Stability of IrTa diffusion barriers

Abstract

The thermal and chemical stability of amorphous and crystalline IrTa diffusion barriers between silicon and aluminium is investigated. A failure temperature of 550°C is found for amorphous Ir 45Ta 55 at the aluminium interface. The reaction between amorphous Ir 45Ta 55 and silicon occurs at temperatures as high as 875°C. The latter reaction temperature is lowered to 700°C when crystalline IrTa is used.