| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 103 === Chemical Mechanical Polishing/Planarization (CMP) has been recognized as an
irreplaceable technology of approaching the IC fabrication with global planarization, solving
the issues of copper metallization and miniaturization of feature size down to 20nm, though
it is expensive and complicated. CMP affects the final efficiency, reliability, and cost of IC
production so that the process has been improved for efficient and defect-free surface
demands. Electrochemical mechanical polishing (ECMP) though gained high removal rate,
unfortunately, it was terminated due to the potential threat to nano-wire devices and
complicated parameters in high volume manufacturing. This study aims to develop a novel
Electro-Kinetic Force assisted CMP (EKF-CMP) to enhance the electro-osmosis flow for
distributing flow on pad asperity to increase the abrasives effectivity. Based on numerical
simulation by a commercial software, COMSOL Multiphysics, of hybrid energy field on
characteristics of EKF-CMP, a novel design of electrode has been developed. Experiments
of EKF-CMP have been performed on Cu-blanket and patterned wafer (SEMATECH 854AZ)
polishing. Results of Cu blanket CMP show that the lower surface roughness have been
observed from Sa 8.62nm to 7.72nm. For Cu patterned wafers CMP, it has achieved in
reducing the total-process time by reducing the over-polishing stage of 37.5% Moreover,
EKF-CMP has also reduced dishing as 2.84%-9.79%, and erosion as 73.78%-96.14% on
100/100, 50/50, and 10/90 pattern. Finally, the EKF-CMP can significantly control not only
slurry circulation to enhance removal rate of copper film, but also to reduce the degrees of
dishing and erosion on the test key patterns. Future study can focus on non-metallic substrate,
such as sapphire and SiC wafers. The electrode design can also be developed for 2D and 3D
FinFET CMP for advanced node applications.
|
|---|
