Thermally induced reactions in TiN/Al–Cu/TiN have been investigated. It is observed that the amount of the reactions is different at the two interfaces between Al–Cu and TiN. While there is minimal reaction between Al–Cu and the TiN overlayer, the reaction between Al–Cu and the TiN underlayer increases the sheet resistance of Al–Cu by as much as 15%. It is further shown that the asymmetric reactions are most likely caused by the different degree of (111) texture of TiN grown on amorphous SiO2and textured, polycrystalline Al–Cu. ©1995 American Institute of Physics.