Use this semiconductor calculation for first-order device, material, fabrication, interconnect, packaging, or reliability estimates when every coefficient and unit convention is known.

Mobility (cm^2/Vs)

Required number in cm^2/Vs. Low-field carrier mobility. Must be greater than 0 cm²/V·s (magnitude only; signed mobility not supported).

The cited overview of Electron mobility supplies background for the terminology and domain context used by this tool.^[1]

Estimate the ballistic mean free path from low-field mobility using λ = (μ·Vt/vsat)·1e7 with thermal voltage Vt=0.02585 V (300 K) and saturation velocity vsat=1e7 cm/s (λ[nm]=μ·0.02585). Input mobility μ>0 cm²/V·s must be the low-field, non-degenerate value; rpm vs linear-velocity and per-area vs total distinctions do not apply. Model assumes Maxwell-Boltzmann statistics and constant vsat, valid only near 300 K as a quasi-ballistic estimate. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Mean free path (nm)

Returned number in nm. Ballistic mean free path (magnitude). At least 0 nm.

• Material composition, geometry, process history, temperature, electric field, bias, interfaces, parasitics, and fitted parameter ranges can invalidate a compact semiconductor model.
• Mobility must be at least 5e-324.
• Use finite inputs in the displayed units, preserve source measurements and assumptions, and independently verify consequential decisions.

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.

• APB Energy Calculator

  Calculate the antiphase boundary (APB) energy per unit area (mJ/m²) from the per-atom APB energy (eV/atom) and the planar atomic density (1/nm²). Model: E = apbEnergyPerAtom × atomDensity × 160.2176634 mJ·m⁻²/(eV·nm⁻²); assumes an ideal planar APB with uniform density. Per-area result is not the total boundary energy (multiply by area for total energy). apbEnergyEvPerAtom must be ≥0 eV (0 yields 0 mJ/m²); atomDensityPerNm2 must be >0 1/nm². No relaxation, segregation, or temperature dependence is included.

• APD Breakdown Voltage Temperature Shift Calculator

  Shift an APD breakdown voltage to operating temperature using the linear temperature coefficient model V(T)=Vref·[1+0.0011·(T-25 °C)]. Valid for reference breakdown Vref>0 V defined at 25 °C and junction temperature T in [-55, 175] °C inclusive; outside this range the 0.11%/°C linear approximation degrades. Vref is the breakdown magnitude (positive, not signed). Result is the breakdown magnitude at temperature. Device-specific tempco may vary.

• BJT Base Width Modulation Calculator

  Quantify BJT base-width modulation (Early effect) from the reverse-biased collector-base junction: fractionalChange = (sqrt(Vbi+VCB)-sqrt(Vbi))·sqrt(2·εSi/(q·NA)) / Wb, with Vbi=builtInVoltageV>0 V, VCB=collectorBaseVoltageV>=0 V, NA=acceptorDopingPerCm3>0 cm^-3, Wb=baseWidthUm>0 um, εSi=11.7·ε0 F/cm, q=1.602e-19 C. Uses stable sqrt difference; checks total voltage finiteness and depletion-factor overflow. One-sided abrupt-junction approximation neglecting emitter side and non-uniform doping; valid for NA not too low and moderate VCB; result >=0, zero when VCB=0.