{
  "schema": "semiagora.process-simulation.v1",
  "experiment_id": "SA-PROC-PVD-EVAP-LINEOFSIGHT-001",
  "title": "Thermal and e-beam evaporation line-of-sight thickness",
  "execution_mode": "precomputed-only",
  "model_boundary": "Educational source-to-wafer geometry replay. It is not a calibrated e-beam/thermal evaporator recipe, material vapor-pressure model, or step-coverage guarantee.",
  "process": {
    "family": "physical vapor deposition",
    "method": "thermal / e-beam evaporation",
    "nominal_center_thickness_nm": 100,
    "wafer_radius_mm": 50,
    "tracked_knobs": [
      "source distance",
      "wafer radius",
      "cosine emission profile",
      "planetary or static mounting",
      "line-of-sight shadowing"
    ]
  },
  "radius_mm": [-50, -40, -30, -20, -10, 0, 10, 20, 30, 40, 50],
  "cases": [
    {
      "id": "long-throw-450mm",
      "label": "Long throw / 100 mm wafer",
      "description": "A point-source-style replay where a long source distance keeps the radial geometry penalty modest.",
      "normalized_thickness_percent": [97.9, 98.7, 99.3, 99.7, 99.9, 100, 99.9, 99.7, 99.3, 98.7, 97.9],
      "thickness_nm": [97.9, 98.7, 99.3, 99.7, 99.9, 100, 99.9, 99.7, 99.3, 98.7, 97.9],
      "center_to_edge_drop_percent": 2.1,
      "half_range_nonuniformity_percent": 1.06
    },
    {
      "id": "short-throw-200mm",
      "label": "Short throw sensitivity",
      "description": "A shorter source distance exaggerates inverse-square and angular sensitivity for the same wafer radius.",
      "normalized_thickness_percent": [88.9, 92.5, 95.3, 97.5, 99.1, 100, 99.1, 97.5, 95.3, 92.5, 88.9],
      "thickness_nm": [88.9, 92.5, 95.3, 97.5, 99.1, 100, 99.1, 97.5, 95.3, 92.5, 88.9],
      "center_to_edge_drop_percent": 11.1,
      "half_range_nonuniformity_percent": 5.74
    }
  ],
  "shadowing_examples": [
    {
      "feature": "vertical sidewall",
      "line_of_sight_factor": 0.18,
      "note": "Sidewalls receive far less flux in a directional evaporation model."
    },
    {
      "feature": "open horizontal field",
      "line_of_sight_factor": 1,
      "note": "Horizontal exposed fields define the normalized reference thickness."
    }
  ],
  "derived_metrics": {
    "long_throw_center_to_edge_drop_percent": 2.1,
    "short_throw_center_to_edge_drop_percent": 11.1,
    "public_claim": "Evaporation can look uniform on open fields while still being strongly line-of-sight limited inside topography."
  },
  "methods": [
    "Normalize each radial profile to the center point.",
    "Use a simple cosine/inverse-square teaching curve for open-field thickness.",
    "Show a separate line-of-sight factor for topography rather than claiming conformal coverage.",
    "Keep source distance and wafer radius visible with every plotted point."
  ],
  "limitations": [
    "No vapor-pressure curve, crucible geometry, melt pool motion, material sticking coefficient, substrate heating, or chamber scattering is modeled.",
    "No lift-off yield, adhesion, film stress, contamination, or crystal texture is predicted.",
    "The sidewall factor is a teaching warning, not a measured step-coverage value.",
    "Facility recipes and measured thickness maps are required before process use."
  ],
  "sources": [
    {
      "label": "UIUC MRL deposition tools",
      "url": "https://mrl.illinois.edu/facilities/research-cores/micronano-fabrication-and-cleanroom/deposition-tools",
      "use": "Public cleanroom context for thermal/e-beam evaporators and line-of-sight deposition language."
    }
  ]
}