Show simple item record

dc.contributor.authorYoo, Dongwonen_US
dc.date.accessioned2007-08-16T17:51:55Z
dc.date.available2007-08-16T17:51:55Z
dc.date.issued2007-07-09en_US
dc.identifier.urihttp://hdl.handle.net/1853/16220
dc.description.abstractA wide variety of group III-Nitride-based photonic and electronic devices have opened a new era in the field of semiconductor research in the past ten years. The direct and large bandgap nature, intrinsic high carrier mobility, and the capability of forming heterostructures allow them to dominate photonic and electronic device market such as light emitters, photodiodes, or high-speed/high-power electronic devices. Avalanche photodiodes (APDs) based on group III-Nitrides materials are of interest due to potential capabilities for low dark current densities, high sensitivities and high optical gains in the ultraviolet (UV) spectral region. Wide-bandgap GaN-based APDs are excellent candidates for short-wavelength photodetectors because they have the capability for cut-off wavelengths in the UV spectral region (λ < 290 nm). These intrinsically solar-blind UV APDs will not require filters to operate in the solar-blind spectral regime of λ < 290 nm. For the growth of GaN-based heteroepitaxial layers on lattice-mismatched substrates, a high density of defects is usually introduced during the growth; thereby, causing a device failure by premature microplasma, which has been a major issue for GaN-based APDs. The extensive research on epitaxial growth and optimization of Al<sub>x</sub> Ga <sub>1-x</sub> N (0 ≤ x ≤ 1) grown on low dislocation density native bulk III-N substrates have brought UV APDs into realization. GaN and AlGaN UV <i> p-i-n </i> APDs demonstrated first and record-high true avalanche gain of > 10,000 and 50, respectively. The large stable optical gains are attributed to the improved crystalline quality of epitaxial layers grown on low dislocation density bulk substrates. GaN <i>p-i-n </i> rectifiers have brought much research interest due to its superior physical properties. The AIN-free full-vertical GaN<i> p-i-n </i> rectifiers on<i> n </i>- type 6H-SiC substrates by employing a conducting AIGaN:Si buffer layer provides the advantages of the reduction of sidewall damage from plasma etching and lower forward resistance due to the reduction of current crowding at the bottom<i> n </i> -type layer. The AlGaN:Si nucleation layer was proven to provide excellent electrical properties while also acting as a good buffer role for subsequent GaN growth. The reverse breakdown voltage for a relatively thin 2.5 μm-thick<i> i </i>-region was found to be over -400V.en_US
dc.publisherGeorgia Institute of Technologyen_US
dc.subjectAvalanche photodiodeen_US
dc.subjectEpitaxial growthen_US
dc.subjectMOCVDen_US
dc.subjectRectifieren_US
dc.subjectGallium nitrideen_US
dc.subjectAluminum gallium nitrideen_US
dc.subject.lcshHeterostructuresen_US
dc.subject.lcshEpitaxyen_US
dc.subject.lcshAvalanche photodiodesen_US
dc.titleGrowth and Characterization of III-Nitrides Materials System for Photonic and Electronic Devices by Metalorganic Chemical Vapor Depositionen_US
dc.typeDissertationen_US
dc.description.degreePh.D.en_US
dc.contributor.departmentMaterials Science and Engineeringen_US
dc.description.advisorCommittee Chair: Dr. Russell D. Dupuis; Committee Member: Dr. Christopher J. Summers; Committee Member: Dr. Joy Laskar; Committee Member: Dr. Shyh-Chiang Shen; Committee Member: Dr. Zhong Lin Wangen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record