Modulators in Silicon Photonics—Heterogenous Integration & and Beyond
- Integration Approaches
4.1. Bonding
Today, there exist many methods of combining III–V semiconductor devices with Silicon PICs. One such popular example is known as flip-chip bonding (FCB), wherein prefabricated optoelectronic devices, such as a laser, are bonded upside down on a substrate which has been prepared to receive this chip [42]. In FCB pre-processed III–V devices are normally flipped, however in such a case the alignment requirements slow the process down, adding to the cost. When seeking to minimize these costs, one seeks to reduce the overall length and time of the process as well as the amount of III–V material needing to be used due to the increased price of III–V material when compared to Silicon. Roelkens’proposal of a die-to-wafer bonding in which unprocessed III–V dies are bonded, epitaxial layers down, to the processed Silicon, seeks to solve these issues of alignment and
wastage [43]. The primary benefit of this technique is the reduced need for accuracy in terms of bonding due to the lack of structures on the die, which can improve process turnaround when compared to classic FCB. Additionally, reduced material consumption improves the cost of the process, as III–V semiconductors are only bonded where they are needed.
“名家芯思维”-硅基光电子集成技术与应用研讨会 暨第72期国际名家讲堂
Lightmatter Passage brings Co-Packaged Optics and Silicon Photonics to the Chiplet Era