Model high-k stacks with interfacial layers and caps. See EOT, capacitance, charge, and fields instantly. Export clean reports for design checks and process comparisons.
| Case | Interfacial Thickness (nm) | Interfacial k | Main Thickness (nm) | Main k | Cap Thickness (nm) | Cap k | Area (um²) | Voltage (V) | Total EOT (nm) |
|---|---|---|---|---|---|---|---|---|---|
| Example A | 0.50 | 3.90 | 4.00 | 20.00 | 1.00 | 7.50 | 12.00 | 1.10 | 1.800000 |
| Example B | 0.70 | 3.90 | 3.50 | 18.00 | 0.00 | 7.50 | 10.00 | 1.00 | 1.458333 |
| Example C | 0.40 | 4.20 | 5.20 | 24.00 | 0.80 | 8.50 | 18.00 | 1.20 | 1.610784 |
Layer EOT contribution: EOTi = ti × (3.9 / ki)
Total EOT: EOTtotal = Σ EOTi
Capacitance density: Cox/A = (ε0 × 3.9) / EOT
Total capacitance: C = (Cox/A) × Area
Stored charge: Q = C × V
Voltage split across each layer: Vi = V × [(ti/ki) / Σ(t/k)]
Field in each layer: Ei = Vi / ti
The calculator assumes ideal series dielectric behavior. It uses silicon dioxide equivalence with k = 3.9.
Effective oxide thickness, or EOT, is a key metric in semiconductor gate dielectric design. It converts a real dielectric stack into an equivalent silicon dioxide thickness. Engineers use it to compare performance across different materials. A lower EOT usually means stronger gate control. That can improve channel electrostatics in advanced transistors.
High-k materials reduce leakage while preserving capacitance. They allow a thicker physical layer than silicon dioxide. That thicker layer limits tunneling current. At the same time, the device can keep a low electrical thickness. This balance is critical in nanoscale CMOS, fin structures, and gate stack optimization.
This calculator estimates total EOT for multilayer dielectric stacks. It also reports capacitance per unit area, total capacitance, stored charge, and voltage distribution. Those outputs help process engineers, device designers, and students. They support fast screening before detailed simulation. They also help validate lab data and process assumptions.
The core idea is simple. Each dielectric layer contributes electrical thickness according to its physical thickness and dielectric constant. A layer with a higher dielectric constant contributes less EOT for the same physical thickness. Interfacial layers still matter. Even a thin low-k interfacial film can raise total EOT noticeably.
Use this tool when comparing hafnium oxide stacks, aluminum oxide layers, silicon oxynitride films, or hybrid dielectric structures. Enter thickness in nanometers and dielectric constants for each active layer. Add gate area and bias when capacitance and charge are needed. The calculator then summarizes layer contributions and total electrical behavior.
Always review the assumptions behind quick estimates. Fringing effects, quantum corrections, interface traps, roughness, and temperature can shift real results. Material constants may also vary by deposition method and anneal history. For design work, treat this calculator as a screening and learning aid. Then confirm results with process data, TCAD, or measured capacitance curves.
Because EOT directly links to inversion capacitance, it influences threshold behavior, drive current, and scaling strategy. Process integration teams often trade leakage, mobility, reliability, and manufacturability against EOT targets. A clear calculator speeds those comparisons. It makes early discussions more consistent. It also creates a reusable record for reports, handoffs, and quick design reviews across multidisciplinary semiconductor teams. During development cycles.
EOT is the silicon dioxide thickness that would provide the same capacitance as a real dielectric stack. It lets engineers compare different gate dielectrics on one common electrical basis.
A lower EOT usually increases gate control over the channel. That can support scaling, stronger inversion, and better electrostatics. Real design choices must still balance leakage and reliability.
No. A thicker layer with a high dielectric constant can still produce a low EOT. That is why high-k materials are attractive in advanced gate stacks.
Its dielectric constant is often much lower than the main high-k film. Even a very thin interfacial layer can noticeably increase total EOT and reduce capacitance density.
Yes. Set the optional cap layer thickness to 0. The calculator will ignore that layer and compute the stack using only the active dielectric layers.
Thickness is entered in nanometers. Area is entered in square micrometers. Voltage is entered in volts. Results include EOT in nanometers, capacitance density in F/m² and fF/um², and field in MV/cm.
No. It is best for early estimates, comparisons, learning, and reporting. Final engineering decisions should include measured data, detailed simulations, and reliability analysis.
The calculator treats the layers as series dielectrics. Voltage divides according to each layer’s thickness-to-dielectric-constant ratio. Higher electrical thickness receives a larger share of the applied voltage.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.