Subject: Raith Update WED. May 19, 2004 1800 hours... Dose increments found in error on one exposure.
From: James Conway <jwc@snf.stanford.edu>
Date: Wed, 19 May 2004 18:06:41 -0700


Greetings:

Today I was working on the Raith much of the day continuing qualifications after the PM. Today I was writing at 20 keV.

The gun emission was stable and working at 20 keV and 10 um aperture I had a Beam Current value of 0.044 nA.
I did notice during my write that the third element was dosed below the first two of the series.  Dose was the same and chip 2 X 1.25 Dose factor in its dose increment.   Dose was set to Areas - 160 uC/cm-2, Lines - 660 uC/cm-2, and dots to 0.5 ms dwell time. However the EBL dose result was low by about 50%, much to my surprise.  The write time per chip was 32 minutes.

I also noticed that the Zoom U, V values were different that the Zoom U = 1.49 Zoom V =1.49 values I normally encountered.
The W.F. to W.F. stitching was poor with breaks on the order of 200  nm in Y. Some write fields appear to be rotated by about - 1 degree. 

Users are requested to carefully inspect their dose arrays to verify you are getting proper dose increments.
Users are requested to report if they see stitching problems in their patterns.

I will review protocol files tomorrow to see if human error may have accounted for the bad chip exposure.
I plan to repeat this exposure on other material as well.

Thank you for your support!

James Conway