This simulator follows a positive-resist lithography process from a bare coated wafer to an etched pattern in a film. Move through each stage, then change dose, wavelength, numerical aperture and target opening width to see when the pattern clears in development and transfers successfully.
• A wafer and film, positive photoresist, a patterned mask, projection optics and UV path, an alignment and wafer chuck, and develop, etch and strip tools. • A process-stage slider covering coat, bake and align, expose, develop, etch, strip and inspect, plus an option to run the sequence automatically. • Controls for open-field exposure dose (10-100 mJ/cm²), exposure wavelength (193-436 nm), numerical aperture (0.3-0.9) and target opening width (0.25-3 µm). • Readouts for the current step, nominal optical scale, feature-to-optical-scale ratio, whether the dose threshold is reached and whether the pattern transfers.
In this teaching model the nominal optical scale is 0.61 λ / NA, and the resolution margin is the target width divided by that scale. The resist clears in development only if the dose reaches the 50 mJ/cm² teaching threshold. The pattern transfers when the margin is at least 1 and the dose meets the threshold. Underexposure leaves the resist in place, so the film remains unpatterned after the sequence; shorter wavelength or higher NA shrinks the optical scale and allows smaller features.
This is a conceptual positive-resist sequence. The 0.61 factor is a nominal diffraction scale, not a foundry design rule, and hard thresholds replace resist chemistry and aerial-image computation. Timings, optics geometry and etch depth are illustrative, and the lab gives no process recipe or yield prediction.
Exposure makes positive resist soluble in the developer, so the exposed areas wash away and the unexposed areas remain as a protective pattern for the etch step.
The nominal optical scale is 0.61 λ / NA, so a shorter wavelength or a larger numerical aperture produces a smaller minimum feature. The lab compares your target width with that value.
If the dose is below the clearing threshold the resist does not become soluble in the exposed areas, so development does not open the windows, and the etch cannot remove film through them.
No. The numbers are teaching values with simple thresholds in place of resist chemistry and optical simulation. It illustrates the sequence and trade-offs, not a production recipe.