Specific Process Knowledge/Lithography/EBeamLithography/FilePreparation: Difference between revisions
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== Alignment and global mark detection == | |||
Alignment of an e-beamed pattern to an existing pattern on wafer or chip (direct writing mode) requires at least two alignment marks, P and Q, preferably positioned in quadrant II and IV of the wafer or chip (the x-coordinate of the global mark Q must be equal to or larger than the x-coordinate of the global mark P). | |||
Before loading the cassette into the e-beam writer, the wafer or chip should be pre-aligned using the optical pre-aligner setup in the e-beam room. A description of this procedure is included in the main manual of the e-beam writer. | |||
HEIMAP is discarded in direct writing mode, it thus is important to insert height measurements, by the HSWITCH and CHIPAL V1 or CHIPAL V4 command in the sdf-file. The height of the substrate will in either case be measured by a laser beam with a spot size 0.94 mm x 0.08 mm on the substrate. | |||
HSWITCH: | |||
HSWITCH ON,OFF: machine focusses beam to the Height average between P and Q marks | |||
HSWITCH OFF,ON: machine focusses beam to the height average of chip marks | |||
HSWITCH ON,ON: machine focusses beam to the height average of chip marks. The chip mark height will overrule the P and Q mark height during exposure. | |||
If HSWITCH is omitted, HSWITCH ON, ON is default | |||
CHIPAL V1/V4: | |||
The virtual CHIPAL command in the sdf-file, CHIPAL V1 or CHIPAL V4, can be used to measure the height of the substrate at well-defined positions on the substrate, thus correcting for height variations before pattern writing. To use this, HSWITCH should be set to 'HSWITCH OFF,ON' or 'HSWITCH OFF,ON'. | |||
CHIPAL V1: machine measures height at chip mark M1 (machine does not scan the mark) and focusses beam to this height before exposing | |||
CHIPAL V4: machine measures height at chip mark M1, M2, M3 and M4 (machine does not scan the marks) and focusses beam to the average height before exposing | |||
<pre> | |||
_____________________________________________________________ | |||
MAGAZIN 'ALIGN' | |||
#1 Cassette from slot no. 1 is used | |||
%4A Wafer of 4" in position A is exposed | |||
JDF 'align',1 Layer block no. 1 of the jdf-file 'align.jdf' is exposed | |||
ACC 100 Acceleration voltage is 100keV | |||
CALPRM '0.2na_ap5' The condition file 0.2na_ap5 is used | |||
DEFMODE 2 Both deflectors are used (default) | |||
GLMDET S Semi-automatic global mark detection is used | |||
CHIPAL 0 No chip-mark detection is used | |||
HSWITCH OFF,ON Height mesaurements at chip mark positions | |||
RESIST 240 A dose of 240 µC/cm2 is used | |||
SHOT A,8 The shot step between individual beam shots is 4 nm | |||
OFFSET(0,0) An offset of 0 µm is applied in both X and Y | |||
END 1 After exposure, cassette no. 1 is left on stage | |||
______________________________________________________________ | |||
</pre> | |||
The parameters in the GLMDET-command can be as follows: | |||