Influence of Overgrown Micropipes in the Active Area of SiC Schottky Diodes on Long Term Reliability

2005 ◽  
pp. 925-928 ◽  
Author(s):  
Roland Rupp ◽  
Michael Treu ◽  
Peter Türkes ◽  
H. Beermann ◽  
Thomas Scherg ◽  
...  
Keyword(s):  
Schottky Diodes ◽  
Active Area

Influence of Overgrown Micropipes in the Active Area of SiC Schottky Diodes on Long Term Reliability

2005 ◽  
Vol 483-485 ◽  
pp. 925-928 ◽  
Author(s):  
Roland Rupp ◽  
Michael Treu ◽  
Peter Türkes ◽  
H. Beermann ◽  
Thomas Scherg ◽  
...  
Keyword(s):  
Leakage Current ◽  
Power Dissipation ◽  
Schottky Diodes ◽  
Physical Structure ◽  
Active Area ◽  
Clear Correlation ◽  
Local Power ◽  
Degradation Mechanisms ◽  
Failure Simulation

Other than open micropipes (MP), overgrown micropipes do not necessarily lead to a^significantly reduced blocking capability of the affected SiC device. However they can lead to a degradation of the device during operation. In this paper the physical structure of overgrown micropipes will be revealed and their contribution to the leakage current will be shown. The possible impact of the high local power dissipation in the surrounding of the overgrown micropipe will be discussed and long term degradation mechanisms will be described. Failure simulation under laboratory conditions shows a clear correlation between the position of overgrown micropipes and the location of destructive burnt spots.

Characterization and Fuel Cell Testing of Radiation-Grafted Psi Membranes

1999 ◽  
Vol 575 ◽  
Author(s):  
H.-P. Brack ◽  
M. M. Koebel ◽  
A. Tsukada ◽  
J. Huslage ◽  
F. Buechi ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Oxidative Stability ◽  
Screening Method ◽  
Exchange Capacity ◽  
Ex Situ ◽  
Active Area ◽  
Rapid Screening ◽  
Raman Spectroscopic ◽  
Current Voltage

ABSTRACTWe have demonstrated earlier the useful performance of our PSI radiation-grafted membranes in terms of the current-voltage characteristics of 30 cm2 active area fuel cells containing these membranes and their long-term testing over 6,000 h at 60 °C. We report here on testing of PSI radiation-grafted membranes in these fuel cells at 80 °C and in short stacks comprised of two or four 100 cm2 active area cells. The in-situ degradation of membranes has been investigated by characterizing membranes both before testing in fuel cells and post-mortem after testing in fuel cells. Characterization was accomplished by means of ion-exchange capacity and infrared and Raman spectroscopic measurements. In addition, a rapid screening method for our ex-situ testing of the oxidative stability of proton-conducting membranes was developed in this work. Comparison of the initial screening test results concerning the oxidative stability of some perfluorinated, partially-fluorinated, and non-fluorinated membranes compare well qualitatively with the relative stability of these same membranes during their long-term testing in fuel cells.

A modular device for large area integrated photoelectrochemical water-splitting as a versatile tool to evaluate photoabsorbers and catalysts

2017 ◽  
Vol 5 (10) ◽  
pp. 4818-4826 ◽  
Author(s):  
J.-P. Becker ◽  
B. Turan ◽  
V. Smirnov ◽  
K. Welter ◽  
F. Urbain ◽  
...  
Keyword(s):  
Water Splitting ◽  
Photoelectrochemical Water Splitting ◽  
Active Area ◽  
Stable Operation ◽  
Large Area ◽  
Solar Water ◽  
Solar Water Splitting ◽  
Versatile Tool

We present a stand-alone integrated solar water-splitting device with an active area of 64 cm2 and a long-term stable operation. The modular setup of the device provides a versatile tool to integrate and evaluate various combinations of photoelectrodes and catalysts.

