GaN-on-SiC Power Structure With Integrated Schottky Freewheeling Path

The patent combines a field-effect transistor with a Schottky diode into a single integrated device structure. The Schottky diode is formed by creating a Schottky barrier contact between a metal layer and the semiconductor substrate, while the field-effect transistor components (gate, source, drain) are integrated on the same substrate. This merging allows the device to simultaneously achieve high efficiency through the field-effect transistor's low on-resistance and high forward voltage withstanding capability through the Schottky diode's inherent properties.

The patent employs composite material structure by combining different semiconductor materials and metal layers. Specifically, it uses a semiconductor substrate with specific doping regions, gate materials, source/drain materials, and Schottky barrier metal layers. The Schottky barrier contact is formed between a metal layer and the doped semiconductor region, creating a heterostructure that provides both low forward voltage drop and high reverse blocking capability, thus resolving the contradiction between efficiency and voltage withstanding.

The Schottky diode and field-effect transistor are merged into a single integrated device where shared components reduce overall complexity. The source region of the field-effect transistor serves dual purposes: as the source contact for the transistor and as the anode contact for the Schottky diode. The gate structure controls both the transistor channel and influences the Schottky barrier formation, reducing the need for separate control mechanisms.

Several components perform multiple functions: the doped semiconductor substrate serves as both the transistor channel region and the Schottky diode anode; the gate structure controls transistor operation while also influencing the Schottky barrier height; the source/drain regions function as both transistor contacts and diode terminals. This multi-functionality reduces the total number of discrete components needed, thereby managing device complexity while achieving high forward voltage resistance.