Selective Electroless Ni-Based Capping Layer on Cu Gate Electrode of TFT-LCD

Abstract

In this study, electroless Ni-based capping layers were selectively deposited on Cu surface without Pd activation. The Pd-free electroless process can eliminate possible Pd diffusion into Cu lines that causes an increase in sheet resistance of Cu. Film composition, surface morphology, film structure, chemical state and barrier function of electroless Ni-based films were discussed in our present work. The developed NiWMoB films have superior thermal stability compared with NiWB film. In addition, the depth profile suggested Cu diffusion was not observed after thermal treatment, rendering it a promising candidate as capping layer.