edfas.org ELECTRONIC DEVICE FAILURE ANALYSIS | VOLUME 26 NO. 1 46 the exact location of a fail, perhaps also finding again for physical analysis after defect localization. Another had to do with the examination of junctions, particularly N+ to PW, in topdown EBIC. More advice followed from the audience. Kleindiek presented a paper recently to IPFA, which stated that the use of four-point-probing, even on small contacts, could greatly reduce contact resistance, and make these measurements easier. Others said that user awareness as to the time at high energy applied to the sample, is key to success. Then there was a discussion about the repeated question of resistance can be captured with a particular EBIRCH system, as if that were a fixed constant. The consensus in the room was that a hard short is difficult, because of the ohmic short, a lack of Seebeck interfaces, and high electrical/thermal conductivity of metals. One suggestion was simply to turn up the current (through the defect) and beam energy as high as possibly can be sustained by the defect. Or to start at higher mag and continually increase the magnification. As far as keeping track of defect locations, tips were offered of using the SEM beam to make a carbon dep near the sample, or using the nanoprobes themselves to make a scratch on the surface. As stated above, the highest possible resolution system might not be of use if one cannot also see the defect’s general vicinity at low magnification. Both Kleindiek and Thermo Fisher showed results from EBIRCH or EBAC showing a defect isolation on a field of view 100-200 microns wide. William Hubbard then gave a short presentation in which he challenged the TEM community to have more “nanoprobe attitude” when analyzing samples. He pointed out the rich array of additional electrical properties that should be in greater use by the industry. Greg Johnson showed a result where the use of an AFM tip in an AFM-in-SEM system had been able to perform EBAC between the well contacts and the NFET contacts of a 7 nm SRAM array, thus providing an indication of well resistance, from current under the N-wells of the sample. Thermo Fisher showed an image of PicoCurrent imaging, highlighting a resistive contact in a DRAM array with an AFP probing system. Nicholas Antoniou showed the group a basic overview of AFP transistor probing, showing results on a 5 nm transistor. A brief audience discussion highlighted that this technique may be especially useful in cases where the underlying devices would be extremely sensitive to electron beam imaging. Results of Kelvin probe force from x-FAB, scanning capacitance from Intel were showcased. Antoniou then gave excerpts of a short tutorial prepared by Phil Kaszuba, who was unable to attend the conference. It showed the strengths of SPM probing in general related to other techniques. Then the value of scanning microwave impedance microscopy (sMIM) was compared to other techniques, such as SCM and SSRM. He showed results of an IGBT sample in cross-section, where sMIM was able to highlight multiple fine structures in the sample. Phil Kaszuba’s results on SCM were also shown, demonstrating the ability to distinguish between the Lpoly and true Leff of a device. The audience discussed some of the fine features in the SCM dopant profiles of a finFET cross-section. “THE HIGHEST POSSIBLE RESOLUTION SYSTEM MIGHT NOT BE OF USE IF ONE CANNOT ALSO SEE THE DEFECT’S GENERAL VICINITY AT LOW MAGNIFICATION.” Advertise in Electronic Device Failure Analysis magazine! For information about advertising in Electronic Device Failure Analysis: Mark Levis, Business Development Manager 440.671.3834, mark.levis@asminternational.org Current rate card may be viewed online at asminternational.org/mediakit.
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