The inverse-narrow-width effect of LOCOS isolated n-MOSFET in a high-concentration p-well

The inverse-narrow-width effect (INWE) of a LOCOS-isolated n-MOSFET formed in high concentration p-wells is described. The threshold behavior is characterized as a function of the concentration of p-well, using experimental data and three-dimensional process/device simulations. In a high-concentration p-well, the devices with a LOCOS isolation show the INWE, which was observed in trench-isolated devices. This effect is enhanced with increase of the p-well concentration. The INWE in the LOCOS-isolated MOSFET is explained by the boron segregation phenomenon during LOCOS process and boron redistribution.<
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