On the Thermal Activation of Negative Bias Temperature Instability

The temperature dependence of negative bias temperature instability (NBTI) is investigated on 2.0nm SiO2 devices from temperatures ranging from 300K down to 6K with a measurement window of ~12ms to 100s. Results indicate that classic NBTI degradation is observed down to ~200K and rarely observed at temperatures below 140K in the experimental window. Since experimental results show the charge trapping component contributing to NBTI is thermally activated, the results cannot be explained with the conventionally employed elastic tunneling theory. A new mechanism is observed at temperatures below 200K where device performance during stress conditions improves rather than degrades with time, which is opposite to the classical NBTI phenomenon

Assessing Ozone-Related Health Impacts under a Changing Climate

Climate change may increase the frequency and intensity of ozone episodes in future summers in the United States. However, only recently have models become available that can assess the impact of climate change on O(3) concentrations and health effects at regional and local scales that are relevant to adaptive planning. We developed and applied an integrated modeling framework to assess potential O(3)-related health impacts in future decades under a changing climate. The National Aeronautics and Space Administration–Goddard Institute for Space Studies global climate model at 4° × 5° resolution was linked to the Penn State/National Center for Atmospheric Research Mesoscale Model 5 and the Community Multiscale Air Quality atmospheric chemistry model at 36 km horizontal grid resolution to simulate hourly regional meteorology and O(3) in five summers of the 2050s decade across the 31-county New York metropolitan region. We assessed changes in O(3)-related impacts on summer mortality resulting from climate change alone and with climate change superimposed on changes in O(3) precursor emissions and population growth. Considering climate change alone, there was a median 4.5% increase in O(3)-related acute mortality across the 31 counties. Incorporating O(3) precursor emission increases along with climate change yielded similar results. When population growth was factored into the projections, absolute impacts increased substantially. Counties with the highest percent increases in projected O(3) mortality spread beyond the urban core into less densely populated suburban counties. This modeling framework provides a potentially useful new tool for assessing the health risks of climate change

Impact Evaluation of the Louisville-Shively-Jefferson County Traffic Alcohol Programs

This report is an evaluation of alcohol enforcement programs conducted by the Louisville, Jefferson County, and Shively police agencies in the Louisville metropolitan area. The following four types of data were collected in order to evaluate the traffic alcohol programs; accident data, arrest and adjudication data, cost-effectiveness, and public opinion data. Results from the before-and-after comparisons and time-series analysis show alcohol-related accidents decreased significantly during the study period, There was a 34.4 percent reduction in alcohol-related accidents during hours of special enforcement and a 30.4 percent reduction during all hours of the day. Time-series analysis of accident data showed a 27.1 percent decrease during hours of increased enforcement and a 26.1 percent decrease during all hours. Results from time-series analysis also indicated that the enforcement programs increased the DUI arrest rate by at least 50 percent in each of the jurisdictions studied. Inclusion of the Slammer Law as a control variable revealed the proportion of convictions among DUI arrests increased by nearly 449 percent. Based on costs associated with the program (enforcement, jail costs, and court costs) and benefits (reduced accident costs and DUI fines); the benefit-cost ratio was 2.81 to 5.67 depending upon the basis for accident costs. The public opinion survey showed strong support for the traffic alcohol programs and 87 percent of the respondents indicated that increased enforcement was an effective means of reducing drinking and driving. In addition, 82 percent of those responding indicated the programs had reduced their chances of an accident

Integrating Through-Wafer Interconnects with Active Devices and Circuits

Through wafer interconnects (TWIs) enable vertical stacking of integrated circuit chips in a single package. A complete process to fabricate TWIs has been developed and demonstrated using blank test wafers. The next step in integrating this technology into 3D microelectronic packaging is the demonstration of TWIs on wafers with preexisting microcircuitry. The circuitry must be electrically accessible from the backside of the wafer utilizing the TWIs; the electrical performance of the circuitry must be unchanged as a result of the TWI processing; and the processing must be as cost effective as possible. With these three goals in mind, several options for creating TWIs were considered. This paper explores the various processing options and describes in detail, the final process flow that was selected for testing, the accompanying masks that were designed, the actual processing of the wafers, and the electrical test results

Limitations of Poole–Frenkel Conduction in Bilayer HfO\u3csub\u3e2\u3c/sub\u3e/SiO\u3csub\u3e2\u3c/sub\u3e MOS Devices

