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Electrical Properties of ZrO 2 /Al 2 O 3 /ZrO 2 ‐Based Capacitors with TiN, Ru, and TiN/Ru Top Electrode Materials
Author(s) -
Lee Woongkyu,
An Cheol Hyun,
Yoo Sijung,
Jeon Woojin,
Chung Min Jung,
Kim Sang Hyeon,
Hwang Cheol Seong
Publication year - 2018
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201800356
Subject(s) - tin , electrode , materials science , atomic layer deposition , capacitor , dielectric , capacitance , analytical chemistry (journal) , layer (electronics) , optoelectronics , metallurgy , composite material , chemistry , electrical engineering , voltage , chromatography , engineering
To improve the electrical properties of metal/insulator/metal capacitors for dynamic random access memory, the effects of the top electrode materials and their structures on the capacitor performance are examined. Three kinds of top electrode types (TiN, Ru, and TiN/Ru) are sputter‐deposited on ZrO 2 /Al 2 O 3 /ZrO 2 (ZAZ) dielectric layers grown via atomic layer deposition (ALD) on TiN bottom electrodes. The TiN/Ru top electrode samples show the highest capacitance density among the three types of top electrodes, and the Ru and TiN/Ru top electrodes show less leakage current density than the TiN top electrode. The interface property is optimized when the Ru directly contacts the insulating layer due to its higher work function. The TiN layer on the 2 nm‐thick Ru top electrode decreases the adverse interfacial reaction layer (TiO x N y ) of the dielectric/TiN bottom electrode through the scavenging oxygen atoms.