Today, in conjunction with the 41st International Symposium for Testing and Failure Analysis (ISTFA), DCG Systems® announced the release of EBIRCH™, a new, unique technology for localizing shorts and other low-resistance faults that may reside in the interconnect structures or the polysilicon base layer of integrated circuits. Named for Electron Beam Induced Resistance Change, EBIRCH offers fault analysis (FA) engineers and yield experts the ability to detect and isolate low-resistance electrical faults without resorting to brute-force binary search approaches that rely on successive FIB* cuts. Its unparalleled ability to quickly isolate low-resistance faults enables EBIRCH to boost the success rate of physical failure analysis (PFA) imaging techniques to well above 90%, accelerating time-to-results and establishing the FA lab as a critical partner organization in solving yield and reliability problems.
“At foundries and IDM* fabs, the process has become more difficult to control using traditional inline measures,” said Mike Berkmyre, business unit manager of the Nanoprobing Group at DCG Systems. “More yield issues are remaining undetected until they show up at final test — and land on the desk of the FA lab manager. The FA engineers must be equipped to localize the fault and supply images of the root cause to process or yield engineers in a timely manner. The ability to quickly and reliably localize low-resistance faults was missing before we developed EBIRCH. With the introduction of EBIRCH, we are helping to solve an FA problem that has been growing in prevalence and importance with each new device node.”
Available on DCG’s current SEM*- based nanoprobing systems, EBIRCH offers the following capabilities:
- Detects and isolates electrical faults with resistances from < 10 ohm to > 50 Mohm;
- Finds faults at surface and several levels below concurrently, significantly accelerating the existing work flow; and
- Can scan areas as large as 1mm by 1mm, and zoom in to areas as small as 50nm by 50nm, providing accurate and actionable fault localization within minutes.
To collect an EBIRCH image, the operator lands two nanoprobes on surface metal layers, straddling the suspected defect site. A bias is applied, and the electron beam rasters across the region of interest. As the e-beam interrogates the defect site, localized heating from the e-beam changes the resistance of the defect, thereby changing the current sensed by the nanoprobe. The EBIRCH map displays the change in current as a function of the e-beam position—typically showing a bright spot at the site of the resistance change. The simultaneously acquired SEM image, together with knowledge of the circuit layout, allows the engineer to determine the exact defect location. The depth at which the defect lies can be explored by optimizing the landing energy as a function of the EBIRCH signal.
Available exclusively on the flexProber™, nProber™ and nProber II™ nanoprobers from DCG Systems, EBIRCH is part of an integrated electron beam current (EBC) module that offers seamless switching from EBAC to EBIRCH, with no re-cabling needed.