Transistor sidewall spacers composed of silicon nitride cvd deposited from a high density plasma source

Abstract

A method is provided for forming high quality nitride sidewall spacers laterally adjacent to the opposed sidewall surfaces of a gate conductor dielectrically spaced above a semiconductor substrate. In an embodiment, a polysilicon gate conductor is provided which is arranged between a pair of opposed sidewall surfaces upon a gate dielectric. The gate dielectric is arranged upon a semiconductor substrate. Nitride is deposited from a high density plasma source across exposed surfaces of the substrate and the gate conductor. The high density plasma source may be generated within an ECR or ICP reactor containing a gas bearing N,and SiH,. The energy and flux of electrons, ions, and radicals within the plasma are strictly controlled by the magnetic field such that a substantially stoichiometric and contaminant-free nitride is deposited upon the semiconductor topography. Thereafter, the nitride is anisotropically etched so as to form nitride spacers laterally adjacent the sidewall surfaces of the gate conductor.