar diamond sensors. We report on the development, production and characterisation of innovative 3D diamond sensors achieving 30% improvement in both space and time resolution with respect to sensors from the previous generation. This is the first complete characterisation of the time resolution of 3D diamond sensors and combines results from tests with laser, beta rays and high energy particle beams. Plans and strategies for further improvement in the fabrication technology and readout systems are also discussed.

In-field demonstrations in real-world scenarios boost the development of a rising technology towards its integration in existing infrastructures. Although quantum key distribution (QKD) devices are already adopted outside the laboratories, current field implementations still suffer from high costs and low performances, preventing this emerging technology from a large-scale deployment in telecommunication networks. Here we present a simple, practical and efficient QKD scheme with finite-key analysis, performed over a 21 dB-losses fiber link installed in the metropolitan area of Florence (Italy). Coexistence of quantum and weak classical communication is also demonstrated by transmitting an optical synchronization signal through the same fiber link.

Evolution of thyristor technology and the design concepts, which brought and maintain the phase control thyristor (PCT) at the top of a power pyramid, are discussed. The state-of-the-art device concepts like electrically triggered thyristor and light triggered thyristor are described for voltage classes up to 8.5 kV and maximal on-state rated current of 6 kA. Main focus is laid on the PCTs for high-voltage direct current transmission, the enabler of power transmission beyond the 10-GW level.

We report about the generation of entangled states obtained by applying delocalized single-photon addition between two uncorrelated light modes populated by coherent states. Such entangled states can contain an arbitrary large number of photons while preserving their non-classical correlations. Besides their importance to study quantum effects in large-scale systems, these states are found to be surprisingly robust against losses and thus well suited to travel over long distances and to be stored in atomic ensembles.

The static and dynamic performance of Silicon Carbide (SiC) MOSFET rated for 1200V applications has been investigated. MOSFETs with a planar design and several different cell pitches have been fabricated. Special attention has been dedicated to the channel design, where a novel retrograde doping profile has been employed. For reference, a more common box profile channel has also been used. Turn-off measurements under high current and over voltage conditions reveal that the MOSFET body diode offers wide safe operating area capability. The MOSFETs feature exceptional ruggedness against long short circuit events, with the retrograde channel designs able to withstand the $10\boldsymbol{\mu} \mathbf{s}$ industry standard specification.

We demonstrate the first integration of high-k/metal gate stacks in vertical 1.2kV SiC power MOSFETs including static and dynamic characterization as well as safe operation area (SOA). The high-k/4H-SiC MOS interface exhibits a remarkably low interface defect state density and improved threshold voltage stability compared to conventional gate stacks based on SiO 2 . Moreover, we achieved an impressive performance boost in terms of on-resistance due to this low-defective interface and increased gate capacitance. Compared to vertical devices with SiO 2 /poly Si gate stacks these devices exhibit a negligible hysteresis.

In this paper, we present and discuss simulation and experimental results obtained from investigating the impact of local alterations of the electric field profile in the power device planar junction termination region. Such local modifications are due to possible various extrinsic causes (manufacturing, operational or environmental) and are shown to have a critical influence on the device voltage blocking capability and reliability. The results point towards junction termination sensitivity to locally modified fields especially under voltage switching conditions due to higher leakage current densities in the modified area compared to the rest of the JT region.

Journal of physics / B 53(7), 072002 (2020). doi:10.1088/1361-6455/ab69a8, Conventional spectroscopy uses classical light to detect matter properties through the variation of its response with frequencies or time delays. Quantum light opens up new avenues for spectroscopy by utilizing parameters of the quantum state of light as novel control knobs and through the variation of photon statistics by coupling to matter. This Roadmap article focuses on using quantum light as a powerful sensing and spectroscopic tool to reveal novel information about complex molecules that is not accessible by classical light. It aims at bridging the quantum optics and spectroscopy communities which normally have opposite goals: manipulating complex light states with simple matter e.g. qubits versus studying complex molecules with simple classical light, respectively. Articles cover advances in the generation and manipulation of state-of-the-art quantum light sources along with applications to sensing, spectroscopy, imaging and interferometry., Published by IOP Publ., Bristol

