Thermal wave characterization of silicon which had been high energy ion implanted and furnace annealed

Fabrication process control is a complex task which has a strategic role in integrated-circuit manufacturing. To achieve satisfactory process yield in all aspects of silicon fabrication, rapid, non-destructive and in situ monitoring of process parameters on device wafers is essential. One area of particular importance is that of ion implant monitoring. In this work, we evaluate the applicability of two rapid and non-contact thermal wave techniques, photothermal radiometric and photodisplacement microscopy for characterizing deep implant damage. Experimental results are presented for 400 keV implants into single-crystal Si(100) wafers. Both p- and n-type doped substrates were employed. The ion dose was varied between 1 × 1012and 1 × 1015ions cm-2. The sensitivity of the above techniques to material parameters such as lattice damage, thermal conductivity and carrier recombination kinetics is discussed. Experimental results are also presented which show the variation in thermal wave signal as a function of the annealed state of the sample. Finally, some novel applications of thermal wave probes are outlined.