Impact of physical and electrical thickness scaling on the reliability of plasma-nitrided gate dielectrics in a 90 nm SOI manufacturing technology
| Autor: | Jörg-Oliver Weidner, Lutz Herrmann, T. Mantei, Falk Graetsch, Rolf Geilenkeuser, Karsten Wieczorek |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Materials science
business.industry Mechanical Engineering Gate dielectric Silicon on insulator Time-dependent gate oxide breakdown Condensed Matter Physics Capacitance PMOS logic Ion implantation Mechanics of Materials Optoelectronics General Materials Science business NMOS logic Leakage (electronics) |
| Zdroj: | Materials Science and Engineering: B. 118:50-54 |
| ISSN: | 0921-5107 |
| Popis: | Appropriate balancing of the polysilicon dopant concentration and the physical gate dielectric thickness is required so as to accomplish a minimized capacitance equivalent thickness (CET) at low gate leakage (JG) and high reliability. Here, we investigate the impact of polysilicon predoping and physical gate-dielectric thickness scaling on the interaction of CET, JG and TDDB reliability for both NMOS- and PMOS-devices for physical thicknesses between 1.28 and 1.58 nm. Furthermore, the impact of an additional N14+ ion implantation into the PMOS gate is investigated. For NMOS both modal lifetime and leakage current density are not influenced by changes of the poly-depletion layer thickness or the CET, respectively, that result from increasing phosphorus implant dose. Since JG scales with physical thickness and since modal lifetime strongly depends upon JG, both physical thickness and leakage current density can be used to determine the thickness scaling of gate dielectrics reliability. A similar result is found for pMOS though the CET is varied less by the increased boron doping level. Boron penetration resulting in degraded TDDB reliability was observed for the physically thinnest split for excess boron doping by p-polysilicon ion-implantation. An additional nitrogen implant into the p-poly proved to prevent pMOS devices from reliability degradation, however, at the expense of any scalability margin that additional boron would eventually offer. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect