Method for manufacturing semiconductor device

A method for manufacturing a semiconductor device, comprising:

• providing a substrate comprising a MEMS region and a connection region thereon;
• providing a dielectric layer disposed on said substrate in said connection region;
• providing a poly-silicon layer disposed on said dielectric layer, wherein said poly-silicon layer serves as an etch-stop layer to prevent wet etchants from contacting said dielectric layer underneath said connection region;
• providing a connection pad disposed on said poly-silicon layer;
• providing a passivation layer covering said dielectric layer, wherein the passivation layer comprises an opening that exposes said connection pad and a transition region between said connection pad and said passivation layer;
• and
• providing a conductive layer conformally covering said connection pad and said poly-silicon layer in said transition region.