Recent progress and future of electron multi-beam mask writer

In this paper, development of NuFlare Technology’s multi-beam (MB) mask writing system MBM-2000 series is reviewed, and future plans for the MBM series are discussed. The MB mask writing systems were designed on the basis of unique concepts suitable for high-volume production of leading-edge masks, i.e. high beam current density, a reliable beam blanking aperture array (BAA) system with a 50 keV single-stage acceleration optics, high-speed inline pixel-level dose correction, and a distinctive hardware system for charging effect reduction. The latest MB mask writing system, MBM-2000PLUS, achieves a high throughput of 8.7 h in a 104 × 130 mm2 writing area for a 150 μC cm−2 resist thanks to a high beam current density of 3.2 A cm−2. In addition, a global position accuracy of 1.2 nm, a local position accuracy of 0.5 nm, and a local critical dimension uniformity of 0.61 nm are achieved. The BAA system has shown long-term stable operation for more than one year. The high productivity and writing accuracy realized by NuFlare Technology’s concepts will contribute to further miniaturization of semiconductors.