Abstract: A process for producing a "metal to compound semiconductor" contact having a potential barrier of predetermined height. By this is meant a Schottky contact or an ohmic contact. The process comprises, before deposition of the metal, perfectly cleaning the semiconductor so as to remove in particular oxygen, then depositing sulphur or selenium on its surface by the action of hydrogen sulphide or hydrogen selenide, and, after deposition of the metal, effecting a heat treatment of the contact. In this way, an ohmic contact is obtained. The Schottky contact is obtained by the action of hydrogen sulphide or hydrogen selenide and then pure oxygen at very low pressure.