{"542301":{"#nid":"542301","#data":{"type":"event","title":"Ph.D. Dissertation Defense - Spyridon Pavlidis","body":[{"value":"\u003Cp\u003E\u003Cem\u003EInvestigation of Wide Band Gap Semiconductors:\u0026nbsp; InGaZnO TFTs for Chemical Sensing and Hybrid GaN\/Organic High-Frequency Packaging and Circuits\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECommittee:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDr. Oliver Brand, ECE, Chair , Advisor\u003C\/p\u003E\u003Cp\u003EDr. Papapolymerou, ECE, Co-Advisor\u003C\/p\u003E\u003Cp\u003EDr. John Cressler, ECE\u003C\/p\u003E\u003Cp\u003EDr. Bernard Kippelen, ECE\u003C\/p\u003E\u003Cp\u003EDr. Burhan Bayraktaroglu, Air Force Research Lab\u003C\/p\u003E\u003Cp\u003EDr. Christos Alexopoulos, ISyE\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAbstract:\u0026nbsp;\u003C\/strong\u003E\u003C\/p\u003E\u003Cp class=\u0022p1\u0022\u003EWide band gap (WBG) semiconductors offer a number of unique properties not achievable by traditional silicon, such as optical transparency in the visible wavelength regime, high carrier mobility and high voltage\/high power operation. This thesis advances the development of two WBG semiconductors, indium gallium zinc oxide (InGaZnO) and gallium nitride (GaN), for chemical sensing and high-frequency applications, respectively. Whereas previous works have relied on high temperature fabrication and\/or device operation that are incompatible with flexible and low-cost substrates, this work successfully exploits low temperature microfabrication methods to manufacture InGaZnO thin film transistors (TFTs) for chemical sensing at room temperature. Gas-phase sensing of volatile organic compounds is demonstrated, and it is shown that sensitivity can be improved through the use of a polymer capping layer. For liquid-phase sensing, reliable passivation remains a challenge. In response, this works shows that low temperature atomic layer deposition of TiO\u003Csub\u003Ex\u003C\/sub\u003E can be used to create dual-gate InGaZnO TFTs with Super Nernstian pH sensitivity and long term reliability within a liquid environment. GaN devices and circuits offer best-in-class high power performance, yet packaging remains a critical issue for practical applications. Traditional methods rely on expensive materials that are lossy at radio frequencies and above. This work proposes a novel, flip-chip bonding packaging technique that involves GaN die encapsulation within multi-layer organic laminates that are both low-cost and low-loss. A 5.4 W hybrid GaN\/organic encapsulated power amplifier operating in the X-Band is demonstrated for the first time.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Investigation of Wide Band Gap Semiconductors:  InGaZnO TFTs for Chemical Sensing and Hybrid GaN\/Organic High-Frequency Packaging and Circuits"}],"uid":"28475","created_gmt":"2016-06-06 17:46:29","changed_gmt":"2016-10-08 02:17:58","author":"Daniela Staiculescu","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2016-06-20T11:30:00-04:00","event_time_end":"2016-06-20T11:30:00-04:00","event_time_end_last":"2016-06-20T11:30:00-04:00","gmt_time_start":"2016-06-20 15:30:00","gmt_time_end":"2016-06-20 15:30:00","gmt_time_end_last":"2016-06-20 15:30:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"434381","name":"ECE Ph.D. Dissertation Defenses"}],"categories":[],"keywords":[{"id":"1808","name":"graduate students"},{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}