| Title |
The Study on Dielectric Property and Thermal Stability of Ta_2O_{5} Thin-films |
| Authors |
김인성(Kim, In-Seong) ; 이동윤(Lee, Dong-Yun) ; 송재성(Song, Jae-Seong) ; 윤무수(Yun, Mu-Su) ; 박정후(Park, Jeong-Hu) |
| Keywords |
Ta_2O_{5} ; Capacitor ; thin films ; thermal stability ; dielectric property |
| Abstract |
Capacitor material utilized in the downsizing passive devices and dynamic random access memory(DRAM) requires the physical and electrical properties at given area such as capacitor thickness reduction, relative dielectric constant increase, low leakage current and thermal stability. Common capacitor materials, SiO_2, Si_3N_4, SiO_2/Si_3N_4,TaN and et al., used until recently have reached their physical limits in their application to several hundred angstrom scale capacitor. Ta_2O_{5} is known to be a good alternative to the existing materials for the capacitor application because of its high dielectric constant (25 ~35), low leakage current and high breakdown strength. Despite the numerous investigations of Ta_2O_{5} material, there have little been established the clear understanding of the annealing effect on capacitance characteristic and conduction mechanism, design and fabrication for Ta_2O_{5} film capacitor. This study presents the structure-property relationship of reactive-sputtered Ta_2O_{5} MIM capacitor structure processed by annealing in a vacuum. X-ray diffraction patterns skewed the existence of amorphous phase in as-deposited condition and the formation of preferentially oriented-Ta_2O_{5} in 670, 700°C annealing. On 670, 700°C annealing under the vacuum, the leakage current decrease and the enhanced temperature-capacitance characteristic stability. and the leakage current behavior is stable irrespective of applied electric field. The results states that keeping Ta_2O_{5} annealed at vacuum gives rise to improvement of electrical characteristics in the capacitor by reducing oxygen-vacancy and the broken bond between Ta and O. |