DENSE 3D HETEROGENEOUS INTEGRATION USING SELECTIVE COBALT ALD DEPOSITION AND RECONSTITUTED TIERS

In this thesis, a new fine-pitch low-temperature bonding technology using selective Cobalt (Co) ALD deposition is presented. The benefits of selective Co ALD bonding are nanometer-scale controllability, low planarity requirement, low bonding temperature (200 oC) and potential for ultra-high-density bonds. To demonstrate selective Co ALD bonding, a Cu/Gap/Cu three-layered structure, which emulates 3D ICs stacking, is fabricated and carefully characterized. The testbed shows seamless Co interconnection between the Cu pads after Co ALD deposition for 1000 cycles. The electrical measurements demonstrate over 90% yield, which prove the Co connectivity between the Cu pads. Moreover, in this thesis, a new type of SiO2-reconstituted-tier stacking technology is proposed. The SiO2-reconstituted-tier stacking technology utilizes low-temperature ICP- PECVD SiO2 to encapsulate multi-sized chiplets. After ICP-PECVD SiO2 encapsulation, the through-oxide-vias and the pads are formed on the SiO2 to complete the reconstituted tier before stacking. Compared with conventional epoxy-molding-compound-based stacking, the SiO2 approach can have smaller loss tangent (10x), lower CTE mismatch (3x) and the higher via density (>400x). The thickness of the proposed technology can be over 10 times smaller than conventional epoxy molding. The two technologies, with further analysis and studies, open up exciting new opportunities for future 3D IC heterogeneous integration.

Level thesis:degree_level

Masters

Department dc:contributor.department

Electrical and Computer Engineering

Grantor dc:publisher

Georgia Institute of Technology

Year dc:date.issued

2021

Author dc:creator

• Li, Ming Jui

Advisor dc:contributor.advisor

• Bakir, Muhannad S.

Committee members dc:contributor.committeemember

• Brand, Oliver
• Yu, Shimeng

• Selective Cobalt ALD Bonding 3D Heterogeneous Integration Advanced Packaging SiO2 Reconstituted Tier

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1853/65112

OAI identifier oai:identifier

oai:repository.gatech.edu:1853/65112