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Title: Evolution of GaAs nanowire geometry in selective area epitaxy

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Publication Date:
Sponsoring Org.:
OSTI Identifier:
Grant/Contract Number:
DMR #1006581
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 106; Journal Issue: 13; Related Information: CHORUS Timestamp: 2016-12-29 07:59:17; Journal ID: ISSN 0003-6951
American Institute of Physics
Country of Publication:
United States

Citation Formats

Bassett, Kevin P., Mohseni, Parsian K., and Li, Xiuling. Evolution of GaAs nanowire geometry in selective area epitaxy. United States: N. p., 2015. Web. doi:10.1063/1.4916347.
Bassett, Kevin P., Mohseni, Parsian K., & Li, Xiuling. Evolution of GaAs nanowire geometry in selective area epitaxy. United States. doi:10.1063/1.4916347.
Bassett, Kevin P., Mohseni, Parsian K., and Li, Xiuling. 2015. "Evolution of GaAs nanowire geometry in selective area epitaxy". United States. doi:10.1063/1.4916347.
title = {Evolution of GaAs nanowire geometry in selective area epitaxy},
author = {Bassett, Kevin P. and Mohseni, Parsian K. and Li, Xiuling},
abstractNote = {},
doi = {10.1063/1.4916347},
journal = {Applied Physics Letters},
number = 13,
volume = 106,
place = {United States},
year = 2015,
month = 3

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1063/1.4916347

Citation Metrics:
Cited by: 5works
Citation information provided by
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  • Nanowires (NWs) grown via selective area epitaxy (SAE) show great promise for applications in next generation electronic and photonic devices, yet the design of NW-based devices can be complicated due to the complex kinetics involved in the growth process. The presence of the patterned selective area mask, as well as the changing geometry of the NWs themselves during growth, leads to non-linear growth rates which can vary significantly based on location in the mask and the NW size. Here, we present a systematic study of the evolution of GaAs NW geometry during growth as a function of NW size andmore » pitch. We highlight a breakdown of NW uniformity at extended growth times, which is accelerated for NW arrays with larger separations. This work is intended to outline potential fundamental growth challenges in achieving desired III–V NW array patterns and uniformity via SAE.« less
  • We investigated the interwire distance dependence on the growth kinetics of vertical, high-yield InAs nanowire arrays on Si(111) grown by catalyst-free selective area molecular beam epitaxy (MBE). Utilizing lithographically defined SiO{sub 2} nanomasks on Si(111) with regular hole patterns, catalyst-free and site-selective growth of vertically (111)-oriented InAs nanowires was achieved with very high yields of {approx}90 percent. Interestingly, the yield of vertically ordered nanowires was independent of the interwire distance and the initial growth stages. Significant size variation in the nanowires was found to depend critically on the interwire distance and growth time. Two growth regimes were identified--(i) a competitivemore » growth regime with shorter and thinner nanowires for narrow interwire distances and (ii) a diffusion-limited growth regime for wider distances, providing good estimates for the surface diffusion lengths. Surprisingly, despite these size-dependent effects the nanowire geometries remained unaltered with uniform, almost nontapered morphologies even over large variation in nanowire density ({approx}mid-10{sup 6}-10{sup 9} cm{sup -2} range). X-ray diffraction further confirmed the vertical (111) directionality with low crystal tilt by rocking curve widths ({omega} scans) as low as {approx}0.6 deg. These findings demonstrate the capability to precisely tailor the position and size of well-oriented III-V semiconductor nanowires through noncatalytic MBE selective area growth and provide an important step toward fully integrated, uniform vertical III-V nanowire array-on-Si devices.« less
  • III-V semiconductor nanowires are unique material phase due to their high aspect ratio, large surface area, and strong quantum confinement. This affords the opportunity to control charge transport and optical properties for electrical and photonic applications. Nanoscale selective area metalorganic chemical vapor deposition growth (NS-SAG) is a promising technique to maximize control of nanowire diameter and position, which are essential for device application. In this work, InP and GaAs nanowire arrays are grown by NS-SAG. We observe enhanced sidewall growth and array uniformity disorder in high growth rate condition. Disorder in surface morphology and array uniformity of InP nanowire arraymore » is explained by enhanced growth on the sidewall and stacking faults. We also find that AsH{sub 3} decomposition on the sidewall affects the growth behavior of GaAs nanowire arrays.« less
  • We delineate the optimized growth parameter space for high-uniformity catalyst-free InGaAs nanowire (NW) arrays on Si over nearly the entire alloy compositional range using selective area molecular beam epitaxy. Under the required high group-V fluxes and V/III ratios, the respective growth windows shift to higher growth temperatures as the Ga-content x(Ga) is tuned from In-rich to Ga-rich InGaAs NWs. Using correlated x-ray diffraction, transmission electron microscopy, and micro-photoluminescence spectroscopy, we identify structural defects to govern luminescence linewidths in In-rich (x(Ga) < 0.4) and Ga-rich (x(Ga) > 0.6) NWs, whereas limitations at intermediate Ga-content (0.4 < x(Ga) < 0.6) are mainly due to compositional inhomogeneities. Most remarkably, the catalyst-freemore » InGaAs NWs exhibit a characteristic transition in crystal structure from wurtzite to zincblende (ZB) dominated phase near x(Ga) ∼ 0.4 that is further reflected in a cross-over from blue-shifted to red-shifted photoluminescence emission relative to the band edge emission of the bulk ZB InGaAs phase.« less
  • Optical-quality GaAs films were successfully grown by molecular beam epitaxy (MBE) through SiO/sub 2/ insulator windows on GaAs (100) substrates, thus making this selective-area epitaxy applicable to the fabrication of GaAs optoelectronic integrated circuits. The photoluminescence spectra at 2.2 K consist of several exciton peaks near 820 nm and broader acceptor-related peaks centered at approximately 830 nm. The spectra are comparable to those observed in high quality planar MBE GaAs grown in other laboratories. The luminescence intensity from the epitaxial layer above the windows is shown by cathodoluminescence to be much higher than that from the polycrystalline GaAs deposited onmore » top of SiO/sub 2/. From transmission electron microscopy and x-ray diffractometry it is found that the GaAs grains on the SiO/sub 2/ grow with their (111) planes preferentially parallel to the SiO/sub 2/ surface.« less