Papers by Author: Keishi Yamaguchi

Abstract: Silicon carbide (SiC) single crystal has many advantages comparing with silicon single crystal, such as wide band-gap, hardness and various stable physical properties at high temperature and severe chemical environments. SiC semiconductor substrate is expected to be applied to high power devices and sensor devices in the severe environments. The polishing process under ultraviolet-ray irradiation has been developed in our laboratory to achieve the mirror-finish process of single-crystal SiC. In this paper, after the confirmation of the elastic deformation behavior of SiC single crystal using the nano-indentation tester, pre-processings of SiC by lapping and constant-pressure grinding were performed to obtain good surface without brittle fracture region. The indentation tests indicate the single-crystal SiC shows a very high elastic recovery rate. SiC substrate was processed by the lapping and the constant-pressure grinding using the constant-pressure processing to avoid the cumulative residual stock removal. As many experimental results, the constant-pressure grinding is found to be suitable for the pre-processing of SiC substrates. Additionally, it is clarified that good surface roughness on the ground surface is achieved by using a diamond wheel with the same protrusion height of abrasive grains.

Abstract: Polycrystalline diamond (PCD) has been widely used for various cutting tools and die components making use of its hardness and wear resistance properties. The polishing method of a single crystal diamond substrate and SiC using ultraviolet irradiation was newly developed to obtain mirror-finished surfaces. Due to the long polishing time in this method, a better pre-machined surface is required to shorten the total processing time. In this work, the constant-pressure grinding was performed using a cup type metal-bonded diamond wheel and a constant pressure device. After the good constant-pressure grinding, the PCD was finished by the polishing under the ultraviolet irradiation, and the microroughness was reached to be 0.71 nmRa.