Transient enhanced diffusion after laser thermal processing of ion implanted silicon

The effect of laser thermal processing (LTP) on implantation-induced defect evolution and transient enhanced diffusion (TED) of boron was investigated. A 270-Å-thick amorphous layer formed by 10 keV $Si+$ implantation was melted and regrown using a 20 ns ultraviolet laser pulse. Transmission electron microscopy revealed that recrystallization of the amorphous layer following LTP results in a high concentration of stacking faults and microtwins in the regrown region. Also, the end-of-range loop evolution during subsequent 750 °C furnace annealing, is different in a LTP sample compared to a control sample. Secondary ion mass spectroscopy of a boron marker layer 6000 Å below the surface showed that LTP alone produced no enhanced diffusion. However, during subsequent furnace annealing, the boron layer in the LTP sample experienced just as much TED as in the control sample which was only implanted and furnace annealed. These results imply that laser melting and recrystallization of an implantation-induced amorphous layer does not measurably reduce the excess interstitials released from the end-of-range implant damage.