Low-Temperature Fabrication of High Quality Gate Insulator in Metal-Oxide-Semiconductor Capacitor Using Laser Annealing

This letter reports the fabrication of a high quality gate oxide for metal-oxide-semiconductor field-effect transistors using a continuous-wave blue laser. A thin Zr metal layer was inserted between the dielectric and substrate to increase laser absorption and reduce the interface layer. A simulation of laser irradiation showed that the metal layer insertion induces a significant increase in temperature during laser annealing compared with the dielectric without a metal layer. The laser annealed capacitor with a 1-nm-thick Zr metal layer showed superior electrical characteristics, such as high capacitance, low leakage current, low fixed charge density, and low interface state density. Based on these results and the economic advantage of blue laser diodes, this technique can be a solution for low temperature processes, such as monolithic 3-dimensional integration, where low temperature processes are required.