== Introduction ==
When we hear the words, semiconductor device, we may think first of the transistors in PCs or video game consoles, but transistors are the basic component in all of the electronic devices we use in our daily lives. Electronic systems are built from components such as transistors, capacitors, wires and other electronic devices such as light emitting diodes and semiconductor lasers. These components are typically integrated into a single chip made of a semiconductor material.
Almost every Electrical Engineering department teaches the fundamental concepts of semiconductor devices. These concepts typically include lattices, crystal structure, bandstructure, band models, carrier distributions, drift, diffusion, pn junctions, solar cells,light-emitting diodes, bipolar junction transistors (BJT), metal-oxide semiconductor capacitors (MOS-cap), and multi-acronym-device field effect transistors (mad-FETs).
Advanced courses go more deeply into semiconductor theory, device physics, fabrication processes, and advanced and special purpose devices, such as heterostructure devices, power devices, and optoelectronic devices.
This nanoHUB "topic page" provides an easy access to selected nanoHUB Semiconductor Device Education Material that is openly accessible and usable by everyone around the world.
We invite you to participate in this open source, interactive educational initiative:
* [http://www.nanohub.org/contribute/ Contribute your content] by uploading it to the nanoHUB. (See "Contribute Content") on the nanoHUB mainpage.
* Provide feedback for the items you use on the nanoHUB through the review system. (Please be explicit and provide constructive feedback.)
* Let us know when things do not work for you - file a ticket through the nanoHUB "Help" feature on every page
* Finally, let us know what you are doing and [http://www.nanohub.org/feedback/suggestions/ your suggestions] improving the nanoHUB by using the "Feedback" section, which you can find under "[http://www.nanohub.org/support/ Support]"
Thank you for using the nanoHUB, and be sure to [http://www.nanohub.org/feedback/success_story/ share your nanoHUB success stories] with us. We like to hear from you, and our sponsors need to know that the nanoHUB is having impact.
=== Crystal Structures, Lattices ===
[[Image(/site/resources/tools/crystal_viewer/si.jpg, 120 class=align-left)]] The [[Resource(3741)]] tool enables the interactive visualization different Bravais lattices, and crystal planes, and materials (diamond, Si, InAs, GaAs, graphene, buckyball). It is supported by a homework assignment available in [/site/resources/2008/01/03815/crystal_hw1.doc MS Word] and [/site/resources/2008/01/03816/crystal_hw1.pdf Adobe PDF] format.
=== Band Models / Band Structure ===
==== [[Resource(kronig_penney, nolink)]] ====
[[Image(/site/resources/tools/kronig_penney/allowed_bands_step_well.png, 120 class=align-left)]] The [[Resource(kronig_penney)]] solves the time independent Schroedinger Equation in a 1-D spatial potential variation. Rectangular, triangular, parabolic (harmonic), and Coulomb potential confinements can be considered. The user can determine energetic and spatial details of the potential profiles, compute the allowed and forbidden bands, plot the bands in a compact and an expanded zone, and compare the results against a simple effective mass parabolic band. Transmission is also calculated through the well for the given energy range.
==== [[Resource(1308, nolink)]] ====
[[Image(/site/resources/tools/bandstrlab/bandstrlab.gif, 120 class=align-right)]] The [[Resource(1308)]] tool enables the study of bulk dispersion relationships of Si, GaAs, InAs. The users can apply tensile and compressive strain and observe the variation in the bandstructure, bandgaps, and effective masses. Advanced users can study bandstructure effects in ultra-scaled (thin body) quantum wells, and nanowires of different cross sections. Bandstructure Lab uses the ''sp3s*d5'' tight binding method to compute E(k) for bulk, planar, and nanowire semiconductors.
==== [[Resource(2815, nolink)]] ====
[[Image(/site/resources/tools/strainbands/strainbands2.png, 120 class=align-left)]] [[Resource(2815)]] uses first-principles density functional theory within the local density approximation and ultrasoft pseudopotentals to compute and visualize density of states, E(k), charge densities, and Wannier functions for bulk semiconductors. Using this tool, you can study and learn about the bandstructures of bulk semiconductors for various materials under hydrostatic pressure and under strain conditions. Physical parameters such as the bandgap and effective mass can also be obtained from the computed E(k). We note here that the bandgaps obtained with DFT-LDA are underestimated, by about a factor of two for some semiconductors (including Si and GaAs), as is well known.
