Abstract: A photo mask, which has subsidiary patterns added into holes formed through a plurality of ring gate patterns having vertically symmetrical structures used in a semiconductor exposure step, such that the subsidiary patterns are separated from the ring gate patterns by a designated distance, and a method for manufacturing patterns using the same. The subsidiary patterns are located in the holes at positions separated from the ring gate patterns by the designated distance, thereby reducing variation of critical dimensions of one pair of the vertically opposite ring gate patterns, which must be the same, due to lens aberration, thereby precisely forming fine patterns.

Abstract: An exposure system for adjusting the critical dimension difference between vertical patterns and horizontal patterns includes a light source for generating a light beam having a predetermined wavelength, a lens for transforming the shape of the light beam generated from the light source into an elliptical shape extended vertically or horizontally, and a lens system for projecting the elliptical light beam passed through the lens onto a wafer through a recticle.