Modelling of the carrier transport properties in nanostructured devices with applications in advanced logic technologies
Ultra-thin high-k oxides are widely used in todays advanced Complementary Metal-Oxide-Semiconductor technology to continue scalability and to increase performance due to a large dielectric constant (k>8) and low leakage current. Understanding conduction mechanisms (CMs) through these oxides is im...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2018 |
| País: | México |
| Institución: | Instituto Nacional de Astrofísica, Óptica y Electrónica |
| Repositorio: | Repositorio Institucional del INAOE |
| Idioma: | inglés |
| OAI Identifier: | oai:inaoe.repositorioinstitucional.mx:1009/1390 |
| Acceso en línea: | http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1390 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/Inspec/AlD info:eu-repo/classification/Inspec/High-K info:eu-repo/classification/Inspec/Conduction mechanisms info:eu-repo/classification/Inspec/MIS capacitor info:eu-repo/classification/Inspec/Resonant tunneling info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/22 info:eu-repo/classification/cti/2203 |
| Sumario: | Ultra-thin high-k oxides are widely used in todays advanced Complementary Metal-Oxide-Semiconductor technology to continue scalability and to increase performance due to a large dielectric constant (k>8) and low leakage current. Understanding conduction mechanisms (CMs) through these oxides is important to accurately make predictions ensuring the long-term operation of these devices. Nevertheless, this task presents several challenges due to several physical and electronic considerations like: 1) precise atomic control of the high-k material in the ultra-thin regime (thickness, stoichiometry, dielectric constant, etc), 2) excessively large gate leakage current levels, 3) appearance of several conduction mechanisms which degrade the performance and reliability of the devices, 4) interfacial defects at the high-k/silicon interface and 5) low thermodynamic stability of the high-k materials. With the purpose to make accurate predictions of lifetime and/or reliability characteristics, this work reviews the conduction mechanisms of fabricated Metal-Insulator-Semiconductor (MIS) devices using ultra-thin Al₂O₃, HfO₂, and TiO₂, (less than 10 nm in thickness for each dielectric) deposited by Atomic Layer Deposition (ALD). This deposition technique presents several advantages like: 1) high reproducibility and conformality, 2) outstanding control (to atomic level) on the thickness and stoichiometry, 3) good interface properties with the semiconductor substrate, and 4) low deposition temperature (T ≤ 250°C) for these metal oxides which enables enhanced performance and therefore, more accurate reliability predictions. After fabrication, MIS devices were electrically characterized using standard Ig-Vg, C-V, and Ig-Vg-temperature measurement to determine the precise carrier conduction mechanism for each dielectric under different conditions of passivation (SiOx) and post-metallization annealing. Physical and electronic parameters such as barrier height ᴃ, energy trap level ᴛ and effective mass m* were extracted and further validated using semi-empirical models in MATLAB and SILVACO and compared with those found in literature, having excellent agreement. From this study a simple but practical correlation between materials’ properties with device performance could be obtained and compared among these high-k oxides. |
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