Via configuration for wafer-to-wafer interconnection

Patent Number: 10,224,312
Issued: 3/5/2019
Official Filing: View the Complete Patent
Abstract: A modification to the standard layout of vias used for vertically-stacked wafer bonding is proposed which has been found to improve the interconnect overlay while avoiding the dishing problems associated with the planarization processes used in the creation of conductive posts within the vias. In particular, the pitch, i.e. the spacing between adjacent posts, is intentionally chosen to be different for each wafer. By using different pitches, there is an increase in the probability of overlap of posts on each wafer, even when one wafer is slightly offset with respect to the other (which is possible when aligning one wafer with another in a standard bonding tool). Advantageously, the use of different pitches allows for the use of relatively small diameter (one micron or less) posts while still creating sufficient overlap for the necessary connections.
Filed: 5/23/2017
Application Number: 15/603,100
Government Interests: STATEMENT OF GOVERNMENT INTEREST This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention.