The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The leakage current of buffer layer deteriorates the electronic properties of GaN-based high-electron mobility transistor (HEMT). We proposed a GaN:C/GaN superlattice to improve the resistivity of buffer layer without reducing its crystallization. The leakage current of HEMT with GaN:C/GaN superlattices reduces one order of magnitude compared to the conventional HEMT with carbon-doped buffer.
AlGaN back barrier with different thickness is used in AlGaN/GaN high electron mobility transistors (HEMTs) to evaluate the device performances. It shows that a proper AlGaN back barrier thickness (tbb ∼100 nm) is beneficial for obtaining low leakage current and high Ion/Ioff ratio of approximately 108. While further increasing the AlGaN thickness can deteriorate the device performances because of...
The vertical leakage current of AlGaN/GaN high-electron-mobility transistors on Si substrates was studied. The effects of the Al content in the AlGaN buffer layer and pit density on the vertical leakage current were not as significant as the effect of the initial AlN layer's crystal quality.
AlGaN/GaN based double heterosturcture high electron mobility transistor (HEMT) structures were grown on GaN buffer/Si(111) substrate by plasma assisted molecular beam epitaxy (PAMBE) technique. The thickness of GaN buffer layer was varied to find out the optimum GaN buffer layer for a crack free heterostructure, exhibiting appreciable structural and optical results. Full width at half maximum (FWHM)...
Two-dimensional analysis of lag phenomena, current collapse and breakdown voltages in source-field-plate AlGaN/GaN HEMTs is performed by considering a deep donor and a deep acceptor in a buffer layer, and the results are compared with those for the case of gate-field-plate structure. It is shown that the reduction rate of drain-lag is similar between the two structures, but the reduction rates of...
Two-dimensional transient analysis of gate-field-plate AlGaN/GaN HEMTs with a backside electrode is performed by considering a deep donor and a deep acceptor in a buffer layer. It is shown that the introduction of gate field plate is effective in reducing buffer-related lag and current collapse when the acceptor density in the buffer layer is high. On the other hand, the introduction of backside electrode...
AlGaN/GaN high electron mobility transistors (HEMTs) were grown on Si substrates by MOCVD. In the HEMT structure, the 1 μm GaN buffer layer was partially doped with Mg in an attempt to increase the resistivity and minimize the buffer leakage current. Afterwards, an AlN spacer layer was inserted between the AlGaN barrier layer and the GaN channel layer to effectively reduce impurity scattering and...
In this paper, GaN-based HFET devices on 4-inch Si substrates were fabricated, and the device characteristics were examined. As a result, the maximum drain current was estimated to be over 115 A using MIS-structures. A trade-off between the specific on-resistance (RonA) and the breakdown voltage (Vb) was improved using carbon doped buffer layers, resulting in obtaining RonA=3D 5.9 mΩcm2 and Vb=3D...
A 1.5 A normally-off GaN transistor for power applications in p-type GaN gate technology with a modified epitaxial concept is presented. A higher threshold voltage is achieved while keeping the on-state resistance low by using an Al-GaN buffer instead of a GaN buffer. Additionally, the AlGaN buffer acts as a back-barrier and suppresses source-drain punch-through currents in the off-state. P-GaN gate...
An AlGaN/GaN-based normally-off GaN MOSFET with p-GaN buffer layer has been demonstrated, for the first time, using over-recessed gate. It is believed that p-GaN buffer layer has advantage of not only increasing the threshold voltage due to depletion effect, but also reducing the buffer leakage current. The fabricated GaN MOSFET with 30 nm-thick ALD Al2O3 as the gate insulator exhibited good device...
In this work we investigated the effect of varying the thickness of the UID GaN buffer, dUID, on the electrical properties of AlGaN/GaN heterostructures and HEMTs. Seven heterostructures with 50 nm < dUID < 500 nm were grown by RF-MBE on free-standing, semi-insulating HVPE-grown GaN substrates. Hall patterns, isolation test patterns, and HEMTs have been fabricated on these structures. We find...
In this paper, GaN-based MIS-HFET devices on 4-inch Si substrates were fabricated, and the device characteristics were examined. As a result, the breakdown voltage was improved to be over 2.45 kV using high-resistive carbon doped buffer layers with a larger thickness of over 7.3 mum. The maximum drain current was estimated to be over 115 A using MIS-structures. A trade-off between the specific on-resistance...
The reliability physics of GaN HFETs has been investigated in order to identify strain related traps originating at the GaN/SiC substrate interface. The buffer layers investigated were deposited by MBE techniques at a series of growth temperatures and thicknesses so as to attain buffer layers with variable trap density. Heterojunction transistors (HFETs) based on AlGaN/GaN heterostructures have been...
Two-dimensional transient analysis of field-plate AlGaN/GaN HEMTs and GaN MESFETs is performed, considering a deep donor and a deep acceptor in the semiinsulating GaN buffer layer. Quasi-pulsed I-V curves are derived from the transient characteristics. It is studied how the existence of a field plate affects buffer-related drain lag, gate lag and current collapse. It is shown that in both FETs, the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.