Shin-Etsu Chemical Co., Ltd. has announced a major development milestone for its QST™ substrate—a 300-mm GaN growth substrate—achieved through collaboration with IMEC.
The 300-mm QST™ substrate was adopted in IMEC’s recently launched 300-mm GaN power device development program. In initial evaluations, a 5 µm-thick HEMT (High Electron Mobility Transistor) structure fabricated on Shin-Etsu’s QST™ substrate demonstrated a record-breaking voltage resistance exceeding 800 V. This represents the highest breakdown voltage ever achieved on a 300-mm GaN substrate that complies with SEMI standards and confirms the substrate’s outstanding in-plane uniformity and crystal quality.
The QST™ substrate was developed by QROMIS, Inc., based in California, and licensed to Shin-Etsu Chemical. Shin-Etsu manufactures 150-mm, 200-mm, and 300-mm QST™ substrates, as well as GaN-on-QST™ epitaxial wafers. In September 2024, the company began offering 300-mm QST™ sample substrates in collaboration with QROMIS, strengthening its commitment to advancing large-diameter GaN manufacturing.
This partnership has enabled Shin-Etsu to supply QST™ substrates for IMEC’s CMOS-based 300-mm GaN fab. The joint program aims to develop both 650 V-rated and future 1200 V+ GaN power devices targeted for high-performance applications, including AI data centers, automotive systems, and industrial power electronics.
The QST™ substrate’s thermal expansion coefficient is closely matched to GaN, which facilitates stable crystal growth and reduces challenges such as wafer warpage that typically hinder high-yield GaN growth on silicon at larger diameters. By solving these limitations, the QST™ platform allows for the cost-effective production of thick-film GaN devices on 300-mm wafers—a key factor in scaling next-generation power semiconductors.
Manufacturing was carried out using Aixtron’s Hyperion MOCVD equipment, which enabled the precise deposition of the HEMT structure during testing. The results confirmed superior yield potential and mechanical integrity at the 300-mm scale, marking a crucial step toward practical large-scale manufacturing of GaN power devices.
Shin-Etsu is currently preparing for mass production of 300-mm QST™ substrates and has already enhanced its facilities for 150-mm and 200-mm variants. The QST™ substrate lineup, ranging from 150 mm to 300 mm, is being evaluated by domestic and international partners for applications in power conversion, RF, and LED markets, particularly in light of growing demand for high-efficiency systems in data centers and electric vehicles.
With its scalable GaN technology, Shin-Etsu aims to accelerate the adoption of GaN devices and support the shift toward more sustainable and energy-efficient technologies across the global electronics industry.
Original – Shin-Etsu Chemical