In this work fabrication of MISCAP structures was achieved on n-type gallium nitride using atomic layer deposited silicon nitride as the dielectric layer and sputtered ruthenium contacts. Preliminary values extracted from C-f data suggests very high capacitance densities up to 3.18 μF∙cm^-2 and very high accumulation-mode field effect mobility, as high as 325 cm²V^-1s^-1 at a bias voltage of 2.5 V.