Atotech Demonstrates Successful Plating of 20nm Dual Damascene Structures with New Cu Chemistries
Albany, New York - Since 2008, Atotech has partnered with the College of Nanoscale Science and Engineering (CNSE) in Albany, New York to develop, evaluate, qualify, and optimize copper chemistries used for plating advanced semiconductor devices.
The device structures are provided by CNSE and meet or exceed the International Technology Roadmap for Semiconductors (ITRS) timing for the logic M1 geometries.
CNSE provides to the Atotech R&D team 300 mm wafers with scaled structures from 90 nm to 22 nm node, while CNSE and Atotech work hand-in-hand to deliver leading plating results on these scaled wafers. For this task, CNSE provides the feature size, including scaled liner barrier seed structures, while Atotech performs the copper plating, which is optimized for each technology node. Additionally, post electrochemical deposition (ECD) processing steps are performed in order to prepare the wafers for electrical and reliability testing.
In the last several years, the Atotech R&D team at CNSE has developed new base electrolytes at medium and high purity specification levels (<100 ppb cat ion specification), as well as advanced plating additives used to support the copper dual Damascene bottom-up fill plating performance.
Critical parameters include defect-free plating, low copper resistance, stable copper-to-copper contact resistance, and superior electro migration (EM) and stress migration (SM) performance.
Very good scaling capabilities were demonstrated by the R&D team, based on the device structures provided by CNSE. Additionally, Atotech has demonstrated successful plating on wafers provided by CNSE's partner companies. These advanced device structures include alternative liner barrier seed layers and features sizes down to 45 nanometers.
This achievement was made possible by the introduction of new suppressor components, and the overburden and dishing control was optimized by new leveler components. The new additive package has been evaluated for stability and repeatability and significantly succeeds previous chemistry performance results.
The next step for Atotech's R&D team is to evaluate and qualify the new chemistry package under manufacturing conditions.