HyFET—A GaN/SiC Hybrid Field-Effect Transistor

We experimentally demonstrate a GaN/SiC hybrid field-effect transistor (HyFET)—a novel power electron device that can harness the complementary merits of GaN and SiC and circumvent their notorious drawbacks. The HyFET regulates currents by gating an AlGaN/GaN high-mobility 2- dimensional-electron-gas (2DEG) channel and blocks voltages with a vertical SiC junction-field-effect-transistor (JFET) structure. The channel mobility can be boosted by ~100 times compared to a SiC MOS-channel. The HyFET can be vertically configured to provide voltage blocking with avalanche capability and be free of the dynamic ON-resistance issue, which are difficult for GaN HEMTs. Critical technology enablers for implementing the GaN/SiC HyFET include a dual-epitaxy SiC JFET structure, GaN epitaxy on patterned 4°- off-axis 4H-SiC substrate, and a Damascene-process-based in- cell interconnection solution. Our experimental demonstration unveils a new power device platform that gears toward the utmost integration of these two prevailing wide-bandgap semiconductors.