Hydrogen permeation, Si defect generation, and their interaction during CHF/sub 3//O/sub 2/ contact etching

Hydrogen permeation and the simultaneous Si substrate defect generation occurring during contact reactive ion etching utilizing CHF/sub 3/-based chemistries were studied using SiO/sub 2//Si structures. The process-parameter space for the etches consisted of magnetic field intensity and overetch percentage. Characterization was carried out by means of 1 MHz capacitance-voltage and deep-level transient spectroscopy measurements. This characterization establishes for the first time that the presence of permeating hydrogen does not prevent Si defect generation but, instead, acts only to passivate such defects. The characterization also demonstrates that this hydrogen permeation into the Si substrate is enhanced by increasing the magnetic field intensity.<
>