AbstractPrior to any attempt to model a charge transport mechanism a precise knowledge of the parameters on which the current depends is essential. In this work the soft breakdown (SBD) failure mode of ultrathin (35 nm) SiU2 layers in polysiliconoxidesemiconductor structures is investigated. This conduction regime is characterized by a large leakage current and by multilevel current fluctuations both at low applied voltages. In order to obtain a general picture of SBD roomtemperature currentvoltage (IV) measurements have been performed on samples with different gate areas oxide thicknesses and substrate types. An astounding matching between some of these IV characteristics has been found. The obtained results and the comparison with the final breakdown regime suggest that the current flow through a SBD spot is largely influenced by its atomicscale dimensions as occurs in a point contact configuration. Experimental data are also presented which demonstrate that specific current fluctuations can be ascribed to a blocking behavior of unstable SBD conduction channels. © 2000 IEEE.
|Journal||IEEE Transactions on Electron Devices|
|Publication status||Published - 1 Jan 2000|
- Charge injection
- Dielectric breakdown
- Leakage currents
- Mos devices