Mask Fabrication
Custom photomasks, shadow masks, and metal stencils for semiconductor lithography, thin film deposition, and precision patterning. Feature sizes down to ~10–20 µm in stainless steel, nickel, and quartz — designed and fabricated to your exact specifications.
Mask types
01
Photomasks
Chrome-on-quartz or emulsion glass masks for UV photolithography. Precision-patterned by laser or e-beam for sub-micron to 10 µm feature definition.
- Chrome-on-quartz (CrOnQ)
- Soda lime glass emulsion
- 5" × 5" and 7" × 7" standard sizes
- 1× and reduction reticles
- Dark-field and clear-field options
02
Shadow masks & metal stencils
Freestanding metal stencils for direct deposition patterning without photoresist. Used for organic electronics, OLEDs, electrode patterning, and rapid device prototyping.
- Stainless steel (304 / 316L)
- Nickel (electroformed)
- Feature sizes ~10–20 µm
- Round, square, custom shapes
- Mounting frame options
03
Quartz & specialty masks
High-purity fused silica masks for deep-UV and broad-band UV lithography. Low thermal expansion and high UV transmission make quartz the preferred mask substrate for critical applications.
- Fused silica substrate
- Chrome or MoSi absorber layers
- DUV and broad-band UV compatible
- Low CTE for thermal stability
- Phase-shift mask options
Fabrication process
How custom masks are made at DR Research Foundry
Design file review & DFM check
Your GDSII, DXF, or Gerber design file is reviewed for minimum feature size, aspect ratio, bridge widths, and process-specific design rules. We provide design-for-manufacturability (DFM) feedback before fabrication begins to avoid costly rework. For shadow masks, structural integrity of thin bridge elements is checked against the chosen material and thickness.
Substrate preparation
For photomasks: a chrome-coated quartz or glass blank is cleaned and inspected for surface defects. For metal stencils: stainless steel or nickel foil of the specified thickness (typically 25–200 µm) is prepared. Substrate flatness and cleanliness are critical to pattern fidelity and feature edge quality.
Pattern writing
Photomasks are written by laser direct write (LDW) or e-beam lithography on resist-coated blanks. Metal stencils are patterned by laser cutting (for features ≥20 µm) or electroformed nickel processes (for finer features). Proximity effect correction and edge compensation are applied to achieve target critical dimensions across the full mask field.
Etching & development
For chrome photomasks: resist is developed and the chrome layer is wet-etched in chromium etchant, leaving the absorber pattern on the quartz substrate. For metal stencils: laser-cut parts are deburred and cleaned; electroformed masks are released from their mandrel. All masks are rinsed, dried, and inspected after etching.
Inspection & CD verification
Completed masks are inspected optically and/or by SEM for CD uniformity, edge roughness, defect density, and pattern placement accuracy. Critical dimensions are measured at representative sites across the mask field and compared to design targets. Defect maps are generated for photomasks to identify printable defects.
Cleaning, packaging & delivery
Masks are cleaned in a cleanroom environment, inspected for particles, and packaged in protective containers (pellicle-protected for critical photomasks, hard case for metal stencils). A dimensional inspection report is included. Masks are shipped with appropriate ESD and contamination protection.
Technical specifications
Mask fabrication capabilities
| Parameter | Specification | Notes |
|---|---|---|
| Min. feature size (metal) | ~10–20 µm | Laser cut; electroform for finer |
| Min. feature size (photomask) | Down to ~1 µm | E-beam written chrome-on-quartz |
| Photomask sizes | 5" × 5", 7" × 7" standard | Custom sizes available |
| Metal stencil thickness | 25 µm – 500 µm | Material & feature size dependent |
| Metal stencil materials | Stainless steel 304/316L, Ni | Electroformed Ni for finest features |
| Photomask substrate | Soda lime glass, fused silica | Quartz for DUV & critical layers |
| Absorber material | Chrome (Cr), MoSi | MoSi for attenuated phase shift |
| Pattern placement accuracy | ±0.5 µm (photomask) | Laser stage interferometry |
| Design file formats | GDSII, DXF, Gerber, DWG | DFM review included |
| Turnaround | 5–15 business days typical | Rush available upon request |
Mask material selection guide
Choosing the right mask material for your application
| Material | Min. feature | Durability | UV transmission | Best for |
|---|---|---|---|---|
| Chrome / quartz | ~1 µm | High | Excellent (DUV) | UV / DUV photolithography, critical layers |
| Chrome / soda lime | ~2 µm | High | Good (i-line) | Standard UV lithography, cost-effective |
| Stainless steel | ~20 µm | Very high | N/A — opaque | Shadow mask, PVD deposition, reusable stencil |
| Nickel (electroform) | ~5–10 µm | Medium | N/A — opaque | Fine shadow mask features, OLED patterning |
| Emulsion / film | ~5 µm | Low | Moderate | Low-cost prototyping, non-critical layers |
Typical applications
UV photolithography
Chrome-on-quartz photomasks for i-line and broad-band UV patterning of semiconductor devices, MEMS, and microfluidic structures.
Thin film deposition
Metal and dielectric shadow masks for PVD, evaporation, and sputtering — enabling resistless patterning of contacts, electrodes, and functional layers.
OLED & organic electronics
Fine-pitch nickel shadow masks for organic layer deposition in OLED displays, organic solar cells, and flexible electronic devices.
MEMS & sensors
Multi-layer photomask sets for MEMS device fabrication — structural layers, sacrificial layers, contact openings, and metal interconnect.
Research prototyping
Rapid mask fabrication for academic and industrial R&D — from first-pass concept validation to optimized production-ready mask sets.
Ion implantation masking
Hard mask patterning and custom stencil masks for selective ion implantation in SiC, GaN, and Si device fabrication.
Design guidelines
Key rules for mask design submission
Minimum feature & space
Metal stencils: min. feature and space ≥ 20 µm (laser), ≥ 5 µm (electroform). Photomasks: min. feature ≥ 1 µm (e-beam written).
Bridge width for open areas
Large open areas in metal stencils require support bridges to prevent membrane deflection. Min. bridge width = 20% of open area span.
Aspect ratio
For metal stencils, feature width-to-thickness aspect ratio should be ≥ 1.5:1 to ensure clean aperture walls and reliable deposition.
Corner rounding
Sharp interior corners are rounded during fabrication. Design with ≥ 5 µm corner radius for metal masks; ≥ 0.5 µm for photomasks.
Accepted file formats
GDSII (.gds), DXF (.dxf), Gerber (.gbr), DWG (.dwg). Include layer assignments and polarity (clear-field / dark-field) specification.
Polarity & tone
Specify clear-field (features are transparent) or dark-field (features are opaque) for photomasks. For shadow masks, specify open aperture geometry.
Ready to order a custom mask?
Upload your GDSII or DXF file and specify material, feature size, and application — our team will review and respond within 48 hours.