In this paper, the use of 3.3 kV SiC MOSFETs, Fast Si IGBTs and the mix of both in the so called Cross-Hybrid Switch (XS) and Bimode Cross-Hybrid Switch (BXS) are considered for their application on Galvanically Insulated Modular Converters (GIMC) cells. The semiconductors typically operate under Soft Switching conditions to allow high frequency operation resulting in size and weight minimization while keeping a high efficiency. The high frequency (10 kHz) and Soft Switching operation in the selected semiconductors have been first evaluated by applying 2D semiconductor device simulations. The simulation results allow to identify the impact of device parameters such as the Si IGBTs Lifetime adjustment and the Si IGBT – SiC MOSFET chip surface ratio on the BXS devices, over the on-state and switching losses. Accordingly, different 3.3kV dual HiPak testing samples have been implemented and experimentally evaluated on a 200 kW DC/DC GIMC cell test bench. The comparison between the 3.3 kV Fast Si IGBTs, SiC MOSFETs and BXS shows clear functional benefits of using MV SiC MOSFETs in resonant mode operation, allowing an increase of the GIMC cell power capability by 30 - 35 % for the same module current rating compared to the use of Fast IGBTs. In a similar way, the BXS devices can provide and intermediate power capability increase of around 20-25%, minimizing the installed Si and SiC chip area that can be used as an enabler for improvement of the GIMC technology impacting the cost and performance of the semiconductor devices applied on the GIMC cells

Proton irradiation is experimentally demonstrated to increase the ruggedness of large area thyristors for HVDC. While maintaining very low On-state losses at V T below 1.7 V and 1.8 V for 7.2 and 8.5 kV classes (I T = 6.25 kA, T = 90 °C), record low leakage current has been achieved at 150 mm silicon wafers together with increased surge current, higher dV/dt capability and lower circuit commutated recovery time t q .

Electrically robust 6.5kV SiC MOSFETs are investigated for the static and dynamic performance, short circuit capability and safe operation area (SOA). SiC MOSFETs rated at 6.5kV were fabricated with different cell pitches from 12μm to 26μm that are able to withstand short circuit pulses of up to 8μs and have a turn-off SOA at 4400V up to twice the nominal current Inom. The paralleling of four MOSFETs was tested to represent a realistic setup while showing a substantial reduction in the switching loss by more than 80% compared to a silicon IGBT and Diode.

In this work, we report the analysis of the electrochemical detection of electroactive species with band microelectrodes that operate under controlled convection. The study focuses on the determination of the collection efficiency of the analyte as a function of inlet flow velocity and microband geometry (inlaid, bumped and recessed), also providing a straightforward method for the theoretical determination of the lower detection limit. The analysis has been carried out by simulating the dimensionless mass transport with the finite element method, delivering the stationary limiting current density. Simulations have been performed on systems consisting of single and double band electrodes to investigate the trail effect on the electrochemical detection. We show that the obtained dimensionless results can be easily turned into dimensional data, providing a tool for the design of devices. The proposed method is general and can easily be extended to systems with different geometry.

The three-dimensional concept in diamond detectors has been applied, so far, to high quality singlecrystal material, in order to test this technology in the best available conditions. However, its application to polycrystalline chemical vapor deposited diamond could be desirable for two reasons: first, the short inter-electrode distance of three-dimensional detectors should improve the intrinsically lower collection efficiency of polycrystalline diamond, and second, at high levels of radiation damage the performances of the poly-crystal material are not expected to be much lower than those of the single crystal one. We report on the fabrication and test of three-dimensional polycrystalline diamond detectors with several inter-electrode distances, and we demonstrate that their collection efficiency is equal or higher than that obtained with conventional planar detectors fabricated with the same material. (C) 2015 Elsevier B.V. All rights reserved.

This work evaluates the feasibility of optimizing SiC power MOSFETs through multiobjective optimizers (MOOs) based on modern elitist genetic algorithms. This technique is validated on a 0D problem of high practical interest — the optimization of the epitaxial drift layer, using the ionization coefficients from [1] and [2] in addition to those from [3], extensively used in literature. Then the results are confirmed with 1D TCAD, removing approximations introduced by [4] and [5]. Finally MOOs are used with 2D TCAD simulations to evaluate the tradeoff of breakdown voltage (V B ), threshold voltage (V T ), saturation current (I dsat ) and on-state resistance (r on ) as the channel profile is varied.

