Thermal stability of TaN-based thin layers for Cu metallization

Abstract

The diffusion of Cu through TaN-based thin layers into a Si substrate has been studied. The barrier efficiency of TaN/Ta/TaN multilayer barrier of 50nm:50nm:50nm in thickness has been investigated and is compared with that of TaN single layers. Thermal stabilities of these TaN-based thin layers were determined from glancing incidence angle X-ray diffraction and transmission electron microscopy, conducted in the temperature range of 773-973 K. The TaN/Ta/TaN barrier appeared to be more efficient than the TaN single layer in preventing Cu diffusion. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.