Forming an alignment mark on a semiconductor structure using an optical lithography to form a metal alignment mark on a substrate of the structure, using the formed metal alignment mark to form a first feature of a semiconductor device being formed on the substrate using optical lithography, and using the formed metal alignment mark to form a second, different feature for the semiconductor using electron beam lithography. In one embodiment, the first feature is an ohmic contact, the second feature is a Schottky contact, the metal alignment mark is a refractory metal or a refractory metal compound having an atomic weight greater than 60 such as TaN and the semiconductor device is a GaN semiconductor device. A semiconductor structure having a metal alignment mark on a zero layer of the structure, the metal alignment mark is a TaN and the semiconductor is GaN.