Radius of an asperity
Radius of an asperity
(OP)
I am trying to determine the "Radius of curvature" of an asperity. I am using a Wyco NT-2000 surface optical profiler. I am not sure if I can determine the radius of curvature from the machine directly?
The machine can output, the "Mean Summit curvature" (as explained here http: //www.imag emet.com/W ebHelp/spi p.htm#roug hness_para meters.htm
) but I am not sure this will be helpful in determining the the radius of curvature of an asperity or even the average radius of asperity curvature. I have attached an image of the test scan with the data available from the scan.
I would really appreciate some advice, thanks.
The machine can output, the "Mean Summit curvature" (as explained here http:
) but I am not sure this will be helpful in determining the the radius of curvature of an asperity or even the average radius of asperity curvature. I have attached an image of the test scan with the data available from the scan.
I would really appreciate some advice, thanks.





RE: Radius of an asperity
RE: Radius of an asperity
RE: Radius of an asperity
A SINGLE asperity? Are you actually looking for an individual asperity, or the class of asperities? For that matter, are these asperities actually round? How big is the sample whose data you are showing? Are your asperities reflected in the roughness value or the summit values, since they are both quite different?
The summit curvature works out to a radius of 305 um, which is awfully big for an "asperity" but small for some thing like wafer bow. The mean density of summits is shown as 1 per ~44 sq. um., but are your asperities really on the order of 6.6 um across?
Your rms roughness is 9 nm, drastically different than the summits.
TTFN
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