1 June 1990 Investigation of reflective notching with massively parallel simulation
Author Affiliations +
A massively parallel simulation program TEMPEST is used to investigate the role of topography in generating reflective notching and to study the possibility of reducing effects through the introduction of special properties of resists and antireflection coating materials. The emphasis is on examining physical scattering mechanisms such as focused specular reflections resist thickness interference effects reflections from substrate grains and focusing of incident light by the resist curvature. Specular reflection from topography can focus incident radiation causing a 10-fold increase in effective exposure. Further complications such as dimples in the surface of positive resist features can result from a second reflection of focused energy by the resist/air interface. Variations in line-edge exposure due to substrate grain structure are primarily specular in nature and can become significant for grains larger than )tresi Local exposure variations due to vertical standing waves and changes in energy coupling due to changes in resist thickness are displaced laterally and are significant effects even though they are slightly less severe than vertical wave propagation theory suggests. Focusing effects due to refraction by the curved surface of the resist produce only minor changes in exposure. Increased resist contrast and resist absorption offer some improvement in reducing notching effects though minimizing substrate reflectivity is more effective. CPU time using 32 virtual nodes to simulate a 4 pm by 2 pm isolated domain with 13 bleaching steps was 30 minutes
© (1990) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Karim H. Tadros, Karim H. Tadros, Andrew R. Neureuther, Andrew R. Neureuther, John Kenneth Gamelin, John Kenneth Gamelin, Roberto Guerrieri, Roberto Guerrieri, } "Investigation of reflective notching with massively parallel simulation", Proc. SPIE 1264, Optical/Laser Microlithography III, (1 June 1990); doi: 10.1117/12.20197; https://doi.org/10.1117/12.20197

Back to Top