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

If the layout is asymmetric, the conversion might result in an offset of the final layout onto the wafer. It is therefore recommended to symmetrise the layout, e.g. by inserting small structures in the corners of a rectangle that covers the layout.

DEFMODE 2                    Both deflectors are used (default)

RESIST 240                    A dose of 240 µC/cm2 is used  

OFFSET(0,0)                  An offset of 0 µm is applied in both X and Y

      

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If the next user of the machine has loaded a cassette in slot #10 and you wish to load that cassette after exposure, you can finalize the sdf-file with 'END 10'.

== Calibration during writing (PATH)==

The inital and cyclic calibration before and during an e-beam run is defined in the jdf-file, e.g. by 'PATH DRF5M'.

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auto calib file    calibrations

  DRF5M             INITIAL: HEIMAP, CURRNT, DRIFT

                     CYCLIC: CURRNT, DRIFT (every 5 minutes without interupting the writing of a field)

                     CYCLIC: CURRNT, DRIFT (every 5 minutes without interupting the writing of a field)

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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).

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.

CHIPAL V1/V4:

RESIST 240                A dose of 240 µC/cm2 is used   

OFFSET(0,0)              An offset of 0 µm is applied in both X and Y

      

[[File:markorientation.jpg|300px]]

== Dose variation ==

The dose modulation is defined in a percentage addition to the base dose, i.e. the final dose, Q, is given by the base dose, RESIST, and modulation, m, by this formula:

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== Double current exposure ==

Before running a double-current exposure, you should receive training from a person from the e-beam staff. If this procedure is not performed correctly, it might end up in large pattern shifts.

== Arrays of arrays ==

If you need to pattern a structure that consists of repetitions of a single pattern, you can easily design the pattern using arrays of arrays in the jdf-file.

== MULTIPASS and OVERLAP ==

When defining the v30-file to be exposed, e.g.  

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Prepare jdf- and sdf-files according to the sections above.

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schd sdfname          Final compilation of sdf, jdf and v30-files, creates a mgn-file

schd -exptim sdfname  Final compilation of sdf, jdf and v30-files, creates a mgn-files and states the writing time estimate

A console may be opened by clicking Console in the Hosts tab (small triangle above 'cpu disk') in the tree at the bottom of the workspace. In the console, Ctrl + p or n may be used to browse through previous commands.

The final check of pattern is performed clicking ‘Achk’ in the Analysis window:

= Examples of sdf and jdf files=

{| class="wikitable collapsible autocollapse"

# The order of commands might be wrong in either the sdf- or jdf-file; check the order of commands in the templates in the directory home/eb0/jeoleb/job/templates

# The sdf- or jdf-files might have been opened in a text-program different from SuperEdi, e.g. notepad; this can corrupt the files and add linefeeds or tokens at line-ends. This can be checked in SuperEdi. In most cases, the problem can be solved by opening the sdf- and jdf-file in SuperEdi and save it again while setting the line endings to UNIX.

# The path writing requires a scan speed larger than 100MHz; increase the shot pitch (SHOT) in the sdf-file and compile again.