Newtown Inventors Develop Semiconductor Manufacturing Illumination

Semiconductor International webzine reported this week that Andrew W. McCullough and Gregg M. Gallatin of Newtown developed an illumination system that is locally spatially controllable to reduce line width variations in a lithographic system.

According to the US Patent & Trademark Office, the invention relates to an “illumination system having an array optical element with different illumination regions corresponding or matched to different line width variations printed on a photosensitive material. The array optical element may be a filter, diffractive optical element, or micro lens array having illumination regions producing different types of illumination properties or characteristics.

“Each of the illumination regions are matched or correspond to a respective region on a patterning device to provide optimized exposure of a photosensitive material.”

An abstract of the invention, released by the Patent Office, said: “The optical element may be used to tailor a conventional illumination system to the unique characteristics of the projection optics used in a system, thereby compensating for vertical and horizontal bias or variations in line width for features oriented in the vertical and horizontal direction.”

The original application was filed on October 12, 2004, and the inventors were issued US Patent No. 7,092,070 on August 15. The patent has been assigned to ASML Holding NV, Veldhoven, the Netherlands.