bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of High-κ Nanolaminates of HfO2 and Al2O3 Used as Gate Dielectrics in pMOSFETs
Authors: Wu Dongping , Lu Jun , Persson Stefan , Hellström Per-Erik , Vainonen-Ahlgren Elizaveta , Tois Eva , Tuominen Marko , Östling Mikael , Zhang Shi-Li 
Published: July 2011

AbstractIn order to combine the merits of both HfO2 and Al2O3 as high-κ gate dielectrics for CMOS technology, high-κ nanolaminate structures in the form of either Al2O3/HfO2/Al2O3 or Al2O3/HfAlOx/Al2O3 were implemented in pMOSFETs and electrically and microstructurally charachterized. ALD TiN film was used as the metal gate electrodes for the pMOSFETs. After full transistor-processing including a rapid thermal processing step at 930 °C, the HfO2 film in the former nanolaminate was found to be crystallized. In contrast, the HfAlOx layer in the latter nanolaminate remained in the amorphous state. Both types of pMOSFETs exhibited a hysteresis as small as ∼20 mV in C-V characteristics in the bias range of +/− 2 V. They also showed a reduced gate leakage current. The pMOSFET with the Al2O3/HfAlOx/Al2O3 nanolaminate was characterized with a subthreshold slope of 77 mV/decade and a channel hole mobility close to the universal hole mobility curve. The pMOSFET with the Al2O3/HfO2/Al2O3, however, exhibited a subthreshold slope of 100 mV/decade and a ∼30% lower hole mobility than the universal curve.
Electrical breakdown in a two-layer dielectric in the MOS structure
Authors: Yang Xiaolong , Xie Qianghua , Tao Meng 
Published: July 2011

AbstractThe formation of interfacial oxide between high-k and Si creates a two-layer dielectric in the MOS structure. In this paper, we present a model to describe electrical breakdown in the two-layer dielectric. Depending on the thickness ratio of the two dielectric layers, electrical breakdown can occur either in one dielectric after the other or simultaneously. In the case of one-by-one breakdown, the current through the two-layer dielectric shows three regimes with applied voltage: tunneling through two layers, tunneling through one layer, and breakdown for both layers. Our model has been compared with experimental data obtained from the HfOx/SiO2 MOS structure, and a good agreement is achieved. This model can be used to estimate either the thickness, breakdown field, or dielectric constant of each of the two dielectric layers. It can also predict the overall breakdown voltage for different combinations of dielectric layers. When combined with C-V measurements, more information about the two-layer dielectric is obtained.
Engineering the nm-thick Interface Layer Formed Between a High-k Film and Silicon
Authors: Lu J. , Tewg J. -Y. , Kuo Y. 
Published: July 2011

ABSTRACTThe interface layer between thin sputter-deposited tantalum oxide (TaOx) high-k film and silicon substrate was engineered with the Hf doping method and the insertion of a thin 5Å TaNx interface. The following results have been obtained: 1) the Hf dopant in the TaOx film was involved in the interface formation process, e.g., forming a new, thinner high-k HfSixOy interface layer rather than the SiOx layer, 2) when the TaNx interface was inserted, the interface layer composition was even more complicated, e.g., including TaOxNy and HfSixOy structures. No hafnium nitride or oxynitride was detected, 3) the interface layer structure was changed, e.g., from single-zone to multi-zone with different compositions, 4) when a low concentration of Hf existed in the TaOx film, the high-k dielectric properties, such as the k value, fixed charge density, dielectric strength, were improved, and 5) when the thin TaNx interface layer was inserted, the above electric properties were further improved. However, the fixed charge density and interface states were increased due to the insertion of the TaNx interface layer. These results were contributed by factors such as the charge-trapping characteristics in the interface layer and the some damage repairing mechanisms. In summary, this research proved that the high-k film's interface layer and bulk properties could be were improved with the doping process as well as the insertion of an ultra-thin TaNx interface film.
Controlling Area-Selective Atomic Layer Deposition of HfO2 Dielectric by Self-assembled Monolayers
Authors: Chen Rong , Kim Hyoungsub , McIntyre Paul C. , Bent Stacey F. 
Published: July 2011

