D
D. Kapolnek
Researcher at University of California, Berkeley
Publications - 16
Citations - 3188
D. Kapolnek is an academic researcher from University of California, Berkeley. The author has contributed to research in topics: Chemical vapor deposition & Thin film. The author has an hindex of 14, co-authored 16 publications receiving 3131 citations.
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Journal ArticleDOI
Role of threading dislocation structure on the x‐ray diffraction peak widths in epitaxial GaN films
B. Heying,X. H. Wu,Stacia Keller,Youli Li,D. Kapolnek,Bernd Keller,Steven P. DenBaars,James S. Speck +7 more
TL;DR: In this article, the authors demonstrate that the anomalously low (002) x-ray rocking curve widths for epitaxial hexagonal GaN films on (001) sapphire are a result of a specific threading dislocation geometry.
Journal ArticleDOI
Defect structure of metal‐organic chemical vapor deposition‐grown epitaxial (0001) GaN/Al2O3
X. H. Wu,Lisa M. Brown,D. Kapolnek,Stacia Keller,Bernd Keller,Steven P. DenBaars,James S. Speck +6 more
TL;DR: In this paper, the defect structures, including threading dislocations, partial dislocation bounding stacking faults and inversion domains, were investigated by transmission electron microscopy for GaN/Al2O3 epilayers grown by metalorganic chemical vapor deposition using a two-step process.
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Anisotropic epitaxial lateral growth in GaN selective area epitaxy
D. Kapolnek,Stacia Keller,Ramakrishna Vetury,Robert D. Underwood,Peter Kozodoy,S. P. Den Baars,Umesh K. Mishra +6 more
TL;DR: In this paper, the lateral mask overgrowth in GaN selective epitaxy has been studied using linear mask features and the lateral growth varies between its maximum and minimum over a 30° angular span and exhibits hexagonal symmetry.
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Very high breakdown voltage and large transconductance realized on gan heterojunction field effect transistors
Yifeng Wu,Bernd Keller,Stacia Keller,D. Kapolnek,Peter Kozodoy,Steven P. DenBaars,Umesh K. Mishra +6 more
TL;DR: In this article, the authors reported record high breakdown voltages up to 340 and 230 V realized on unintentionally doped (1.5 μm gate length) and Si doped(1 μm/GaN modulation doped field effect transistors (MODFETs), respectively.
Journal ArticleDOI
Structural evolution in epitaxial metalorganic chemical vapor deposition grown GaN films on sapphire
D. Kapolnek,X. H. Wu,B. Heying,Stacia Keller,Bernd Keller,Umesh K. Mishra,Steven P. DenBaars,James S. Speck +7 more
TL;DR: The structural evolution of epitaxial GaN layers grown on basal plane sapphire has been studied by atomic force microscopy, x-ray diffraction, and transmission electron microscopy (TEM).