The gate leakage current of metal–oxide– semiconductors (MOSs) composed of hafnium oxide (HfO2) exhibits temperature dependence, which is usually attributed to the standard Poole–Frenkel (P–F) transport model. However, the reported magnitudes of the trap barrier height vary significantly. This paper explores the fundamental challenges associated with applying the P–F model to describe transport in HfO2/SiO2 bilayers in n/p MOS field-effect transistors composed of 3- and 5-nm HfO2 on 1.1-nm SiO2 dielectric stacks. The extracted P–F trap barrier height is shown to be dependent on several variables including the following: the temperature range, method of calculating the electric field, electric-field range considered, and HfO2 thickness. P–F conduction provides a consistent description of the gate leakage current only within a limited range of the current values while failing to explain the temperature dependence of the 3-nm HfO2 stacks for gate voltages of less than 1 V, leaving other possible temperature-dependent mechanisms to be explored

Temperature (5.6-300K) Dependence Comparison of Carrier Transport Mechanisms in HfO2/SiO2 and SiO2 MOS Gate Stacks

Temperature dependent measurements have been used to examine transport mechanisms and energy band structure in MOS devices. In this study, a comparison between high-k HfO2 dielectrics and conventional SiO2 dielectrics is made to investigate dielectric specific thermally activated mechanisms. Temperature dependent measurements on large area n/pMOSFETs composed of SiO2 and HfO2/SiO2 gate dielectrics were performed from 5.6 K to 300 K. A large increase in the gate leakage current is observed at the formation of the minority carrier channel. The data indicate that gate leakage current prior to the formation of the minority channel is carrier rate limited while gate leakage current is tunneling rate limited above the threshold voltage. Gate leakage current measurements show two distinct Arrhenius transport regimes for both SiO2 and HfO2 gate dielectrics. The Arrhenius behavior of the gate leakage current is characterized by a strong temperature dependent regime and a weak temperature dependent regime. The activation energy of the strong temperature regime is found to vary with the applied gate voltage. Frenkel-Poole or other electric field models are able to explain the gate voltage dependence of the gate leakage current for the low-temperature/voltage regime investigated. The data suggest that the variation of the activation energy for the Arrhenius behavior is weakly electric-field driven and strongly voltage, or Fermi energy level, driven

Pharmacological Blockade of TRPM8 Ion Channels Alters Cold and Cold Pain Responses in Mice

TRPM8 (Transient Receptor Potential Melastatin-8) is a cold- and menthol-gated ion channel necessary for the detection of cold temperatures in the mammalian peripheral nervous system. Functioning TRPM8 channels are required for behavioral responses to innocuous cool, noxious cold, injury-evoked cold hypersensitivity, cooling-mediated analgesia, and thermoregulation. Because of these various roles, the ability to pharmacologically manipulate TRPM8 function to alter the excitability of cold-sensing neurons may have broad impact clinically. Here we examined a novel compound, PBMC (1-phenylethyl-4-(benzyloxy)-3-methoxybenzyl(2-aminoethyl)carbamate) which robustly and selectively inhibited TRPM8 channels in vitro with sub-nanomolar affinity, as determined by calcium microfluorimetry and electrophysiology. The actions of PBMC were selective for TRPM8, with no functional effects observed for the sensory ion channels TRPV1 and TRPA1. PBMC altered TRPM8 gating by shifting the voltage-dependence of menthol-evoked currents towards positive membrane potentials. When administered systemically to mice, PBMC treatment produced a dose-dependent hypothermia in wildtype animals while TRPM8-knockout mice remained unaffected. This hypothermic response was reduced at lower doses, whereas responses to evaporative cooling were still significantly attenuated. Lastly, systemic PBMC also diminished cold hypersensitivity in inflammatory and nerve-injury pain models, but was ineffective against oxaliplatin-induced neuropathic cold hypersensitivity, despite our findings that TRPM8 is required for the cold-related symptoms of this pathology. Thus PBMC is an attractive compound that serves as a template for the formulation of highly specific and potent TRPM8 antagonists that will have utility both in vitro and in vivo

Emotional communication in HIV care : an observational study of patients’ expressed emotions and clinician response

Emotional support is essential to good communication, yet clinicians often miss opportunities to provide empathy to patients. Our study explores the nature of emotional expressions found among patients new to HIV care, how HIV clinicians respond to these expressions, and predictors of clinician responses. Patient-provider encounters were audio-recorded, transcribed, and coded using the VR-CoDES. We categorized patient emotional expressions by intensity (subtle 'cues' vs. more explicit 'concerns'), timing (initial vs. subsequent), and content (medical vs. non-medical). Emotional communication was present in 65 of 91 encounters. Clinicians were more likely to focus specifically on patient emotion for concerns versus cues (OR 4.55; 95% CI 1.36, 15.20). Clinicians were less likely to provide space when emotional expressions were repeated (OR 0.32; 95% CI 0.14, 0.77), medically-related (OR 0.36; 95% CI 0.17, 0.77), and from African American patients (OR 0.42; 95% CI 0.21, 0.84). Potential areas for quality improvement include raising clinician awareness of subtle emotional expressions, the emotional content of medically-related issues, and racial differences in clinician response