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Wafer Level Supercritical Carbon Dioxide-Based Metal Deposition for Microelectronic Applications
Title: Director of R&D
Phone: (919) 313-2108
Email: jdeyoung@micell.com
Title: Director of R&D
Phone: (919) 313-2108
Email: jdeyound@micell.com
This research project involves the application, development, and commercial
scale up of a process for the deposition of copper and copper barrier materials
such as ruthenium, titanium, and other metals. This process could replace copper
electroplating currently used to fill deep trenches and thin-film deposition
in microelectronic circuit manufacturing. In addition, physical vapor deposition
and electroless deposition of barrier materials also could be replaced. The
electroplating process generates large quantities of aqueous wastes with copper
ions and other dangerous chemicals that must be treated in place.
MiCell Technologies, Inc.’s proposed process uses liquid or supercritical
carbon dioxide (CO2) solvent to transport a metal precursor to a semiconducting
wafer substrate. In addition to being environmentally benign, this process
provides additional control of the metal deposition process to create superior
films and electrical interconnects. This research project is part of an overall
strategy to replace aqueous and organic solvents in microelectronics fabrication.
The wafer to be coated will be immersed in supercritical CO2 solvent containing
the precursor. The wafer is heated independently of the chamber and a reactant
is added to initiate a reaction with a metal precursor leaving behind a metal
film on the wafer substrate surface. Because of the low surface tension and
viscosity of the CO2 phase, the precursor will penetrate uniformly into the
narrow gaps on the surface of the patterned substrate. After the conversion
of the metal precursor, a solid metallic layer remains on the surface that
forms the desired interconnect, thin layer structure, or barrier layer.
Because of the never-ending demand for faster processor speeds and enhanced
storage capacities, smaller and more sophisticated structures are required
in modern semiconductor products. As dimensions shrink, copper interconnects
and metallic barrier and seed layers will be scrutinized like never before
in efforts to achieve maximum yields. New processes and materials will be adopted
in the coming years to meet the challenges of evolving semiconductor products.
As an environmentally benign and technically superior process, metal deposition
from supercritical CO2 will have a preferred position in the marketplace.
* Information listed above is at the time of submission. *