A 3D semiconductor device, the device including: a first level; a second level; and a third level, where the first level includes single crystal silicon and a plurality of logic circuits, where the second level is disposed directly above the first level and includes a first plurality of arrays of memory cells, where the third level is disposed directly above the second level and includes a plurality of RF circuits, and where a portion of interconnections between the plurality of logic circuits includes the RF circuits.

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.

A method for bonding a first substrate to a second substrate on mutually facing contact surfaces of the substrates, wherein the first substrate is mounted on a first chuck and the second substrate is mounted on a second chuck, and wherein a plate is arranged between the second substrate and the second chuck, wherein the second substrate with the plate is deformed with respect to the second chuck before and/or during the bonding. Furthermore, the present invention relates to a corresponding device and a corresponding plate.

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.

Embodiments of bonded semiconductor structures and fabrication methods thereof are disclosed. In an example, a method for forming a semiconductor device is disclosed. A first device layer is formed on a first substrate. A first bonding layer including a first bonding contact and a first bonding alignment mark is formed above the first device layer. A second device layer is formed on a second substrate. A second bonding layer including a second bonding contact and a second bonding alignment mark is formed above the second device layer. The first bonding alignment mark is aligned with the second bonding alignment mark, such that the first bonding contact is aligned with the second bonding contact. The first substrate and the second substrate are bonded in a face-to-face manner, so that the first bonding contact is in contact with the second bonding contact at a bonding interface, and the first bonding alignment mark is in contact with the second bonding alignment mark at the bonding interface.

A process includes forming through vias needed to connect a bottom device layer in a bottom silicon wafer to the one in the top device layer in a top silicon wafer including a silicon-on-insulator (SOI) wafer. Through vias are disposed in such a way that they extend from the middle of the line (MOL) interconnect of the top wafer to the buried oxide (BOX) layer of the SOI wafer with appropriate insulation provided to isolate them from the SOI device layer. A resultant article of manufacture is also disclosed.

A stacked semiconductor device is disclosed that includes a plurality of semiconductor dies. Each die has oppositely disposed first and second surfaces, with pads formed on each of the surfaces. A plurality of through-vias connect respective pads on the first surface to respective pads on the second surface. The through-vias include a first group of through-vias coupled to respective I/O circuitry on the semiconductor die and a second group of through-vias not coupled to I/O circuitry on the semiconductor die. The plurality of semiconductor dies are stacked such that the first group of through-vias in a first one of the plurality of semiconductor dies are aligned with respective ones of at least a portion of the second group of through-vias in a second one of the plurality of semiconductor dies.

Various embodiments of the present application are directed towards a method for workpiece-level alignment with low alignment error and high throughput. In some embodiments, the method comprises aligning a first alignment mark on a first workpiece to a field of view (FOV) of an imaging device based on feedback from the imaging device, and further aligning a second alignment mark on a second workpiece to the first alignment mark based on feedback from the imaging device. The second workpiece is outside the FOV during the aligning of the first alignment mark. The aligning of the second alignment mark is performed without moving the first alignment mark out of the FOV. Further, the imaging device views the second alignment mark, and further views the first alignment mark through the second workpiece, during the aligning of the second alignment mark. The imaging device may, for example, perform imaging with reflected infrared radiation.

The invention concerns the calibration of a component mounting apparatus configured to mount components on a substrate whose mounting places do not contain local markings. The substrate contains either global substrate markings attached to its edge or other global features that can be used to mount the components. Calibration is carried out by means of a calibration plate which has several calibration positions distributed two-dimensionally over the calibration plate and provided with first optical markings, a test chip which has second optical markings, and a holder attached to the bonding station for temporarily accommodating the calibration plate. The number and arrangement of the calibration positions of the calibration plate and the number and arrangement of the mounting places of the substrate areapart from possible exceptionsdifferent from one another.

In a method of aligning wafers, a second wafer having at least one second alignment key may be arranged over a first wafer having at least one first alignment key. At least one alignment hole may be formed by passing through the second wafer to expose the second alignment key and the first alignment key. The first wafer and the second wafer may be aligned with each other using the first alignment key and the second alignment key exposed through the alignment hole. Thus, the first alignment key and the second alignment key exposed through the alignment hole may be positioned at a same vertical line to accurately align the first wafer with the second wafer.