Shin-Etsu Chemical to Develop a QSTTM Substrate for 300-mm GaN

September 05, 2024,TOKYO, Japan : Shin-Etsu Chemical Co., Ltd. (TOKYO: 4063)(Head Office: Tokyo; President: Yasuhiko Saitoh; hereinafter, “Shin-Etsu Chemical”) has created a 300-mm (12-inch) QSTTM 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) QSTTM substrates and GaN on QSTTM 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) QSTTM 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 QSTTM 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 QSTTM substrates already in progress, Shin-Etsu Chemical will work on mass-producing 300-mm QSTTM substrates.

Since QSTTM 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 QSTTM 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 QSTTM substrates and GaN on QSTTM 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 QSTTM 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.