Study Of Interface Properties Of High-K Gate Dielectric/GeO_x/Ge-Based Gate Structure

As Si-transistor technology advances beyond the 10 nm node,it has been more difficult to further enhance the performance of MOSFET on Si platform due to inherent limitations of Si material.The device research community is increasingly paying close attention to the replacement materials of Si with novel and high mobility as the transistor channel.Among several possible candidate materials,germanium?Ge?is a promising one.However,several issues still need to be solved before germanium can be completely applied as a proven technology to the field-effect-transistor?FET?with high performance.One of the critical issues is to provide a high-quality interfacial layer,which can avoid causing substantial drive current degradation in both low equivalent oxide thickness and short channel regime.Recently,high-quality GeO₂ has recently been reconsidered as a promising passivation layer due to its extremely low Dit and its potential to enable high performance Ge n-MOSFETs.And wonderful electrical characteristics can be gained from the devices which equipe with a GeOx interface layer formed by Plasma Post Oxidation.If the growth mechanism of it can be grasped,the fundamental of decreasing dangling bonds and improving device performance of GeOx interface layer would be further understood,which is significant for the improvement and perfection of the fabrication technology of devices.In this paper,four of Ge surface passivation methods have been compared and analyzed that the advantages of low preparation conditions and good passivation effect have been found on the plasma post oxidation?PPO?.What's more,the study about the passivation mechanism of this method is not yet perfect.To this end,several representative spectroscopy have been investigated.And the X-ray photoelectron spectroscopy is chosen as the core detection technique for researching the growth mechanism of PPO GeOx.Finally,the growth mechanism of GeOx interface layer formed by Plasma Post Oxidation is systematically investigated based on angle resolved X-ray photoelectron spectroscopy?AR-XPS?.By analyzing the area intensity ratio of different states of Germanium element as a function of GeOx thickness or takeoff angle,we find that the GeOx grown by PPO does not obey layer-by-layer growth mode.