Mask Writing is the process of transferring the fractured design pattern onto a mask blank using a precision writing tool — either an electron beam (e-beam) writer or a laser writer exposes the resist on the mask blank according to the fracture data, defining the pattern that will later be etched into the mask.

Mask Writing Technologies

• E-Beam (VSB): Variable Shaped Beam — uses rectangular apertures to create variable-sized shots. High resolution, but serial.
• Multi-Beam: Massively parallel e-beam — 250K+ beamlets write simultaneously. High throughput + high resolution.
• Laser: Direct-write laser — lower resolution but faster for non-critical masks and older nodes.
• Resist: Chemically amplified resist (CAR) or non-CAR resists optimized for mask writing chemistry.

Why It Matters

• Resolution: Mask writer resolution determines the minimum mask feature — limits OPC/ILT correction capability.
• Throughput: Write time is a bottleneck — advanced masks take 10-24+ hours per write.
• Cost: Mask writers cost $50-100M+ — mask shops are major capital investments.

Mask Writing is printing the print master — using precision e-beam or laser systems to inscribe nanoscale patterns onto the mask that will pattern billions of transistors.