Nanoporous materials integration into advanced microprocessors

Abstract

Future microprocessor technologies will require interlayer dielectric (ILD) materials with a dielectric constant (K-value) less than 2.5. Organosilicate glass (OSG) materials must be nanoporous to meet this demand. However, the introduction of nanopores creates many integration challenges. These challenges include 1) integrating nanoporous films with low mechanical strength into conventional process flows, 2) managing etch profiles, 3) processinduced damage to the nanoporous ILD, and 4) controlling the metal/nanoporous ILD interface. This paper reviews research to maximize mechanical strength by engineering optimal pore structures, controlling trench bottom roughness induced by etching and understanding its relationship to pore size, repairing plasma damage using silylation chemistry, and sealing a nanoporous surface for barrier metal (liner) deposition. © 2005 Materials Research Society.