NT-MDT presents conductive probes with the modified coating W2C+
Modified conductive coating of cantilevers W2C+
Spreading resistance imaging is one of the most exacting of AFM methods. Cantilevers for SRI should be coated with a hard conductive layer which could hold heating due to high-density currents flowing during scanning with a strong tip-sample pressure. At the same time probe’s curvature radius shouldn’t theoretically exceed 35-40 nm thus providing good lateral resolution during topography measurements.
Some time ago we started production of AFM cantilevers with W2C conductive coating (http://www.ntmdt.com/news/view/w2c-cantilevers-crash-test-reveals-unique-stability) of thickness not more than 25 nm and holding high currents and pressures. Now we’re glad to present modified W2C+ cantilevers.
Such materials as TiN and W2C with all advantages tend to degrade in high humidity atmosphere. For elimination of this problem W2C conductive coating was modified by volume doping with anticorrosion elements.
Several experiments were carried out to check the result. Two sets of probes coated by W2C and W2C+ layers correspondingly were being placed into atmosphere of more than 90% humidity for several days. Performance capabilities of the probes were tested by current-voltage curves and scans on HOPG. Before being held in humid air all cantilevers worked correctly showing good conductivity. But already after 8 days old-type coating have been losing their conductive properties. The same time probes W2C+ didn’t stop conducting even after 16 days of storage in 90% and more humidity. On the images below you may find typical I-V curves for both types of cantilevers.
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| Test curve made by the W2C coated probe after 8 days being held in 90% humidity atmosphere |
Test curve made by the W2C+ coated probe after 16 days being held in 90% humidity atmosphere |
Thus the new conductive coating of NT-MDT AFM cantilevers W2C+ combines stability in different working regimes, reasonable size for getting good lateral resolution and possibility of work in high humidity conditions.
We’re also delighted to announce that we will sell only new W2C+ probes from our web-site. The same time, cost of this model stays the same.
More of all, we will be glad if our customers try these probes’ possibilities on practice. When the one orders any model of conductive probes from our web-site (http://www.ntmdt-tips.com/) this summer we will add to the order a test box of 3 cantilevers HA_C/W2C or HA_NC/W2C at choice.