For almost forty years technological progress and economic benefit drives the scaling of CMOS-technology. The use of silicon dioxide as the gate dielectric on one hand, and highly-doped poly-silicon as the gate electrode on the other hand, offers several simplifications in processing while maintaining excellent device characteristics. However, the continuative scaling by using this material combination leads to quantum-mechanical effects that result in dramatically increased gate leakage currents. By the implementation of new materials with a high dielectric constant - if necessary in combination with metal-gate electrodes instead of poly-silicon electrodes - this problem can be preliminary solved, and hence can ongoing scaling of CMOS-devices be enabled. The present work addresses the investigation of high- dielectrics and their applicability in CMOS-devices using metal-gate electrodes. The contents firstly include the deposition of zirconium dioxide and hafnium dioxide from the gas phase using organometallic precursors, and their physico-chemical characterization. In the following, MOS-capacitors are fabricated by the selective deposition of gate electrodes made from aluminum, molybdenum, nickel, or titanium-nitride, and characterized regarding their electrical behavior.
Furthermore, these material systems are investigated regarding their thermodynamical stability.
Results demonstrate that well balanced and correctly applied annealing of the devices clearly improves electrical behaviour. However, the processed oxides do not exhibit the necessary thermodynamical stability in contact with silicon, which limits the achievable 'electrical thickness'. Nickel, molybdenum, and titanium-nitride behave as mid-gap metals regarding to silicon. We attribute these metals high potential to be applied in near-future CMOS-technology, if doped with the proper nitrogen content, or implemented as silicides.