Plasma-assisted ALD of TiN/Al2O3 stacks for MOS trench capacitor applications

The increasing demand for high performance and multifunctional electronic products requires more efficient system integration technologies. System in Package technology is a recent development in silicon based packaging technology. For integration of passives large interest exists in high-density MOS (Metal Oxide Semiconductor) trench capacitors for rf decoupling and filtering applications, with which high capacitance densities can be realized. To realize this, Atomic Layer Deposition (ALD) is used for deposition of oxides and metals in high aspect ratio structures. In this work the application of plasma-assisted ALD TiN/Al2O3 stacks deposited in situ at a single deposition temperature is studied for trench MOS capacitors. This investigation is pursued in three steps. First as-deposited planar TiN/Al2O3/p-Si stacks are characterized. Here, the objective is to gain a fundamental understanding of the processing and characterization of MOS trench capacitors. Based on this characterization possibilities for optimization of performance and processing are strived for in the next step. Finally, TiN/Al2O3 stacks are deposited in high aspect ratio trenches and its performance is characterized for MIM and MIMIM trench capacitors. The measurement and analysis techniques can be categorized into structural and electrical measurements. With structural measurements properties such as the atomic composition and the crystal structure are investigated. Electrical measurements include I-V and C-V measurements, which are extensively applied in this work. Prior to the processing of MOS capacitors, literature research of their theoretical background is performed allowing for a broad insight into the quality of MOS capacitors by means of the mentioned measurement and analysis techniques. Planar as-deposited TiN/Al2O3/p-Si stacks have successfully been deposited for different Al2O3 thicknesses and at different deposition temperatures from 300?C to 400?C. High quality of the asdeposited stacks is confirmed by high Al2O3 k values of ? 8, low leakage current (? 10?9 A/cm2), high intrinsic breakdown electric fields between 7 and 12 MV/cm and excellent Fowler-Nordheim tunneling behavior. No significant or unexpected trends are observed as a function of the deposition temperature or Al2O3 thickness. A series of TiN/Al2O3/p-Si stacks have successfully been deposited on planar substrates with different separation times between the end of the Al2O3 and beginning of the TiN deposition. Unprecedented separation times are achieved from 15 s to 60 s. TiN/Al2O3/n++-Si stacks are successfully deposited on trenched silicon with an aspect ratio of ? 17. High stepcoverage of Al2O3 (93 ± 7 %) and sufficient TiN (41 ± 6 %) stepcoverage is achieved. Despite the large area of the trenched capacitors, excellent scaling of the capacitance with the electrode area is confirmed. For the MIMIM stack with 10 nm Al2O3 for both oxides a total capacitance density of ? 180 nF/mm2 has been demonstrated. A broad understanding of the properties and the processing of TiN/Al2O3/Si MOS trench capacitors is obtained as a result of this work. The experience and knowledge gained this work can function as a first step towards in situ plasma-assisted ALD processing of other high-k oxides and/or electrodes in 3D silicon to achieve even higher capacitance densities. The increasing demand for high performance and multifunctional electronic products requires more efficient system integration technologies. System in Package technology is a recent development in silicon based packaging technology. For integration of passives large interest exists in high-density MOS (Metal Oxide Semiconductor) trench capacitors for rf decoupling and filtering applications, with which high capacitance densities can be realized. To realize this, Atomic Layer Deposition (ALD) is used for deposition of oxides and metals in high aspect ratio structures. In this work the application of plasma-assisted ALD TiN/Al2O3 stacks deposited in situ at a single deposition temperature is studied for trench MOS capacitors. This investigation is pursued in three steps. First as-deposited planar TiN/Al2O3/p-Si stacks are characterized. Here, the objective is to gain a fundamental understanding of the processing and characterization of MOS trench capacitors. Based on this characterization possibilities for optimization of performance and processing are strived for in the next step. Finally, TiN/Al2O3 stacks are deposited in high aspect ratio trenches and its performance is characterized for MIM and MIMIM trench capacitors. The measurement and analysis techniques can be categorized into structural and electrical measurements. With structural measurements properties such as the atomic composition and the crystal structure are investigated. Electrical measurements include I-V and C-V measurements, which are extensively applied in this work. Prior to the processing of MOS capacitors, literature research of their theoretical background is performed allowing for a broad insight into the quality of MOS capacitors by means of the mentioned measurement and analysis techniques. Planar as-deposited TiN/Al2O3/p-Si stacks have successfully been deposited for different Al2O3 thicknesses and at different deposition temperatures from 300?C to 400?C. High quality of the asdeposited stacks is confirmed by high Al2O3 k values of ? 8, low leakage current (? 10?9 A/cm2), high intrinsic breakdown electric fields between 7 and 12 MV/cm and excellent Fowler-Nordheim tunneling behavior. No significant or unexpected trends are observed as a function of the deposition temperature or Al2O3 thickness. A series of TiN/Al2O3/p-Si stacks have successfully been deposited on planar substrates with different separation times between the end of the Al2O3 and beginning of the TiN deposition. Unprecedented separation times are achieved from 15 s to 60 s. TiN/Al2O3/n++-Si stacks are successfully deposited on trenched silicon with an aspect ratio of ? 17. High stepcoverage of Al2O3 (93 ± 7 %) and sufficient TiN (41 ± 6 %) stepcoverage is achieved. Despite the large area of the trenched capacitors, excellent scaling of the capacitance with the electrode area is confirmed. For the MIMIM stack with 10 nm Al2O3 for both oxides a total capacitance density of ? 180 nF/mm2 has been demonstrated. A broad understanding of the properties and the processing of TiN/Al2O3/Si MOS trench capacitors is obtained as a result of this work. The experience and knowledge gained this work can function as a first step towards in situ plasma-assisted ALD processing of other high-k oxides and/or electrodes in 3D silicon to achieve even higher capacitance densities

