Abstract
Low k films required to enable smaller feature sizes on IC chips call for development of new post breakthrough (BT) cleans that are effective and more compatible with the relatively fragile nature of these materials. Water-in-CO 2 microemulsions combine the process advantages of supercritical CO 2 with the solvent strength required to remove highly polar post BT cleans. This paper describes the use of water-in-CO 2 microemulsions as the basis for effective post BT cleaning formulations on patterned JSR 5109, dense SiLK ™ and porous SiLK™ wafers. Favorable results from compatibility studies with these clean formulations on blanket low k films using spectroscopic ellipsometry, FTIR spectroscopy and Al dot tests will also be described.