Tantalum as an insulating barrier can take the place of Al in magnetic tunnel junctions (MTJs). Ta barriers in MTJs were fabricated by natural oxidation. X-ray photoelectron spectroscopy (XPS) was used to characterize...Tantalum as an insulating barrier can take the place of Al in magnetic tunnel junctions (MTJs). Ta barriers in MTJs were fabricated by natural oxidation. X-ray photoelectron spectroscopy (XPS) was used to characterize the oxidation states of Ta barrier. The experimental results show that the chemical state of tantalum is pure Ta^(5+) and the thickness of the oxide is 1.3 nm. The unoxidized Ta in the barrier may chemically reacted with NiFe layer which is usually used in MTJs to form an intermetallic compound, NiTa_2. A magnetic 'dead layer' could be produced in the NiFe/Ta interface. The 'dead layer' is likely to influence the spinning electron transport and the magnetoresistance effect.展开更多
Tantalum as an insulating barrier can take the place of Al in magnetic tunneljunctions (MTJs). Ta barriers in MTJs were fabricated by natural oxidation. X-ray photoelectronspectroscopy (XPS) was used to characterize t...Tantalum as an insulating barrier can take the place of Al in magnetic tunneljunctions (MTJs). Ta barriers in MTJs were fabricated by natural oxidation. X-ray photoelectronspectroscopy (XPS) was used to characterize the oxidation states of Ta barrier. The experimentalresults show that the chemical state of tantalum is pure Ta^(5+) and the thickness of the oxide is1.3 nm. The unoxidized Ta in the barrier may chemically reacted with NiFe layer which is usuallyused in MTJs to form an intermetallic compound, NiTa_2. A magnetic 'dead layer' could be produced inthe NiFe/Ta interface. The 'dead layer' is likely to influence the spinning electron transport andthe magnetoresistance effect.展开更多
Multi Tunnel Junctions (MTJs) have attracted much attention recently in the fields of Single-Electron Transistor (SET) and Single-Electron Memory (SEM). In this paper, we investigate a nano-device structure using a tw...Multi Tunnel Junctions (MTJs) have attracted much attention recently in the fields of Single-Electron Transistor (SET) and Single-Electron Memory (SEM). In this paper, we investigate a nano-device structure using a two one dimensional array MTJs connected to the basic Single Electron Circuits, in order to analyze the impact of physical parameters on the performances and application of this structure. The device generates can operate at room temperature. The simulation of single-electron circuit demonstrates with Monte Carlo simulator, SIMON.展开更多
文摘Tantalum as an insulating barrier can take the place of Al in magnetic tunnel junctions (MTJs). Ta barriers in MTJs were fabricated by natural oxidation. X-ray photoelectron spectroscopy (XPS) was used to characterize the oxidation states of Ta barrier. The experimental results show that the chemical state of tantalum is pure Ta^(5+) and the thickness of the oxide is 1.3 nm. The unoxidized Ta in the barrier may chemically reacted with NiFe layer which is usually used in MTJs to form an intermetallic compound, NiTa_2. A magnetic 'dead layer' could be produced in the NiFe/Ta interface. The 'dead layer' is likely to influence the spinning electron transport and the magnetoresistance effect.
基金This work was financially supported by the National Natural Science Foundation of China and the Research Foundation for the Doctoral Program of Higher Education of China under Grant No.50271007 and 20030008003, respectively
文摘Tantalum as an insulating barrier can take the place of Al in magnetic tunneljunctions (MTJs). Ta barriers in MTJs were fabricated by natural oxidation. X-ray photoelectronspectroscopy (XPS) was used to characterize the oxidation states of Ta barrier. The experimentalresults show that the chemical state of tantalum is pure Ta^(5+) and the thickness of the oxide is1.3 nm. The unoxidized Ta in the barrier may chemically reacted with NiFe layer which is usuallyused in MTJs to form an intermetallic compound, NiTa_2. A magnetic 'dead layer' could be produced inthe NiFe/Ta interface. The 'dead layer' is likely to influence the spinning electron transport andthe magnetoresistance effect.
文摘Multi Tunnel Junctions (MTJs) have attracted much attention recently in the fields of Single-Electron Transistor (SET) and Single-Electron Memory (SEM). In this paper, we investigate a nano-device structure using a two one dimensional array MTJs connected to the basic Single Electron Circuits, in order to analyze the impact of physical parameters on the performances and application of this structure. The device generates can operate at room temperature. The simulation of single-electron circuit demonstrates with Monte Carlo simulator, SIMON.
