APPLICATION OF POSITRON-ANNIHILATION IN THE SI INTEGRATED-CIRCUIT (IC) INDUSTRY

Currently the trend in the Si IC industry is to produce epitaxial mate rial layers by advanced growth and deposition techniques. Examples of these are Si and SiGe low temperature epitaxy, Si selective epitaxy an d metallic silicide epitaxy. In order to obtain good electrical proper ties it is important that the epitaxial material shows no extended lat tice defects and has a minimal concentration of lattice point defects. Given the concentrations of these phenomena a sensitive experimental technique is required to characterise the materials. The application o f the positron annihilation technique in this IC research area is demo nstrated by two examples, namely, characterization of Si Molecular Bea m Epitaxy (MBE) and Atmospheric Pressure Chemical Vapour Deposition (A PCVD) epi-layers and the assessment of the quality of CoSi2 epi-layers produced by the solid-state reaction with the Si substrate and an amo rphous Co75W25 sputtered layer. Results will be presented in terms of defect concentrations derived from positron diffusion lengths.