Regensburg 2010 – scientific programme

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DS: Fachverband Dünne Schichten

DS 24: High-k and Low-k Dielectrics II (Joint Session DS/DF)

DS 24.1: Talk

Wednesday, March 24, 2010, 11:15–11:30, H8

Electrical and structural characteristics of SrTaO/SrTiO based M-I-M capacitors — •Canan Baristiran Kaynak¹, Mindaugas Lukosius¹, Bernd Tillack¹, Christian Wenger¹, Guenther Ruhl², and Tom Blomberg³ — ¹IHP Im Technologiepark 25, 15236 Frankfurt Oder, Germany — ²Infineon Technologies AG, Wernerwerkstr. 2, 93049 Regensburg, Germany — ³ASM Microchemistry Ltd., Väinö Auerin katu 12 A, 00560 Helsinki, Finland

In this work, on-chip M-I-M capacitors are realized using SrTiO /SrTaO dielectric stacks. The deposition of the SrTiO dielectric is done by ALD and to get a crystalline state correspondingly high k value, 550 °C annealing temperature is applied. Moreover, SrTaO is considered as a part of barrier stack due to its amorphous characteristic at 550°C annealing temperatures. In this way, it is expected to improve the electrical characteristic of the devices. A set of M-I-M stacks such as Au/SrTiO/TaN/Si, Au/SrTaO/SrTiO/TaN/Si and Au/SrTiO/SrTaO/TaN/Si have been deposited and analyzed by means of electrical and analytical characterizations. The effect of thickness of SrTaO was also evaluated. From the C-V and J-V measurements, dielectric constant, corresponding capacitance densities and leakage current performance were extracted. For the investigation of interfaces between the stacks XPS and ToF-SIMS were utilized. The results mainly demonstrate that the use of SrTaO material in the barrier stack strongly improves the leakage current density of M-I-M capacitors due to its amorphous state which serves as a strong barrier between the dielectric and the electrode of the M-I-M capacitor.