InAlN/GaN HEMTs on Si with 0.18-Ω•mm Contact Resistance and 2.1-A/mm Drain Current Density

In this paper, we proposed a Ti5Al1/TiN gold-free ohmic contact on InAlN/GaN high electron mobility transistors (HEMTs). The fabricated devices exhibited a very low contact resistance of 0.183 Ω•mm and achieved very good on-state performance with a high maximum drain current (Id, max) of 2.10 A/mm, on-resistance (RON) of 1.75 Ω•mm and the maximum transconductance (gm, max) of 339 mS/mm with source-to-drain distance of 4 um. These results revealed this new type of alloy ohmic contact could improve the InAlN/GaN HEMTs performance by reducing the contact resistance, which shows great potential for high-performance and low-cost radio frequency (RF) application.