Patent ID: 6977133
Filing Date: 2005-12-20
Classification: G03F

Abstract:
1. A method for forming a resist pattern on a semiconductor substrate, comprising: using a photomask having a mask pattern including a junction at which two line patterns are connected to each other with one line pattern being orthogonal to the other line pattern so as to form a T-shape, or a proximity portion at which two line patterns are located close to each other with one line pattern being substantially orthogonal to the other line pattern so as to form a T-shape, wherein a small pattern is formed on a side edge of the line pattern in the vicinity of the junction or the proximity portion so as to form a wide portion of the line pattern, the small pattern being provided within a range between 0.79 and 1.8 λ/(NA·K) of a distance from a neighboring side edge of the other line pattern, where λ is a wavelength of exposure illumination light, NA is a numerical aperture of a lens used, and K is a transfer reduction ratio; and transferring the mask pattern of the photomask onto a photoresist on the semiconductor substrate with the transfer reduction ratio K ranging from ⅕ to ¼, wherein the photomask is irradiated with off-axis illumination light during the transfer of the mask pattern, and annular light with an annular ratio of not more than ⅔ or quadrupole is used as the off-axis illumination light.