Berlin 2015 – scientific programme

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DS: Fachverband Dünne Schichten

DS 36: Poster Session I

DS 36.21: Poster

Thursday, March 19, 2015, 09:30–12:00, Poster A

Resistive switching behavior of HfO₂ thin films grown by plasma-assisted atomic layer deposition — •Alexander Hardtdegen and Susanne Hoffmann-Eifert — Peter Grünberg Institut (PGI-7) and JARA-FIT, Forschungszentrum Jülich, 52425 Jülich, Germany

Thin films of HfO₂ utilized in resistive switching memory (ReRAM) devices are usually grown by sputtering or thermal atomic layer deposition (ALD) using water or ozone as oxygen sources. Another interesting technique is plasma-assisted ALD, where the oxygen source is supplied by an oxygen-plasma. Advantages of this method are higher growth rates and extension of the ALD regime to lower deposition temperatures.

In this study we investigate the potential of plasma assisted ALD HfO₂ films for application in resistive switching memory cells. Thin HfO₂ films are grown by plasma assisted ALD from tetrakis[ethylmethylamino]hafnium (TEMAH) and oxygen plasma as the co-reactant. The effect of variations in the growth conditions on the thin films properties is analyzed. Thin film characterization with respect to the thickness, density, roughness, and chemical composition is performed by a variety of analytical methods.

Further, different HfO₂ films are integrated into metal/HfO₂/metal crossbar structures of about 2 µ m² size. The influence of the film quality and film thickness on the switching behavior is studied with respect to electroforming, SET and RESET steps, and the OFF/ON resistance ratio. The results are discussed in comparison to literature reports.