Provided are a method of forming a metal layer wiring structure on the backside of a wafer, a metal layer wiring structure formed using the method, a method of stacking a chip package, and a chip package stack structure formed using the method. The method of stacking a chip package includes: forming recess patterns on a backside of wafers; forming a passivation layer on the backside of the wafers except for an area corresponding to a through electrode; forming a metal layer on the passivation layer; planarizing the metal layers to expose only the recess patterns; forming a lower insulating layer on the planarized metal layers except for an area corresponding to a contact portion with another wafer; forming an adhesive layer on the lower insulating layer of each of the wafers; and adhering the wafers to one another, wherein the recess patterns are formed using a laser.