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MOS Virtual Lab Bench
Semiconductor Devices (MOS) · Instructor: Prof. Mohammad Razaghi · University of Kurdistan
Sample: reference device

Instrument

setup

Test structure: square MOS capacitor on the same wafer, area given on the sample datasheet.

Datasets

overlay

No measurements yet. Press Run.

Display
Analysis on
Hover a curve to read values. Use the analysis tools to fit lines and extract parameters.

Inside the device

at the cursor bias

Cross-section is schematic (not to scale): depletion depth and inversion-layer density are computed from the model at the bias point under the cursor. Watch them change while a sweep is running.

Experiment guide

lab manual

Student

Your Student ID also selects your personal mystery sample on the Samples tab.

Summary of extracted parameters

Saved plots

added from the bench

Discussion notes

per experiment

Choose the sample on the probe station

The same ID always gives the same wafer, so your instructor can check your results.

θ adds vertical-field mobility degradation and λ adds channel-length modulation. Both are zero in the book's long-channel model (Chapter 4), and small but non-zero on the mystery wafers to make the extraction realistic.

Sample datasheet

Instructor

Answer key for a student's mystery sample

The code is UOK-MOS (tell students only after grading). This offline file is not a secure exam tool: the parameters can be computed by anyone who reads the source.

About this virtual lab

The bench simulates a semiconductor parameter analyzer (four source-measure units on gate, drain, source and body) and a C–V meter connected to a probe station. The "measured" data come from the physical models of Tsividis & McAndrew, Operation and Modeling of the MOS Transistor, the course textbook:

  • C–V: the exact two-terminal MOS relation with holes and electrons (Chapter 2, eqs. 2.4.19–2.4.24). Quasi-static C follows all charges; the 1 MHz curve lets only holes and the depletion charge respond.
  • I–V: the complete all-region charge-sheet model (Chapter 4, eqs. 4.3.14–4.3.15), valid from weak through moderate to strong inversion without any region switching. The source and drain surface potentials are found numerically.
  • Temperature: ni(T) ∝ T3/2e−Eg/2kT, φt = kT/q, µ ∝ T−3/2, and the gate–body work-function difference follows ΦF(T).
  • Instrument realism: a current floor of ~0.1 pA with gain noise of ~0.03 %, drain-junction generation leakage that grows with ni(T), and C–V noise of ~0.02 pF.

Real-device effects that are outside the long-channel model (short-channel effects, velocity saturation, series resistance, interface traps) are not included, except the optional θ and λ factors.

Everything runs inside this single file, without an internet connection. Your notebook (results, notes and saved plots) is kept in this browser on this computer. Download the report to hand it in.

Prepared for the graduate course Semiconductor Devices (MOS) · Instructor: Prof. Mohammad Razaghi · University of Kurdistan.