Explanation of anomalous narrow width effect for nMOSFET with LOCOS/NSL isolation by compressive stress

The anomalous threshold voltage characteristics of narrow width nMOSFET fabricated with LOGOS and Nitride Sidewall (NSL) LOCOS isolation is predicted by means of 2D process and 3D device simulation. Isolation structure and encroachment of the channel stop dopant is not sufficient to explain submicron device's threshold characteristics. The compressive stress which generated during isolation process, enhances dopant-point diffusion. This is one of the factors that explains the threshold voltage characteristics of the submicron device.