Low-Temperature Ta/Al-Based Ohmic Contacts to AlGaN/GaN Heteroepitaxial Structures on Silicon Wafers

摘要

The formation features of a low-temperature Ta/Al-based ohmic contact to Al0.25Ga0.75N/GaN heteroepitaxial structures on silicon substrates are studied. The fabricated ohmic contacts based on Ta/Al/Ti (10/300/20 nm) compositions have a low contact resistance (0.4 mm) and smooth surface morphology of the contact area and its edge after 60-s annealing at T = 550 degrees C in a nitrogen atmosphere.