Resist stripping process development for porous low-k dielectric materials

In this paper, we will report the result of developing resist strip processes compatible with low-k materials at International Sematech (ISMT) using a standalone Ulvac Environ™ resist stripping system with dual plasma sources. Processes with non-oxygen chemistry were successfully developed and characterized for several non-porous low-k materials, such as spin-on hybrid siloxane-organic polymer and CVD OSG. However, extensive experiments performed on porous MSQ low-k materials reveal the need for directional resist stripping and low wafer temperatures to avoid damage to porous low k materials. Desirable process results were achieved for the porous low-k film in the modified Enviro™ chamber with turbo molecular pump and electrostatic chuck.