View source for TRACER

TRACER is part of the [[BEAMER]] software package.

Using TRACER you can calculate a point spread function (PSF) for your specific substrate and material stack.
It is done by defining material layers and running a Monte Carlo simulation for a large number of electrons.
The result can be exported for use in Beamer PEC.

[https://www.genisys-gmbh.com/tracer.html Website]

== How to: make a PEC for a new material stack ==
This is a short step-by-step guide. For a more thorough introduction, please check the documentation within Tracer:

''Help > Introduction > Quick Start''
=== Creating a new PSF ===
For a detailed description of the simulation process:

''Help > Setting Up and Running a Simulation''

In Tracer:
# File > New Simulation... (Ctrl-R)
# Make your material stack (substrate, any intermediate layers, resist stack)
#* Get resist thickness either from:
#** Thickness measurement of your spun and baked resist, e.g. stylus profiler over a scratch
#** Estimate from technical data sheet
#**: e.g. PMMA A4 950K is approx. 2000 Å = 200 nm
#* Substrate thickness doesn't matter too much, but better be safe than sorry. Most common substrates at QDev are 500 um.
#*; Substrate thickness is crucial if you're exposing on membranes!
#*: In this case you might need two PSFs, one for membrane, one for full substrate stack.
# Change beam energy and spot size
#* Calculate the beam FWHM using [https://sid.erda.dk/share_redirect/HUEfw6ttjf/index.html Shiv's Unofficial Dose Calculator]
#*: e.g. 100 kV tool, 40 um aperture, 500 pA current gives a spot with FWHM of approx. 2.7375 nm
# Don't make the number of electrons too small. 1 million is OK, more is better but takes time.
#* On Design 5 it's roughly 200 000 electrons per minute.
#* On Design 7 it's roughly 100 000 electrons per minute.
# Don't make the update interval small, it takes away resources from simulation. 60 s is okay.
# Right click the bolded simulation line > Z-Average 2D... > OK
# Right click the averaged PSF > Export PSF...
#: Save in your folder on Z drive

=== Importing the PSF to Beamer ===
In Beamer:
# Double-click any PEC module
# Click Archive
# Click Import...
# Select your file
# Clear the tag or edit it to something concise like your name, or perhaps add extra information. E.g. the current for which you calculated the FWHM or a standard substrate name.
# Click OK
=== Using the new PSF for PEC ===
In Beamer:
# Double-click the PEC module
# Click Archive
# Select the desired PSF
# Click OK
# Done!

== How to: predict base dose for a known process but a different substrate ==
If you want to use an existing resist process for a different substrate:
# Simulate both known and unknown substrates with the same resist stack
# Select representative PSFs to compare in the simulation list for each substrate
# Right click > Dose Factor
# Done!
#: This will not be 100% accurate but will give you an idea for dose test values

Detailed background and instructions [https://www.genisys-gmbh.com/base-dose-factor.html online].