On March 18, 2023, Advanced Micro Semiconductors Co., Ltd. (referred to as “AMSFAB” or “the Company”) announced that the development of the 40V enhanced (p-GaN) power device process platform based on gallium-nitride-on-silicon (GaN-on-Si) 6-inch/150mm wafer has been completed and that the platform is officially released for mass production. The process platform adopts industry-leading Au-free process and integrated circuit interconnection and supports Through-GaN-Via (TGV) and Circuit-Under-Pad (CUP). Compared to traditional silicon-based power chips, chips produced using this platform have lower conduction resistance, faster switching speed, and smaller size.

Power devices produced using this process platform have many advantages, including low gate, low on-resistance, and high reliability, providing solutions with smaller physical size, less weight, and higher energy efficiency for low-voltage power conversion scenarios. Relying on these remarkable features, the process platform can provide power products with excellent quality, smaller size and lower costs, which can be widely applied in cellphones, tablets, laptops, etc.

Cross section of the 40V gallium nitride power device

AMSFAB's 40V gallium nitride power device process platform has a large process window and ensures good process consistency and stability. For the Au-free process adopted, RC < 0.4 Ω·mm; the gate uses a self-alignment process, which makes good gate morphology, and the minimum line width is 0.5 µm. The platform also adopts integrated circuit interconnection processes including (contact hole tungsten) tungsten bolts and the global planarization of wafer surface (CMP), and supports Circuit-Under-Pad. It has been recognized by customers for its excellent performance and has been successfully integrated into many designs.

Typical parameters of a device prepared by this process

AMSFAB also has its own power epitaxial technology, which uses the silicon-based GaN heteroepitaxy widely used in the industry to reduce costs. Due to the significant lattice mismatch and differences in thermal expansion coefficients between GaN and silicon, the 6-inch high-quality silicon-based GaN epitaxy is very challenging. AMSFAB's epitaxial technology team has developed the high-quality 6-inch silicon-based GaN epitaxy process for many different applications based on technologies including stress regulation and active layer design. The process realizes the silicon-based GaN epitaxy with low defect density and can be used for many high- and low-voltage power devices.

Schematic diagram of the 6-inch silicon-based gallium nitride power epitaxial structure and epitaxial layer thickness map

The AMSFAB GaN power device process platform has made a good start in the market. AMSFAB will further launch mass production processes of medium- and high-voltage (100 V, 150 V and 650 V) power devices. Boasting high efficiency, high frequency and high reliability, the processes can help customers excel in various applications including consumer electronics, industry and communication. Please stay tuned.