US Patent 11183488 Three-dimensional memory devices with stacked device chips using interposers

Embodiments of three-dimensional (3D) memory devices with stacked device chips using interposers and fabrication methods thereof are disclosed. In an example, a method for forming a 3D memory device is disclosed. An alternating conductor/dielectric stack is formed at a first side of a chip substrate. A memory string extending vertically through the alternating conductor/dielectric stack is formed. A chip contact is formed at a second side opposite to the first side of the chip substrate and is electrically connected to the memory string. A first interposer contact is formed at a first side of an interposer substrate. A second interposer contact is formed at a second side opposite to the first side of the interposer substrate and is electrically connected to the first interposer contact through the interposer substrate. The first interposer contact is attached to the chip contact.