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Self-aligned AlGaN/GaN transistors for sub-mm wave applications

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dc.contributor.advisor Tomás Palacios. en_US Saadat, Omair I en_US
dc.contributor.other Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. en_US 2010-08-31T14:36:56Z 2010-08-31T14:36:56Z 2010 en_US 2010 en_US
dc.description Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010. en_US
dc.description Cataloged from PDF version of thesis. en_US
dc.description Includes bibliographical references (p. 69-73). en_US
dc.description.abstract This thesis describes work done towards realizing self-aligned AlGaN/GaN high electron mobility transistors (HEMTs). Self-aligned transistors are important for improving the frequency of AlGaN/GaN HEMTs by reducing source and drain access resistance. The eventual fabrication of self-aligned transistors required the development of two different technologies that are described in this thesis. First, gate stacks that can survive the high temperature anneal necessary for forming ohmic contacts were demonstrated. Devices with three different gate stacks, composed of tungsten and a high-k dielectrics like HfO₂, A1₂O₃ and HfO₂/Ga₂O₃, were studied and compared with respect to DC transistor measurements, capacitor measurements and pulsed-IV measurements. Not only did these transistors survive the ohmic anneal but they showed superior performance with respect to transconductance, current density and dispersion than transistors with standard gates. Following the development of the gate stack, silicide-like technology where thin Ti-based films are deposited and annealed on the access regions to reduce access resistance was developed. Depositing and annealing thin Ti films were shown to reduce the sheet resistance by up to 30%. Finally, preliminary results regarding the fabrication of self-aligned transistors by using these gate stacks and the Ti-based access region metallization are reported in this thesis. en_US
dc.description.statementofresponsibility by Omair I. Saadat. en_US
dc.format.extent 73 p. en_US
dc.language.iso eng en_US
dc.publisher Massachusetts Institute of Technology en_US
dc.rights M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. en_US
dc.rights.uri en_US
dc.subject Electrical Engineering and Computer Science. en_US
dc.title Self-aligned AlGaN/GaN transistors for sub-mm wave applications en_US
dc.type Thesis en_US S.M. en_US
dc.contributor.department Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. en_US
dc.identifier.oclc 635955160 en_US

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