TOKYO -- Shin-Etsu Chemical Co., Ltd. (TOKYO: 4063)(Head Office: Tokyo; President: Yasuhiko Saitoh; hereinafter, “Shin-Etsu Chemical”) has created a 300-mm (12-inch) QST substrate, which is a substrate dedicated to GaN epitaxial growth, and recently started supplying samples.

Shin-Etsu Chemical has sold 150-mm (6-inch) and 200-mm (8-inch) QST substrates and GaN on QST epitaxial substrates of each diameter. Meanwhile, the company worked on further increasing the diameter in response to strong customer demand and successfully developed a 300-mm (12-inch) QST substrate. GaN device manufacturers cannot benefit from increasing the diameter of materials because of the lack in large-diameter substrate suitable for GaN growth, despite the fact that they can use the existing Si production line for GaN. This 300-mm QST™ substrate enables GaN epitaxial growth without warping or cracks, which was unattainable on Si substrates, thus significantly reducing device costs. In addition to the enhancement of facilities for 150-mm and 200-mm QST™ substrates already in progress, Shin-Etsu Chemical will work on mass-producing 300-mm QST™ substrates.

Since QST substrates have the same coefficient of thermal expansion as that of GaN, it is possible to constrain warping and cracks of GaN epitaxial layer on QST substrate of the SEMI standard thickness. This substrate material allows for high-quality and thick GaN epitaxial growth with a large diameter. Leveraging this feature, many customers are evaluating QST substrates and GaN on QST epitaxial substrates for power devices, high-frequency devices, and LEDs. Despite the challenging business environment, customers have entered the development phase toward practical to address the recently increasing interest in power devices, including power supplies for data centers.

The addition of the 300-mm QST substrate to the lineup of the 150-mm and 200-mm can significantly accelerate the spread of GaN devices. Shin-Etsu Chemical is committed to contribute to the realization of a sustainable society where energy can be used efficiently through the social implementation of GaN devices.

Note that the company plans to exhibit this 300-mm QST substrate at SEMICON TAIWAN, which will be held in Taipei, Taiwan, from September 4 to 6, 2024.

*1: The QST substrate is a composite material dedicated to GaN growth developed by Qromis (CA, U.S.A, CEO: Cem Basceri) and was licensed to Shin-Etsu Chemical in 2019. QST is a U.S. trademark of Qromis (registration No. 5277631).