Microfabrication Processes
General Information
The Process of Fabricating a MOSFET
This tutorial shows the basic steps involved in creating an N-MOS transistor
Chemistry Recipe Calculators ('Moles to Anything')
This page includes many helpful calculators for calculating measurements in chemical recipes.
Photolithography Resources
Lithography Materials
Information on photoresists, adhesion promoters, and spin-on materials used in the IML.
A table of many photoresists with information about them and their manufacturers.
Photoresist Recipes (Lithography Chemicals and Materials)
Information about the different photoresists, adhesion promoters, and spin-on materials used in the IML, including recipes and spin speeds.
This page includes the basics of SU-8 recipes and many specific recipes for SU-8.
Here are some tips for improving AZ 3330 adhesion to a glass substrate.
Lithography Procedures
Contains a basic lithography tutorial, a tutorial for mask alignment, and step by step instructions for doing lithography in the IML.
Basic Interactive Lithography Tutorial
A simple tutorial on the basics of the photolithography process.
Photoresist Photolithography Procedures
Step by step directions for using photoresist for photolithography.
Mask Alignment Tutorial
A tutorial for learning the mask alignment procedure.
Definitions of common lithography terms.
Photomasks
Contains a tutorial for designing photomasks using Cadence and instructions on getting a photomask fabricated here in the IML or through an outside company.
Mask Design
We usually design our photomasks with Cadence. This is a tutorial on using Cadence.
High resolution printing can be used as a lower-cost solution to make photomasks with features down to 50 microns.
In-House Mask Production (Pattern Generator)
We can produce our own photomasks with the pattern generator in the IML.
Links to several commercial photomask production facilities.
Thin Film Deposition and Growth
The Ellipsometry calculator uses the P1, A1, P2, and A2 angles found using an ellipsometer to calculate delta, psi, index and thickness. A "Time and Rate Calculator" is also included; it uses the thickness calculated from the Ellipsometry calculator along with the test wafer growth time and desired thickness to calculate the rate of growth and the time needed to grow the desired thickness at that rate.
Recipies for Plasma Enhanced Chemical Vapor Deposition of silicon nitride, silicon dioxide, amphorous silicon, and silicon oxynitride.
Information on different methods of metal deposition including E-beam evaporation, thermal filament evaporation, and sputtering. Also includes information on deposition uniformity and step coverage.
Thin Film Evaporation Reference
This guide lists many properties of common thin film materials including density, Z-ratio, melting point, vapor pressures. Preferred evaporation methods and crucible liners are also listed.
Oxide Growth Resources
Input the initial and desired thickness, temperature, crystal orientation, and environment to calculate the thermal oxide growth time on silicon.
Enter the initial thickness, temperature, crystal orientation, environment, and time to determine final thickness of thermally grown oxide on silicon.
Oxide Film Color Calculator and Chart
Determines the visible color for silicon dioxide and silicon nitride films given the film thickness and viewing angle.
Etching Resources
Chemical Etching
This guide provides information on etching metals and semiconductors including mixing ratios of different etchants.
Selective Chemical Etching
A list providing some general etch information. Specific etches of certain materials are given, along with information about what else should or should not be etched by the etchant. Some etch rates are provided.
Wet Chemical Etching of Metals and Semiconductors
A comprehensive list of etchants for over 50 different metals, semiconductors and cleanroom materials. Some etch rates are given.
Etch rates For silicon, silicon nitride, and silicon dioxide in varying concentrations and temperatures of KOH.
Etch rates and products for semiconductor etching. All information is from Transene. Also includes links to other Chemical Etching Companies.
Directions for cleaning substrates to remove organic, oxide, and metallic contaminants
Explains the process of Reactive Ion Etching and lists recipes for etching of different materials, including silicon, silicon nitride, silicon dioxide, and photoresist.
Semiconductor Doping Resources
Diffusion Calculator and Graph
Calculate impurity and dopant concentrations at various depths in silicon, gallium arsenide, and other semiconductor substrates for intrinsic diffusion. This calculator includes both constant-total and constant-surface concentration profiles! Interactive graph plots the impurity concentration vs. substrate depth or diffusion profile for various input parameters such as annealing temperature and time.
Ion Implant Resources
Calculators and interactive graphs for ion implantation profiles, projected range and straggle, and ionization breakdown for various dopants and substrates. Also provides links to some commercial ion implantation houses.
Ion Implantation Profile Calculator
Arsenic, Boron, and Phosphorous implantation into silicon substrates. Diffusion can also be calculated. Interactive graph plots up to six implants and their sum. Data available in CSV format.
Projected Ion Range and Straggle Calculator
Calculate the projected range and straggle for ion implantation of various dopants, substrates, and ionization energies.
Provides links to several ion implantation houses and other services.
Silicon Wafer Bonding
A simple instructional guide to the basic steps of silicon wafer bonding.