An approach to implement electrically robust MOSFETs in a functioning half-bridge will be investigated. For the first time, reverse conducting 3.3kV SiC MOSFETs have been fabricated with dilferent cell pitches from 14μm (p1.0) to 26μm (pl.8) that are able to withstand short circuit pulse of up to 10μs and a 9ms surge current event up to 15x the nominal current. LinPak half-bridge modules have been fabricated showing reduction of the switching loss by more than 90% compared to a silicon IGBT/diode half bridge.

We present the results of direct interferometric measurements on the pulse-to-pulse phase jitter of a metrological, fiber-based, infrared (IR) frequency comb. We show that the short-time evolution of such phase fluctuations, which cannot be actively controlled by any feedback system, imposes a stringent limit on the tooth linewidth of extreme ultraviolet (XUV) combs produced by high-order harmonic conversion, thus explaining the difference of 9 orders of magnitude between the coherence times of state-of-the-art IR and XUV frequency combs.

The selective and simultaneous production of hydrogen and chemicals from renewable alcohols was accomplished by using an electrolyzer, for which the anode electrocatalyst was an organometallic complex, [Rh(OTf)(trop2NH){P(4-BuC6H4)3}] (trop2NH=bis(5H-dibenzo[a,d]cyclohepten-5-yl)amine; -OTf=CF3SO3 -), deposited on amorphous carbon and appropriately designed to promote the partial and selective oxidation of alcohols. The electrolyzer converted alcohols into industrially relevant chemicals and high-purity hydrogen at high volume and with very low energy consumption.

Medium voltage high-power applications are usually realized using high voltage semiconductors (3.3 kV and above) operated in the hard switching mode with low switching frequencies (several hundreds of hertz). However, for high-power dc–dc converters employing a transformer for galvanic isolation, it is attractive to increase the switching frequency so that the transformer size can be reduced. An increase of the switching frequency implies an increase of the switching losses, and this has to be mitigated somehow, usually by choice of resonant topologies or soft switching techniques. Main focus of the paper is on the operation of the insulated gate bipolar transistor (IGBT) within a high-power dc–dc LLC resonant converter, in order to explore interactions between semiconductor and circuit properties, which both must be simultaneously considered in order to achieve the best utilisation of a high voltage power semiconductor operating at higher switching frequencies. For these purposes, switching properties of a standard 6.5 kV IGBT are compared with switching properties of two different optimized versions of a 6.5 kV IGBT. Experimental results are included to support theoretical considerations and findings.

In this letter, a trench-insulated gate bipolar transistor (IGBT) design with local charge compensating layers featured at the cathode of the device is presented and analyzed. The superjunction or reduced surface effect proves to be very effective in overcoming the inherited ON-state versus breakdown tradeoff appearing in conventional devices, such as the soft punch through plus or field stop plus (FS+) IGBTs. This design enhances the ON-state performance of the FS+IGBT by increasing the plasma concentration at the cathode side without affecting either the switching performance or the breakdown rating.

We present an experimental and theoretical investigation of Ramsey-type interference fringes using high-order harmonic generation. The ninth harmonic (lambda = 88nm) of a femtosecond Ti:sapphire laser was used to excite a pair of autoionizing states of krypton. The outcome of the ionization process, detected by an ion-mass spectrometer, shows the characteristic quantum interference pattern. The behavior of the fringe contrast was interpreted on the basis of a simple analytical model, which reproduced well the experimental results without any free parameter. Finally, we also present a proposal for a similar experiment to be performed on high-lying bound state of atomic argon, with the aim of achieving even higher resolving power.

We investigate the single-event transient (SET) response of bandgap voltage references (BGRs) implemented in SiGe BiCMOS technology through heavy ion microbeam experiments. The SiGe BGR circuit is used to provide the input reference voltage to a voltage regulator. SiGe HBTs in the BGR circuit are struck with 36-MeV oxygen ions, and the subsequent transient responses are captured at the output of the regulator. Sensitive devices responsible for generating transients with large peak magnitudes (more than 5% of the dc output voltage) are identified. To determine the effectiveness of a transistor-layout-based radiation hardened by design (RHBD) technique with respect to immunity to SETs at the circuit level, the BGR circuit implemented with HBTs surrounded by an alternate reverse-biased pn junction (n-ring RHBD) is also bombarded with oxygen ions, and subsequent SETs are captured. Experimental results indicate that the number of events causing transients with peak magnitude more than 5% above the dc level have been reduced in the RHBD version; however, with the inclusion of the n-ring RHBD, new locations for the occurrence of transients (albeit with smaller peak magnitude) are created. Transients at the transistor-level are also independently captured and are presented. It is demonstrated that while the transients are short at the transistor level (ns duration), relatively long transients are obtained at the circuit level (hundreds of nanoseconds). In addition, the impact of the SET response of the BGR on the performance of an ultra-high-speed 3-bit SiGe analog-to-digital converter (ADC) is investigated through simulation. It is shown that ion-induced transients in the reference voltage could eventually lead to data corruption at the output of the ADC.

