Self-limiting method of reducing contamination in a contact opening, method of making contacts and semiconductor devices therewith, and resulting structures

摘要

A method of forming a contact opening including removing a residual carbon/halide layer which may form in the contact opening during the etching of the dielectric layer, or which may be intentionally deposited in the contact opening, wherein the removal of the carbon/halide layer also advantageously removes an adjacent portion of the active-device region of the semiconductor substrate which has become damaged or dopant depleted during the fabrication process. The removal of the carbon/halide layer is effected by a directional, energetic ion bombardment to activate the halides in the carbon/halide layer which, in turn, removes both the carbon/halide layer and a portion of the active-device region in a substantially anisotropic manner. The method of present invention is self-limiting because, once the halides within the carbon/halide layer are activated and thereby depleted, the removal of material in the adjacent active-device region ceases.