mask writing

**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.