Off-Area Bonding of HgCdTe Photoconductive Infrared Detectors using Tri-Layer Photolithography and Wet/Dry Etching Techniques

1996 ◽  
Vol 450 ◽  
Author(s):  
Sridhar Manthripragada ◽  
Kelley Hu ◽  
Frank Peters ◽  
Andre Burgess ◽  
Sachidananda Babu ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Infrared Detectors ◽  
Chemical Etching ◽  
Metal Film ◽  
Active Area ◽  
Material Damage ◽  
Fabrication Technique ◽  
Detector Arrays ◽  
Bonding Scheme

ABSTRACTOn-area wire bonding of HgCdTe photoconductive (PC) infrared detectors usually causes material damage underneath the bonding pads. Such damage may propagate into the active area, potentially degrading performance and posing long-term reliability problems. Some off-area bonding fabrication techniques can also induce some degree of semiconductor material damage. In this paper, we report a relatively straightforward off-area bonding scheme that solves these problems. The process uses multiple photolithography and chemical etching steps to create a continuous slope or staircase in the HgCdTe leading down to the epoxy surface. The staircase ensures smooth step coverage for the subsequent metalization. Tri-layer photolithography (resist /metal/resist) and reactive ion etching (RIE) is then used to remove the epoxy in the bonding pad area. Since all areas other than the pad region are protected by the metal film, no RIE radiation damage is induced to the active area. The contact metalization is achieved by using standard liftoff techniques. Our so called staircase off-area bonding fabrication technique can be used to fabricate highly reliable, high density, small-size, detector arrays.

Defect Reduction in Si-based Metal-Semiconductor-Metal Photodetectors with Cryogenic Processed Schottky Contacts

2005 ◽  
Vol 864 ◽  
Author(s):  
M. Li ◽  
W. A. Anderson
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Dark Current ◽  
Schottky Barrier Height ◽  
Schottky Diodes ◽  
Schottky Contacts ◽  
Metal Deposition ◽  
Active Area ◽  
Electrode Spacing ◽  
Metal Semiconductor Metal

AbstractMetal-Semiconductor-Metal photodetectors (MSM-PD's) and simple Schottky diodes were fabricated using a low temperature (LT) technique to greatly reduce the device dark current. LT processing for metal deposition increased Schottky barrier height by improving the interface between metal and semiconductor to reduce the leakage current of the device. The structure consists of a 20 Å oxide over the active area to passivate surface states, a thicker oxide under contact pads to reduce dark current and the interdigitated Schottky contacts. A comparison was made for Schottky metal deposited with the substrate at 25 °C or -50 °C (LT). The devices fabricated using the LT process had better I-V characteristics compared to detectors fabricated using the standard room temperature (RT) metal deposition technique. The dark current for the LT film was found to be one to three orders lower in magnitude compared to the film deposited at RT. In one case, for example, the dark current was significantly reduced from 1.69 nA to 4.58 pA at 1.0 V. The active area for the device was determined to be 36 × 50 μm2 with 4 μm electrode width and 4 μm electrode spacing. Additionally, LT-MSM-PD's exhibited an excellent linear relationship between the photo-current and the incident light power. The Schottky barrier height for LT processing was found to be 0.79 eV; however, this value was 0.1 eV more than that of the same contact obtained by RT processing.

scholarly journals SARS-CoV-2 (COVID-19) and the Endocrine System

2020 ◽  
Vol 4 (11) ◽  
Author(s):  
Michelle D Lundholm ◽  
Caroline Poku ◽  
Nicholas Emanuele ◽  
Mary Ann Emanuele ◽  
Norma Lopez
Keyword(s):  
Severe Disease ◽  
Clinical Manifestations ◽  
Endocrine System ◽  
The Body ◽  
Active Area ◽  
Gonadal Function ◽  
Long Term Effects ◽  
The World ◽  
The Impact

Abstract As SARS-CoV-2 (COVID-19) overtakes the world, causing moderate to severe disease in about 15% of infected patients, COVID-19 is also found to have widespread effects throughout the body with a myriad of clinical manifestations including the endocrine system. This manuscript reviews what is known about the impact of COVID-19 on the pathophysiology and management of diabetes (both outpatient and inpatient) as well as pituitary, adrenal, thyroid, bone, and gonadal function. Findings in this area are evolving, and long-term effects of infection remain an active area of further research.

