Fresh approach needed for evaluating reliability of copper lines and vias
Forward-looking research indicates a fresh approach is needed for evaluating the reliability of copper lines and vias in advanced semiconductor processes. New test techniques, such as constant voltage EM (CVEM), show great promise in complementing the traditional method of constant current EM (CIEM) stress. With MPEM, Cascade Microtech now provides the first commercial EM test to support this intriguing new CVEM evaluation method.
"Extremely scaled interconnects at 7 nm and beyond will necessarily have dramatically different barrier layer characteristics which, in turn, alter the behavior of conductors as they experience the primary EM failure mechanism of void formation," said Kristof Croes, Ph.D., Senior Researcher and Group Leader, Reliability, Electrical Test, and Modeling, imec. "Constant voltage EM induces more realistic biases that lead to better void detection capability. Therefore, a constant voltage EM approach could become a better alternative for future generation interconnects."
Dr. James Lloyd, professor at SUNY Polytechnic College of Nanoscale Science and Engineering, and a pioneer in semiconductor interconnect research, explains further: "With its immunity to dimensional variation, CVEM is free to better discern processing variations and defects in the material being studied."
Multipurpose EM versatility
The new MPEM module provides multiple stress bias types for testing copper interconnects, typically with geometries of 32 nm or less. With MPEM, the company added constant voltage electromigration (CVEM) and low frequency pulsed current electromigration (LFPEM) applications to its existing lineup of constant current electromigration (CIEM) and stress migration capabilities.
Offering versatility by providing three types of EM tests in one convenient platform, customers can compare multiple test methods. Additionally, the MPEM module effectively leverages the traditional advantage of Cascade Microtech's EM solutions: a fully parallel, high-speed measurement system that is uniquely capable of capturing momentary, self-healing voids. The system offers a broad measurement range, with set points as low as 10 µA or 10 mV.
MPEM expands line of fully integrated reliability tools
Cascade Microtech's 1164 and Symphony systems with MPEM modules are the industry's only fully integrated tools for these combined interconnect test applications. 1164 and Symphony systems provide package- and wafer-level solutions with high parallel capacity for efficient testing, multiple test types in a single flexible platform, very long life device under test (DUT) boards, and a rapid continuous measurement technique to ensure rigorous technology evaluation. The 1164 system's Notebook Oven architecture offers flexibility and efficiency/throughput advantages for package-level reliability (PLR) testing.
"This new approach using constant voltage EM is on the leading edge of wafer technology evaluation, and the industry needs innovative tools to enable its continued progress. Cascade Microtech is constantly pioneering technologies and techniques that allow our customers to characterize IC reliability more accurately, achieve better yield, and reach the market faster," said Michael Burger, President and CEO.
To learn more about the latest reliability test products, visit: http://www.cmicro.com/products/reliability-test.
About Cascade Microtech, Inc.
Cascade Microtech, Inc. (
FOR MORE INFORMATION, CONTACT: Laurie Winton Cascade Microtech, Inc. (503) 601-1934 Laurie.Winton@cmicro.com