Molecular Beam Epitaxial Growth of InAs Quantum Dots Directly on Silicon

Abstract

InAs quantum dots (QD) embedded in a silicon matrix show a photoluminescence line at a wavelength of about 1.3 µm [Semicond. Sci. Technol. 13 (1998) 1262]. This wavelength range is very interesting for the integration of classical silicon technology with optical fiber applications for chip-to-chip or intra-chip communication. To get InAs QDs of reproducible size and shape the growth conditions for the formation of quantum dots have to be optimized. Here, we report on detailed investigations on the molecular beam epitaxial growth of InAs QDs on silicon and their embedding in a silicon matrix. A variety of surface analytical techniques have been used, including in-situ electron diffraction (RHEED), in-situ photoelectron spectroscopy (XPS) and ex-situ atomic force microscopy (AFM).

Growth and Characterization of InAs Quantum Dots on Silicon

“…(001) substrates were hydrogenpassivated, details on their preparation and optimized growth conditions can be found in [9,10]. (001) substrates were hydrogenpassivated, details on their preparation and optimized growth conditions can be found in [9,10].…”

“…In a former study on the embedding of QDs in a silicon matrix we reported on the possibility of growing up to 10 11 cm --2 InAs QDs and the formation of large indium clusters between the InAs QDs [9]. Further, we investigated the QD size distribution, ways of improving their uniformity as well as the defect structure in the QDs, information which is essential for a later application of this system [10].…”

Growth and characterization of InAs quantum dots on Si(001) substrates

“…Secondly, arsenic (As) beam equivalent pressure (BEP) dependence of dot formation was studied throughout the entire pressure range from 9.2 Â 10 À6 to 1.2 Â 10 À7 Torr. This subject was studied by Hansen et al, who observed that a small As/In ratio is crucial for obtaining high dot density [7]. The reason of this is still not very clear.…”

Effects of growth temperature and arsenic pressure on size distribution and density of InAs quantum dots on Si (001)

“…The interest in InAs quantum dots has been extended to those fabricated on Si substrates because of the potential application in Si-based optoelectronic devices [6][7][8]. From the standpoint of materials physics, InAs quantum dots on Si represents a substantially more complex subject.…”

“…In comparison to InAs quantum dots on GaAs (001), InAs/ Si(001) is associated with a much higher lattice mismatch (11%) as well as a polar-nonpolar interface. Currently, the understanding of the formation mechanism of InAs quantum dots on Si is lacking [7,9,10]. There is very little knowledge in the literature with regard to controlling the dot size distribution and density, two important concerns for optoelectronic applications.…”