Reflectivity control through angle is challenging at hyper NA, especially for Logic devices which have various pitches in the same layer. When patterning critical layers, a multilayer antireflectant system is required in order to control complex reflectivity resulting from various incident angles. Multilayer antireflectants typically consist of an organic and inorganic (TiN and SiON) layers. Fewer or thinner layers are desired for etch pattern transfer. However, it would make the reflectivity control through angle more difficult. We have investigated several antireflectants for a simplified multilayer stack. The organic films differ in terms of n, k, thickness and etch rate. The n, k, and thickness span the ranges of 1.60-1.85, 0.15-0.30, and 30-130nm, respectively. The overall patterning performance including profiles, line width roughness (LWR), overlap depth of focus margin (ODOF) and critical dimension uniformity (CDU) has been evaluated. An immersion tool at 1.35NA was used to perform lithography. Simulation was performed using Prolith^TM software.

Date Published: 10 April 2009
PDF: 7 pages
Proc. SPIE 7273, Advances in Resist Materials and Processing Technology XXVI, 727317 (10 April 2009); doi: 10.1117/12.816393

Published in SPIE Proceedings Vol. 7273:
Advances in Resist Materials and Processing Technology XXVI
Clifford L. Henderson, Editor(s)