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

Material Parameters

• 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)

Wet Etching

• 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.

Refractive Indices

Optical constants of many common materials. Useful for laser etch monitoring, optical filter/mirror/anti-reflection coating design, photonic devices etc.

• LuxPop.com
• RefractiveIndex.info
• Filmetrics Inc.
• Ioffe Institute

Scripts + Programs

Analysis Programs

• FIJI - scientific image anaylsis software
  • This is just ImageJ pre-packaged with many of the most useful plugins
  • The Microscope Measurement Tools plugin allows you to save scaling settings for various microscopes & draw measurements.
  • There are many other useful plugins, for particle counting, creating animations etc.
• Gwyddion - free analysis software for Atomic Force Microscopes (AFMs) and other 3D data.
  • Sophisticated leveling, slicing, roughness analysis functions etc.
  • Can open Bruker NanoScope files, from the AFM
• ProfilmOnline.com (Filmetrics) - online analysis/storage/sharing of 3D topographical data and images.
  • You can share an interactive 3D render of your AFM or Wyko scans with this tool.
  • Example AFM Scan, shared online for interactive analysis (slice, flatten etc.).

CAD Layout Programs

Use these for designing your lithography mask plates.

• L-Edit - 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 Manuals/Software folder.
  • See this L-Edit Tutorial for a good starter guide. Written by Cherry Gupta, courtesy of Prof. Sumita Pennathur.
• KLayout - A free, open-source, and fast/simple CAD tool for mask/reticle layout.
  • 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.
  • 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 because GDS files do not have a "circle" primitive built-in. Make sure you include enough polygon points, eg. 200.
  • ‘Before’ starting your design, set the Layout Properties > Database Unit to something small eg. 0.0001 µm (0.1nm)

General Calculators

• 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".
• 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).

Python Scripts

These scripts are best run in the Spyder IDE, which is easily installed via Anaconda, Python(X,Y), or by directly compiling Spyder using a command-line package manager.

• 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.