Ultrathin Poly(Methyl Methacrylate) Resist Films for Microlithography
Abstract
To improve pattern fidelity of electron beam lithography in the nanometer regime a new class of ultrathin resist (less than 20 nm) has been investigated. Such films can be exposed with very low energy (less than 1 keV) electrons to virtually eliminate proximity effects or, at conventional energies, to allow easier proximity effect correction. In this paper we have investigated the lithographic performance of LB PMMA films with thicknesses ranging from 0.85 nm (one monolayer) to 7.7 nm (nine monolayer) exposed with different electron beam energies. Two types of defects, with sizes less than 20 nm, have be observed in the films after exposure and pattern transfer into chromium. The first type, observed only in films less than seven layers thick, was uniformly distributed over the sample; the second type was only observed around the exposed regions for films thicker than nine layers. Comparisons are made with Monte Carlo simulation.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 30, 1989
- Accession Number
- ADA208894
Entities
People
- C. W. Frank
- David R. Allee
- S. W. Kuan
- T. Eimori
- Y. H. Lee
Organizations
- Stanford University