For decades, electromigration (EM) reliability testing has been predominantly performed as a package-level reliability (PLR) activity, and has stubbornly remained so even as many other intrinsic reliability tests have shifted toward wafer-level reliability (WLR) for reasons including:

These motivations apply equally to EM test, but EM has special requirements such as long test times (days, weeks, or even months), high temperature (up to 350°C is common), and large sample sizes (requiring many parallel test channels). Challenges like these have traditionally been more easily and less expensively solved by testing packaged test structures in ovens (PLR), rather than directly on wafer (WLR).

Fortunately, recent breakthroughs in probe station capabilities now enable efficient electromigration evaluation at the wafer level. FormFactor’s Estrada-EM probe system for electromigration is the industry’s first Integrated Measurement Solution (IMS) for high-performance EM WLR testing to deliver the faster results, better data integrity, and legitimacy needed for WLR. Estrada’s four key elements that deliver on these three benefits are all optimized to provide unmatched functionality and performance for the challenging EM WLR application.

  1. A specially-designed version of our flagship CM300xi shielded and semi-automated / fully-automated 300mm probe station that delivers:
  • Patented PureZone™ nanochamber technology
  • 350°C thermal system
  • Assisted multisite probe alignment
  1. A specially-designed T350 EM-specific probe card from Celadon Systems provides:
  • High site count – up to several dozen test sites across the wafer surface
  • Edge-to-edge 300 mm wafer coverage
  • In-situ probe alignment
  1. Our Symphony™ and 1164 test systems with Conductor software provide:
  • The industry’s best integrated system EM measurement detail
  • Programmable compliance and multiple test algorithms (constant current, constant voltage, low frequency pulse, SWEAT, and isothermal)
  1. We deliver the full solution for EM WLR application needs:
  • The Estrada-EM is an inclusive, self-contained, fully-functional test cell with all the pieces necessary to implement EM WLR. There’s no need to choose options from various vendors and worry about their applicability and compatibility for EM WLR – in Estrada-EM the best available tools have already been designed and pre-validated for suitability and high performance for the EM application and its unique requirements, to ensure a smooth, risk-free deployment.
  • The entire system is supported by our worldwide organization, for peace of mind and simplified/fast response if maintenance or repair is required.
  • The entire system is available from a single vendor, via a single purchase order, with several pre-defined packages to simplify the ordering process.

Wafer-level testing of intrinsic Electromigration offers excellent advantages over traditional package-level EM test in terms of faster results and better data integrity and has been shown to be a valid and useful complementary test method. Our innovative, integrated, and validated Estrada-EM solution is the first to truly meet the demands of EM WLR, and further offers a number of unique performance capabilities to produce the best available EM WLR test experience and results.

For more information on wafer-level electromigration testing and the Estrada-EM WLR IMS, download the technical brief here (PDF).