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Measure Low Resistance - Problem

Posted: July 1st, 2015, 4:40 am
by brooksone
I measured the resistance of a via using a Kelvin structure. I applied a current of 10mA and measured the the potentials at the top of the via and on the bottom of the via. All the current needs to go through the via i could easy calculate the resistance of the via by substracting the potentials divided by the current (expected resistance mOhm till few Ohms). Everthing seemed okay until i sweeped the current (from 0 to some mA) and found that the potential difference between the top and the bottom of the via always stays the same. This would result in a changing resistance.
I used a SCS 4200 with a Matrix 707B (4 SMUs (2 with preamp), Triax cables, DUT in shielded housing).
Does anybody has an idea what the problem might be?

Re: Measure Low Resistance - Problem

Posted: July 1st, 2015, 7:06 am
by Andrea C
Are any of the SMU entering a compliance limit?

The voltage drop across the via will be SMU1-SMU2. But what is the starting value of SMU1? Is it at 200mV (the compliance limit)?