Design of a Multi-Wafer Reactor for Supercritical Fluid Deposition of Cu in Mass Production: (1) Reaction Mechanism and Kinetics

The feasibility of a wafer-scale reactor for supercritical fluid deposition (SCFD) has been evaluated in a series of papers for mass production of Cu interconnects in ultra-large-scale integration (ULSI) based on two criteria: reactor throughput and film thickness uniformity on 12-inch wafers. This study experimentally extracts the reaction kinetics and transport properties of the source precursor within SCFD using a lab-scale flow reactor. The dependence of the growth rate (GR) on the source precursor and by-product (ligand of the precursor) concentrations was investigated. The source precursor exhibited Langmuir-Hinshelwood (LH) reaction kinetics, while increased by-product concentrations resulted in decreased GRs. The diffusion coefficient (D) of the source precursor under SCFD conditions was estimated using macrocavity analysis, and D was found to be approximately 10(-7) m(2)/s. The obtained kinetic information will be used to design a mass production-scale reactor for SCFD of Cu (Cu-SCFD).