Chemical Stability of Vb2 and ZrB2 with Aluminum

Abstract

ABSTRACTThe chemical stability of boride thin films with aluminum is investigated. Only two diborides, VB2 and HfB2 have a positive heat of reaction which makes them potential candidates for thermodynamically stable diffusion barriers between Al and Si. Thin films of VB2, and ZrB2 for comparison, prepared by rf sputtering of composite targets were chosen for this study. Multilayer samples of these borides and aluminum were investigated by differential scanning calorimetry to determine if, according to calculations, a reaction between Al and the borides takes place, and to measure the heat of reaction. We find that an exothermic chemical reaction occurs between ZrB2 and Al and that an exothermic crystallization reaction takes place in the VB2 and Al sample. The reaction products were determined using X-ray diffraction.