학술논문

Strategies relating to CMP for die to wafer interconnects utilizing hybrid direct bonding
Document Type
Conference
Source
2020 IEEE 70th Electronic Components and Technology Conference (ECTC) Electronic Components and Technology Conference (ECTC), 2020 IEEE 70th. :1950-1956 Jun, 2020
Subject
Components, Circuits, Devices and Systems
Plugs
Copper
Corrosion
Integrated circuit interconnections
Application specific integrated circuits
Resistance
Language
ISSN
2377-5726
Abstract
In this study we examine a split-foundry multilevel application specific integrated circuit (ASIC) Si-interposer and die bonded using the direct bond interface (DBI) process, in addition to shortloop vehicles. The designs have been subject to relaxed pattern density rules, and exhibit chemical mechanical planarization (CMP) systematic process issues of varying degrees. We find that the interconnect formation is robust against moderate dielectric thickness variation, as well as a moderate degree of copper corrosion. We discuss and demonstrate various CMP methods which have a clear and repeatable impact. Pattern density effects and defectivity on the bond quality are examined using focused ion beam scanning electron microscope (FIB-SEM) images at the feature scale (sub 100 um) and intra-die scale (few mm). Impact to the CMP performance, including plug recess, and defectivity are discussed.