We present an innovative approach to integrate arrays of isolated, strain-free GaN crystals on patterned Si substrates. First, micrometer-sized pillars are patterned onto Si(0 0 1) substrates. Subsequently, 2.5 μm Si substrates are deposited by low-energy plasma-enhanced chemical vapor deposition, forming crystals mostly bounded by {1 1 1}, {1 1 3}, and {15 3 23} facets. Plasma-assisted molecular beam epitaxy is then used for GaN deposition. GaN crystals with slanted {0 0 0 1} facets having a root-mean-square surface roughness of 0.7 nm are obtained for a deposited material thickness of >3 μm. Microphotoluminescence measurements performed at room and cryogenic temperature show no yellow luminescence and a neutral donor-bound A exciton transition at 3.471 eV (10 K) with a full width at half-maximum of 10 meV. Microphotoluminescence and micro-Raman spectra reveal that GaN grown on Si pillars is strain-free. Our results indicate that the shape of GaN crystals can be tuned by the pattern periodicity and that a reduction of threading dislocations is achieved in their top part.

Isa, F., Cheze, C., Siekacz, M., Hauswald, C., Lahnemann, J., Fernandez Garrido, S., et al. (2015). Integration of GaN crystals on micropatterned Si(0 0 1) substrates by plasma-assisted molecular beam epitaxy. CRYSTAL GROWTH & DESIGN, 15(10), 4886-4892 [10.1021/acs.cgd.5b00727].

Integration of GaN crystals on micropatterned Si(0 0 1) substrates by plasma-assisted molecular beam epitaxy

MIGLIO, LEONIDA
2015

Abstract

We present an innovative approach to integrate arrays of isolated, strain-free GaN crystals on patterned Si substrates. First, micrometer-sized pillars are patterned onto Si(0 0 1) substrates. Subsequently, 2.5 μm Si substrates are deposited by low-energy plasma-enhanced chemical vapor deposition, forming crystals mostly bounded by {1 1 1}, {1 1 3}, and {15 3 23} facets. Plasma-assisted molecular beam epitaxy is then used for GaN deposition. GaN crystals with slanted {0 0 0 1} facets having a root-mean-square surface roughness of 0.7 nm are obtained for a deposited material thickness of >3 μm. Microphotoluminescence measurements performed at room and cryogenic temperature show no yellow luminescence and a neutral donor-bound A exciton transition at 3.471 eV (10 K) with a full width at half-maximum of 10 meV. Microphotoluminescence and micro-Raman spectra reveal that GaN grown on Si pillars is strain-free. Our results indicate that the shape of GaN crystals can be tuned by the pattern periodicity and that a reduction of threading dislocations is achieved in their top part.
Articolo in rivista - Articolo scientifico
Light-emitting-diodes; high-quality gan; yellow luminescence; undoped gan; 111 silicon; si(111); growth; photoluminescence; si; layers
English
4886
4892
7
Isa, F., Cheze, C., Siekacz, M., Hauswald, C., Lahnemann, J., Fernandez Garrido, S., et al. (2015). Integration of GaN crystals on micropatterned Si(0 0 1) substrates by plasma-assisted molecular beam epitaxy. CRYSTAL GROWTH & DESIGN, 15(10), 4886-4892 [10.1021/acs.cgd.5b00727].
Isa, F; Cheze, C; Siekacz, M; Hauswald, C; Lahnemann, J; Fernandez Garrido, S; Kreiliger, T; Ramsteiner, M; Dasilva, Y; Brandt, O; Isella, G; Erni, R; Calarco, R; Riechert, H; Miglio, L
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/99762
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