ＴｉＮｉ金属薄膜／ガラス２層界面のＡｒイオンミキシングとシリサイド形成

Abstract

Atomic mixing between TiNi metallic thin films and glass substrates (silica and borosilicate glass) was induced by Ar ion bombardment and inverstigated by means of Auger electron spectroscopy. Ar ion bombardment at 150keV was carried out at room temperature to doses of 5×1016 and 1×1017ions/cm2. The Auger analysis demonstrated that significant intermixing occurred at the TiNi-glass interface after Ar ion bombardment, and that the degree of atomic mixing varied depending on the constituent atom species. It was found that Ti atoms were always transported deeper into the glass substrate than Ni atoms, and Si atoms diffused into the TiNi overlayer more than O atoms. The lighter B atoms in borosilicate glass were found to diffuse least during Ar ion bombardment. It is suggested that some metal silicides and oxides are formed in the reacted interface regions. Indentation-fracture tests revealed that adhesion between the TiNi films and the glass substrates was improved substantially by Ar ion mixing. The atomic mixing of each of the constituent atoms was discussed qualitatively using a model of isotropic cascade mixing. The improved adhesion at the interface was thought to result from interface mixing and the resultant formation of metal silicides and titanium oxides of various valence states in the interface region.