We investigate transistor-level layout-based techniques for SEE mitigation in advanced SiGe HBTs. The approach is based on the inclusion of an alternate reverse-biased pn junction (n-ring) designed to shunt electron charge away from the sub-collector to substrate junction. The inclusion of the n-ring affects neither the DC nor AC performance of the SiGe HBT and does not compromise its inherent multi-Mrad TID tolerance. The effects of ion strike location and angle of incidence, as well as n-ring placement, area, and bias on charge collection are investigated experimentally using a 36 MeV O2 microbeam. The results indicate that charge shunting through the n-ring can result in up to a 90% reduction in collector collected charge for strikes outside the DT and a 18% reduction for strikes to the emitter center. 3-D transient strike simulations using NanoTCAD are used to verify the experimental observations, as well as shed insight into the underlying physical mechanisms. Circuit implications for this RHBD technique are discussed and recommendations made.

The impact of 63.3 MeV proton and 10 keV X-ray irradiation on the DC and AC performance of complementary SiGe HBTs on thick-film SOI is investigated. Proton and X-ray induced changes in the forward and inverse Gummel characteristics, the output characteristics, and avalanche multiplication are reported for both npn and pnp SiGe HBTs, at both room temperature (300 K) and at cryogenic temperatures (down to 30 K). Comparison of room temperature and cryogenic data suggests interface trap formation at two distinct physical locations in the transistors. Experimental data and calibrated TCAD simulations are used to compare the radiation response of both thick-film SOI devices and thin-film SOI SiGe HBTs.

A comprehensive investigation of the performance dependencies of irradiated SiGe precision voltage reference circuits on (1) total ionizing dose (TID), (2) circuit topology, and (3) radiation source is presented. Two different bandgap voltage references were designed using a first-generation (50-GHz) SiGe BiCMOS technology platform, and subsequently exposed to X-rays at doses of 1080 krad(SiO2) and 5400 krad(SiO2). The degradation in circuit performance following X-ray irradiation depends on both the TID level and the chosen circuit topology. Measurement results show that large TID levels can significantly shift the magnitude of the output voltage. Explanations for the observed shifts are provided by utilizing detailed analyses of the two circuit topologies and considering device-to-circuit interactions. The primary factor responsible for the difference in the circuit response before and after irradiation can be attributed to the excess base leakage current in the SiGe HBT. To investigate the impact of radiation source, the circuit topology showing the worst-case degradation from the X-ray experiment was independently exposed to 63-MeV protons at the same effective TID level. A clear source dependence in the circuit response was observed, and possible origins of this behavior are identified.

We report the generation and the tomographic analysis of novel quantum states of light generated by the controlled addition and subtraction of single photons to and from a classical and fully incoherent thermal light field. Time-domain quantum tomography is used to thoroughly investigate the character of the resulting states. Several different criteria are employed to test and quantify nonclassicality of photon-added thermal states, while the peculiar features concerning the mean photon number of photon-subtracted thermal states are clearly observed.

The inverse-mode operational regime of silicon germanium (SiGe) heterojunction bipolar transistors (HBTs) has to date been largely ignored and is typically dismissed as a viable possibility for circuit applications due to the general perception of its limited dc and ac performance capabilities. In this paper, the inverse-mode performance of four distinct generations of SiGe HBTs is investigated and is found to improve impressively with generational scaling. The physics behind these scaling-induced improvements is examined in detail using a combination of measurements and calibrated simulations. A novel lateral dependence of the inverse-mode base current is identified and is shown to potentially present new opportunities for even larger improvements in inverse-mode performance in SiGe HBTs. A record peak fT in inverse mode of 25 GHz is reported for a prototype fourth-generation device

