Specific Process Knowledge/Lithography/EBeamLithography/JEOLAlignment: Difference between revisions

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 =Troubleshooting=
 Alignment on the JEOL system can be tricky, in this section we will briefly try and explain the cause and remedy for the most common problems encountered during the alignment process or job execution.
+==Nothing detected in P mark rough scan==
+===Possible cause===
+#The gain settings are not correct.
+#The scan width is not big enough, i.e. the scan does not hit the mark.
+#Scan width is already 500 µm but still there is no signal.
+===Solutions===
+#If the gain settings are not correct they can be adjusted via the automatic gain correction program '''AGCRG''' as described in the procedure above.
+#Increase scan width to 500 µm. There is cassette dependent offset between the prealigner stage coordinate and the actual system coordinate, increasing the scan width to 500 µm should however always overcome this offset.
+#If the mark is made with a very thin line it can be hard to detect in a wide scan. The scan will consist of 4000 datapoints, if for instance the scan width is 500 µm the resolution of the scan is 125 nm. If the mark is only 1 µm wide it would show up in 8 points out of 4000 datapoints, that is not enough for the system to accept it as a feature.
+==Using the SEM for position verification==
+If marks can not be found it can be necessary to use the SEM mode to manually verify the stage coordinate of the mark. Using the SEM mode should be kept at a minimum as the SEM mode will expose the area you are looking at and, more importantly to the tool, it will evaporate resist off your sample and into the system. Thus SEM use should be kept at a minimum and SEM should not be used on resist covered areas at beam currents higher than 6 nA.