The barrier heights of Er and ErSi2on oxide‐freep‐Si have been reported to be identical (&fgr;pB∼0.8 eV), suggesting that the stoichiometry of the metallic contact does not appear to affect the barrier heights as long as a specific metal is present at the interface. In this work, the effects of Ge in the Er film on the barrier height have been investigated. Our results show that the ratio of Ge to Er in an Er/(GexSi1−x)2compound layer in contact withp‐Si affects the barrier heights significantly. A linear relationship between &fgr;pBandxhas been found and can be expressed as &fgr;pB=0.778 −(2x) (0.098). This experimental finding indicates that the barrier height of a metallic compound on Si may depend not only on the metal species, but also on the composition of the compound.