The nanoimprint molds are usually fabricated by electron beam (EB) lithography. In recent years, a large-area mold fabrication with a high throughput is required to use nanoimprint lithography to produce devices in mass production. Using a conventional EB system to fabricate a large-area mold requires a very long exposure. To shorten the time, the authors have newly developed an EB stepper. The hole pattern (300 nm hole and 600 nm pitch) was exposed on a whole 4 in. SiO2/Si substrate with ZEP-520A (ZEON Co.) positive resist by the stepper. The exposure time was only 15 min. After this exposure, the authors did reactive ion etching and thermal nanoimprinting by using the 4 in. SiO2/Si mold. The whole patterns on the 4 in. SiO2/Si mold were imprinted on a 4 in. Si substrate coated with ZEP-520A. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3449270]