ABSTRACTA series of self-assembled molecules have been investigated as deactivating agents for the HfO2 atomic layer deposition (ALD). Three important factors of self-assembled monolayers (SAMs) deactivating efficiency towards ALD--chain length, reactivity and steric effect--have been investigated and discussed as well as the initial blocking mechanism of this process. This investigation shows that in order to achieve satisfactory deactivation, it is crucial to choose high reactivity, low steric effect molecules with certain chain length to form condensed, high hydrophobic organic monolayers.
Structural, Dielectric and Pyroelectric properties of Lanthanum modified Lead Titanate Thin Films
Authors: Chopra Sonalee , Sharma Seema , Goel T.C. , Mendiratta R.G. 
Published: July 2011

ABSTRACTFerroelectric lead lanthanum titanate (Pb1−xLaxTi1−x/4O3) (PLTx) thin films (x=0.04,0.08 and 0.12) have been prepared by sol-gel spin coating process on ITO coated 7059 Corning glass substrates. Investigations have been made on the crystal structure, surface morphology, dielectric and ferroelectric properties of the thin films. For a better understanding of the crystallization mechanism, the structural investigations were carried out at various annealing temperatures (350°C, 450°C, 550°C and 650°C). Characterization of these films by X-ray diffraction shows that the films annealed at 650°C exhibit tetragonal structure with perovskite phase. Replacement of lanthanum in lead titanate results in reduction of tetragonal ratio (c/a), resulting in better mechanical stability. Microstructural analysis of the films are carried out by taking the Atomic Force Microscope (AFM) pictures. AFM images are characterized by slight surface roughness with a uniform crack free, densely packed structure. Dielectric, pyroelectric and ferroelectric studies carried out on these films have been reported. Dielectric constant and pyroelectric coefficient increase while Curie temperature decreases with increase in La content. The pyroelectric figures of merit of the films have also been calculated which suggest that 8% lanthanum is best suited material for pyroelectric detectors owing to its high pyroelectric coefficient (∼ 29nC/cm2 K), high voltage responsivity (∼420Vcm2/J), high detectivity (∼1.04×10−5Pa−1/2) and low variation of pyrocoefficient with temperature.
Effects of Annealing on the Mechanical and Electrical Properties of DC Sputtered Tantalum Pentoxide (Ta2O5) Thin Films
Authors: Purswani J. M. , Pons A. P. , Glass J. T. , Evans R. D. , Cogdell J. D. 
Published: July 2011

ABSTRACTTantalum oxide (Ta2O5) films were deposited onto p-type silicon substrates using reactive DC magnetron sputtering, and then annealed for one hour in a dry air ambient at temperatures of 730°C, 780°C, and 830°C. Annealing was shown to reduce stress from the as-deposited sample, and resulted in a compressive stress state for samples annealed at 730°C and a tensile stress state for the other samples. Hardness values were approximately 8 GPa, with the exception of the sample annealed at 780°C that demonstrated a hardness of 13 GPa. Leakage current generally decreased with annealing, especially at the lower temperatures. Electrical breakdown was observed for as-deposited and the 830°C annealed films. Resistivities of the films ranged from 6.5 × 109 to 6.1 × 1012 ω-cm, with the film annealed at 830°C being the most conductive. Annealing also led to an increase in dielectric constant. Dielectric constants varied from 9.3 for the as-deposited to greater than 30 for the 780°C and 830°C annealed sample. Annealing resulted in crystalline films that were close to stoichiometric.
Tunable Workfunction with TaN Metal Gate on HfO2-HfxSiyO Dielectrics
Authors: Olsen Christopher S. , Kraus Philip A. , Ahmed Khaled Z. , Kher Shreyas , Hung Steven , Krishna Nety , Chen Jeff , Date Lucien , Burey Marc , Campbell Jason 
Published: July 2011

AbstractMOS capacitors were fabricated from MOCVD HfO2 and HfxSiyO gate dielectrics with ALD TaN / PVD Ta metal electrodes. Dielectrics with 1.8 to 2.6 nm capacitance equivalent thickness (CET) were investigated with gate leakage (Jg) of 1×10−7 to 1×10−3 A/cm2 at Vg = Vfb−1V in accumulation. In addition to the C-V and I-V characterization of the MOSCAPs, XPS physical characterization was performed on monitor wafers to determine composition and physical thickness. From the combined results of the electrical and physical characterization, the relative dielectric constants of the Hf-Si-O films and the metal electrode work functions are determined, and simple models for the compositional dependence of the dielectric constant are formulated. Capacitors with the same dielectric composition and thickness exhibited 100 mV Vfb change when the thickness of the ALD TaN electrode layer was changed from 40-80Å. This change is attributed to a change in the work function of the aggregate TaN / Ta metal electrode. Workfunctions were found to be located near middle of the Si band gap, with workfunctions of 4.6 eV to 4.7 eV.
Physical characterization of HfO2deposited on Ge substrates by MOCVD.
Authors: Van Elshocht S. , Brijs B. , Caymax M. , Conard T. , De Gendt S. , Kubicek S. , Meuris M. , Onsia B. , Richard O. , Teerlinck I. , Van Steenbergen J. , Zhao C. , Heyns M. 
Published: July 2011

