Shin-Etsu Chemical Co., Ltd. has created a 300mm (12-inch) QST^TM substrate. Specifically, this substrate will contribute to the further growth of GaN epitaxial. The company has already started supplying samples.

Shin-Etsu Chemical has sold 150mm (6-inch) and 200mm (8-inch) QST^TM substrates and GaN on QST^TM epitaxial substrates of each diameter. Meanwhile, Shin-Etsu Chemical worked on further increasing the diameter in response to strong customer demand. Therefore, it has successfully developed a 300mm (12-inch) QST^TM substrate.

Towards Mass Producing 300mm

GaN device manufacturers cannot benefit from increasing the diameter of materials because of the lack in large-diameter substrate suitable for GaN growth. This is although they can use the existing Si production line for GaN. Moreover, this 300mm QST^TM substrate enables GaN epitaxial growth without warping or cracks. This was unattainable on Si substrates. Thus, significantly reducing device costs.

In addition to the enhancement of facilities for 150mm and 200mm QST^TM substrates already in progress, Shin-Etsu Chemical will work on mass-producing 300mm QST^TM substrates.

Because QST^TM substrates have the same coefficient of thermal expansion with GaN, it is possible to constrain warping and cracks of GaN epitaxial layer on QST^TM substrate. Specifically, 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^TM substrates and GaN on QSTTM epitaxial substrates for power devices. This is in addition to 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 300mm QST^TM substrate to the lineup of the 150mm and 200mm can significantly accelerate the spread of GaN devices. Thus, Shin-Etsu Chemical remains committed in contributing to the realization of a sustainable society. Specifically, where it possible to use energy efficiently through the social implementation of GaN devices.
Meanwhile, the company is exhibiting this 300mm QST^TM substrate at SEMICON TAIWAN. Currently, the annual event will run until Sept. 6, 2024.

Note:

*1: The QST^TM 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^TM is a U.S. trademark of Qromis (registration No. 5277631).

05 September 2024