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Text fixture for MESFET reliability life tests
No full textDC tests may be the method on which to found an unitary methodology for setting and analysis of GaAs MESFET reliability studies. Each failure mechanism must be stressed without introducing erroneous one, due to the artificial conditions of accelerated tests. A text fixture for these tests must enable the hgghest contro of aging conditions
Effects of high current and temperature in power MESFET metallization
No full textEffects of high current density and temperature closely combine to degrade power MESFETs during their operating life in radio-link systems. To understand failure mechanisms and distinguish between those accelerated by high current and/or by temperature, we have performed various dc tests and measured thermal resistance and thermal maps of tested devices
Electromigration effects in power MESFET rectifying and ohmic contacts
No full textBoth gate and source/drain electromigration are significant failure mechanisms in power MESFTs. The correlation between electromigration effects due to high current density and measured electrical degradation is investigated in devices of different technologies. A safety zone of operation for ohmic contact electromigration is defined
Failure mechanisms of GaAs power MESFETs due to gate metallization
No full textThis paper summarizes reliability problems of GaAs MESFETs due to interdiffusion and electromigration effects of the gate metallizatio
Increase In Barrier Height of Al/n-gaas Contacts Induced By High-current
No full textHigh forward-gate current density induces an increase of the Al/n-GaAs barrier height from 0. 8 to 0. 96 eV, thus suggesting the formation of a Ga//x Al//1- //x As layer at the interface. Results show that this interaction is more enhanced by the electron current from the semiconductor to the metal than by thermal treatments. The intense electron flow is believed to contribute to the breaking of the interfacial oxide layer present at the metal-semiconductor interface, thus promoting Al/GaAs interdiffusion. Data were obtained on power MESFETs with Al metallized gate
Degradation Mechanisms Induced By Temperature In Power Mesfets
No full textTwo independent failure mechanisms, mainly induced by temperature, were observed in unpassivated, Au-metallized, commercially available power MESFETs. They result in a high gate/source (drain) leakage and in an increase in the open channel resistance, and may explain the 'burn-out' of the devices in practical applications
Gate Metallization Sinking Into the Active Channel In Ti/w/au Metallized Power Mesfets
No full textCommercial power MESFETs with Ti/W/Au gate metallization show a failure mode consisting of a decrease in I//D //S //S and V//P and an increase in R//O. The failure mechanism was investigated by electrical and structural analysis with SEM, microprobe, and Auger spectrometry, and is found to be thermally activated Au-GaAs interdiffusion, leading to encroachment of the gate metal on the channel. This may be common to all Au-metallized MESFETs and can lead to burn-out of devices
Degradation Mechanisms Induced By High-current Density In Al-gate GaAs-mesfets
No full textHigh gate-current density, which can arise due to RF overdrive, induces two degradation mechanisms in Al-gate power GaAs MESFET's: 1) high current density through the Al-gate finger section causes gate interruption at the beginning of the metal stripe due to electromigration and makes it impossible to reach the pinchoff condition; 2) high current density through the Schottky junction promotes a fast Al/GaAs interaction, causing an increase in the Schottky-barrier height from 0.80 to 0.96 eV owing to the formation of an AlxGa1-xAs interfacial layer. Al/GaAs interaction appears to be enhanced by the electron current at a given temperature
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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