ABSTRACTGermanium is because of its intrinsically higher mobility than Si, currently under consideration as an alternative approach to improve transistor performance. Germanium oxide, however, is thermodynamically unstable, preventing formation of the gate dielectric by simple oxidation. At present, high-k dielectrics might be considered as an enabling technology as much progress has been made in the deposition of thin high-quality layers.In this paper, we study the growth and physical properties of HfO2 deposited on Ge by MOCVD, using TDEAH and O2 as precursors, and compare the results to similar layers deposited on silicon substrates. Our results show that the physical properties of MOCVD-deposited HfO2 layers on Ge are very similar to what we have observed in the past for Si. Unfortunately, some of the negative aspects observed for Si, such as diffusion of substrate material in the high-k layer, a low density for thinner layers, or a rough top surface, are also observed for the case of Ge. However, careful surface pretreatments such as NH3 annealing the Ge substrate prior to deposition, can greatly improve the physical properties. An important observation is the very thin interfacial layer between HfO2 and Ge substrate, allowing a more aggressive scaling for Ge.
Defect Energy Levels in HfO2, ZrO2, La2O3 and SrTiO3
Authors: Xiong K , Peacock P W , Robertson J 
Published: July 2011

AbstractDefect energy levels of oxygen vacancies in various high K oxides HfO2, ZrO2, La2O3 and SrTiO3 have been calculated using methods which give the correct band gap, such as the screened exchange and weighted density approximation.
Ultrathin Dielectric Films Grown by Solid Phase Reaction of Pr with SiO2
Authors: Müssig Hans-Joachim , Dąbrowski Jarek , Wenger Christian , Łupina Grzegorz , Sorge Roland , Formanek Peter , Zaumseil Peter , Schmeißer Dieter 
Published: July 2011

ABSTRACTWe have fabricated Pr-based high-k gate dielectric films by physical vapor deposition of metallic Pr on SiO2 under ultra-high vacuum (UHV) conditions at room temperature, followed by oxidation and annealing steps. The films have been analyzed by electrical measurements, X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM). Some insight into the physical processes involved has been obtained from ab initio calculations. The high-k gate stacks consist of a SiO2-based buffer with an enhanced dielectric constant and a Pr silicate barrier with a high dielectric constant. The role of the buffer is to preserve the high quality of the SiO2/Si(001) interface, and the role of the barrier is to keep the tunneling currents low by increasing its physical thickness. A Pr film deposited on a 1.8 nm SiO2 layer, oxidized at room temperature by air, and annealed in N2 atmosphere with O2 partial pressure of 10−3 mbar results in a stack with the Capacitance Equivalent Thickness of 1.5 nm and leakage of 10−4 A/cm2.
Atomic Vapour Deposition (AVD™) Process for High Performance HfO22 Dielectric Layers
Authors: Cosnier V. , Dabertrand K. , Blonkowski S. , Lhostis S. , Zoll S. , Morand Y. , Descombes S. , Guillaumot B. , Hobbs C. , Rochat N. , Rolland G. , Renault O. , Garros X. , Cassé M. , Mitard J. , Lehnen P. , Miedl S. , Lindner J. , Schumacher M. 
Published: July 2011

ABSTRACTHf-family compounds have been widely studied as high k gate dielectric materials, they can be elaborated in a wide range of deposition techniques but ALD and MOCVD are the most advanced. In this contribution, the deposition of pure HfO2 is performed by Atomic Vapour Deposition, which is a sort of pulsed-mode MOCVD. The precursor, diluted into a solvent, is pulsed through specific injectors (TriJet®), micro-droplets are vaporised and distributed to the substrate through a showerhead. ATR-FTIR and Hg-probe measurements have been extensively used to evaluate the materials. The advantage of this specific MOCVD system is that it allows working within a wide range of liquid injection frequencies. Thus, we have been able to show that the frequency of injection has a huge impact on the structural and electrical properties of the material. It has been evidence that working at low frequencies is crucial in order to get good electrical behaviour. Higher temperature deposition shows also a clear benefit. An EOT of 1.15 nm with 6.10−2 A/cm2 at |Vfb| + 1 V, that is to say about 3 orders of magnitude below what is obtained with SiO2 has been obtained on capacitors with TiN gate. This is a very good achievement fore pure HfO2 deposited by MOCVD.This work has been made in the frame of MEDEA + T207 European project with the help of Air Liquide and Epichem.
Impact of an Antimicrobial Allergy Label in the Medical Record on Clinical Outcomes in Hospitalized Patients
Authors: Charneski Lisa , Deshpande Gaurav , Smith Sheila Weiss 
Published: July 2011

