Direct measurement of the reaction front in chemically amplified photoresists.
The continuing drive by the semiconductor industry to fabricate smaller structures using photolithography will soon require dimensional control at length scales comparable to the size of the polymeric molecules in the materials used to pattern them. The current technology, chemically amplified photoresists, uses a complex reaction-diffusion process to delineate patterned areas with high spatial resolution. However, nanometer-level control of this critical process is limited by the lack of direct measurements of the reaction front. We demonstrate the use of x-ray and neutron reflectometry as a general method to measure the spatial evolution of the reaction-diffusion process with nanometer resolution. Measuring compositional profiles, provided by deuterium-labeled reactant groups for neutron scattering contrast, we show that the reaction front within the material is broad rather than sharply defined and the compositional profile is altered during development. Measuring the density profile, we directly correlate the developed film structure with that of the reaction front.
Lin
Eric K
EK
Polymers Division and, Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8541, USA. eric.lin@nist.gov
Soles
Christopher L
CL
Goldfarb
Dario L
DL
Trinque
Brian C
BC
Burns
Sean D
SD
Jones
Ronald L
RL
Lenhart
Joseph L
JL
Angelopoulos
Marie
M
Willson
C Grant
CG
Satija
Sushil K
SK
Wu
Wen-Li
WL