Alignment target for electron-beam write system.

摘要

An alignment target for an electron-beam direct write system is formed on a wafer of semiconductor material. First, a layer of silicon oxide is formed on a surface of the wafer. Then a layer of silicon nitride is formed on the oxide. Next, an opening is etched in the nitride layer to expose a surface portion of the oxide. The surface portion of the oxide is then etched to form a hole in the oxide. The hole is formed such that the oxide layer is undercut beneath the nitride layer such that a cantilevered nitride overhang is formed around the perimeter of the hole. A layer of aluminum is then deposited over the nitride layer.