Semiconductor device and forming method thereof

A method includes forming a metal seed layer over a first conductive part of a wafer; forming a patterned photoresist on the metal seed layer; forming a second conductive part in an opening of the patterned photoresist; heating the wafer to create a gap between the second conductive part and the patterned photoresist; and plating a protective layer on the second conductive part. The method further includes removing the patterned photoresist, and etching the metal seed layer. The embodiment of the invention also relates to a semiconductor device and a forming method thereof. 方法包括在晶圆的第一导电部件上方形成金属晶种层，在金属晶种层上形成图案化的光刻胶，在图案化的光刻胶的开口中形成第二导电部件，以及加热晶圆以在第二导电部件和图案化的光刻胶之间产生间隙。在第二导电部件上镀保护层。该方法还包括去除图案化的光刻胶，以及蚀刻金属晶种层。本申请的实施例还涉及半导体器件及其形成方法。