High-NA EUV Lithography Simulator

Research and education simulator for 0.55 NA EUV lithography. The project models the path

source -> illuminator -> reflective mask -> projection optics -> wafer -> resist -> correction

with reduced Fourier optics, partial coherence, wafer defocus, Mask 3D approximations, resist models, and SMO/PMWO/OPC/ILT optimization helpers.

This repository is designed for study, visualization, parameter sweeps, and qualitative understanding. It is not an industry-grade scanner replica and does not claim real-equipment 1:1 validation.

Start Here

Goal	Read / Run
Install and run the first simulation	docs/getting_started.md
Understand the project scope and remaining work	PROJECT_OVERVIEW.md
Learn how the validation and 3D demo notebooks are built	docs/3d_implementation_guide.md
Inspect the phase-by-phase physics decisions	docs/phase1_design.md, docs/phase2_illumination_design.md, docs/phase3_design.md, docs/phase4_M3D_design.md, docs/phase5_resist_models.md, docs/phase6_optimization_design.md
Run all tests	python3 -m pytest tests/ -v
Open the first notebook	jupyter lab notebooks/0_first_aerial_image.ipynb

Quick Start

python3 -m pip install -r requirements-dev.txt
python3 -m pytest tests/ -v
jupyter lab notebooks/0_first_aerial_image.ipynb

If you only want to check that the code imports and the most important simulation path works:

python3 -m pytest tests/integration_end_to_end.py -v

Recommended Learning Path

1. Run notebooks/0_first_aerial_image.ipynb to see the basic mask -> aerial-image path.
2. Run notebooks/4a_threshold_resist.ipynb to close the aerial image -> printed resist path.
3. Run the validation notebooks. The focus and resist notebooks start with 2D heatmaps/line plots for physical checks, then keep 3D surfaces as demo-only views:
   • notebooks/3d_focus_stack.ipynb
   • notebooks/3d_pupil_wavefront.ipynb
   • notebooks/3d_resist_depth.ipynb
4. Run notebooks/5_SMO_PMWO.ipynb to see the SMO/PMWO/OPC/ILT optimization loop.
5. Read docs/3d_implementation_guide.md if you want to add a new 3D visualization.

What Is Implemented

Phase	Scope	Status	Main files
1	Scalar Fourier optics MVP	Complete	src/aerial.py, src/pupil.py, src/mask.py
2	Source shapes and partial coherence	Part 01 complete	src/illuminator.py, data/source_shapes/basic_sources.json
3	Wafer topography and DOF	Complete through k2 fitting	src/wafer_topo.py, src/dof.py
4	Mask 3D effects	Part 04 complete	src/mask_3d.py, data/mask3d_lookup/
5	Threshold, blur, depth, stochastic resist	Complete through calibration gates	src/resist_threshold.py, src/resist_blur.py, src/resist_depth.py, src/resist_stochastic.py
6	SMO / PMWO / OPC / ILT	Part 04 complete	src/smo.py, src/pmwo.py, src/ilt.py, src/opc.py

Notebook Map

Notebook	Purpose	Best first question
0_first_aerial_image.ipynb	Phase 1 coherent aerial image	What does the first image solver output look like?
1_partial_coherence.ipynb	Phase 2 source-shape comparison	How do point/annular/etc. sources change contrast?
3d_focus_stack.ipynb	2D focus heatmap, contrast curve, and demo-only 3D surface	How does defocus reshape intensity?
3d_pupil_wavefront.ipynb	3D Zernike wavefront comparison	What do pupil aberration modes look like?
3d_resist_depth.ipynb	2D x-depth dose validation and demo-only 3D surface	How does dose attenuate through resist?
3_M3D_effects.ipynb	Reduced Mask 3D effects	What qualitative M3D knobs are modeled?
4a_threshold_resist.ipynb	Threshold resist MVP	How does aerial intensity become printed pattern?
4b_resist_levels.ipynb	Blur/depth/stochastic resist	How do resist refinements change CD/EPE/LWR?
5_SMO_PMWO.ipynb	Optimization demo	How do SMO/PMWO/OPC/ILT candidates improve a target?

Common Commands

# Full local validation
python3 -m ruff check src tests
python3 -m mypy src --ignore-missing-imports
python3 -m pytest tests/ -v --tb=short --cov=src --cov-report=term-missing

# Run one phase
python3 -m pytest tests/phase6_smo.py tests/phase6_pmwo.py tests/phase6_ilt.py tests/phase6_opc.py -q

# Execute a notebook headlessly
MPLBACKEND=Agg jupyter nbconvert \
  --to notebook \
  --execute notebooks/3d_focus_stack.ipynb \
  --output-dir /tmp/high_na_euv_nbcheck \
  --ExecutePreprocessor.timeout=120

Validation And 3D Implementation

The current visualization workflow uses Matplotlib, not a browser rendering engine. Focus and resist validation should be read from 2D heatmaps and line plots; 3D surfaces are kept as demo views after the validation cells.

For the full implementation pattern, extension checklist, and validation commands, read docs/3d_implementation_guide.md.

Project Documents

• docs/getting_started.md - installation, first run, troubleshooting, and suggested reading path.
• docs/3d_implementation_guide.md - how the 2D validation plots and demo-only 3D notebook views are implemented.
• PROJECT_OVERVIEW.md - inventory, roadmap, remaining work checklist, and operating context.
• PROJECT_PLAN.md - phase plan, KPI tracking, deliverables, risk register, and change history.
• references/papers/README.md - reference-paper index and study notes.
• audits/AUDIT_LOG.md - audit history and test-count progression.
• docs/study_grade_relaxation.md - why this project uses study-grade gates rather than industrial validation gates.
• docs/github_claude_automerge_setup.md
  • repository automation and merge policy.

License

Research and education use. Commercial use requires separate agreement.