MOSFET TCAD Simulation & SPICE Parameter Extraction

This repository contains a complete 2D numerical simulation of an N-channel MOSFET using Silvaco Victory Device (executed via nanoHub). The project automates the extraction of essential DC, saturation, and short-channel SPICE parameters using advanced syntax blocks directly from simulated electrical behavior.

📐 Simulated Device Physical Profile

Based on the DeckBuild mesh and region geometry, the simulated NMOS physical specifications are:

• Gate Length ($L_g$): $0.6\text{ }\mu\text{m}$ (Gate electrode spanning $x = 0.2$ to $x = 0.8$)
• Gate Oxide Thickness ($T_{ox}$): $100\text{ }\text{Å}$ ($0.01\text{ }\mu\text{m}$, from $y = 0.0$ to $y = 0.01$)
• Substrate / Bulk Doping ($N_A$): P-type, $1 \times 10^{17}\text{ cm}^{-3}$ (Uniform)
• Source/Drain Doping ($N_D$): N-type Gaussian profile, Peak $1 \times 10^{20}\text{ cm}^{-3}$

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📊 Automated SPICE Parameter Extraction Results

The simulation executes targeted sweeps to extract key mathematical parameters used in SPICE models:

1. Linear Region Parameters ($V_{ds} = 0.05\text{ V}$)

• Vt_lin: Linear Threshold Voltage extracted via the maximum slope intercept method, adjusted for $V_{ds}/2$.
• gm_max: Maximum transconductance ($g_m = \frac{\partial I_d}{\partial V_{gs}}$).
• gm_over_Id: Sub-threshold efficiency index ($\frac{g_m}{I_d}$).

2. Saturation Region Parameters ($V_{ds} = 2.0\text{ V}$)

• Vt_sat: Saturation Threshold Voltage extracted via the $V_{gs}$ vs $\sqrt{I_d}$ intercept method.
• gm_max_sat: Peak transconductance under strong saturation conditions.

3. Channel & Output Parameters (Extracted at $V_{gs} = 2.5\text{ V}$)

• ro: Output Channel Resistance ($r_o = \frac{\partial V_{ds}}{\partial I_d}$) evaluated at peak bias conditions.
• lambda ($\lambda$): Channel Length Modulation parameter ($\lambda = \frac{1}{r_o \cdot I_{d,sat}}$) extracted from the maximum $I_d\text{-}V_{ds}$ swing.

4. Substrate Body Effect Parameters

• Vt_bs0: Base Threshold voltage at zero body bias ($V_{bs} = 0\text{ V}$).
• gamma_calc ($\gamma$): Body effect parameter calculated analytically using substrate parameters and gate oxide capacitance ($C_{ox} = 3.45\text{ fF/}\mu\text{m}^2$).

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📈 Generated Characterization Plots

Note: Visual outputs exported directly from Silvaco TonyPlot.

Transfer Characteristics ($I_d$ vs $V_{gs}$)

Normal / Linear Scale	Saturation Region ($V_{ds} = 2.0\text{V}$)	Log Scale (Subthreshold)

Output Characteristics ($I_d$ vs $V_{ds}$)

Body Effect Threshold Voltage Shift ($V_{bs}$ Modulation)

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🛠️ Execution Instructions

1. Clone this repository to your local environment or workspace.
2. Upload the simulation/mosfet_characterization.in file to your Silvaco DeckBuild session inside nanoHub.
3. Click Run.
4. Upon successful completion, the runtime terminal output window will print the precise numeric values for all the custom extract parameters (Vt_lin, lambda, ro, etc.).
5. Open any generated .log file inside TonyPlot to inspect the curves visually.