Calculators + Utilities
This page lists a few online calculators and utilities that are useful to lab users.
Fabrication Processes & Converters
- Thermal Oxide Calculator (BYU)
- Thermal Oxide Calculator (Leland Stanford Jr.)
- This Thermal Ox calculator allows you to tweak the calculation using the Partial Pressure variable, to match your experimental data.
- Conversion of Pressure Units (calculatoredge.com)
- Mean Free Path tables (Pfeiffer Vacuum)
- LelandStanfordJunior.com: Film Stress, Ion Implant, Thermal Oxidation, KOH Etching & online curve-fitting
- WebElements: Compounds
- Boiling points of various compounds can tell you how volatile an etch product may be in a reactive ion etch, or whether they need to be wet-etched instead.
- Physical Properties of Semiconductors (Ioffe Institute)
- Transene Inc. Chemical Compatibility Chart
- This table shows common metals and which Transene etchants they are attacked by/impervious to.
- A.R. Clawson, "Guide to references on III±V semiconductor chemical etching", 2001
- Enormous review of published wet etches of many semiconductors and alloys. The only thing it's missing is a hyperlinked table of contents.
Optical constants of many common materials. Useful for laser etch monitoring, optical filter/mirror/anti-reflection coating design, photonic devices etc.
Scripts + Programs
- FIJI - scientific image anaylsis software
- Gwyddion - free analysis software for Atomic Force Microscopes (AFMs) and other 3D data.
- Sophisticated leveling, slicing, roughness/particulate analysis functions etc.
- Can open Bruker NanoScope files, from the AFM
- ProfilmOnline.com (Filmetrics) - online analysis/storage/sharing of 3D topographical data and images.
CAD Layout Programs
Use these for designing your lithography mask plates.
Powerful multi-layer layout program. Sophisticated object instantiation and array layout, to reduce files sizes and easily push changes to multiple cells.
- The NanoFab will provide a network license for academic users.
- Windows only.
- Log into the NanoFiles SFTP server, and download L-Edit & Install instructions from the
- See this L-Edit Tutorial for a good starter guide. Written by Cherry Gupta, courtesy of Prof. Sumita Pennathur.
A free, open-source, and fast/simple CAD tool for mask/reticle layout. Download at klayout.de.
- Available on Windows, Mac or *Nix.
- Easily scriptable with Python or Ruby, with decent tutorials.
- Fast and very effective viewing of layer overlay, overlay multiple files, cell hierarchy etc.
- ‘Before’ starting your design, set the Layout Properties > Database Unit to something small eg. 0.0001 µm (0.1nm).
- The only confusing part about KLayout is how to draw circles. You have to draw a square, and then apply the Edit>Selection>Round Corners function. This is for compatibility, because GDS files do not have a "circle" primitive built-in. Make sure you include enough polygon points, eg. 200. See the forum help pages on this for more info.
CAD Design Tips
It is highly recommended that you understand and use the concept of "Cells" in your design. This circumvents many problems with enormous file sizes (due to huge numbers of identical polygons), and if used properly, helps tremendously with programming the Stepper lithography machines. Links to documentation below:
- Create a new cell, and instancing that cell: KLayout Docs : Creating a Cell instance
- Viewing only some levels of the heirachy, to prevent drawing all objects: KLayout Docs: Viewing Cell Heirarchy
- Anaconda Python
- A free Matlab-like IDE and GUI, using the Python language. The Spyder interface is modeled after Matlab.
- Includes the scientific Python libraries needed for array math (numpy), plotting (matplotlib), data science (pandas) and many others. Many open-source packages are available to extend capabilities. The PyVisa module adds equipment control capabilities for automated measurements.
- Octave Online Interpreter (online-utility.org)
- A Matlab-like command-line interface, powered by Python Octave.
- Wolfram Alpha
- A versatile online interpreter/calculator, allowing calculations such as "Volume of 1.5g of Silicon", "melting point of SiO2" or "520°C in Fahrenheit".
- Keithley I-V Sweep
- Sweep voltage and plot current vs. voltage using a Keithley SMU.
- Already installed at the Probe Station in Bay 4, and on the QFI Thermal Microscope (Use Python(X,Y) to run).
- Requires the pyvisa python module.
- QFIScope Thermal Analysis
- Import 2D temperature data from the IR Thermal Microscope (QFI) and plot temperature profiles at user-specified locations.
- Already installed on the QFI Infrared Microscope.
- Laser Etch Monitor Simulation in Python
- Simulate your laser endpoint signal as you dry-etch through a stack of thin-film layers, using an open-source electromagnetics module.
- nk.py (Demis D. John)
- Python functions for returning n (ref. idx.) & k (ext. coeff.) of various NanoFab thin-films at a specified wavelength (aka. dispersion models).