Umesh K. Mishra
University of California, Santa Barbara
929 Papers
10.5K Citations
Umesh K. Mishra is an academic researcher from University of California, Santa Barbara. The author has contributed to research in topics: Gallium nitride & High-electron-mobility transistor. The author has an hindex of 96, co-authored 912 publications. Previous affiliations of Umesh K. Mishra include North Carolina State University & University of California.
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Papers
N-face GaN/AlN/GaN/InAlN and GaN/AlN/AlGaN/GaN/InAlN high-electron-mobility transistor structures grown by plasma-assisted molecular beam epitaxy on vicinal substrates
Elaheh Ahmadi,Feng Wu,Haoran Li,Stephen W. Kaun,Maher Tahhan,Karine Hestroffer,Stacia Keller,James S. Speck,Umesh K. Mishra +8 more
TL;DR: In this paper, the growth of InAlN on vicinal (4° miscut along GaN GaN-on-sapphire substrates) was studied using scanning transmission electron microscopy (STEM).
Effect of dislocations on electron mobility in AlGaN/GaN and AlGaN/AlN/GaN heterostructures
TL;DR: In this paper, the authors show that threading dislocation scattering contributed to reduced mobility in these heterostructures, especially when sheet concentration was low or when an AlN interlayer was present.
Study of Pore Geometry and Dislocations in Porous GaN Based Pseudo-Substrates Using TEM
Shubhra S. Pasayat,Feng Wu,Chirag Gupta,Steve P. Den Baars,Shuji Nakamura,Stacia Keller,Umesh K. Mishra +6 more
TL;DR: In this article , the authors discuss the cross-sectional transmission electron microscopy (TEM) results of compliant porous GaN underlayer based substrates across multiple stages of the substrate technology development.
Polarization-induced charge and electron mobility in algan/gan heterostructures grown by plasma-assisted molecular-beam epitaxy
I. P. Smorchkova,C. R. Elsass,J. P. Ibbetson,Ramakrishna Vetury,B. Heying,Paul T. Fini,E. Haus,Steven P. DenBaars,James S. Speck,Umesh K. Mishra +9 more
TL;DR: In this article, the formation of the 2DEG in unintentionally doped AlxGa1−xN/GaN (x⩽0.31) heterostructures grown by rf plasma-assisted molecular-beam epitaxy is investigated.
Structural and morphological evolution of GaN grown by metalorganic chemical vapor deposition on SiC substrates using an AlN initial layer
Brendan Jude Moran,Feng Wu,Alexey E. Romanov,Umesh K. Mishra,Steven P. DenBaars,James S. Speck +5 more
TL;DR: In this paper, the morphological and structural evolution of GaN grown by metalorganic chemical vapor deposition on (0, 0, 0) 4H and 6H SiC substrates is presented.