The present application provides a semiconductor device and a method for preparing the semiconductor device. The semiconductor device includes a bonding pad disposed over a semiconductor substrate, and a first spacer disposed over a sidewall of the bonding pad. The semiconductor device also includes a first passivation layer covering the bonding pad and the first spacer, and a conductive bump disposed over the first passivation layer. The conductive bump is electrically connected to a source/drain region in the semiconductor substrate through the bonding pad.