Study Objective. To determine the impact of having an antimicrobial allergy label in the medical record on clinical outcomes in hospitalized patients.Design. Retrospective cohort study.Setting. Urban academic teaching hospital.Patients. A total of 11,872 adults admitted to nonsurgical patient care wards who received at least one antimicrobial between August 1, 2007, and July 31, 2008; of these patients, 1324 (11.2%) had an antimicrobial allergy label and 10,548 (88.8%) did not have an allergy label documented in the medical record.Measurements and Main Results. The following clinical outcomes were compared in patients with allergy labels versus patients without allergy labels: length of stay, admission to the intensive care unit (ICU), number of antimicrobials received during hospitalization, readmission within 4 weeks of hospital discharge, and death during hospitalization. Presence of an allergy label in the medical record was associated with increased length of stay, a higher ICU admission rate, receipt of more than one antimicrobial, and a higher mortality rate during the hospitalization. Logistic regression models were used to assess the association of allergy label with these outcomes while adjusting for covariates (age group, sex, surgery during hospitalization, and season of admission); multiple regression was used to model the association of allergy label with length of stay. On average, length of stay was 1.21 days (unadjusted) and 1.16 days (adjusted for covariates) longer in patients with allergy labels. The likelihood of an ICU admission were 1.4 times (adjusted odds ratio [OR 1.42, 95% confidence interval [CI 1.21–1.67) higher in patients with allergy labels. Presence of an allergy label was also associated with receipt of more than one antibiotic during the hospitalization (crude OR 1.61, 95% CI 1.43–1.81) and a 1.6fold higher risk of dying during the hospitalization (crude OR 1.56, 95% CI 1.20–2.04). Presence of an allergy label was not associated with an increased risk of readmission within 4 weeks of discharge (adjusted OR 0.71, 95% CI 0.63–0.80).Conclusion. Presence of an allergy label in the medical record was associated with increased length of hospital stay and worse clinical outcomes compared with no allergy label in hospitalized patients treated with antimicrobials.
The Anabolic 500 Survey: Characteristics of Male Users versus Nonusers of Anabolic‐Androgenic Steroids for Strength Training
Authors: Ip Eric J. , Barnett Mitchell J. , Tenerowicz Michael J. , Perry Paul J. 
Published: July 2011

Study Objective. To contrast the characteristics of two groups of men who participated in strength‐training exercise—those who reported anabolic‐androgenic steroid (AAS) use versus those who reported no AAS use.Design. Analysis of data from the Anabolic 500, a cross‐sectional survey.Participants. Five hundred six male self‐reported AAS users (mean age 29.3 yrs) and 771 male self‐reported nonusers of AAS (mean age 25.2 yrs) who completed an online survey between February 19 and June 30, 2009.Measurements and Main Results. Respondents were recruited from Internet discussion boards of 38 fitness, bodybuilding, weightlifting, and steroid Web sites. The respondents provided online informed consent and completed the Anabolic 500, a 99‐item Web‐based survey. Data were collected on demographics, use of AAS and other performance‐enhancing agents, alcohol and illicit drug use, substance dependence disorder, other Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision diagnoses, and history of sexual and/or physical abuse. Most (70.4%) of the AAS users were recreational exercisers who reported using an average of 11.1 performance‐enhancing agents in their routine. Compared with nonusers, the AAS users were more likely to meet criteria for substance dependence disorder (23.4% vs 11.2%, p<0.001), report a diagnosis of an anxiety disorder (10.1% vs 6.1%, p=0.010), use cocaine within the past 12 months (11.3% vs 4.7%, p<0.001), and report a history of sexual abuse (6.1% vs 2.7%, p=0.005).Conclusion. Most of the AAS users in this study were recreational exercisers who practiced polypharmacy. The AAS users were more likely than nonusers to meet criteria for substance dependence disorder, report a diagnosis of an anxiety disorder, report recent cocaine use, and have a history of sexual abuse. The information uncovered in this study may help clinicians and researchers develop appropriate intervention strategies for AAS abuse.
Association of Apolipoprotein E Genotype with Duration of Time to Achieve a Stable Warfarin Dose in African‐American Patients
Authors: Cavallari Larisa H. , Butler Christopher , Langaee Taimour Y. , Wardak Nargis , Patel Shitalben R. , Viana Marlos A. G. , Shapiro Nancy L. , Nutescu Edith A. 
Published: July 2011

