Microscopic four-point probe based on SU-8 cantilevers

A microscopic four-point probe (u4PP) for resistivity measurements on thin films was designed and fabricated using the negative photoresist SU-8 as base material. The device consists of four microscopic cantilevers, each of them supporting a probe tip at the extremity. The high flexibility of SU-8 ensures a stable electrical point contact between samples and probe tip with all four electrodes even on rough surfaces. With the presented surface micromachining process, u4PPs with a probe-to-probe spacing of 10–20 um were fabricated. Resistivity measurements on thin Au, Al, and Pt films were performed successfully. The measured sheet resistances differ by less than 5% from those obtained by a commercial macroscopic resistivity meter. Due to the low contact forces (Fcont<10^−4 N), the u4PP is suitable to be applied also to fragile materials such as conducting polymers. Here the authors demonstrate the possibility of performing resistivity measurements on 100-nm-thick pentacene (C22H14) films with a sheet resistance Rs>10^6 ohm/.


Published in:
Review of Scientific Instruments, 76, 12, 125102 (4 pages)
Year:
2005
Laboratories:




 Record created 2006-02-10, last modified 2018-12-03

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