This paper demonstrates the fabrication of InAs-on-insulator (InAs-OI) structures with high crystallinity using the Smart Cut process, which combinates direct wafer bonding with a wafer splitting process by implanted H+. Controlling the implantation dose and rate allows us to produce wafer-level InAs-OI structures on Si substrates by H+ implantation at room temperature, which can be performed in standard implantation equipment. It is found that (111) InAs-OI has a much flatter surface after splitting than (100) one. After thinning by using CMP and wet etching, 15 nm thick InAs-OI structures are realized with the high thickness uniformity.
Electronic transport properties of InAs nanowires are studied systematically. The nanowires are grown by molecular beam epitaxy on a SiOx-covered GaAs wafer, without using foreign catalyst particles. Room-temperature measurements revealed relatively high resistivity and low carrier concentration values, which correlate with the low background doping obtained by our growth method. Transport parameters, such as resistivity, mobility, and carrier concentration, show a relatively large spread that is attributed to variations in surface conditions. For some nanowires the conductivity has a metal-type dependence on temperature, i.e. decreasing with decreasing temperature, while other nanowires show the opposite temperature behavior, i.e. temperature-activated characteristics. An applied gate voltage in a field-effect transistor configuration can switch between the two types of behavior. The effect is explained by the presence of barriers formed by potential fluctuations. Source:IOPscience
Current-injected light emission was confirmed for metal organic vapor phase epitaxy (MOVPE) grown (Ga)InAs/InP quantum dots (QDs) on directly bonded InP/Si substrate. The InP/Si substrate was prepared by directly bonding of InP thin film and a Si substrate using a wet-etching and annealing process. A p–i–n LED structure including Stranski–Krastanov (Ga)InAs/InP QDs was grown by MOVPE on an InP/Si substrate. No debonding between Si substrate and InP layer was observed, even after MOVPE growth and operation of the device under continuous wave conditions at RT. The photoluminescence, current/voltage, and electroluminescence characteristics of the device grown on the InP/Si substrate were compared with reference grown on an InP substrate. Source:IOPscience For more information, please visit our website: www.semiconductorwafers.net, send us email at firstname.lastname@example.org and email@example.com
An InAs/Si heterojunction formed by a wet wafer bonding method with an annealing temperature of 350 °C was investigated by transmission electron microscopy (TEM). InAs and Si were observed to be uniformly bonded without any voids in a 2-µm-long field of view in a bright-field TEM image. A high-resolution TEM image revealed that, between the InAs and Si lattice images, there existed a transition layer having an amorphous-like structure 10–12 nm thick, which had the role of atomically combining the two crystals. The transition layer was separated into two layers of different brightnesses in a high-angle annular dark-field scanning TEM image. The distributions of In, As, Si, and O atoms in the vicinity of the heterointerface were examined by energy dispersive X-ray spectroscopy. The amounts of In, As, and Si atoms gradually changed within a 20-nm-thick intermediate layer including the transition layer. Accumulated O atoms were detected in the transition layer. Source:IOPscience For more information, please visit our website: www.semiconductorwafers.net, send us email at firstname.lastname@example.org and email@example.com