Structure for Reduction of E Beam Charging on Multilevel Metal Structures
Original Publication Date: 1981-Nov-01
Included in the Prior Art Database: 2005-Feb-12
The need for multilevel metal (>/- 3 levels) is well known. As the number of metal levels increases, the total thickness of the insulator on a wafer also increases. As the insulator becomes thicker, charging can occur during E-beam writing for pattern definition. The result of this charging is an offset of the written pattern. The amount of offset is dependent upon the density of the pattern being written by the E-beam. Multi-metal layer structures can have a charging problem when the E-beam exposes the second level metal pattern. Artificially generated corrections to the deflection signal are conventionally used to minimize the problem.