A wafer bonding method includes providing a first wafer including a first wafer surface, forming a first metal layer on the first wafer surface, and forming a first annular retaining wall structure including a first annular retaining wall and a second annular retaining wall surrounded by the first annular retaining wall. The first metal layer is formed between the first annular retaining wall and the second annular retaining wall. The method includes providing a second wafer including a second wafer surface, forming a second metal layer on the second wafer surface, and forming a second annular retaining wall structure including a third annular retaining wall and a fourth annular retaining wall surrounded by the third annular retaining wall. The second metal layer is formed between the third annular retaining wall and the fourth annular retaining wall. The method further includes bonding the first metal layer to the second metal layer.

A semiconductor device includes: a conductive structure, a conductive bump extending into the conductive structure and contacting the conductive structure along a first surface, the conductive bump configured to interface with an external semiconductor device at a second surface opposite the first surface, the conductive bump being wider along the first surface than the second surface.

Some embodiments relate to a three-dimensional (3D) integrated circuit (IC). The 3D IC includes a first IC die comprising a first semiconductor substrate, and a first interconnect structure over the first semiconductor substrate. The 3D IC also includes a second IC die comprising a second semiconductor substrate, and a second interconnect structure that separates the second semiconductor substrate from the first interconnect structure. A seal ring structure separates the first interconnect structure from the second interconnect structure and perimetrically surrounds a gas reservoir between the first IC die and second IC die. The seal ring structure includes a sidewall gas-vent opening structure configured to allow gas to pass between the gas reservoir and an ambient environment surrounding the 3D IC.

Some embodiments relate to a three-dimensional (3D) integrated circuit (IC). The 3D IC includes a first IC die comprising a first semiconductor substrate, and a first interconnect structure over the first semiconductor substrate. The 3D IC also includes a second IC die comprising a second semiconductor substrate, and a second interconnect structure that separates the second semiconductor substrate from the first interconnect structure. A seal ring structure separates the first interconnect structure from the second interconnect structure and perimetrically surrounds a gas reservoir between the first IC die and second IC die. The seal ring structure includes a sidewall gas-vent opening structure configured to allow gas to pass between the gas reservoir and an ambient environment surrounding the 3D IC.

A semiconductor device includes: a conductive structure, a conductive bump extending into the conductive structure and contacting the conductive structure along a first surface, the conductive bump configured to interface with an external semiconductor device at a second surface opposite the first surface, the conductive bump being wider along the first surface than the second surface.

A wafer bonding method includes providing a first wafer including a first wafer surface, forming a first metal layer on the first wafer surface, and forming a first annular retaining wall structure including a first annular retaining wall and a second annular retaining wall surrounded by the first annular retaining wall. The first metal layer is formed between the first annular retaining wall and the second annular retaining wall. The method includes providing a second wafer including a second wafer surface, forming a second metal layer on the second wafer surface, and forming a second annular retaining wall structure including a third annular retaining wall and a fourth annular retaining wall surrounded by the third annular retaining wall. The second metal layer is formed between the third annular retaining wall and the fourth annular retaining wall. The method further includes bonding the first metal layer to the second metal layer.

A three-dimensional (3D) integrated circuit (IC) includes a first IC die and a second IC die. The first IC die includes a first semiconductor substrate, and a first interconnect structure over the first semiconductor substrate. The second IC die includes a second semiconductor substrate, and a second interconnect structure that separates the second semiconductor substrate from the first interconnect structure. A seal ring structure separates the first interconnect structure from the second interconnect structure and perimetrically surrounds a gas reservoir between the first IC die and second IC die. The seal ring structure includes a sidewall gas-vent opening structure configured to allow gas to pass between the gas reservoir and an ambient environment surrounding the 3D IC.

A three-dimensional (3D) integrated circuit (IC) includes a first IC die and a second IC die. The first IC die includes a first semiconductor substrate, and a first interconnect structure over the first semiconductor substrate. The second IC die includes a second semiconductor substrate, and a second interconnect structure that separates the second semiconductor substrate from the first interconnect structure. A seal ring structure separates the first interconnect structure from the second interconnect structure and perimetrically surrounds a gas reservoir between the first IC die and second IC die. The seal ring structure includes a sidewall gas-vent opening structure configured to allow gas to pass between the gas reservoir and an ambient environment surrounding the 3D IC.

A method of fabricating a semiconductor chip includes the following steps. A bonding material layer is formed on a first wafer substrate and is patterned to form a first bonding layer having a strength adjustment pattern. A semiconductor component layer and a first interconnect structure layer are formed on a second wafer substrate. The first interconnect structure layer is located. A second bonding layer is formed on the first interconnect structure layer. The second wafer substrate is bonded to the first wafer substrate by contacting the second bonding layer with the first bonding layer. A bonding interface of the second bonding layer and the first bonding layer is smaller than an area of the second bonding layer. A second interconnect structure layer is formed on the semiconductor component layer. A conductor terminal is formed on the second interconnect structure layer.