Sheet resistance and surface topology time dynamics of intrinsic oxide film on InSe crystals

Abstract

It has been shown that a result of InSe crystal oxidation is formation of an intrinsic oxide film that has not insulating but conductive properties. This conductive film forms a potential barrier with the semiconductor substrate. Sheet resistance measurements of the InSe oxide film in dependence on the oxidation time under various temperature conditions were carried out. The resistance was also tested for oxide films obtained for two mutually orthogonal crystal faces: perpendicular and parallel to the с axis. It has been established that the film sheet resistance is substantially changed only for 5 min of the oxidation time, and further oxidation does not affect its value that is about 100-150 Ohm/square. Surface topology of InSe intrinsic oxide was studied using the atomic-force microscopy method. It was found that this surface becomes nanostructured and contains nanoneedles oriented perpendicularly to the plane of sample surface. Dynamics of surface topology changes in dependence on temperature-time conditions of the oxidation process has been ascertained. It manifests itself in a change of lateral and vertical dimensions of nanoneedles as well as their density.