High-Temperature 1.3 µm InAs/GaAs Quantum Dot Lasers on Si Substrates Fabricated by Wafer Bonding

We present 1.3 µm InAs/GaAs quantum dot lasers on Si substrates operating at high temperatures. Our lasers are fabricated through epitaxial growth on GaAs substrates of the InAs/GaAs quantum dot laser double heterostructure, and subsequent GaAs/Si wafer bonding and layer transfer onto Si substrates. Both of the on-Si lasers by direct- and metal-mediated bonding exhibit lasing temperatures over 100 °C. Partial p-type doping in the InAs/GaAs quantum dot core layer is found to significantly increase the characteristics temperature T0. This result verifies the suitability of III–V quantum dot lasers as a light source in Si photonic integrated circuits.


Source:IOPscience

For more information, please visit our website:  www.semiconductorwafers.net,
send us email at sales@powerwaywafer.com and powerwaymaterial@gmail.com

Dry etching of deep air holes in GaAs/AlGaAs-based epi-wafer having InAs quantum dots for fabrication of photonic crystal laser

Photonic crystal (PhC) structures are often fabricated on epi-wafers with a heterostructure to realize various micro- or nanophotonic devices by dry etching processes. We discuss the dry etching process for a GaAs/AlGaAs-based epi-wafer using a resist mask to fabricate a proposed PhC laser. The epi-wafer has multiple stacked layers of InAs quantum dots (QDs) with a high density of 6 × 1010 cm−2, which cause the reduction of the diameter of the etched air holes. A higher density and more stacked layers of QDs intensify the reduction effect. By enhancing the physical etching effect, the verticality of the profile of the air holes etched in the epi-wafer with a five stacked InAs QD layers is greatly improved. The results show that the improved etching conditions make it feasible to fabricate the proposed PhC laser structure.

Source:IOPscience

For more information, please visit our website:  www.semiconductorwafers.net,
send us email at sales@powerwaywafer.com and powerwaymaterial@gmail.com

Uniform and position-controlled InAs nanowires on 2'' Si substrates for transistor applications

This study presents a novel approach for indirect integration of InAs nanowires on 2'' Si substrates. We have investigated and developed epitaxial growth of InAs nanowires on 2'' Si substrates via the introduction of a thin yet high-quality InAs epitaxial layer grown by metalorganic vapor phase epitaxy. We demonstrate well-aligned nanowire growth including precise position and diameter control across the full wafer using very thin epitaxial layers (<300 nm). Statistical analysis results performed on the grown nanowires across the 2'' wafer size verifies our full control on the grown nanowire with 100% growth yield. From the crystallographic viewpoint, these InAs nanowires are predominantly of wurtzite structure. Furthermore, we show one possible device application of the aforementioned structure in vertical wrap-gated field-effect transistor geometry. The vertically aligned InAs nanowires are utilized as transistor channels and the InAs epitaxial layer is employed as the source contact. A high uniformity of the device characteristics for numerous transistors is further presented and RF characterization of these devices demonstrates an ft of 9.8 GHz.

Source:IOPscience

For more information, please visit our website:  www.semiconductorwafers.net,
send us email at sales@powerwaywafer.com and powerwaymaterial@gmail.com

Room temperature contactless electroreflectance characterization of InGaAs/InAs/GaAs quantum dot wafers

Contactless electroreflectance (CER) mapping has been performed on InGaAs capped InAs/GaAs quantum dot (QD) wafers of 2 inch diameter grown by molecular beam epitaxy. The CER spectra have revealed several features related to InAs self-assembled QDs and a quantum well (QW) formed of the InAs wetting layer and the InGaAs cap layer. The particular optical transitions have been identified based on theoretical calculations of the energy levels in the InAs/InGaAs/GaAs wetting layer related step-like QW, performed within the effective mass approximation. The influence of possible uncertainties in cap content or band offsets has also been analysed. The advantages of modulation spectroscopy, namely its absorption-like character and high sensitivity to optical transitions with even very low oscillator strength including those between the excited states, have allowed the energies of all the transitions along the wafer to be followed. The latter has shown that within experimental error the transition energies are independent of the position of the probing spot on the sample. It demonstrates not only a very high uniformity of the dot ensemble but also the wetting layer related QW and hence also the content and thickness of the InGaAs cap.

Source:IOPscience

For more information, please visit our website:  www.semiconductorwafers.net,
send us email at sales@powerwaywafer.com and powerwaymaterial@gmail.com