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Title: Selective area growth of III-V semiconductor compounds using Ga+ FIB deposition during MBE growth
Author: Beere, H. E.
Awarding Body: University of Cambridge
Current Institution: University of Cambridge
Date of Award: 2001
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Abstract:
Selective area growth of III-V semiconductor compounds using molecular beam epitaxy (MBE) has been envisaged as an in situ fabrication method for integrated circuits on a nanometer scale. However, conventional selective area growth techniques using MBE are limited to only two dimensional, template-like, pattering of the epilayer. The work presented in this dissertation describes the selective area growth of AlGaAs based structures using a Ga+ focused ion beam (FIB) as one of the group III matrix element sources in a MBE growth chamber. Since stoichiometric epitaxy of a III-V semiconductor compound can be achieved with an excess supply of the group V element, supplying the Ga matrix element as a FIB, under standard MBE growth conditions, was shown to facilitate a maskless, in situ, lateral selective area growth technique for GaAs. Consequently, this FIB-MBE growth technique, FIMBE, has the potential of exploiting the precise control over the elemental composition afforded by MBE in the growth (z) direction with the high spatial resolution of FIB technology in the lateral (xy) plane. Moreover, it offers the unique facility of growing fully integrated three-dimensional structures into one as-grown epilayer structure. The necessary modifications required to a standard FIB column and MBE growth chamber to fully exploit the combination of these two technologies, along with the operational performance of the fully integrated FIMBE growth system are presented. A study of the effect of incident ion energy (Eion) on the film growth rate identified two growth rate limiting processes; (i) the inherent properties of the Ga+ FIB (Eion <25eV) and (ii) material sputtering from the growing GaAs film (Eion>100eV). However, a systematic reduction in the surface roughness of the FIMBE grown GaAs films was observed with increasing incident ion energy.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.596523  DOI: Not available
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