Forums
Bruker Media
Community Media
Bruker AFM Probes
SPM Digest
Application Notes
NanoTheater
Website
中文
Brochures & Datasheets
Publications
Probes Catalog
Events
Manuals & Documentation
Presentations
Guide to AFM Modes
News
Journal Club
Webinars & Video
Nanovations
Other
Hi friends,
I would like to measure local IV spectra by D3100, NS4. I used the conductive AFM probe ´SCM-PIC´ (Pt/Ir coated highly dope Si probe).
As I tried out with a new conductive probe on the sample chuck as reference (sample chuck is stainless steel and biased), its IV spectrum as shown below is very abnormal. I expected a linear IV curve instead of such a ´diode´ behavior.
Other references, such as a bulk metal plate and a piece of Al foil, showed either the strange ´diode´ IV behavior or no current at all between -10 V to +10V.
Taking the surface native oxide into consideration, how large the DC bias should be to break it down? Do you have any suggestions to conduct IV spectra reliably?
Thanks a lot!
Solong
Hi, you may try increasing your setpoint. Have you got reasonable topography image before ramp?
Ang Li
Hello Ang Li,
Thank you for your reply!
Yes, I have tried increasing the deflection setpoint. It turned out to make no difference, or suddenly no more deflection during the ramp,e.g. no deflection v.s. DC bias plot after -6 V to +10V.
I let it scan the surface for a while and the topography image looked reasonable before I turned on ramp,. But after several ramps, CAFM had no reaction and could not get IV curves any more even keeping pressing 'single ramping' button. Then I had to switched back to image mode. The confusing thing was the topography was a horizontally straight line when I switched back. It was solved by decreasing the deflection setpoint, i.e. lifting the tip a little bit up. Afterward, the topography appeared and looked normal again.
I thought non-linear IV curve measured on the sample chuck because of some local oxide. So I increased the DC bias gradually during 2x2 micrometer square topography scanning and expected the increasing of current signal at some points. Unfortunately, the current signal kept the same even to several volts.
Have you achieved a linear IV curve by CAFM?
Thank you very much!