scholarly journals A portable muon telescope based on small and gas-tight resistive plate chambers

2018 ◽  
Vol 377 (2137) ◽  
pp. 20180139 ◽  
Author(s):  
Sophie Wuyckens ◽  
Andrea Giammanco ◽  
Eduardo Cortina Gil ◽  
Pavel Demin
Keyword(s):  
Cosmic Ray ◽  
Active Area ◽  
Light Weight ◽  
Future Directions ◽  
Muon Telescope ◽  
Compact Size ◽  
Resistive Plate Chambers ◽  
Gas Tight ◽  
Gas Tightness

We report on the first steps in the development of a small-size muon telescope based on glass resistive plate chambers with small active area (16 × 16 cm 2 ). The long-term goal of this project is to focus on applications of muography where the telescope may have to be operated underground and/or inside small rooms, and in challenging logistic situations. Driving principles in our design are therefore compact size, light weight, gas tightness and robustness. The first data-taking experiences have been encouraging, and we elaborate on the lessons learnt and future directions for development. This article is part of the Theo Murphy meeting issue ‘Cosmic-ray muography’.

scholarly journals Long term continuous radon monitoring in a seismically active area

2015 ◽  
Vol 58 (4) ◽  
Author(s):  
Antonio Piersanti ◽  
Valentina Cannelli ◽  
Gianfranco Galli
Keyword(s):  
Seismic Activity ◽  
Meteorological Parameters ◽  
Time Window ◽  
Active Area ◽  
Acquisition Time ◽  
Seismic Events ◽  
Small Magnitude ◽  
Radon Measurement ◽  
Radon Monitoring

We present the results of a long term, continuous radon monitoring experiment started in April 2010 in a seismically active area, affected during the 2010-2013 data acquisition time window by an intense micro seismic activity and by several small seismic events. We employed both correlation and cross-correlation analyses in order to investigate possible relationship existing between the collected radon data, seismic events and meteorological parameters. Our results do not support the feasibility of a robust one-to-one association between the small magnitude earthquakes characterizing the local seismic activity and single radon measurement anomalies, but evidence significant correlation patterns between the spatio-temporal variations of seismic moment release and soil radon emanations, the latter being anyway dominantly modulated by meteorological parameters variations.

High temperature long term stability of SiC Schottky diodes

2011 ◽  
Vol 51 (9-11) ◽  
pp. 1778-1782 ◽  
Author(s):  
A. Testa ◽  
S. De Caro ◽  
S. Russo ◽  
D. Patti ◽  
L. Torrisi
Keyword(s):  
High Temperature ◽  
Schottky Diodes ◽  
Term Stability ◽  
Long Term Stability

The Schottky Parameter Test for Combined Diffusion Welded and Sputter Large Area Contacts

2007 ◽  
Vol 556-557 ◽  
pp. 737-740
Author(s):  
Oleg Korolkov ◽  
Natalja Sleptsuk ◽  
Toomas Rang ◽  
A. Syrkin ◽  
Vladimir Dmitriev
Keyword(s):  
Schottky Diodes ◽  
Schottky Contact ◽  
Diffusion Welding ◽  
Large Area ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Parameter Test ◽  
And Diffusion ◽  
Surprising Fact

For more authentic comparison of Schottky parameters between combined sputter (Ti/Ni/Au) and diffusion welded (DW) Al contact and direct DW Al contact to SiC the forward current-voltage characteristics were measured at the temperature range 293-473 K on full-packed 0.3 cm2 Schottky diodes. Surprising fact was discovered that the temperature behaviour of parameters remains of the same character for both kind of contacts but for the combined sputter- DW samples the values of parameters is much closer in magnitude to sputter contacts. Apparently, chemical treatment before the DW process preserves untouched the contact surface layer formed by annealing of initial sputter metallization of the chips (e.g. Ni2Si, Ti3SiC2), and this layer serves as barrier during diffusion welding. In the second part of the work we give the results on long-term reliability testing where through the SiC Schottky diode with the DW Al contacts during 300 hr has been passed constant forward stabilized current of 100 A/cm2 density. The primary and final values of Uf for DW Schottky contact have not changed during the test.

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