Soft breakdown of ultra-thin gate oxide layers
| Autor: | M. Depas, Tanya Nigam, M.M. Heyns |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Materials science
Dielectric strength business.industry Gate dielectric Electrical engineering Oxide Time-dependent gate oxide breakdown Electronic Optical and Magnetic Materials law.invention Capacitor chemistry.chemical_compound chemistry law Gate oxide Optoelectronics Breakdown voltage SILC Electrical and Electronic Engineering business |
| Zdroj: | IEEE Transactions on Electron Devices. 43:1499-1504 |
| ISSN: | 0018-9383 |
| Popis: | The dielectric breakdown of ultra-thin 3 nm and 4 nm SiO/sub 2/ layers used as a gate dielectric in poly-Si gate capacitors is investigated. The ultra-thin gate oxide reliability was determined using tunnel current injection stressing measurements. A soft breakdown mechanism is demonstrated for these ultra-thin gate oxide layers. The soft breakdown phenomenon corresponds with an anomalous increase of the stress induced leakage current and the occurrence of fluctuations in the current. The soft breakdown phenomenon is explained by the decrease of the applied power during the stressing for thinner oxides so that thermal effects are avoided during the breakdown of the ultra-thin oxide capacitor. It is proposed that multiple tunnelling via generated electron traps in the ultra-thin gate oxide layer is the physical mechanism of the electron transport after soft breakdown. The statistical distributions of the charge to dielectric breakdown and to soft breakdown for a constant current stress of the ultra-thin oxides are compared. It is shown that for accurate ultra-thin gate oxide reliability measurements it is necessary to take the soft breakdown phenomenon into account. |
| Databáze: | OpenAIRE |
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