Effects of target bias voltage in magnetic tunnel junctions grown by ion beam deposition
| Autor: | Dao N. H. Nam, Wei Chen, Stuart A. Wolf, Jiwei Lu, Kevin G. West |
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| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 106:013905 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | Magnetic tunnel junctions (MTJs) with an AlOx barrier were fabricated by a biased target ion beam deposition (BTIBD) sputtering technique using a low energy ion source (0–50 eV) and voltage biased targets. The BTIBD system applies a bias voltage directly onto the desired targets, providing enough sputtering energy and avoiding overspill contamination during film deposition. The successful deposition of AlOx-MTJs demonstrated the capability of the BTIBD to make multilayer structures with good film quality. MTJ thin film surface roughness and intermixing between layers are among the key problems leading to low tunneling magnetoresistance (TMR) performance. Here we study the effects of bias voltage on MTJ properties via the measurements of the Neel coupling field and TMR. We suggest that a lower bias voltage reduces the intermixing that occurs when a top CoFe free layer is deposited on an AlOx barrier, but produces relatively high surface roughness. On the other hand, higher energy deposition enhances both i... |
| Databáze: | OpenAIRE |
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