Subject: Raith Blanking concerns were not observed on test today.
From: James Conway <jwc@snf.stanford.edu>
Date: Fri, 10 Oct 2003 17:34:26 -0700
Fri, 10 Oct 2003 17:34:26 -0700

Greetings:

Today I spent significant time troubleshooting two reports of blanking
problems with the RAITH 150 System.

My test:
On bare un-patterned 100 nm PMMA I exposed areas at 0.500 um pitches
blanking between moves as follows:
Test were conducted in column (V) from 1, 1 to 9, 1 U:V.

Test One:  I examined the picoammeter with signals blanked and unblanked
and did not see Beam Current above the meter noise when blanked.  I
performed this on charging and metal surfaces with no difference.
Beam I 10 keV 30 um aperture:  Beam ON 0.128 nA. Beam Off 0.000 - 0.006
nA.  NO PROBLEM

Test Two:
2.1:   1, 1 to 1, 9 U:V
Expose a field of view at 600X for ~10 seconds, Blank, Move stage V 0.5
mm and unblank, expose again. Repeat 20 times moving in a column in V
direction across chip.  NO PROBLEM

2.2:  2,9 - 2,1 U:V
Exposed a field of view at 600X for ~10 seconds. without blanking Move
stage V 0.5 mm increments.
       NO PROBLEM  I see scan artifacts at the ends of the column but
along the path.
2.3:  3, 1 to 3, 9 U:V
Scanned again another V column every 0.5 mm staying blanked the entire
time  No features unexpected.
        NO PROBLEM  No artifacts.
2.4: 5, 9 to 5, 1 U:V
With the LEO PC in TV mode repeated test 2.2 NO PROBLEM NO artifacts.

2.5  7, 1 to 7, 9 U:V
Back to SEM mode Expose a field of view at 600X for ~10 seconds, Blank,
Change mag to 300X, unblank and expose for ~20 seconds. Print a short
contamination dot.  No Problem, features as expected where expected.  I
did find one small spot shot at the end of the first raster line.

Conclusions:

We should all continue to carefully inspect our patterns to continue
this evaluation but I conclude that the report by kaimei fu may have
been a result of scanning across her sample while the system was
scanning in either scan rate 1 or 2 while the stage was moving.  This
may have been inadvertent move by other users across her sample or by
her.
Other EBL writes I did this afternoon will show this problem if there is
a problem.
We will inspect those patterns Monday evening.

Thank you for your support!

James Conway




 
Greetings:

Today I spent significant time troubleshooting two reports of blanking problems with the RAITH 150 System.

My test:
On bare un-patterned 100 nm PMMA I exposed areas at 0.500 um pitches blanking between moves as follows:
Test were conducted in column (V) from 1, 1 to 9, 1 U:V.

Test One:  I examined the picoammeter with signals blanked and unblanked and did not see Beam Current above the meter noise when blanked.  I performed this on charging and metal surfaces with no difference.
Beam I 10 keV 30 um aperture:  Beam ON 0.128 nA. Beam Off 0.000 - 0.006 nA.  NO PROBLEM

Test Two:
2.1:   1, 1 to 1, 9 U:V
Expose a field of view at 600X for ~10 seconds, Blank, Move stage V 0.5 mm and unblank, expose again. Repeat 20 times moving in a column in V direction across chip.  NO PROBLEM

2.2:  2,9 - 2,1 U:V
Exposed a field of view at 600X for ~10 seconds. without blanking Move stage V 0.5 mm increments.
       NO PROBLEM  I see scan artifacts at the ends of the column but along the path.
2.3:  3, 1 to 3, 9 U:V
Scanned again another V column every 0.5 mm staying blanked the entire time  No features unexpected.
        NO PROBLEM  No artifacts.
2.4: 5, 9 to 5, 1 U:V
With the LEO PC in TV mode repeated test 2.2 NO PROBLEM NO artifacts.

2.5  7, 1 to 7, 9 U:V
Back to SEM mode Expose a field of view at 600X for ~10 seconds, Blank, Change mag to 300X, unblank and expose for ~20 seconds. Print a short contamination dot.  No Problem, features as expected where expected.  I did find one small spot shot at the end of the first raster line.

Conclusions:

We should all continue to carefully inspect our patterns to continue this evaluation but I conclude that the report by kaimei fu may have been a result of scanning across her sample while the system was scanning in either scan rate 1 or 2 while the stage was moving.  This may have been inadvertent move by other users across her sample or by her.
Other EBL writes I did this afternoon will show this problem if there is a problem.
We will inspect those patterns Monday evening.

Thank you for your support!

James Conway
 
 


["image/jpeg" not shown]
["image/jpeg" not shown]