Etching spin-on trilayer masks

Abstract

Spin-on trilayer materials are increasingly being integrated in high density microfabrication that use high NA ArF lithography due to dwindling photoresist film thicknesses, lower integration cost and reduced complexity compared to analogous CVD stacks. To guide our development in spin-on trilayer materials we have established etch conditions on an ISM etcher for pattern transfer through trilayer hard masks. We report here a range of etch process variables and their impact on after-etch profiles and etch selectivity with AZ trilayer hard mask materials. Trilayer pattern transfer is demonstrated using 1 st and 2 nd minimum stacks with various pattern types. Etch recipes are then applied to blanket coated wafers to make comparisons between etch selectivities derived from patterned and blanket coated wafers.

Lithography options and challenges for sub-45nm node interconnect layers

“…The carbon mask is then again used to etch the desired substrate ( Figure 6). With this more complex system, even higher aspect ratios can be achieved after etch, in combination with good planarization and reflection control for litho [14,15]. Full spin-on solutions of such systems are believed to have lower integration cost compared to analogous CVD stacks.…”

“…Full spin-on solutions of such systems are believed to have lower integration cost compared to analogous CVD stacks. Figure 6: Trilayer rest scheme that allows high aspect ratio etch into the substrate [14].…”

Cost-Effective Sub-20 nm Lithography: Smart Chemicals to the Rescue

“…Photoresists play a key role in enabling the patterning process, acting as chemical rectifiers to • Top protection coatings for immersion lithography 11,20,21 • Hardmasks (spin-on or deposited)…”