Specific Process Knowledge/Lithography/EBeamLithography/JBX9500Manual: Difference between revisions

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 = Alignment of exposure to existing pattern on wafer =
-If you need to align an exposure to an existing pattern on a wafer you need wafer marks (or global marks) to align your exposure to. This step requires extra training.
+If you need to align an exposure to an existing pattern on a wafer you need wafer marks (or global marks) to align your exposure to. This requires global marks and chip marks on the wafer, optimization of gain settings of backscattered electron detector ('''ACGRG'''), and execution of subprograms that detects global marks and chip marks ('''SETWFR''' and '''CHIPAL'''). This section describes these procedures in detail.
-First time you align on a type of wafer marks, you need to optimise the gain settings of the scan. The gain settings will depend on resist thickness, mark type (metal or etch) and substrate type. The gain settings can be found by the subprogram '''ACGRG'''.
-When the gain settings are known, you can execute '''SETWFR''' and '''CHIPAL'''.
 '''Please note that manual alignment (using the SEM) is not allowed.''' You should use semi-automatic alignment only. In rare cases where semi-automatic alignment is impossible, you should remove the resist around the wafer marks before loading the wafer/chip into the machine.