The novel method allows monitoring of nitrogen processes by making use of the fact that the incorporation of nitrogen near the surface in silicon, or in a thin silicon nitride layer on the silicon surface, inhibits the diffusion of oxygen during the subsequent thermal oxidation. Accordingly, the oxidation rate of the thermal oxidation is reduced and the growth of the oxide layer on the silicon surface is inhibited. The thickness of the oxide layer is thus used as a measure for the nitrogen content, i.e., for the quality of the nitrogen process.

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