A method for fabricating a semiconductor structure includes providing a substrate with a first surface and a second surface, wherein at least one soldering pad is formed on the first surface of the substrate. The method also includes forming at least one via to expose each soldering pad by etching the substrate from the second surface, forming a seed layer to cover the second surface of the substrate and the sidewall and the bottom surfaces of each via, and then forming a redistribution metal layer over a portion of the seed layer formed on the sidewall and the bottom surfaces of each via and the second surface of the substrate surrounding each via. The method further includes alternately performing a pre-wetting process and a chemical etching process to completely remove the portion of the seed layer not covered by the redistribution metal layer.