Subthreshold Swing Calculator
Compute MOSFET subthreshold swing from absolute temperature and the depletion-to-oxide capacitance ratio using S = ln(10) kT/q (1 + Cdep/Cox).
Description
Compute MOSFET subthreshold swing from absolute temperature and the depletion-to-oxide capacitance ratio using S = ln(10) kT/q (1 + Cdep/Cox).
Subthreshold Swing Calculator is a focused tool for the following task. Compute MOSFET subthreshold swing from absolute temperature and the depletion-to-oxide capacitance ratio using S = ln(10) kT/q (1 + Cdep/Cox). It reports Subthreshold swing from the values you provide rather than inventing measurements, coefficients, or professional judgment that are not part of the input.
When to use Subthreshold Swing
Use this semiconductor calculation for first-order device, material, fabrication, interconnect, packaging, or reliability estimates when every coefficient and unit convention is known.
- Depletion-to-oxide capacitance ratio
- Required number. Ratio of depletion capacitance to oxide capacitance.
- Temperature (K)
- Optional number in K. Absolute device temperature.
The cited overview of MOSFET supplies background for the terminology and domain context used by this tool.1
How Subthreshold Swing works
Compute MOSFET subthreshold swing from absolute temperature and the depletion-to-oxide capacitance ratio using S = ln(10) kT/q (1 + Cdep/Cox). Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.
- Subthreshold swing (mV/decade)
- Returned number in mV/decade. Subthreshold swing in millivolts per decade.
Limitations and assumptions
- Material composition, geometry, process history, temperature, electric field, bias, interfaces, parasitics, and fitted parameter ranges can invalidate a compact semiconductor model.
- Depletion-to-oxide capacitance ratio must be at least 0.
- Use finite inputs in the displayed units, preserve source measurements and assumptions, and independently verify consequential decisions.
Alternative or Complementary approaches
Compare the estimate with measured process data, current device documentation, and a higher-fidelity circuit, field, thermal, quantum, or TCAD model when the decision requires it.
References
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MOSFET — Wikipedia contributors
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