[Spm] RE: Spm Digest, Vol 37, Issue 8 Cleaning waffle calibration gratings (Don Chernoff at ASM

[Igor Sokolov]

Dear Don,
We tried for fun to clean with ultrasonic (also not megasonic) in piranha
acid which partial success (in principle, the quality was not too bad).
Plasma cleaning and even etching with SEM plasma sputter/ cleaner/etcher
gave not a lot success (worth than the piranha treatment). What we have
found the most positive so far is that the flat surface can be cleaned with
ultrapure water and a brush type of polymeric pad used in postCMP
(chemical-mechanical planarizarion) processes to remove abrasive
nanoparticles.
If you find any other good method, please tell me.
Best regards,
Igor

_____________________________________
Igor Sokolov, Ph.D.
Associate Professor,
Departments of Physics, Chemistry,
Center for Advanced Materials Processing,
Clarkson University,
Potsdam, NY 13699-5820, USA

office:	315-268-2375
fax: 		315-268-6610 
cell:		315-212-4865
Skype:	sokig2007
E-mail:	isokolov at clarkson.edu
Web:		http://www.clarkson.edu/~isokolov/
______________________________________


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Message: 2
Date: Mon, 20 Aug 2007 12:11:59 -0400
From: "Don Chernoff at ASM" <donc at asmicro.com>
Subject: [Spm] Cleaning waffle calibration gratings
To: "SPM  List" <spm at spmlist.di.com>
Message-ID: <003101c7e344$d9d143c0$6701a8c0 at asm15>
Content-Type: text/plain; charset="iso-8859-1"

Many AFMs are supplied with a 'waffle grating' to calibrate the XYZ axes.
Typically, the pattern consists of 5 um wide pits on a square grid with 10
um pitch.  The pits are normally 180 nm deep (older gratings) or 200 nm deep
(newer gratings).  Many  of the older gratings seem to accumulate small
bumps (< 0.5 um wide) that are 10-50 nm high.  
What cleaning techniques are useful for these gratings so that nano-dirt
does not interfere with the measurements?  For example, has anyone tried CO2
snow cleaning?  Plasma cleaning?  

I myself have tried ultrasonic cleaning, using an ordinary small lab unit
(not megasonic).  This succeeded in breaking large clumps into smaller ones
and spreading them across the surface, so that the specimen was less useful
than before. 

regards,
Don
=============================================
Don Chernoff, Ph.D., President
Advanced Surface Microscopy, Inc.    E-Mail:  donc at asmicro.com
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[business activities:  analytical services in AFM, AFM probes, consulting,
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