Process For E-Beam Registration For Planer SiO(2)/Metal Structure
Original Publication Date: 1979-Dec-01
Included in the Prior Art Database: 2005-Feb-20
The construction of multilevel metal interconnections in integrated circuits of increasing density requires greater and greater planarity of the initial layers. Moreover, the lithography used to generate the patterns is being rapidly shifted to electron (E)-beam exposures due to linewidth, overlay, and part number considerations. With Al or AlCu as the metallurgy and SiO(2) as the insulator, the electron beam cannot register over such planar structures. The materials do not have a sufficient difference in scattering of the electrons to allow registration without topology.