Case Note: The South China Sea Dispute and the Role of UNCLOS in the Settlement of the Dispute

In the summer of 2016, the Permanent Court of Arbitration (PCA) in the Hague ruled on a territorial dispute between the Philippines and the People’s Republic of China (PRC) over the South China Sea (SCS). In brief, the PCA found the claims of the PRC over most areas of the South China Sea illegitimate and therefore did not recognize the PRC’s claim of territoriality over these waters. In this case note, I explore the details of this PCA case, through a close analysis of the relevant case documents. I conclude the note by looking at different precedents set by this particular case. To do so, I also briefly turn attention to the relevant legal concepts of maritime law and the mechanisms for maritime dispute settlement, provided for in the United Nations Convention on the Law of the Sea (UNCLOS). In doing so, I identify how these legal concepts come into play in this particular case and explore its possible implications on future cases of maritime dispute settlement.À l’été 2016, la Cour permanente d’arbitrage (CPA) de La Haye s’est prononcée sur un différend territorial entre les Philippines et la République populaire de Chine (RPC) concernant la mer de Chine méridionale. En résumé, la CPA a jugé les revendications de la RPC sur la plupart des régions de la mer de Chine méridionale illégitimes et n’a donc pas reconnu la prétention de la RPC à la territorialité sur ces eaux. Dans cette note de jurisprudence, j’explore les détails de cette affaire en analysant de près les documents pertinents du cas. Je conclus la note en examinant différents précédents établis par ce cas particulier. Pour ce faire, j’attire également brièvement l’attention sur les concepts juridiques pertinents du droit maritime et sur les mécanismes de règlement des différends maritimes, prévus dans la Convention des Nations Unies sur le droit de la mer (CNUDM). Ce faisant, j’identifie la manière dont ces concepts juridiques entrent en jeu dans ce cas particulier et explore ses implications possibles sur les futurs cas de règlement des différends maritimes.En el verano de 2016, la Corte Permanente de Arbitraje (CPA) de La Haya falló sobre una disputa territorial entre Filipinas y la República Popular China (RPC) respecto al mar del Sur de China. En resumen, la CPA consideró ilegítimos la mayoría de los reclamos de la RPC y, por lo tanto, no reconoció su reclamo de territorialidad sobre estas aguas. En este análisis de la decisión, exploro los detalles del caso analizando detenidamente los documentos relevantes. Concluyo la nota examinando los precedentes establecidos por este fallo. Para ello, llamo brevemente la atención sobre los conceptos jurídicos relevantes del derecho marítimo y los mecanismos para la solución de controversias marítimas previstos en la Convención de las Naciones Unidas sobre el Derecho del Mar (CNUDM). También identifico cómo estos conceptos legales interactúan en este caso particular y exploro sus posibles implicaciones para la resolución de futuras disputas marítimas