The advancements of Si electronics from the past to the present are reviewed and the future technological trends are discussed based on the semiconductor roadmap. The development of the heterogeneous integration is also discussed.

Si photonics based on heterogeneous integration will play an important role in Society 5.0. In particular, an optical phase shifter is an essential building block for high-speed optical interconnection. We have developed efficient and low-loss optical phase shifter using a III-V/Si hybrid metal-oxide-semiconductor (MOS) capacitor. We have also applied a hybrid MOS optical phase shifter to realize a programmable photonic integrated circuit for deep learning accelerator.

InGaAs photo field-effect transistors (photoFETs) on Si is one of the promising candidates for a high responsivity Short-Wave Infra-Red (SWIR) photodetector toward monolithic integration with Si-LSI. We have demonstrated InGaAs photoFETs integrated on Si through layer transfer technology. According to the scanning transmission electron microscopy (STEM) and Raman measurement, the InGaAs layer was transferred onto Si without the degradation of crystal quality or the introduction of strain. To evaluate the SWIR photosensitivity of InGaAs photoFETs, we derive the spectral responsivity characteristics at a constant incident power from 1000 nm to 1800 nm. It is found that InGaAs photoFETs present higher and broader responsivity than that of InGaAs photodiode in the SWIR region.

Diamond has various useful material properties such as a wide bandgap, high carrier mobility, high breakdown field, and high thermal conductivity. Therefore, diamond is expected as high-frequency, low-loss and high-power device materials. Our fabricated diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) showed normally off properties, which is important for power devices. However, the MOSFETs suffer from low field-effect mobility, which is mainly attributed to existence of high interface state density near the valence band edge on diamond. In this report, we introduce the lateral growth technique and the OH termination technique. We also discuss electrical properties of diamond MOSFETs and MOS capacitors.

We have developed spatiotemporal measurement and analysis techniques in x-ray photoelectron spectroscopy. To begin with, time-division depth profiles of gate stacked film interfaces have been achieved by NAP-HARPES (Near Ambient Pressure Hard x-ray Angle-Resolved PhotoEmission Spectroscopy) data. We then have promoted our methods to quickly perform peak fittings and depth profiling from time-division ARPES data, which enables us to realize 4D-XPS analysis. It is found that the traditional maximum entropy method (MEM) combined with Jackknife averaging of sparse modeling in NAP-HARPES data is effective to perform dynamic measurement of depth profiles with high precision.

The Japanese electronics industry has remarkably declined in the 21st century. Its domestic production in 2019 was less than half of the peak. The trade balance of it has shown deficit in recent years. The turning point was 1985. The deregulation of communication businesses and movements toward the end of the cold war have then established a new global sharing system of design and fabrication. Japanese electronics firms, however, disliked the new sharing system, and they have chosen the way for the decline.