Evaluating suitability of green laser annealing in developing phosphorous-doped silicon for semiconductor devices

This study reports the comprehensive investigation of the green laser annealing (GLA) technique for phosphorus (P)-doped silicon (Si). The aim of this study was to examine the suitability of GLA in improving the properties of P-doped Si for semiconductor devices. This study explored the electrical, chemical, and crystalline characteristics of P-doped Si under major laser-annealing conditions. Multiple characterization techniques, including the fourpoint probe method, Hall effect measurement, transmission electron microscopy (TEM), secondary ion mass spectroscopy (SIMS), X-ray diffraction (XRD), and atomic force microscopy (AFM), were used to investigate the interaction between the laser beam and P-doped Si under different laser annealing conditions. A considerable decrease in the sheet resistance, carrier mobility, and Hall resistance and an increase in the carrier concentration of the material were observed after GLA. The TEM images indicated a transition from partial polycrystallization to complete crystallization with epitaxial growth, depending on the GLA conditions. The SIMS data showed low P diffusion in the depth direction of the Si and relatively uniform P concentrations near the surface of the Si after annealing. Furthermore, XRD analysis revealed no considerable changes in the lattice spacing for the main (400) XRD peak, confirming insignificant strain effects from GLA. AFM analysis showed a minimal increase in the surface roughness compared to that of the as-implanted sample, indicating that GLA did not significantly alter the surface morphology of the material. GLA is a promising method for enhancing the electrical properties of Pdoped Si without considerable dopant diffusion or changes in the atomic structure, making it suitable for industrial applications.