Procedural layout generation is common practice in digital, analog or RF circuit layout design. Designers generate mask designs by specifying only the key parameters of devices, digital or analog blocks and have algorithms construct the complete layout. But automated layout design is limited to Manhattan structures (orthogonal shapes) or to devices with 45° angles (typically octagonal inductors). This work introduces for the first time procedural layout generation to wafer-size power semiconductor devices such as Phase Controlled Thyristors (PCTs), characterized by arbitrary angles and shapes, including curved geometries. The proposed technique offers many advantages such as saving of time, automatic enforcement of design rules and best practices, and ease of modification of an existing design. In particular, this work focuses mainly on the key advantage of this approach: device performance and reliability improvement through automated placement of the PCT shorts.

A new IGBT type structure, namely the p-ring FS+ Trench IGBT, with improved performance has been demonstrated. The improvement has been achieved through the utilization of p doped buried layers (p-rings) which allows for the simultaneous increase in the n enhancement layer doping concentration above the conventional levels without compromising the device breakdown rating. This unique lateral charge compensation approach is demonstrated to be highly effective in lowering the on-state losses. The experimental results show a 20% reduction in the on-state losses for a 1.7kV device.

We introduce a new generation of 100 mm electrically triggered phase controlled thyristor (PCT) with on-state voltage V T T = 1.5 kA and T = 90 °C and nominal forward and reverse blocking voltages of 8.5 kV. This PCT employs a new junction termination, which allows us to reduce the original device thickness by 7 % and hereby the V T by 13 %. This device has thinner p-type active regions with both the wafer and doping profiles specially shaped around the negative bevel. As a result, the reach-through effect is absent in the active area, the leakage current is reduced and the maximal junction temperature is increased by 25 °C.

We developed an ultra-stable and accurately-controllable Michelson interferometer to be used in a deeply unbalanced arm configuration for split-pulse XUV Ramsey-type spectroscopy with high-order laser harmonics. The implemented active and passive stabilization systems allow one to reach instabilities in the nanometer range over meters of relative optical path differences. Producing precisely delayed pairs of pump pulses will generate XUV harmonic pulses that may significantly improve the achievable spectral resolution and the precision of absolute frequency measurements in the XUV.

We demonstrate that the interaction of ultrashort single photons with a dense resonant atomic sample deeply modifies the temporal shape of their wavepacket mode without degrading their non-classical character, and effectively generates zero-area single-photon pulses.

Micro-fabrication in diamond is involved in a wide set of emerging technologies, exploiting the exceptional characteristics of diamond for application in bio-physics, photonics, radiation detection. Micro ion-beam irradiation and pulsed laser irradiation are complementary techniques, which permit the implementation of complex geometries, by modification and functionalization of surface and/or bulk material, modifying the optical, electrical and mechanical characteristics of the material. In this article we summarize the work done in Florence (Italy) concerning ion beam and pulsed laser beam micro-fabrication in diamond., 14 pages, 5 figures

The three-dimensional concept in particle detection is based on the fabrication of columnar electrodes perpendicular to the surface of a solid state radiation sensor. It permits to improve the radiation resistance characteristics of a material by lowering the necessary bias voltage and shortening the charge carrier path inside the material. If applied to a long-recognized exceptionally radiation-hard material like diamond, this concept promises to pave the way to the realization of detectors of unprecedented performances. We fabricated conventional and three-dimensional polycrystalline diamond detectors, and tested them before and after neutron damage up to 1.2 x 10(16) cm(-2), 1 MeV-equivalent neutron fluence. We found that the signal collected by the three-dimensional detectors is up to three times higher than that of the conventional planar ones, at the highest neutron damage ever experimented. (C) 2015 AIP Publishing LLC.

