Title :
Resolution enhancement by oblique illumination optical lithography using a pupil filter
Author :
Horiuchi, T. ; Takeuchi, Y. ; Matsuo, S. ; Harada, K.
Author_Institution :
NTT LSI Labs., Atsugi, Japan
Abstract :
A novel technique to enhance patterning resolution is investigated. A pupil filter with a transmittance distribution corresponding to the shape of the secondary light source is used in the projection lens in addition to annular oblique illumination. As an experimental result, superior conventional lithography and annular oblique resolution about 20% higher than that of the conventional method is obtained, and 0.28-/spl mu/m projection lens with and without the pupil filter. Periodical patterns are replicated using an i-line stepper with an NA of 0.52. Subjects for further study are also discussed.<>
Keywords :
integrated circuit technology; lenses; optical filters; photolithography; 0.28 micron; annular oblique resolution; i-line stepper; oblique illumination; optical lithography; patterning resolution enhancement; projection lens; pupil filter; secondary light source; transmittance distribution; Apertures; Lenses; Light sources; Lighting; Lithography; Optical diffraction; Optical distortion; Optical filters; Particle beam optics; Shape;
Conference_Titel :
Electron Devices Meeting, 1993. IEDM '93. Technical Digest., International
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-1450-6
DOI :
10.1109/IEDM.1993.347226
