Aspects of the present disclosure provide a multi-tier semiconductor structure. For example, the multi-tier semiconductor structure can include a lower semiconductor device tier, and a lower signal wiring structure electrically connected to the lower semiconductor device tier. The multi-tier semiconductor structure can further include a primary power delivery network (PDN) structure disposed over the lower semiconductor device tier and the lower signal wiring structure and electrically connected to the lower semiconductor device tier. The multi-tier semiconductor structure can further include an upper semiconductor device tier disposed over and electrically connected the first PDN structure, and an upper signal wiring structure disposed over the primary PDN structure and electrically connected to the upper semiconductor device tier.