Swift ion irradiation effect on high-k ZrO2- and Al2O3-based MOS devices |
| |
Authors: | Ashwath Rao Priyanka Chaurasia B. R. Singh |
| |
Affiliation: | Department of Microelectronics, Indian Institute of Information Technology, Allahabad, India |
| |
Abstract: | This paper describes the heavy ion-induced effects on the electrical characteristics of reactively sputtered ZrO2 and Al2O3 high-k gate oxides deposited in argon plus nitrogen containing plasma. Radiation-induced degradation of sputtered high-k dielectric ZrO2/Si and Al2O3/Si interface was studied using 45?MeV Li3+ ions. The devices were irradiated with Li3+ ions at various fluences ranging from 5?×?109 to 5?×?1012?ions/cm2. Capacitance–voltage and current–voltage characteristics were used for electrical characterization. Shift in flat band voltage towards negative value was observed in devices after exposure to ion radiation. Post-deposition annealing effect on the electrical behavior of high-k/Si interface was also investigated. The annealed devices showed better electrical and reliability characteristics. Different device parameters such as flat band voltage, leakage current, interface defect density and oxide-trapped charge have been extracted.The surface morphology and roughness values for films deposited in nitrogen containing plasma before and after ion radiation are extracted from Atomic Force Microscopy. |
| |
Keywords: | Al2O3 swift ion radiation high-k ZrO2 |
|