Study Objective. To test the hypothesis that genotypes for proteins affecting vitamin K availability influence the duration of time required to achieve a stable warfarin dose in African‐American patients.Design. Retrospective cohort study.Setting. Pharmacist‐managed antithrombosis clinic.Patients. Ninety‐two African‐American adults whose warfarin therapy was initiated between September 2, 1999, and July 8, 2009.Measurements and Main Results. During a routine anticoagulation clinic visit, a sample was collected from each patient for genetic analysis. Genotyping was performed for the following variants: apolipoprotein E ε2, ε3, and ε4; NAD(P)H:quinone oxidoreductase (NQO1)*2; cytochrome P450 (CYP) 4F2 V433M; CYP2C9*2, *3, *5, *8, and *11; and vitamin K epoxide reductase complex 1 (VKORC1) ‐1639G>A. Patients' medical records were then reviewed, and data were collected retrospectively for each anticoagulation clinic visit during the first 6 months of warfarin therapy or until dose stabilization. The median time required to reach a stable warfarin dose, defined as the dose that produced therapeutic anticoagulation for three consecutive clinic visits, was 83 days. Compared with the 46 patients who achieved a stable warfarin dose within 83 days, the 46 patients who required longer durations for dose stabilization had a higher frequency of the apolipoprotein E ε3/ε3 genotype (37% vs 59%, p=0.037). Sixty‐one percent of patients with the ε3/ε3 genotype versus 40% of those with an ε2 or ε4 allele had a delay in achieving a stable dose (p=0.037). Neither the CYP4F2 nor NQO1 genotype was associated with warfarin dose stabilization.Conclusion. Our data support the hypothesis that the apolipoprotein E genotype is associated with duration of time to reach a stable warfarin dose in African‐American patients. Further insight into the genetic effects on warfarin dose stabilization could reveal novel methods to improve anticoagulation control during the warfarin initiation period.
A Phase II Trial of Bevacizumab plus Everolimus for Patients with Refractory Metastatic Colorectal Cancer
Authors: Altomare Ivy , Bendell Johanna C. , Bullock Karen E. , Uronis Hope E. , Morse Michael A. , Hsu S. David , Zafar S. Yousuf , Blobe Gerard C. , Pang Herbert , Honeycutt Wanda , Sutton Linda , Hurwitz Herbert I. 
Published: July 2011

Abstract

Purpose.
For patients with metastatic colorectal cancer (mCRC), no standard therapy exists after progression on 5-fluorouracil, oxaliplatin, irinotecan, bevacizumab, and cetuximab or panitumumab. Preclinical data demonstrated that combined vascular endothelial growth factor and mammalian target of rapamycin inhibition has greater antiangiogenic and antitumor activity than either monotherapy. A phase I study of bevacizumab plus everolimus demonstrated that the combination is safe; activity was seen in several patients with refractory mCRC.

Methods.
Fifty patients with refractory mCRC were enrolled and received bevacizumab at 10 mg/kg every 2 weeks and everolimus at 10 mg orally daily.

Results.
Of the 50 patients enrolled, the median age was 56 years and the median number of prior regimens was four. Forty-seven patients (96%) had prior bevacizumab exposure and 42 patients (84%) had documented progression on prior bevacizumab-based therapy. Forty-nine patients were evaluable for response; eight patients had minor responses (16%) and an additional 15 patients (30%) had stable disease (SD). No complete or partial responses were seen. The median progression-free survival interval was 2.3 months; however, 26% of patients achieved prolonged SD for ≥6 months, and three patients (6%) were on study for &gt;1 year. The median overall survival duration was 8.1 months. The most common grade 1–2 toxicities were mucositis (68%) and hyperlipidemia (64%). Clinically significant grade ≥3 toxicities included hypertension (14%), fistula/abscess/perforation (8%), mucositis (6%), and hemorrhage (2%).

Conclusions.
Bevacizumab plus everolimus is generally tolerable but may have risks related to mucosal damage and/or wound healing. Bevacizumab plus everolimus appears to have modest activity in refractory mCRC in patients.