The Role of Transmission Electron Microscopy (TEM) in the Development of Advanced Metallization Systems

The capabilities of the transmission electron microscope are reviewed for studying advanced metallization systems. Two different metallization technologies used in the fabrication of advanced MOS devices are examined. The first of these consists of layered structures of TiSi2/Si and TiSi2/poly-Si/SiO2/Si. The microstructure of these materials is investigated using cross-sectional and plan view TEM in order to understand the high temperature behaviour of TiSi2 films. The second metallization system studied is WSi2/poly-Si/SiO2/Si formed by low pressure chemical vapour deposition (LPCVD). Both as-deposited and high-temperature annealed films are studied.