III–V compound semiconductors provide highly efficient light emission, whereas silicon, being an indirect-band-gap semiconductor, is intrinsically inefficient as a light source. In this research, a wafer containing epitaxially grown III–V light-emitting layers and an SOI wafer incorporating optical waveguides are surface-treated and directly bonded at 150°C. This low-temperature process forms a low-defect III–V/Si bonding interface while minimizing thermal damage to the crystalline layers and fabricated device structures.
In the resulting III–V/Si hybrid laser diode, light generated in the III–V semiconductor can be coupled into a silicon optical waveguide. The technique therefore provides a promising platform for wafer-scale integration of high-performance light sources into silicon photonic circuits. Potential applications include compact and highly functional systems for optical communications, optical sensing, and photonic computing.

Complex strain distributions arise in semiconductor nanostructures because of lattice mismatch between films and substrates, nanoscale patterning, and surface and interface effects. Such strain strongly influences crystal growth, defect formation, and device performance. In this research, a focused nanobeam X-ray is scanned across nanopatterned AlN structures in both the in-plane and depth directions, and the diffraction intensities recorded at each position are used to construct three-dimensional reciprocal-space maps.

Analysis of the positions, shapes, and intensities of the diffraction peaks enables high-spatial-resolution visualization of lattice deformation from the film/substrate interface to the sample surface. Extending this approach to devices under applied voltage or operating current could allow nondestructive tracking of strain changes inside active devices and around buried structures. This capability is expected to facilitate strain-based device optimization and clarify the local origins of degradation and failure.