Transfer Length Calculator
Convert specific contact resistivity and sheet resistance into the contact transfer length. Formula: Lt [µm] = 1e4 · sqrt(ρc [Ω·cm²] / Rsh [Ω/sq]). Inputs: ρc > 0 Ω·cm², Rsh > 0 Ω/sq. Output: Lt > 0 µm. Assumes uniform sheet resistance under the contact and the transmission-line model (long contact, negligible metal resistance).
Description
Convert specific contact resistivity and sheet resistance into the contact transfer length. Formula: Lt [µm] = 1e4 · sqrt(ρc [Ω·cm²] / Rsh [Ω/sq]). Inputs: ρc > 0 Ω·cm², Rsh > 0 Ω/sq. Output: Lt > 0 µm. Assumes uniform sheet resistance under the contact and the transmission-line model (long contact, negligible metal resistance).
Transfer Length Calculator is a focused tool for the following task. Convert specific contact resistivity and sheet resistance into the contact transfer length. Formula: Lt [µm] = 1e4 · sqrt(ρc [Ω·cm²] / Rsh [Ω/sq]). Inputs: ρc > 0 Ω·cm², Rsh > 0 Ω/sq. Output: Lt > 0 µm. Assumes uniform sheet resistance under the contact and the transmission-line model (long contact, negligible metal resistance). It reports Transfer length from the values you provide rather than inventing measurements, coefficients, or professional judgment that are not part of the input.
When to use Transfer Length
Use this semiconductor calculation for first-order device, material, fabrication, interconnect, packaging, or reliability estimates when every coefficient and unit convention is known.
- Specific contact resistivity (ohm*cm^2)
- Required number in ohm*cm^2. Specific contact resistivity of the ohmic contact. Must be greater than 0 Ω·cm².
- Sheet resistance (ohm/sq)
- Required number in ohm/sq. Sheet resistance of the semiconductor layer under the contact. Must be greater than 0 Ω/sq.
The cited overview of Semiconductor device supplies background for the terminology and domain context used by this tool.1
How Transfer Length works
Convert specific contact resistivity and sheet resistance into the contact transfer length. Formula: Lt [µm] = 1e4 · sqrt(ρc [Ω·cm²] / Rsh [Ω/sq]). Inputs: ρc > 0 Ω·cm², Rsh > 0 Ω/sq. Output: Lt > 0 µm. Assumes uniform sheet resistance under the contact and the transmission-line model (long contact, negligible metal resistance). Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.
- Transfer length (um)
- Returned number in um. Current transfer length of the contact. At least 0 µm.
Limitations and assumptions
- Material composition, geometry, process history, temperature, electric field, bias, interfaces, parasitics, and fitted parameter ranges can invalidate a compact semiconductor model.
- Specific contact resistivity must be at least 5e-324.
- Sheet resistance must be at least 5e-324.
- 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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Semiconductor device — Wikipedia contributors
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