Probe Apex Characterization and Qualification - New Thread

Reply

Don Chernoff Posted: Tue, May 11 2010 1:33 PM

rated by 0 users

I'm trying to demonstrate the tip width of a "1-nm radius" tip by scanning isolated features (bumps or ridges).  Does anyone have a favorite specimen that has features 1 nm wide?

Reply

SeanHand replied on Wed, May 12 2010 9:23 PM

rated by 0 users

Good Evening Don -

    I am not famililar with a sample with < 1nm feature sizes with which to accurately measure the tip width.  How far up the probe do you want to characterize it's shape?  You could probably get an inferred measurement from a calibrated linewith with low line edge roughness and linewidth variation by comparing the calibrated linewidth. 

   The NanoCD calibration structure has a top corner edge radius < 5nm.  You could make some cylindrical assumptions about the top corner shape and deconvolve that quater cylinder from your measured top corner rounding.  The residual will be an approximation of your tip shape.

   This will only get you a slice through your probe.  However,  you could play the same game with a probe.  You could scan the circular nitride cap at the end of a CDR130SiN probe.   You can think of this as a very flat disk at the end of a post.   The SiN probes also have <5nm edge radii, but in this case, as they are circular,  you could get an idea of the full shape of your probe.  Again though,  these would be just approximations.

Best Regards,

-Sean

Reply

chanmin su replied on Fri, May 14 2010 3:52 AM

rated by 0 users

Another possibility is to image DNA and look at the width expansion. If you do have DNA width near 2 nm, your tip must be very close to 1 nm in radius.  In case you don't want to bother working with DNA you could look at HOPG step and see how sharp you can get to.

Reply

Peter Markiewicz replied on Thu, May 20 2010 12:33 PM

rated by 0 users

Hello Don,

Besides the DNA suggested, you might also try carbon nanotubes or buckyballs and look at the distortion of width vs. height to figure out the quality of your tip. I'd recommend the tubes since they would stick to the substrate better than buckyballs (which might contaminate your tip).

Peter Markiewicz.

P.S. What sort of tip do you have? Is it one with a CNT?

Reply

Mike Maybrun replied on Thu, May 27 2010 3:46 PM

rated by 0 users

Don,

I have heard the "Nio Probe" sample is good for tip radius less than 10nm (where the "tip check" sample doesn't work so well).  Link is below...

viewPrd.asp?idproduct=166