Rectifier and process for producing the rectifier

The present invention provides a rectifier element that has a titanium oxide layer interposed between first and second electrodes containing a transition metal with an electronegativity larger than that of Ti, wherein, in the titanium oxide layer, only the interface on the side facing any one of the electrodes has a stoichiometric composition, and wherein the average composition of the whole layer is represented by the formula TiO x (wherein x satisfies the relationship 1.6≦x<2), and wherein the rectifying characteristics can be reversed by applying a reverse electrical signal that exceeds the critical reverse electric power between the first and second electrodes in an opposite direction. The present invention also provides a process for producing a rectifier element, which includes the steps of depositing a first electrode that contains a transition metal with an electronegativity larger than that of Ti on a substrate; depositing a layer of titanium oxide (TiO x , wherein x satisfies the relationship 1.6≦x<2) on the first electrode; exposing the surface of the titanium oxide (TiO x ) layer to oxygen atmosphere; and depositing a second electrode containing a transition metal with an electronegativity larger than that of Ti on the surface of the titanium oxide (TiO x ) layer exposed to the oxygen atmosphere.