A multilayer mask set provides a separate optical pattern for each lithography step. Shared alignment features connect openings, conductors and other successive structures to a common coordinate system.
Use a set when later exposures must register to earlier structures, such as electrode, opening and alignment layers in a microfabrication process.
A mask set contains separate patterns for successive process steps, not several coating layers on one plate. Alignment marks connect the masks to the same workpiece coordinate system; overlay also depends on the exposure tool and substrate behaviour.
Layer order, shared datums, overlay marks, per-layer polarity, repeated fields and readable layer/revision identification can be coordinated.
The product is a patterned glass or fused-silica mask, or an identified set of masks for successive layers. Exposure equipment, photoresist-coated workpieces and the finished devices are separate from the mask itself. Inspection records and packaging form part of the order specification.
| Product configuration | Coordinated mask set with shared alignment datums |
|---|---|
| Layer control | Layer identity, polarity and artwork revision per mask |
| Alignment reference | 225 nm or 350 nm 2nd-layer alignment reference by configuration |
| Data package | Shared origin, global/local marks and coordinate transforms |
| Acceptance focus | Inter-mask registration and revision traceability |
Inspect layer identity, feature dimensions and registration against shared datums; retain the approved artwork revision for each mask.
Coordinated sets of glass photomasks with shared alignment marks, layer identification and artwork revision control for sequential exposures.
A mask set contains different patterns intended to build related layers. Shared datums and alignment marks help each exposure locate features relative to earlier layers. This is useful in compatible sensor, microelectronic and microfluidic fabrication routes requiring more than one patterning step.
Treat the layers as a coordinated design: identify reading side, polarity, process order and common reference coordinates. A correct individual mask can still belong to the wrong revision of a set. Keeping the full layer map together reduces mismatched exposures.
Manufacturing capability
A multi-layer set is prepared as a coordinated data package. Shared origins, global and local alignment marks, layer polarity and revision control are checked before writing so each mask can be inspected against the same reference.
Choose glass or synthetic fused silica around the exposure wavelength, thermal requirements and fixture. State chromium optical density, reflectance, film-side orientation and allowed defect classes. The clear and opaque regions must be unambiguous in the approved artwork.
Quality & Inspection PhotolithographyCoordinated layers with shared alignment datums.
Related mask layers with consistent alignment features.
Coordinated mask layers for shared alignment and artwork revision control.
No. Final overlay also depends on exposure alignment, substrate deformation and process conditions. State both requirements separately.
Multi-layer photomask sets place the patterns for successive processing steps on a coordinated set of masks.
Define layer identifiers, revisions, shared coordinates and alignment marks. Manage inter-layer registration separately from local line width.
Layer artwork, process order, origin, alignment marks, polarity, revisions and layer-specific requirements.
The layers combine on the same workpiece and need shared datums and compatible revisions. Checking each pattern independently does not establish registration between layers.