Systems and methods for measuring electrical characteristics of a material using a non-destructive multi-point probe
This disclosure describes an elastic multi-contact probe that includes conductive strips each of which comprises a conductive elastomer; dielectric strips formed on a back surface of a respective conductive strip; and a layer of a thermoplastic formed on back surfaces of the dielectric strips. The disclosure also describes a method that includes measuring a first I-V curve between a pair of inner probes of the an elastic multi-contact probe based on a first current applied to a pair of outer probes; determining a first slope of a linear region of the first I-V curve; measuring a second I-V curve between the pair of inner probes based on a second current applied to the pair of inner probes; determining a second slope of a linear region of the second I-V curve; and calculating a sheet resistance and a contact resistivity of the semiconductor material based on the first and second slopes.
1. An elastic multi-contact probe comprising:
a plurality of conductive strips each of which comprises a conductive elastomer, the plurality of conductive strips being spaced apart from each other, and a front surface of the conductive strips being configured to be placed on a surface of a substrate to be probed;
a plurality of dielectric strips, each of the plurality of dielectric strips being formed directly on a back surface of a respective one of the plurality of conductive strips, and wherein each of the plurality of dielectric strips mirror a shape of the respective one of the plurality of conductive strips; and
a single layer of a thermoplastic formed on back surfaces of the dielectric strips such that the dielectric strips separate the plurality of conductive strips from the single layer of the thermoplastic.
2. The elastic multi-contact probe of claim 1 , wherein the plurality of conductive strips comprises a plurality of linear conductive strips parallel to each other.
3. The elastic multi-contact probe of claim 2 , wherein the plurality of linear conductive strips includes:
a pair of outer conductive strips having a first length, and
a pair of inner conductive strips having a second length that is shorter than the first length.
4. The elastic multi-contact probe of claim 3 , wherein the plurality of dielectric strips comprises a plurality of linear dielectric strips having a same length as the respective conductive strip.
5. The elastic multi-contact probe of claim 4 , wherein the plurality of linear dielectric strips includes:
a pair of outer linear dielectric strips having the first length, and
a pair of inner linear dielectric strips having the second length.
6. The elastic multi-contact probe of claim 4 , wherein each of the linear dielectric strips has a same width as the respective linear conductive strip.
7. The elastic multi-contact probe of claim 1 , wherein the plurality of conductive strips comprises a plurality of ring conductive strips, each of the ring conductive strips having a different radius and being concentric with a center of the elastic multi-contact probe.
8. The elastic multi-contact probe of claim 7 , wherein the plurality of ring conductive strips comprises:
a first ring conductive strip having a first radius,
a second ring conductive strip having a second radius that is larger than the first radius,
a third ring conductive strip having a third radius that is larger than the second radius, and
a fourth ring conductive strip having a fourth radius that is larger than the third radius.
9. The elastic multi-contact probe of claim 8 , wherein the plurality of dielectric strips comprises a plurality of ring dielectric strips, each of the ring dielectric strips having a same radius as the respective ring conductive strip.
10. The elastic multi-contact probe of claim 9 , wherein each of the ring dielectric strips has a same width as the respective ring conductive strip.
11. The elastic multi-contact probe of claim 1 , wherein the plurality of conductive strips comprises a solid conductive circle concentric with a center of the elastic multi-contact probe and a plurality of ring conductive strips, each of the ring conductive strips having a different radius and being concentric with the center of the elastic multi-contact probe.
12. The elastic multi-contact probe of claim 11 , wherein:
the solid conductive circle has a first radius, and
the plurality of ring conductive strips comprises:
a first ring conductive strip having a second radius that is larger than the first radius,
a second ring conductive strip ring having a third radius that is larger than the second radius, and
a third ring conductive strip having a fourth radius that is larger than the third radius.
13. The elastic multi-contact probe of claim 12 , wherein the plurality of dielectric strips comprises a solid dielectric circle having a same radius as the solid conductive circle and a plurality of ring dielectric strips, each of the ring dielectric strips having a same radius as the respective ring conductive strip.
14. The elastic multi-contact probe of claim 13 , wherein each of the ring dielectric strips has a same width as the respective ring conductive strip.
15. The elastic multi-contact probe of claim 1 , wherein the plurality of dielectric strips comprises a dielectric rubber.
16. The elastic multi-contact probe of claim 1 , wherein the layer of thermoplastic comprises a polyoxymethylene (POM).
17. The elastic multi-contact probe of claim 1 , wherein the elastic multi-contact probe is attached to a self-aligning applicator.
18. The elastic multi-contact probe of claim 17 , wherein the elastic multi-contact probe is configured to be adjusting using the self-aligning applicator.