A semiconductor element is provided with a micro-structured metal layer over conductive features of a hybrid bonding surface. The micro-structured metal layer comprises fine metal grain microstructure, such as nanograins. The micro-structured metal layer can be formed over the conductive features by providing a metal oxide and reducing the metal oxide to metal. The micro-structured metal layer can be formed selectively if the metal oxide is formed by oxidation. When directly bonded to another element, the micro-structured metal layer forming strong bonds at the bonding interface can substantially reduce annealing temperature.