Implementation of III-V quantum nanodevices on Si based-circuitry is an important goal to pursue the integration between “classical” and “quantum” electronics on a single technological Si based platform [1-2]. In this contribution we explore the results obtained by droplet epitaxy for the fabrication of III-V material quantum nanostructures. Droplet epitaxy is an intrinsically low thermal budget technique, being fully performed at temperature between 200 and 350°C, perfectly suited for the realization of growth procedures compatible with CMOS back-end integration. We can distinguish two main areas where fabrication of III-V quantum nanostructures on Si substrate could play a fundamental role. The first area is the realization of local artificial substrates for heterogeneous integration of quantum nanostructures. The second concerns the fabrication of nanostructured active layers with designed density of states for optimum device performance. For the first approach we present the fabrication of GaAs islands on Si as local artificial substrates. Nucleation of quantum dots atop an island is an attractive approach to address radiative recombination issues and dot uniformity as the island both separates the dot from the interface with the substrate and provides a nucleation platform of sufficiently small dimension to realize quantum size effects. For this purpose we fabricated self-assembled GaAs islands highly tunable in density (from 10 7 to 109 cm-2) and size (from 75 nm to 250 nm, see fig. 1) and with a size dispersion below 10%. The islands, made by single relaxed crystals, show well defined shapes with a high aspect ratio [2]. For the second approach, we present the growth and optical characterization of high quality GaAs quantum nanostructures grown by droplet epitaxy on Ge substrates and on Si through a Ge virtual substrates [3]. Single quantum dot spectroscopic characterization has been performed by means of a micro-photoluminescence apparatus, without the need of further sample processing. Optical quality of the GaAs quantum dots is almost comparable with quantum dots directly grown on GaAs substrates, clearly demonstrating a new procedure for the integration of high efficient light emitters, based on III-V semiconductors, directly on IV-column semiconductor substrates, and opening the route to wide applications to optoelectronics, photonics and quantum information technology. [1] S. Bietti, C. Somaschini, S. Sanguinetti, N. Koguchi, G. Isella, and D. Chrastina, Applied Physics Letters 95, 241102 (2009). [2] C. Somaschini, S. Bietti, N. Koguchi, F. Montalenti, C. Frigeri, and S. Sanguinetti, Applied Physics Letters 97, 053101 (2010). [3] L. Cavigli, M. Abbarchi, S. Bietti, C. Somaschini, S. Sanguinetti, N. Koguchi, A. Vinattieri and M. Gurioli, Applied Physics Letters, 98(10), 103104 (2011).
Bietti, S., Somaschini, C., Koguchi, N., Sanguinetti, S. (2011). Implementation of high quality III-V quantum nanostructures on Si substrates. In 3rd International Workshop on Epitaxial Growth and Fundamental Properties of Semiconductor Nanostructures.
Implementation of high quality III-V quantum nanostructures on Si substrates
BIETTI, SERGIO
;SANGUINETTI, STEFANO
2011
Abstract
Implementation of III-V quantum nanodevices on Si based-circuitry is an important goal to pursue the integration between “classical” and “quantum” electronics on a single technological Si based platform [1-2]. In this contribution we explore the results obtained by droplet epitaxy for the fabrication of III-V material quantum nanostructures. Droplet epitaxy is an intrinsically low thermal budget technique, being fully performed at temperature between 200 and 350°C, perfectly suited for the realization of growth procedures compatible with CMOS back-end integration. We can distinguish two main areas where fabrication of III-V quantum nanostructures on Si substrate could play a fundamental role. The first area is the realization of local artificial substrates for heterogeneous integration of quantum nanostructures. The second concerns the fabrication of nanostructured active layers with designed density of states for optimum device performance. For the first approach we present the fabrication of GaAs islands on Si as local artificial substrates. Nucleation of quantum dots atop an island is an attractive approach to address radiative recombination issues and dot uniformity as the island both separates the dot from the interface with the substrate and provides a nucleation platform of sufficiently small dimension to realize quantum size effects. For this purpose we fabricated self-assembled GaAs islands highly tunable in density (from 10 7 to 109 cm-2) and size (from 75 nm to 250 nm, see fig. 1) and with a size dispersion below 10%. The islands, made by single relaxed crystals, show well defined shapes with a high aspect ratio [2]. For the second approach, we present the growth and optical characterization of high quality GaAs quantum nanostructures grown by droplet epitaxy on Ge substrates and on Si through a Ge virtual substrates [3]. Single quantum dot spectroscopic characterization has been performed by means of a micro-photoluminescence apparatus, without the need of further sample processing. Optical quality of the GaAs quantum dots is almost comparable with quantum dots directly grown on GaAs substrates, clearly demonstrating a new procedure for the integration of high efficient light emitters, based on III-V semiconductors, directly on IV-column semiconductor substrates, and opening the route to wide applications to optoelectronics, photonics and quantum information technology. [1] S. Bietti, C. Somaschini, S. Sanguinetti, N. Koguchi, G. Isella, and D. Chrastina, Applied Physics Letters 95, 241102 (2009). [2] C. Somaschini, S. Bietti, N. Koguchi, F. Montalenti, C. Frigeri, and S. Sanguinetti, Applied Physics Letters 97, 053101 (2010). [3] L. Cavigli, M. Abbarchi, S. Bietti, C. Somaschini, S. Sanguinetti, N. Koguchi, A. Vinattieri and M. Gurioli, Applied Physics Letters, 98(10), 103104 (2011).File | Dimensione | Formato | |
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