A semiconductor package includes: a first semiconductor chip including a plurality of front surface pads disposed on a first active surface of a first semiconductor substrate, at least one penetrating electrode penetrating at least a portion of the first semiconductor substrate and connected to the front surface pads, a first rear surface cover layer disposed on a first inactive surface of the first semiconductor substrate, a first rear surface dummy conductive layer penetrating a portion of the first rear surface cover layer; a second semiconductor chip including a second front surface cover layer disposed on a second active surface of a second semiconductor substrate, and a second front surface dummy conductive layer penetrating a portion of the second front surface cover layer; and at least one first bonded pad penetrating the first rear surface cover layer and the second front surface cover layer.

Alignment of a first wafer bonded to a second wafer can be determined using electrical wafer alignment methods. A wafer stack can be formed by overlaying a second wafer over a first wafer such that second metal bonding pads of the second wafer contact first metal bonding pads of the first wafer. A leakage current or a capacitance measurement step is performed between first alignment diagnostic structures in the first wafer and second alignment diagnostic structures in the second wafer for multiple mating pairs of first semiconductor dies in the first wafer and second semiconductor dies in the second wafer to determine the alignment.

A method includes providing a first wafer including a respective set of first metal bonding pads and at least one first alignment diagnostic structure, providing a second wafer including a respective set of second metal bonding pads and a respective set of second alignment diagnostic structures, overlaying the first wafer and the second wafer, measuring at least one of a current, voltage or contact resistance between the first alignment diagnostic structures and the second alignment diagnostic structures to determine an overlay offset, and bonding the second wafer to the first wafer.

A method for wafer bonding includes receiving a layout of a bonding layer with an asymmetric pattern, determining whether an asymmetry level of the layout is within a predetermined range by a design rule checker, modifying the layout to reduce the asymmetry level of the layout if the asymmetry level is beyond the predetermined range. The method also includes outputting the layout in a computer-readable format.

A method for bonding a first substrate to a second substrate on mutually facing contact surfaces of the substrates includes a device in which the first substrate is mounted on a first chuck and the second substrate is mounted on a second chuck. A plate is arranged between the second substrate and the second chuck. The second substrate with the plate is deformed with respect to the second chuck before and/or during the bonding.

Embodiments of bonded semiconductor structures and fabrication methods thereof are disclosed. In an example, a semiconductor device includes a first semiconductor structure, a second semiconductor structure, and a bonding interface between the first semiconductor structure and the second semiconductor structure. The first semiconductor structure includes a substrate, a first device layer disposed on the substrate, and a first bonding layer disposed above the first device layer and including a first bonding contact and a first bonding alignment mark. The second semiconductor structure includes a second device layer, and a second bonding layer disposed below the second device layer and including a second bonding contact and a second bonding alignment mark. The first bonding alignment mark is aligned with the second bonding alignment mark at the bonding interface, such that the first bonding contact is aligned with the second bonding contact at the bonding interface.

In an embodiment, a method includes: stacking a plurality of first dies to form a device stack; revealing testing pads of a topmost die of the device stack; testing the device stack using the testing pads of the topmost die; and after testing the device stack, forming bonding pads in the topmost die, the bonding pads being different from the testing pads.

Structures and techniques provide bond enhancement in microelectronics by trapping contaminants and byproducts during bonding processes, and arresting cracks. Example bonding surfaces are provided with recesses, sinks, traps, or cavities to capture small particles and gaseous byproducts of bonding that would otherwise create detrimental voids between microscale surfaces being joined, and to arrest cracks. Such random voids would compromise bond integrity and electrical conductivity of interconnects being bonded. In example systems, a predesigned recess space or predesigned pattern of recesses placed in the bonding interface captures particles and gases, reducing the formation of random voids, thereby improving and protecting the bond as it forms. The recess space or pattern of recesses may be placed where particles collect on the bonding surface, through example methods of determining where mobilized particles move during bond wave propagation. A recess may be repeated in a stepped reticule pattern at the wafer level, for example, or placed by an aligner or alignment process.

A method of manufacturing a semiconductor memory device includes processing a first substrate including a first align mark and a first structure, processing a second substrate including a second align mark and a second structure, orientating the first substrate and the second substrate such that the first structure and the second structure face each other, and controlling alignment between the first structure and the second structure by using the first align mark and the second align mark to couple the first structure with the second structure.

A semiconductor package is provided. The semiconductor package includes a first conductive layer, a plurality of first conductive pads, a plurality of second conductive pads, and a first dielectric layer. The first conductive pads are electrically connected to the first conductive layer. The second conductive pads are electrically disconnected from the first conductive layer.