On a two-layer Si$_{3}$N$_{4}$/SiO$_{2}$ dielectric mask for low-resistance ohmic contacts to AlGaN/GaN HEMTs

The fabrication of a two-layer Si$_{3}$N$_{4}$/SiO$_{2}$ dielectric mask and features of its application in the technology of non-fired epitaxially grown ohmic contacts for high-power HEMTs on AlGaN/GaN heterostructures are described. The proposed Si$_{3}$N$_{4}$/SiO$_{2}$ mask allows the selective epitaxial growth of heavily doped ohmic contacts by nitride molecular-beam epitaxy and the fabrication of non-fired ohmic contacts with a resistance of 0.15–0.2 $\Omega$ mm and a smooth surface and edge morphology.