Shin-Etsu Chemical Industry Co., Ltd. (hereinafter referred to as "Shin-Etsu Chemical") recently announced that it has collaborated with OKI Corporation to develop an innovative technology that enables the stripping of gallium nitride (GaN) functional layers from Shin-Etsu Chemical's QST substrates and bonding them to substrates of different materials. This breakthrough paves the way for the realization and widespread application of vertical GaN power devices.
GaN power devices are regarded as the key technologies for next-generation power semiconductors due to their advantages in high frequency, high efficiency, and low power consumption. However, to commercialize these devices at scale, two major challenges need to be addressed: increasing wafer diameters to increase production efficiency, and achieving vertical conduction to control high currents.
Shin-Etsu Chemical's QST substrate technology provides a solution. The QST substrate is a composite substrate specifically designed for GaN epitaxial growth, and its coefficient of thermal expansion matches that of GaN, effectively reducing wafer warpage and cracking, making it possible to grow thick-film GaN crystals on wafers of 8 inches or larger in diameter. This feature is critical for the fabrication of power devices with high breakdown voltages.
OKI's CFB (Crystalline Thin Film Bonding) technology further advances this process. This technology enables the GaN functional layer to be stripped from the QST substrate and bonded to a conductive substrate with high heat dissipation, resulting in vertical conduction and high heat dissipation, which is essential for high-current control.
Figure: Shin-Etsu Chemical has developed a large-scale substrate
Shin-Etsu Chemical has succeeded in growing thick-film GaN of more than 20 microns on a QST substrate and achieving a breakdown voltage of 1800V in power devices. In addition, the company is actively developing larger QST substrates, including 8-inch and 12-inch products, to meet the market demand for large-size substrates. Shin-Etsu Chemical plans to start providing samples of 300 mm (12 in) QST substrates in 2024.
The collaboration between Shin-Etsu Chemical and OKI not only demonstrates the strong strength of the two companies in the fields of materials science and precision engineering, but also provides a solid foundation for the commercialization and popularization of GaN power devices. The commercialization of this technology is expected to reduce the cost of vertical GaN power devices, making them more widely used in fields such as electric vehicles, 5G communications, and micro LED displays.
Shin-Etsu Chemical and OKI's collaboration model includes the provision of QST substrates or epitaxial substrates, as well as the provision of CFB technology through collaboration and licensing. Through this collaboration, the two companies aim to promote the realization and popularization of GaN power devices in society, and contribute to the efficient use of energy and a sustainable society.
About Shin-Etsu Chemical Industry Co., Ltd.:
Shin-Etsu Chemical is a leading global chemical and materials company focused on providing innovative solutions to meet the needs of customers worldwide. The company's products are widely used in semiconductors, electronics, automobiles and medical fields
