PORTLAND, Ore. -- A cheaper, quicker-curing polymer aims to lower the cost and improve the efficiency of fabricating semiconductors, according to researchers at the Rensselaer Polytechnic Institute. Working with materials experts at Polyset Company Inc. (Mechanicville, New York), the new formulation of polyset epoxy siloxane (PES) could enhance semiconductor performance for conventional photolithography, as well as ease the transition to nanoimprint lithography.
"PES is cheaper and more reliable [for] chip manufacturers [who] will be able to trim several steps from their production and packaging processes," said professor Toh-Ming Lu at Rensselaer Polytechnic Institute. "And for on-chip imprint applications, we can now print dual-damascene structures directly on the dielectric."
For traditional photolithography, PES can be used on the redistribution layers at the wafer-level. When PES, instead of benzocyclobutene and polyimide, is deposited in multiple photolithography and metallization steps it can redistribute the input-output pattern with lower signal propagation delays and better protection from environmental and mechanical damage, according to Lu. He also claims the ability to use the PES as a thin film with ultraviolet light for nanoimprint lithography will ease the transition from traditional lithography.
PES uses a lower curing temperature--165 degrees Celsius instead of 250--has lower water absorption, better thermal stability, has less thermal expansion, a low dielectric constant, and lower leakage current, according to Lu. He claims these attributes make PES a promising candidate for optical devices, flat-panel displays, biosensors and micro-electro-mechanical systems (MEMS).
Also contributing to the formulation of PES was Rensselaer research associate Pei-I Wang, materials science and engineering professor Omkaram Nalamasu, research Andrew Li at Applied Materials Inc. (Santa Clara, Calif.), as well as researchers Rajat Ghoshal and Ram Ghoshal at Polyset and research Charles Schaper at Transfer Devices Inc. (Santa Clara, Calif.).
Funding was provided by the New York State Foundation for Science, Technology and Innovation and Rensselaer's Center for Integrated Electronics.