Wafer-scale laser pantography: Fabrication of n-metal-oxide-semiconductor transistors and small-scale integrated circuits by direct-write laser-induced pyrolytic reactions

Abstract
A complete set of processes sufficient for manufacture of n‐metal‐oxide‐semiconductor (n‐MOS) transistors by a laser‐induced direct‐write process has been demonstrated separately, and integrated to yield functional transistors. Gates and interconnects were fabricated of various combinations of n‐doped and intrinsic polysilicon, tungsten, and tungsten silicide compounds. Both 0.1‐μm and 1‐μm‐thick gate oxides were micromachined with and without etchant gas, and the exposed p‐Si [100] substrate was cleaned and, at times, etched. Diffusion regions were doped by laser‐induced pyrolytic decomposition of phosphine followed by laser annealing. Along with the successful manufacture of working n‐MOS transistors and a set of elementary digital logic gates, this letter reports the successful use of several laser‐induced surface reactions that have not been reported previously.