List of Simulation Applets

1. Crystal Structure
•  Zincblende and Diamond structures ( GaAs, Si, etc.) : unitcell with lists of material property. It shows a 3D view of the unitcell and a 3D view of the covalent bonds.
  
  
2. Energy Bands and Charge Carriers
• Visualization of diffusion, drift and recombination of excess minority carriers in a semiconductor. tried to improve, June 1998.
• Indirect recombination via an energy state in the band gap. It also introduces the four basic processes in the Shockley-Read-Hall statistics.
• AlGaAs: Band diagram and E-K diagram
  
  
3. Charge Carriers and Fermi Level [Semiconductor Statistics]
• Fermi Function and Localized Energy States and the Temperature effect.
• Carrier Concentration vs. Fermi Level and the doping of donor and acceptor impurities. improved June 1998. improved, Nov98
• Carrier Concentration vs. Fermi Level and the Density of States New, Dec.98
• Moderate-doping vs. Heavy-doping [non-degenerate vs. degenerate] new Dec98
  
  
4. Charge Supply/Injection thru Junctions, and Charge Neutrality.
• Semiconductor as a container of electric charge.
• Carrier supply by an Ohmic contact (junction)
• Carrier supply by a Forward-biased pn junction.
• Carrier supply by a Reverse-biased pn junction.
• A semiconductor contacted by two junctions.
  
  
5. PN Junction Diode at Equilibrium
• A graphical illustration of the formation of a PN junction diode and its band diagram. It shows both the band diagram and a schematic cross-section of the device as the junction approaches its thermal equilibrium.
• PN junction diode, space charge profile and electric field. It shows a cross-section of the sample, space charge and the electric field in depletion layer as the junction approaches the thermal equilibrium. Jan.27, 1999.
  
  
6. PN Junction Diode under Applied Bias Voltage
• Biased PN Junction: band diagram, diffusion and drift currents, etc.  It shows both the energy band under bias and the animated carriers flowing across the junction.  With a quiz.  Improved June 1998.
• Space charge and electric field in biased PN junction. Jan.28, 1999.
• [Current flow in forward-biased pn junction It shows an animated flow of carriers in a simplified band. Will be removed soon ...]
• PN junction diode: C-V and I-V.  Aug. 1999 (java1.1)
• PN junction and Schottky diodes: I-V. Aug. 1999 (java1.1)
  
  
7. Device Application of PN Junction
• Photodetector, Solar Cells, Rectifier, LED, Laser Diode
  
  
8. PNP or NPN Bipolar Junction Transistor (BJT)
• Short-base vs. long-base BJT. Mar. 1999
• Charge Flow into/out-of the Base region. Mar.1999
• BJT Dynamic Operation (Switching). Aug.1999 (java1.1), modified Oct.1999. (original version)
  
  
9. Device Fabrication
• PN Junction Diode : a multimedia approach to the fabrication steps. May 19, 1997
• n-channel MOSFET, both side-view and top-view and full Photoresist steps.   
• BJT-FET pair on the same chip, side-view and full Photoresist steps.
• CMOS Inverter, side-view, an abstract device fabrication steps.
• Fabrication @ various companies.
  
  
10. Metal-Oxide-Semiconductor (MOS) FET     
• Summary  Three applets on enhancement MOS: Inversion channel threshold by gate bias; dependence on gate-source bias V_gs and gate-drain bias V_gd; and the output characteristics. (Java1.0) April 7, 1998; Java1.1 version.
• Individual applets:
• Channel ON-OFF behaviors. Inversion channel threshold control by the gate bias. (Java1.0) March 18, 1998 ;  Java1.1 version. March 19, 1998
• Channel ON-OFF by Vgs, Pinchoff-Continuous by Vgd. The dependences of inversion channel and the drain current I_d on the gate-source bias V_gs and on the gate-drain bias V_gd. (Java1.0) March 18, 1998;   Java1.1 version. March 31, 1998
• Device cross-section and Output characteristics (I_d vs. V_gs, V_ds) The MOSFET output characteristics. April 6, 1998 ;  Java1.1 version April 6, 1998
• Planar device structure
  
  
11. MOS Capacitor
• Principles of MOS Capacitor
• MOS Charge-Energy Band with bias control. (Charge and Energy band: accumulation, depletion, inversion) June 1998.
• MOS Charge-Field-Potential  with bias control. Sound effect. June 1998.
• MOS Charge-Energy Band, equilibrium state. Sound effect. June 1998.
• MOS Charge-Field-Potential, equilibrium state. Sound effect. June 1998.
• the Body effect.
  
• Discussions on Threshold Voltage (borwser: IE4.0, or Net4.0 w. Java: 1.1 patch)
• Work Function difference between Gate Metal and Si.   (java1.1.).  April 1997, modified April 1998.
• A MOS calculation tool for Flat-Band Voltage (V_FB) and the Threshold Voltage (V_T)  (java 1.1.).  May 15, 1997, modified April 1998.
  
  
12. Junction Field Effect Transistor (JFET)
• Output characteristics, Device cross-section, Circuit diagram.Nov. 1998.
  
  
13. Heterojunctions
• Energy band diagrams
• Laser, LED, PD
  
  
14. Simple circuits: amplifiers with BJT and MOSFET
• Single-stage amplifier
  
  
15. Digital Circuits
• CMOS Inverter : The V_T-matching issues (for the design of threshold voltage of MOSFET).  May 14, 1997
  
  
16. Applets on Transistors (incomplete):
• n-channel MOSFET drain characteristics .
  
  
17. Device Fabrication and Processing Technology (incomplete)
•  Self-aligned gate technology versus the conventional processing of MOSFET.
  
  
18. Problems general to Semiconductor Devices (incomplete)
• Space charge, electric field, and potential profile. With quizes.
  
  
19. A Comprehensive List of Topics for Applets

Solid State, Microelectronics, etc.:

• Website Links for Solid State, Semiconductor Processes, etc.
• Thermoelectric effect, thermoelectric device.
• Photoelectric effect.
• Qualitative analysis of Analog Circuits.
• Simple circuit theory.
• EM Wave in Waveguide.
• Scaling function and wavelet for a low-pass filter.
• Various CMOS Gates by J.C.Dufourd.
• KV Diagram and Logic Minimization.
• Logic: DL, RTL, DTL, TTL, ECL, CMOS

Miscellaneous Educational Applets:

• Random Numbers: transformation of uniform deviates to linear deviates.
• Binary Representation and Bitwise Operators
• Mathematical applets

Other interesting educational applets (engineering)

Here are links to some very good educational applets in electrical engineering and in other disciplines.

• Simulation of various CMOS gates
• Simulation of basic CMOS gates with explanatory text
• Digital Simulator (source code included)
• Eddy current simulator
• Numerical simulation of Lorentz equation
• The Normal Distribution
• Interactive Amplitude Modulation Model

Links to Simulation and Semiconductor Web Sites

• National Center for C omputational Electronics
• IBM-DAMOCLES Project
• Stanford TCAD
• HP's Educator's Corner Website
• Educational Object Economy