Mask writer

Notes

IMS Nanofabrication, owned by Intel, and NuFlare dominate the advanced mask writer market.

Overview

A mask writer is the machine in a mask shop that draws a chip layer's pattern into the resist on a photomask blank, which is then developed, etched, inspected and repaired to make the finished mask. Every mask a lithography scanner uses starts in a mask writer, so the writer's accuracy and speed limit how fine and how complex mask patterns can be, and how long a new mask set takes. Leading-edge masks are written with electron beams, using either a single variable shaped beam or a multi-beam array.

How it works

The writer takes mask data that has already been corrected (by OPC or ILT) and split into shapes it can expose. It holds the coated blank on a precise stage and exposes the pattern area by area, after which the resist is developed and the pattern etched into the mask.

A variable shaped beam (VSB) writer forms a single electron beam into rectangles of adjustable size and flashes them one after another. Write time therefore grows with the number of shapes, which became a serious problem as OPC added ever more small features and as inverse lithography produced curved shapes that must be broken into very many pieces. Speed has long been the main battleground: in 2003 NuFlare said its new EBM-5000 shaped-beam writer would write twice as fast as its predecessor.

A multi-beam writer splits the beam into a large array of tiny beams, each switched on and off individually, and builds the pattern as a grid of pixels with set doses. IMS Nanofabrication's first proof-of-concept unit used 262,144 programmable beams. Because every pixel is visited anyway, write time depends little on how complex the pattern is, and IMS quotes write times of under ten hours, which made curvilinear ILT masks practical. The cost is enormous data rates: IMS raised its tool's data path to 120 Gbit/s in 2016.

Examples

• IMS Nanofabrication's MBMW Alpha, completed in February 2014 as the first commercial multi-beam mask writer, built with a consortium including Intel, TSMC, DNP and Photronics.
• IMS MBMW-101 production tools, used for 7 nm masks from 2016, followed by MBMW-201 tools for 5 nm masks from 2019.
• NuFlare's EBM-5000, a 50 kV variable shaped beam writer announced in 2003 for 90 nm and 65 nm masks.
• Full-chip curvilinear ILT masks, whose write time dropped from weeks to hours once multi-beam writers arrived.

Why it matters

Mask writers are among the most important tools in a mask shop, so photomask and mask writer process engineers work to keep them accurate and busy, and mask data preparation engineers shape data to suit them. Their speed decides how quickly a new design or a fix reaches the fab, and their capability decides whether advanced corrections such as curvilinear ILT can be used at all.

In the chip lifecycle, the mask writer comes right after tapeout and mask data preparation, writes every mask in the set before first silicon, and is used again for each later revision of a layer.

It matters most to: E-beam / Multi-Beam Mask Writer Engineer, Mask Data Preparation Engineer, Mask Writer Process Engineer, Photomask Process Engineer

Common confusions

Not the same as a lithography scanner

A scanner copies an existing mask onto many wafers with light, at high throughput. A mask writer creates the mask itself, one plate at a time, usually with electron beams.

Not the same as maskless or direct-write lithography

Direct-write tools use electron beams to pattern wafers themselves, with no mask. They are used for research and small volumes; mask writers serve volume production by making the masks that scanners use.

Sources

1. Products (opens in a new tab), IMS Nanofabrication, 2026-10-22
2. History (opens in a new tab), IMS Nanofabrication, 2026-10-22
3. Toshiba's e-beam unit readies new 65-nm tool (24 July 2003) (opens in a new tab), EE Times, 2026-10-22
4. What Happened To Inverse Lithography? (Mark LaPedus, 20 October 2016) (opens in a new tab), Semiconductor Engineering, 2026-10-22
5. Accelerating High-Volume Manufacturing for Inverse Lithography Technology (Danping Peng, 6 May 2022) (opens in a new tab), NVIDIA Technical Blog, 2026-10-22

Related terms

• Multi-beam mask writer
• Mask shop

Where it appears on the Hub

Used on 7 pages of the Hub. In each group, the pages that mention it most come first.