Focus-Exposure Matrix (FEM) Analysis

Process Window Optimization & Bossung Curve Analysis

0.35 μm
Depth of Focus (DOF)
12.5%
Exposure Latitude
2.8
Mask Error Factor
1.2
Image Log Slope
Key Physics Equations:
Bossung Curve: CD(f) = CD₀ + α·f + β·f² + γ·f³
DOF = k₂λ/NA² where k₂ = 0.5-1.0
Exposure Latitude: EL = (Emax - Emin)/Enominal × 100%
MEF = (∂CD/∂M) / (∂CD/∂E) × (E/M)
Image Log Slope: ILS = λ/(pitch × NILS)

Process Parameters

Focus Offset (μm) 0.00
Exposure Dose (mJ/cm²) 30
Numerical Aperture (NA) 0.40
σ Inner 0.50
σ Outer 0.80
Pitch (nm) 100
CD Target (nm) 50
Resist Contrast (γ) 8

1. Bossung Curves - CD vs Focus at Different Exposures

2. FEM Matrix - CD Heatmap (Focus × Exposure)

3. Process Window - Acceptable CD Region

4. Exposure Latitude vs Feature Size

5. Depth of Focus vs NA and Pitch

6. Mask Error Factor (MEF) vs Pitch

7. Common Process Window - Multiple Features

3D Resist Profile Visualization