Quantitative Study of Charge‐to‐Breakdown of Thin Gate Oxide for a p+‐Poly‐Si Metal Oxide Semiconductor Capacitor
| Autor: | Li‐shuenn Wang, Mou‐shiung Lin |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Dopant
Renewable Energy Sustainability and the Environment Chemistry Doping Analytical chemistry Oxide Charge density Charge (physics) Condensed Matter Physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry.chemical_compound Ion implantation Band bending Electric field Materials Chemistry Electrochemistry |
| Zdroj: | Journal of The Electrochemical Society. 144:698-704 |
| ISSN: | 1945-7111 0013-4651 |
| DOI: | 10.1149/1.1837471 |
| Popis: | The charge-to-breakdown (Q bd ) for p + -poly-Si MOS capacitors under positive and negative gate-bias stress was investigated. Among the various boron-implanted poly-Si samples, Q bd (+) increases with dopant concentration, but Q bd (-) decreases with the boron concentration. Meanw ile a large difference was found between the Q bd (+) and Q bd (-) values. Evidence for various degree of band bending of poly-Si was observed from C-V and Fowler-Nordheim tunneling measurements. From gate-voltage shift (ΔV g ) data after constant current stress, the centroid of the generated positive trapped charge can be determined. We modified the charge-trapping model to explain the above Q bd behavior. Hole trapping is the cause of oxide breakdown. The observed difference between gate-positive and gate-negative Q bd is due to a polarity-dependent critical trapped charge density which depends on the critical electrical field somehow related to the boron implantation. As the generated positive trapped charge reaches a critical value, part of the localized electric field near the anode disappears and the remaining part of the electric field (E) is enhanced. This critical E field triggers thermal runaway and oxide breakdown. Therefore, we determine that the amount of Q bd is related to the boron implantation. |
| Databáze: | OpenAIRE |
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