E-Beam
Lithography
You will find in this page a few notes on electron beam lithography
(EBL), on drawing principals and a few sample or drawing templates.
Standard references by MC2 are found at the former SNL laboratory at http://fy.chalmers.se/assp/snl/.
Sketch of the multiple 5x5 sample holders:
Old round: JEOL
5x5mm holder.ppt
New holder (3in mask
type): new 5x5 holder.pdf
Sketch of the cassette loading position: JEOL Cassette.ppt
EOS tables: JEOL-EOS-tables.pdf
EBeam
conversion instructions.pdf
JEOL
operation introduction.ppt or JEOL
operation introduction.pdf
The
following command file can be placed in the root directory to have JEBCAD
display by default the various doses with colors.
I use AutoCAD to draw the lithography patterns. Thru export in DXF
format, AutoCAD is fully compatible with the JEOL file system. Here are some
notes on the basics of EBL and the use of AutoCAD as drawing software.
e-beam lithography and
design principles.pdf
I have written some useful scripts for AutoCAD to verify drawings, close
polylines and do grain boundary rotation. Download and extract the files
contained in this zip file. They should go to the proper directory. Note: it will replace the ACAD.LSP file which
makes no harm if you have not modified it yourself.
It is possible to study the proximity effect present in e-beam
lithography using a simple convolution of a pattern and a beam shape. The
following MATLAB functions perform such calculations.
Regarding the interaction the electron beam with matter and the
scattering processes involved, one can use CASINO, a software developed at
Université de Sherbrooke. It is free and simple to use. Here is an example of a problem definition using multiple layers of
PMMA/SiO2/W/Si.
Set
of alignment marks for 5mm x 5mm chips. This template can be used for both
our standard e-beam lithography grain boundary alignment strategy (cross
alignment marks and rulers) and for photolithography (Moiré patterns and
normal cross alignment marks). |
|
Pattern
example (Josephson junctions of various width) |
|
Dot-matrix
like characters to be used in lithography (normal text does not work) |
Scripts
used in typical bicrystal process -
First lithography (without alignment) Alignment marks
and rulers (low current) Contact pads
(high current) -
Second lithography (with alignment) Josephson
junctions and small features (low current) Connections (high
current) |
|
Scripts
used for mask making (single current) |
|
Scripts
used for mask making (two currents) |
N/A |
Workshop agenda and references: EBL
workshop.ppt
Drawing file format conversion: VLSI Drawings
transferring limitations.ppt
Multiple exposure strategy: Multiple current exposure.ppt
CASINO software: Casino.ppt