| 摘要 |
A microlithograpic tool, such as a projection stepper, for manufacturing integrated circuits, shapes light that illuminates a photomask with a chevron illumination system. The system uses either a chevron aperture mask of diffractive optical elements to shape a light source into four chevrons ( 110 b, 120 b, 130 b, 140 b). The chevrons are located in the corners of the circular pupil of the condenser lens. The chevrons may be a small a square poles at the corners or as large as an annular square ring. The chevrons provide superior performance for illuminating conventional X and Y oriented features of a photomask. |
