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

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 (∼MV/cm) along the common growth direction of <0001>. Such large polarization fields 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.

Atomic-Scale Phase Transition of Epitaxial GaN on Nanostructured Si(001): Activation and Beyond

“…Previously, we have reported phase-modulated growth of GaN on a (111)-faceted v-groove array fabricated into a Si(001) substrate, , where nm-scale, defect-free c -phase is separated from h -phase through the h - to c -phase transition ( h - c transition) activated at the regions predefined by the topography of the substrate surface. A similar result was reported by other research group . We refer to this growth as heterophase epitaxy (HPE).…”

Growth and Characterization of GaP/GaPAs Nanowire Heterostructures with Controllable Composition

“…From the original HRTEM image and its FFT analysis, it is clearly seen that the GaP 1 − x As x ND crystal structure differs from that of GaP and corresponds to hexagonal WZ structure. The expected theoretical [11–20] WZ, [1–10] ZB, and [−110] ZB (rotational twin) zone axis patterns are marked in the FFT images with blue, red solid, and red dashed circles, correspondingly, and matches with observed FFT pattern periodicity and symmetry . Thus, we conclude that in contrast to GaP NW segments showing lamellar twinned ZB structure, GaP 1 − x As x ND tends to adopt metastable WZ structure.…”

Movpe Studies of Zincblende Gan on 3c-Sic/Si(001)

“…As was observed for the samples of set A (in Fig. 5(b)), the broadening parallel to [1 1 0] is larger than that along [1][2][3][4][5][6][7][8][9][10].…”