We report a study of the electrical properties of Schottky barrier heights of column IIB metals (Hg, Cd, and Zn) on chemically cleanedn‐type InP(100). Hg/InP diodes were formed by using a commercially available mercury probe, while Cd/InP diodes and Zn/InP diodes were fabricated by electroplating techniques. Dark forward bias current‐voltage as well as dark reverse bias capacitance‐voltage measuring techniques were used to characterize the samples. The barrier heights were found to be 0.92, 0.62, and 0.43 eV for Hg/n‐InP, Cd/n‐InP, and Zn/n‐InP, respectively. The barrier heights for Hg/n‐InP and Cd/n‐InP are higher than commonly thought possible onn‐type InP.