The history of silicon transistors through more than a half century will be described. In particular, advanced CMOS device technologies and “More than Moore” technologies will also be discussed for various applications.

Due to its extreme properties, diamond has an excellent figure of merit (FOM) for high power switching devices. It is expected as a next generation material; however, R&D has been limited due to its overly small size single crystal. Recently, we have developed two state-of-the-art technologies for a large size single crystal wafer, and succeeded in making 20x40mm² size wafers by utilizing the so-called direct wafer fabrication technique” and the “Mosaic technique”. Now, a 2 inch size diamond wafer is expected in the very near future. Also for the device, we have successfully demonstrated a 250°C switching operation with a high speed and low loss type of Schottky barrier diode to verify the advantages of the diamond.

Silicon (Si) power devices are used as the power semiconductors for power conversion systems and are widely applied to power electronics for energy creation, energy saving and reducing CO₂ emissions. Currently, the performance development of Si devices is coming close to being saturated due to the limits of the material. However, many kinds of developments such as a new device structure for a Super Junction (SJ) MOSFET, an RB-IGBT device for a new circuit topology and an HV-IC for a drive circuit have been breaking through the performance limits. This paper introduces a general outline of Si power devices, and SJ and RB-IGBT devices, as the latest Si devices, and a power IC that is necessary for the control of these power devices.

High mobility Ⅲ-Ⅴ compound semiconductors and Ge have been the most promising channel materials for future metal-oxide-semiconductor (MOS) field-effect transistors (FETs) beyond the traditional device scaling of Si MOSFETs. Heterogeneous integration of Ⅲ-Ⅴ compound semiconductors and Ge on the Si platform has been intensely investigated, enabling monolithic integration of Ⅲ-Ⅴ and Ge-based photonics by complementary metal-oxide-semiconductor (CMOS) processes, owing to their superior optical properties. In this paper, we will review the research trends for Ⅲ-Ⅴ/Ge device technologies for electronic-photonic integrated circuits (EPIC) on the Si platform.

We have been developing phase-change memory driven by a poly-Si MOS transistor to realize large-capacity non-volatile memory, namely post-flash memory. A thin-film phase-change layer on a Si channel makes it possible to reduce the reset current, and as a result, phase-change memory can be driven by a poly-Si MOS transistor, for which the on-current is smaller than the transistors on a Si substrate. A one-time dry etching process utilized for memory holes enables the realization of an ultra-low bit cost for phase-change memory. The reset operation of the developed phase-change memory at 45 µA and 30 ns corresponds to about a 1-GB/s programming throughput.

It is indispensable to control the strain based on a detailed analysis and evaluation to realize a high-performance LSI. In the present study, we improved the spatial resolution of Raman spectroscopy using quasi-line shape laser excitation, a high NA liquid emersion lens, super-resolution using digital signal processing and peak extraction techniques. The strain analyses were performed for patterned SiN film, a gate-last pMOSFET with various gate lengths, a commercial 32nm-node-LSI and SSOI/SGOI substrates with and without patterning. We clarified the mechanism of the strain introduction in the MOSFET and observed a huge strain induced in the advanced LSI. We also proposed a multi-axis strain evaluation technique using a high-NA objective lens. Moreover, a SERS evaluation was proposed to save exposure time for the multi-axis evaluation.

The macroscopic properties of bulk multi-crystals strongly depend on the microscopic distribution of constituent elements such as crystal grains, grain boundaries, impurities, dislocations, etc. Artificial control of these structural elements could alter the macroscopic properties of the multi-crystals, which are equivalent to a high-quality single crystal. In this article, we will introduce our recent activities toward the development of an ultra-high-quality multi-crystalline Si ingot for solar cells based on a cost effective directional solidification.

The improvement of the substrate quality is important to apply SiC materials to high-performance power devices. A solution growth method is attracting attention as the technique for “ultra-high quality” crystal growth. In our research, it has been revealed that threading dislocations are converted to other defects in the basal planes and they are swept from the crystal during the growth process. Utilizing this conversion phenomenon, we have demonstrated ultra-high quality growth. Recently, reports of improvements in the crystal growth rate and the expansion of the crystal size have also been made using other groups. We have almost established the solution growth as a full-scale quality SiC bulk crystal growth technology.

The advantages of epitaxy exist in the possibilities of growing thin crystals 1) of high purity and high quality, 2) with nano~micro structures and 3) that have no bulk crystal. This technology was developed in the late 1950s to 1970s and then employed to realize many modern electro-optical devices. To understand the mechanism of epitaxy, key parameters such as supersaturation and the surface diffusion length are explained. Then, it is demonstrated that the surfaces where the growth is taking place can be classified into 3 kinds such as singular, vicinal and atomically rough surfaces. The growth behavior on each surface is discussed.