Preparation of a new tetragonal copper oxynitride phase by reactive magnetron sputtering

Abstract

Cu–O–N layers were deposited on Si-〈100〉 wafers at a temperature of 90°C in a reactive magnetron sputtering ion plating system (R-MSIP). For this, a Cu-target was sputtered by a nitrogen/oxygen plasma, and the influence of the oxygen partial pressure on composition, structure, and texture of the Cu–O–N layers was investigated. The analyses of the films with EPMA, XRD, and HEED yielded the following results: with an appropriate setting of the oxygen partial pressure, the oxygen content of the Cu–O–N layers could be controlled between 2.4 and about 50 at. %. Structure analyses have shown changes in the crystal structure of the films with increasing oxygen and decreasing nitrogen content from the simple cubic (sc) structure of Cu 3N, followed by a two phase region, where the sc structures of Cu 3N and Cu 2O appear, to a single phase film with the sc structure of Cu 2O. With an oxygen content of 43.6 at. % a new Cu–O–N phase with the tetragonal structure of paramelaconite (≈Cu 12 2+Cu 4 +O 14) and the composition Cu 27O 22N was grown. The film with an oxygen content of about 50 at. % consists of monoclinic CuO.