Title :
A uniform, large-area thermionic cathode as a high emittance electron source for the SCALPEL(R) tool
Author :
Katsap, V. ; Sewell, P.B. ; Kwaskiewicz, W.K. ; Zhu, W.
Author_Institution :
Lucent Technol. Bell Lab., Murray Hill, NJ, USA
Abstract :
The column of the SCALPEL electron beam lithography exposure tool consists of an illumination system and projection system, working in conjunction to expose wafer features as small as 0.1 /spl mu/m and below. In the illumination system a 1/spl times/1 mm wide high energy (100 kV) electron beam illuminates a thin membrane mask. After passing through the mask, electrons are focused by means of a projection doublet onto the silicon wafer with a 4/spl times/ demagnification. This illumination system possesses an unusually high depth of focus (at least 10/sup 11/) reproducing nonuniformity of emission at the cathode surface at the mask plane and subsequently by the projector system at the wafer plane, thus downgrading the exposure quality.
Keywords :
electron beam lithography; electron sources; masks; thermionic cathodes; 0.1 micron; 100 kV; SCALPEL tool; demagnification; depth of focus; electron beam lithography exposure tool; exposure quality; high emittance electron source; illumination system; large-area thermionic cathode; mask plane; projection doublet; projection system; thin membrane mask; wafer features; wafer plane; Brightness; Cathodes; Electron beams; Electron sources; Lighting; Scanning electron microscopy; Surface discharges; Surface topography; Temperature; Testing;
Conference_Titel :
Vacuum Electronics Conference, 2000. Abstracts. International
Conference_Location :
Monterey, CA, USA
Print_ISBN :
0-7803-5987-9
DOI :
10.1109/OVE:EC.2000.847422