Investigation of Electrically Active Defects in Epitaxial Gallium Nitride (GaN)

Research output: Book/anthology/dissertation/reportPh.D. thesisResearch

  • Ievgen Boturchuk
The prospective use of the compound semiconductor gallium nitride (GaN) in electronic devices is hindered by the growth-initiated incorporation of defects. The fundamental understanding of their physical origin, nature, and electrical properties is required in order to eliminate and/or engineer the harmful impact of the defect-induced deep levels in the bandgap on the ultimate device performance.

Throughout this work, the properties and concentration of the defects (i.e. deep levels) are characterized by means of deep level transient spectroscopy (DLTS), in certain cases the precision is improved by using Laplace DLTS, and the point-like or extended nature of the defects is distinguished with varying filling pulse duration.

Although the electrically active defects in GaN have been studied for more than 20 years, there are still big gaps in our understanding of their properties. This dissertation results in a paper, and manuscript which are aimed to fulfil some of these gaps, studying commercially available, prime-grade GaN epilayers grown on silicon carbide (SiC). Paper 1 concerns the evolution of defects, as a consequence of fabrication of diodes used for electrical characterization. Manuscript 2 reports and analyses the unusual bistable-like properties of some of the defects. Potential Publication 3, which is under preparation, focuses on comparing the quality of the commercial GaN epilayers grown on different perspective substrates (SiC and Si).

Finally, the thesis brings out the electrical properties of the in-house, homoepitaxially grown GaN layers by molecular beam epitaxy.
Original languageEnglish
PublisherAarhus Universitet
Number of pages100
Publication statusPublished - Nov 2018

Bibliographical note

Termination date: 22.11.2018

    Research areas

  • n-type gallium nitride (GaN), Au Schottky diodes, electrically active defects, deep level transient spectroscopy (DLTS), Laplace DLTS

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