We present an investigation of the observed variations in the total dose tolerance of the emitter-base spacer and shallow trench isolation oxides in a commercial 200 GHz SiGe HBT technology. Proton, gamma, and X-ray irradiations at varying dose rates are found to produce drastically different degradation signatures at the various oxide interfaces. Extraction and analysis of the radiation-induced excess base current, as well as low-frequency noise, are used to probe the underlying physical mechanisms. Two-dimensional calibrated device simulations are employed to correlate the observed results to the spatial distributions of carrier recombination in forward- and inverse-mode operation for both pre- and post-irradiation levels. Possible explanations of our observations are offered and the implications for hardness assurance testing are discussed

The off-state drain current leakage characteristics of 130 nm CMOS technology are investigated using x-ray irradiation and operating temperature as variables. Radiation-induced interface traps in the gate oxide to gate-drain overlap region strongly enhance the off-state leakage as a function of gate bias. Due to the thin gate oxide in these 130 nm devices, we find that drain-edge direct tunneling is more plausible than conventional gate-induced-drain-leakage in explaining the observed increase in drain leakage. Radiation-induced traps in the shallow trench isolation oxide create parasitic channels in the p-well and produce another source of off-state drain leakage with increasing total dose. The drain current increase from both the gate overlap region and the shallow trench edge are enhanced with increasing total dose and suppressed by cooling

A comprehensive investigation of the effects of proton irradiation on the performance of SiGe BiCMOS precision voltage references intended for extreme environment operational conditions is presented. The voltage reference circuits were designed in two distinct SiGe BiCMOS technology platforms (first generation (50 GHz) and third generation (200 GHz)) in order to investigate the effect of technology scaling. The circuits were irradiated at both room temperature and at 77 K. Measurement results from the experiments indicate that the proton-induced changes in the SiGe bandgap references are minor, even down to cryogenic temperatures, clearly good news for the potential application of SiGe mixed-signal circuits in emerging extreme environments

X-ray total ionizing dose effects in both fully-depleted and partially-depleted SiGe HBT-on-SOI transistors are investigated at room and at cryogenic temperatures for the first time. Devices irradiated in grounded and forward-active mode configurations exhibit a different behavior depending on the collector doping of the device. The degradation produced by 10 keV x-rays is compared to previously reported 63 MeV proton results on the same fully-depleted SiGe HBT-on-SOI devices, showing decreased degradation for proton irradiation. Both collector and substrate bias are shown to affect the two-dimensional nature of the current flow in these devices, resulting in significant differences in the avalanche multiplication characteristics (hence, breakdown voltage) across temperature

We propose and experimentally verify a novel method for the remote preparation of entangled bits (ebits) made of a single photon coherently delocalized between two well-separated temporal modes. The proposed scheme represents a remotely tunable source for tailoring arbitrary ebits, whether maximally or non-maximally entangled, which is highly desirable for applications in quantum information technology. The remotely prepared ebit is studied by performing two-mode homodyne tomography with an ultra-fast time-domain balanced homodyne detection scheme recently developed in our laboratory.

We have developed a technique for dual-temporal-mode, ultrafast, time-domain, balanced homo- dyne detection. We have tested it by performing homodyne measurements on pairs of picosecond-duration tem- poral modes (or "time bins") carrying a delocalized single photon. The experimental homodyne data have been used to reconstruct both the density matrix and the two-mode Wigner function of the delocalized state, thus showing the correlations existing between the pair of temporal modes carrying the single photon.

Proton radiation effects in vertical SiGe HBTs fabricated on CMOS-compatible silicon-on-insulator (SOI) are investigated for the first time. Proton irradiation at 63 MeV is found to introduce base leakage current at low base-emitter voltage, delay the onset of Kirk effect at high injection, and increase the frequency response of SiGe HBTs on SOI. The latter two effects are in contrast to those found in conventional bulk SiGe HBTs. Proton irradiation also generates positive fixed oxide and interface charge in the buried oxide, which alters both M-1 and BV/sub CEO/ in the SiGe HBT by modulating the electric field in the collector region.

We present a Ramsey technique using high-order harmonics for high-resolution atomic spectroscopy in the extreme ultraviolet. Pairs of time-delayed and phase-coherent harmonic pulses generated by the interaction of ultrashort and intense laser pulses with a noble gas are used to study excited states of krypton.

We investigate the coherence properties of a linear array of white-light sources produced in bulk media by ultrashort laser pulses. The array is generated out of the spatial interference pattern between two laser pump pulses, so that the number of supercontinuum sources and their separations can be easily manipulated by varying the geometry of the laser beam interaction. We find that all the secondary white-light sources which arise from the generation of filaments in the optical medium are well phase-locked and are thus able to generate stable and high-visibility multiple-beam interference patterns in the far-field. Observations are compared to the results of a simple model which takes into account a clamping of the peak laser intensity inside the filaments and includes intensity-dependent phase shifts among the different sources.