Cubic Phase GaN on Nano-grooved Si (100) via Maskless Selective Area Epitaxy

TitleCubic Phase GaN on Nano-grooved Si (100) via Maskless Selective Area Epitaxy
Publication TypeJournal Article
Year of Publication2014
AuthorsBayram, C, Ott, JA, Shiu, K-T, Cheng, C-W, Zhu, Y, Kim, J, Razeghi, M, Sadana, DK
JournalAdvanced Functional Materials
Volume24
Issue28
Pagination4492 - 4496
Date Published2014/07/23/
Abstract

A method of forming cubic phase (zinc blende) GaN (referred as c-GaN) on a CMOS-compatible on-axis Si (100) substrate is reported. Conventional GaN materials are hexagonal phase (wurtzite) (referred as h-GaN) and possess very high polarization fields (similar to MV/cm) along the common growth direction of <0001>. Such large polarization fi elds lead to undesired shifts (e.g., wavelength and current) in the performance of photonic and vertical transport electronic devices. The cubic phase of GaN materials is polarization-free along the common growth direction of <001>, however, this phase is thermodynamically unstable, requiring low-temperature deposition conditions and unconventional substrates (e.g., GaAs). Here, novel nano-groove patterning and maskless selective area epitaxy processes are employed to integrate thermodynamically stable, stress-free, and low-defectivity c-GaN on CMOS-compatible on-axis Si. These results suggest that epitaxial growth conditions and nano-groove pattern parameters are critical to obtain such high quality c-GaN. InGaN/GaN multi-quantum-well structures grown on c-GaN/Si (100) show strong room temperature luminescence in the visible spectrum, promising visible emitter applications for this technology.