DEPOSITION OF THIN METAL, METAL OXIDE AND METAL ALLOY FILMS: KINETICS, ADHESION AND APPLICATIONS

摘要

Conformal deposition of metal, metal oxide and metal alloy films are of interest for a number of applications ranging from electrodes for dynamic random access memory (DRAM), gate oxides, and conducting diffusion barrier layers for copper interconnects in integrated circuits for the microelectronics industry to alternative materials for energy storage applications. Many processes either require or would benefit from a highly conformal and controllable deposition method in complex geometries with high aspect ratios. Supercritical fluid deposition (SFD) has enabled the rapid, efficient and conformal deposition of device quality conformal metal, metal oxide and metal alloy films in high aspect ratio features, which is due in part to high fluid phase precursor concentrations that are enabled by the use of a supercritical fluid (SCF) as the process medium. These precursor concentrations can be orders of magnitude higher than precursor concentrations typical of chemical vapor deposition. Here we report the kinetics of conformal ruthenium film deposition via the hydrogen assisted reduction of bis (2,2,6,6- tetramethyl heptane-3, 5-dionato) (1,5-cyclooctadiene) ruthenium, (Ru(tmhd)_2cod). This study was performed in order to determine reaction orders and develop a reaction mechanism. Additionally, four point bend fracture mechanics was used to quantify the adhesion energy of deposited films at interfaces of interest. Finally, co-deposition of Ce/Pt in supercritical CO_2 is shown to form a mixed metal system at reduced deposition temperatures.