| abstract |
Capping protective self aligned buffer (PSAB) layers are layers of material that are selectively formed at the surface of metal layers in a partially fabricated semiconductor device. Encapsulating PSAB layers are formed not only at the surface of the metal layers, but also within the unexposed portions of the metal lines. Encapsulating PSAB layer, for example, can surround the metal line with the PSAB material, thereby protecting interfaces between the metal line and diffusion barriers. Encapsulating PSAB layers can be formed by treating the exposed surfaces of metal lines with GeH 4 . Capping PSAB layers can be formed by treating the exposed surfaces of metal lines with SiH 4 . Interconnects having both a silicon-containing capping PSAB layer and a germanium-containing encapsulating PSAB layer provide good performance in terms of adhesion, resistance shift, and electromigration characteristics. |