Proposal and development of a novel high-speed/high-pressure polishing machine aiming at the super high efficiency process of the hard-to-process substrates

In recent years, wide band gap semiconductors, such as SiC and GaN, are attracting extensive attention as an alternative material of Si semiconductors. However, issues such as reduction of the production cost and improvement of the productivity prevent wide-spread application of these materials in the world. This study was conducted under the collaborative research and development with various specialized companies such as machine/system, polishing pad and abrasive/ slurry. We aim at the establishment of high efficiency and high-grade processing of the wide gap semiconductor substrate. We introduce an outline of the high-speed / high-pressure polishing machine, which remarkably outperforms the conventional polishing equipment (Wafer pressure: 1,000 MPa (Max), platen/ wafer rotation speed; 1000 min-1 (Max)). This machine enabled the high efficiency polishing of the hard-to-process substrates by adopting a high-performance / high power motor and rigid frame structure. Moreover, to solve the problems of slurry scattering at high-speed operation and resulting pad heating under the high pressure condition, we have developed a slurry self-returning system. This novel machine tremendously improve the productivity of the high efficiency wide gap semiconductor devices in terms of production efficiency, reduction of processing time and cost through fusion of each elemental technology such as polishing pad, abrasive/slurry, the developed machine/system, and optimization of process condition.