rapidly, with many new achievements and records reported by research groups at the 2017 Symposium on VLSI Technology and Circuits in Kyoto, Japan (5–9 June). Most of the reported work involved indium gallium arsenide (InGaAs), particularly integrated with silicon (Si) substrates aiming for low-cost mass production. We report here on those sessions, along with research aimed at gallium nitride (...

The dislocation distribution of high-quality single-crystal gallium nitride (GaN) films grown by the hybrid vapor phase epitaxy was analyzed. This study examined the domain structure of GaN from the dislocation distribution on the macroscale by optical microscopy. The surface structure of GaN consisted of domains with microcolumns as the substructure. The inner domains contained a lower density...

Semiconductor spintronics is an alternative to conventional electronics that offers devices with high performance, low power and multiple functionality. Although a large number of devices with mesoscopic dimensions have been successfully demonstrated at low temperatures for decades, room-temperature operation still needs to go further. Here we study spin injection in single-crystal gallium nitr...

Semiconductor nanowires have received increasing focus from researchers due to their one dimensional characteristics, which offer new horizons for device designs. Nanowire growth has been shown to yield crystalline material on non-lattice matched substrates. Concerning gallium nitride nanowires, common growth substrates have been silicon (100) and (111) substrates. This manuscript discusses the...

This paper presents the progress of monolithic technology for microwave application, focusing on gallium nitride technology advances in the realization of integrated power amplifiers. Three design examples, developed for microwave backhaul radios, are shown. The first design is a 7 GHz Doherty developed with a research foundry, while the second and the third are a 7 GHz Doherty and a 7–15 GHz d...

In wide bandgap GaN a large number of interesting and important scientific questions remain to be answered. For example, the large free electron concentration reaching 1019 to 1020 cm-3 in nominally undoped material are ascribed to intrinsic defects because no chemical impurity has been found at such high concentrations. According to theoretical models a nitrogen vacancy acts as a donor but its...

There is much current interest in the optical properties of semiconductor nanowires, because the cylindrical geometry and strong two-dimensional confinement of electrons, holes and photons make them particularly attractive as potential building blocks for nanoscale electronics and optoelectronic devices, including lasersand nonlinear optical frequency converters. Gallium nitride (GaN) is a wide...