=== Carrier Distributions ===
[[Image(/site/resources/2008/01/03885/cd_pg1.jpg, 120 class=align-right)]] The [[Resource(fermi)]] demonstrates electron and hole density distributions based on the Fermi-Dirac and Maxwell Boltzmann equations. This tool shows the dependence of carrier density, density of states and occupation factor on temperature and fermi level. User can choose between doped and undoped semi-conductors. Silicon, Germanium, and GaAs can be studied as a function of doping or Fermi level, and temperature. It is supported by a [/resources/3878/ homework assignment] in which Students are asked to explore the differences between Fermi-Dirac and Maxwell-Boltzmann distributions, compute electron and hole concentrations, study temperature dependences, and study freeze-out.
=== Bulk Semiconductors - Drift Diffusion ===
[[Image(/site/resources/tools/semi/excess_carrier_profile_light_top.png, 120 class=align-right)]] The [[Resource(semi)]] enables a user to understand the basic concepts of DRIFT and DIFFUSION of carriers inside a semiconductor slab using different kinds of experiments. Experiments like shining light on the semiconductor, applying bias and both can be performed. This tool provides important information about carrier densities, transient and steady state currents, fermi-levels and electrostatic potentials. It is supported by two related homework assignements [/resources/4191/ #1] and [/resources/4188/ #2] in which Students are asked to explore the concepts of drift, diffusion, quasi Fermilevels, and the response to light.
=== Semiconductor Process Modeling ===
Semiconductor process modeling is a vast field in which several commercial products are available and in use for production in industry and to some extent in education. nanoHUB is serving a few applications that are primarily geared towards education. The four tools entitled 'Process Lab ...'[/tools/prolabox/ Oxidation], [/tools/prolaboxflux/ Oxidation Flux], [/tools/prolabcdd/ Concentration Dependent Diffusion], and [/tools/prolabdcd/ Point Defect Coupled Diffusion] are all educational front-ends to the general [[Resource(prophet)]] tool.
==== [[Resource(prolabox, nolink)]] ====
[[Image(/site/resources/tools/prolabox/prolabox.gif, 120 class=align-right)]] The [[Resource(prolabox)]] simulates the oxidation process in integrated circuit fabrication. It is supported by a [/site/resources/2006/10/01904/oxidation.pdf supplemental document] that describes the theory and potential experiments that can be conducted.
==== [[Resource(prolaboxflux, nolink)]] ====
[[Image(/site/resources/tools/prolaboxflux/prolaboxflux.gif, 120 class=align-right)]] The [[Resource(prolaboxflux, nolink)]] simulates the oxidation flux in the oxide growth process in integrated circuit fabrication. It is supported by a [/site/resources/2006/10/01905/oxidationflux.pdf supplemental document] that describes the theory and potential experiments that can be conducted.
==== [[Resource(prolabcdd, nolink)]] ====
[[Image(/site/resources/tools/prolabcdd/prolabcdd.gif, 120 class=align-right)]] The [[Resource(prolabcdd, nolink)]] simulates the oxidation flux in the oxide growth process in integrated circuit fabrication.
==== [[Resource(prolabdcd, nolink)]] ====
[[Image(/site/resources/tools/prolabdcd/prolabdcd.gif, 120 class=align-right)]] The [[Resource(prolabdcd)]] the point-defect-coupled diffusion process in integrated circuit fabrication.
==== [[Resource(prophet, nolink)]] ====
[[Image(/site/resources/tools/prophet/prophet.jpg, 120 class=align-left)]] [[Resource(prophet)]] was originally developed for semiconductor process simulation. Device simulation capabilities are currently under development. PROPHET solves sets of partial differential equations in one, two, or three spatial dimensions. All model coefficients and material parameters are contained in a database library which can be modified or added to by the user. Even the equations to be solved can be specified by the end user. It is supported by an extensive set of [/site/resources/tools/prophet/doc/guide.html User Guide] pages and a seminar on [/resources/973/ Nano-Scale Device Simulations Using PROPHET].
==== [[Resource(tsuprem4, nolink)]] ====
[[Image(/site/resources/tools/tsuprem4/tsuprem2.png, 120 class=align-right)]] [[Resource(tsuprem4)]] simulates the processing steps used in the manufacture of silicon integrated circuits and discrete devices. The types of processing steps modeled by the current version of the program include ion implantation, inert ambient drive-in, silicon and polysilicon oxidation and silicidation, epitaxial growth, and low temperature deposition and etching of various materials.
Because of the way TSUPREM-4 is licensed, it is available only to users on the West Lafayette campus of Purdue University. Note that you must use a network connection on campus, or else you will get an 'access denied' message.