The formation of quasi‐one‐ and zero‐dimensional electron systems on InSb (111) by Schottky barriers has proven to be a very successful method. The lateral confinement underlying these structures is achieved by a metal grating deposited directly onto the surface of the semiconductor. A large number of metals, ranging from strongly reactive alloys like NiCr to less reactive metals like Au is used to study the formation of the lateral confining potential. The confining potentials are characterized by their intraband resonances using far‐infrared spectroscopy. Discussing our results we take advantage of previous results for the Schottky barrier formation.