Gate Oxide Thickness Calculator

Inputs

Pick a method, enter values, then submit.

ε0 = 8.854187817×10⁻¹² F/m

Method *

Choose based on your available measurements.

Relative permittivity, k *

Use 3.9 for SiO₂. Enter your dielectric’s k.

Output unit

Result always includes nm and Å too.

Cox (capacitance per area) *

Cox unit

Tip

If you only know C and A, use “C and A”.

Capacitance, C *

C unit

Area, A *

Area unit

What this does

Computes Cox = C/A, then tox = εox/Cox.

EOT (SiO₂ equivalent) *

EOT unit

High‑k permittivity, k_high‑k *

Used only for EOT conversion.

Voltage across oxide, V_ox *

Tip

If V splits, use the oxide voltage component.

Electric field, E_ox *

E unit

Field method note

Good for quick estimates when E-field is known.

Reset

Formula used

Four common ways to estimate gate oxide thickness.

How to use this calculator

Example data table

Case	Method	Inputs	Output (approx.)
1	Areal Cox	Cox = 3.45 µF/cm², k = 3.9	tox ≈ 1.0 nm
2	C & A	C = 250 pF, A = 0.01 cm², k = 3.9	tox ≈ 1.38 nm
3	EOT	EOT = 1.0 nm, khigh‑k = 20	tox ≈ 5.13 nm
4	Field	Vox = 1.0 V, Eox = 10 MV/cm	tox ≈ 1.0 nm

Examples are illustrative and depend on measurement conditions.