Special Sessions on Integrated Materials

Some Key Process Enablers for 3D Sequential Integrations

Sylvain Maitrejean
CEA-Leti

Abstract: 3D Sequential integration (3DSI) technologies have been studied by various groups in order to address a large panel of devices and applications. In the more moore area we can expect state optimization of computing performance, power efficiency or cost. Regarding more than moore, RF or smart sensors applications are considered.
3DSI can be opposed to 3D assembly technologies where bottom and top tiers are fabricated in parallel and then assembled using a bonding step and process modules such as trough Silicon Via or Hybrid Bonding. In 3DSI, the top tiers is sequentially processed on the top of the bottom layer. Thanks to this process 3D, contact pitch can be highly reduced. Nevertheless, major process challenges occurs when you need to process a performant front-end device on the top of an active layer. Management of thermal budget, contamination and cost optimization are one of them.
In this paper we will show how key processes can be developed to address these challenges.