Semiconductor dies include collections of transistors and other components in a wafer. Commonly, these wafers are semiconductor materials, and, in particular, silicon. The semiconductor wafers are singulated or diced to form semiconductor dies.
Semiconductor wafers may be stacked during manufacturing of products such as stacked ICs. Wafer-to-wafer bonding involves stacking the semiconductor wafers before being singulated into semiconductor dies. However, wafer-to-wafer bonding requires wafers and dies of equal size. Stacked ICs often include dies of different type or manufacturing process. For example, a stacked IC may have a memory device stacked on a processor. In this case, the memory device may not occupy as much die area as the processor.
When the dies do not align for wafer-to-wafer stacking, alternate semiconductor manufacturing techniques are employed. These less efficient techniques includes die-to-die bonding, die-to-substrate bonding, and die-to-wafer bonding. In die-to-substrate bonding, dies are placed on a substrate from two wafers, bonded and packaged to form a stacked die. In die-to-die bonding, two dies are individually stacked, bonded and packaged to form a stacked die. In die-to-wafer bonding, dies are individually placed on a wafer, bonded and packaged. All of these processes have low throughput compared with wafer-to-wafer processes.
Thus, there is a need for efficient semiconductor manufacturing of dissimilar die and/or wafer sizes.
USPTO Backgrounds
USPTO Backgrounds