Effect of titanium interlayers on adhesion enhancement of platinum films on titanium oxide films and on temperature coefficient of resistivity of platinum films

摘要

The effect of insertion of a titanium (Ti) layer to enhance adhesion between platinum (Pt) and titanium oxide films has been investigated. Ti is known to be effective in enhancing adhesion, but it diffuses through the Pt films and oxidizes during heat-treatment in an oxygen atmosphere. Both diffusion and oxidation influence the temperature coefficient of resistivity (TCR) of the Pt films. High resolution electron microscopy revealed that the most of the Ti atoms in the titanium interlayer diffused through the grain boundaries of the Pt film and precipitated at the top surface grain boundaries of the film, while the rest of the Ti was oxidized inside the film. The optimum thickness of the adhesion-promoting Ti layer for enhancing adhesion and suppressing the decline of TCR was 10 nm.