화학공학소재연구정보센터
Journal of Vacuum Science & Technology B, Vol.25, No.6, 2258-2265, 2007
Multiple beam sub-80-nm lithography with miniature electron beam column arrays
Miniature electron beam columns have the potential for high resolution, high throughput maskless lithography applications because they can be scaled in number to form high density column arrays with low fabrication costs. This is achieved using manufacturing techniques that leverage rf packaging technologies and standard bulk micromachining and integrated circuit fabrication processes to produce reliable components with repeatable performance characteristics. A 1x4 electrostatic column array designed to target the 45 nm node has been built using monolithically fabricated lenses and packages. The lenses, which consist of stacks of patterned silicon and insulator, are mounted to a ceramic package. Internal to the package are traces which carry all interconnects to drive the column. Each column in the array is individually correctable. The monolithic lens design simplifies the pick-and-place assembly of high density column arrays and enables precise column-to-column registration. The design also facilitates scaling up of the column density to achieve higher throughput, and simulations presented previously suggest that the design can be extended to meet the 22 nm resolution requirement. This article presents the first results from simultaneous multiple beam lithography using miniature column arrays. Independent patterns were exposed synchronously at 1 keV using two columns in a 1x4 monolithic column array, resulting in 75 nm features written into ZEP-520A resist. Other experiments suggest reliable high voltage lens performance and good beam current and position stability. These preliminary results from arrays of limited numbers of columns demonstrate progress toward the development of full-scale direct write lithography systems driven by miniature column arrays. (c) 2007 American Vacuum Society.