Hi All,
        Myself Madhav. I am a Graduate Research
student, in University of Arkansas, Fayetteville. I am
working on SEM- FEI - E beam lithography. I am having
problems in Alignment issues. I am using NPGS software
to do e beam lithography.

I am having a sample (size = 1cm * 1cm) containing Al
lines of 10um wide, 40um length and 500nm thickness.
After spin coating the sample, when I want to pattern
Nickel dots across the Al lines, I am having surface
charge problems. Hence I then produced a similar
sample and this time, I deposited a layer of Al (10nm
thick) on top of PMMA. Now with this sample, I am not
able to see the underlying Al pattern, through which I
am going to align my pattern.

Can you please suggest how to remove the surface
charge, during alignment? I will really appreciate.

Thanks

Regards,
Madhav.
Research Student,
Microep,
University of Arkansas, Fayetteville.