At the heart of transistors are materials driving performance and reliability.
GaN’s superior properties make it the ideal semiconductor material for high-performance switching applications. It offers a high breakdown field, low on-resistance and high-temperature stability, enabling high-frequency switching with power densities unmatched by silicon or other materials.
Exagan has a unique academic and industrial history spanning more than 20 years. The roots of our GaN-on-silicon technology stretch back to the late 1990s and materials development work done at CNRS-CRHEA, a world-leading center for GaN materials. In 2012, engineered-substrate producer Soitec and the research institute CEA-Leti joined forces to develop a 200-mm CMOS-compatible, GaN-based FET technology by leveraging Soitec’s proprietary and optimized materials technology to address the technical and economic challenges of 650-volt and 1,200-volt power switching.
Using standard but state-of-the-art epitaxial equipment from leading MOCVD vendors, Exagan’s GaN-on-silicon process – called G-Stack™ – allows tight control of all the material’s crystalline properties including defects, impurities and thickness. This allows the production of FETs with high breakdown voltage, low leakage and low dispersion.
With G-Stack, we first create a unique sequence of GaN-based materials that is stacked as an insulating buffer atop the base substrate. Strain-management layers are then inserted into the stack to prevent cracking in the low-defect-density GaN crystal. Our proprietary technology is the most effective way to achieve the ultimate balance of high-quality crack-free material, reliable stress management and flat 200-mm wafers.
This approach enables standardized manufacturing of GaN-on-silicon devices for applications up to 1,200 volts. Since Exagan controls its own materials technology, we can tailor the epitaxial layers to achieve the desired device properties for each intended application.
