A millimeter-wave AlN/GaN MIS-HEMT device for low operating voltage application is proposed. An epitaxial material was redesigned, and an AlN barrier epitaxial layer was grown on the SiC substrate. Based on this SiC substrate, several MIS-HEMT devices were fabricated. The ohmic contact process was optimized in the aspect of high temperature RTA. The DC tests were performed for the fabricated devices. The results show that the maximum drain current is 2.4 A/mm, the extrinsic peak gm is 518 mS/mm, the small signal ft is 85 GHz, and the fmax is over 141 GHz. The large signal tests at 28 GHz of 5G millimeter-wave band show that the output power density (POUT) is 0.55 W/mm, and the power additional efficiency (PAE) is 40.1% at VDS = 3 V. At VDS = 6 V, the POUT is 1.6 W/mm, and the PAE is 47.8%. The AlN/GaN MIS-HEMT device demonstrate its potential in future millimeter-wave applications.