How did the OEM test the break-down of capacitors?

The OEM tested the break-down of the capacitors using test structures that were not made with the same design and did not include the seams. Therefore, stress test boards were developed to test a total of 192 undamaged devices in parallel.

How can you tell if a capacitor is failing?

There were no visual deformities seen under standard microscopy on the capacitor’s top metal. Most subtle failures in a capacitor are those in the dielectric which are difficult to find under standard spectroscopy . To determine the location of the short, a current of 50 mA was forced through the failed capacitor.

How do you test a capacitor?

Typical testing for capacitors is a voltage break-down test done on parallel test structures made on-wafer . The OEM tested the break-down of the capacitors using test structures that were not made with the same design and did not include the seams.

What should be done if a capacitor is damaged?

If there are indications of capacitor damage from the inspections, further physical analysis is to be carried out to expose the defect site. The early involvement and constant communications with foundry, product line, EIPD experts, quality and design teams had been instrumental on the success of the three (3) case studies.

What is failure analysis of integrated capacitors?

Therefore, failure analysis of integrated capacitors is the key to identify the root cause but, on some cases, is also a challenging task. Three case studies were discussed that includes the FA approaches and techniques that were utilized to understand the defect sites.

How to identify a defect site in a nwell capacitor?

To localize the defect site in the NWell capacitor, further fault isolation analysis using nanoprobing and EBIC techniques was performed confirming the leakage between the plates and detected localized hot spot. FIB cross section followed by STEM and/or TEM analyses found subtle gate oxide damage and/or rupture .