Growth of tantalum nitride film as a Cu diffusion barrier by plasma-enhanced atomic layer deposition from bis((2-(dimethylamino)ethyl)(methyl)amido)methyl(tert-butylimido)tantalum complex

AbstractFor a diffusion barrier against Cu, tantalum nitride (TaN) films have been successfully deposited by both conventional thermal atomic layer deposition (ALD) and plasma assisted atomic layer deposition (PAALD), using pentakis (ethylmethlyamino) tantalum (PEMAT) and ammonia (NH3) as precursors. The growth rate of PAALD TaN at substrate temperature 250° was slightly higher than that of ALD TaN (0.80 Å/cycle for PAALD and 0.75 Å/cycle for ALD). Density of TaN films deposited by PAALD was as high as 11.0 g/cm3, considerably higher compared to the value of 8.3 g/cm3 obtained by ALD. The N: Ta ratio for ALD TaN was 44: 37 in composition and the film contained approximately 8∼10 atomic % carbon and 11 atomic % oxygen impurities. On the other hand, the ratio for PAALD TaN layers was 47: 44 and the respective carbon and oxygen contents of TaN layers decreased to 3 atomic % and 4 atomic %. The stability of 10 nm-thick TaN films as a Cu diffusion barrier was tested through thermal annealing for 30 minutes in N2 ambient and characterized by XRD, which proves the PAALD deposited TaN film to maintain better barrier properties against Cu below 800°.

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Low Temperature Two-Step Atomic Layer Deposition of Tantalum Nitride for Cu Diffusion Barrier

Journal of The Electrochemical Society ◽

10.1149/1.3223989 ◽

2009 ◽

Vol 156 (11) ◽

pp. H832 ◽

Cited By ~ 6

Author(s):

Jung-Dae Kwon ◽

Seong-Jun Jeong ◽

Jae-Wook Kang ◽

Do-Geun Kim ◽

Jong-Kuk Kim ◽

...

Keyword(s):

Low Temperature ◽

Atomic Layer Deposition ◽

Diffusion Barrier ◽

Atomic Layer ◽

Tantalum Nitride ◽

Layer Deposition ◽

Cu Diffusion Barrier

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The Integration of Plasma Enhanced Atomic Layer Deposition (PEALD) of Tantalum-Based Thin Films for Copper Diffusion Barrier Applications

MRS Proceedings ◽

10.1557/proc-766-e10.4 ◽

2003 ◽

Vol 766 ◽

Author(s):

Degang Cheng ◽

Eric T. Eisenbraun

Keyword(s):

Atomic Layer Deposition ◽

Diffusion Barrier ◽

Hydrogen Plasma ◽

Atomic Layer ◽

Barrier Properties ◽

Tantalum Nitride ◽

Copper Metallization ◽

X Ray ◽

Layer Deposition ◽

Electron Spectrometry

AbstractA plasma-enhanced atomic layer deposition (PEALD) process for the growth of tantalumbased compounds is employed in integration studies for advanced copper metallization on a 200- mm wafer cluster tool platform. This process employs terbutylimido tris(diethylamido)tantalum (TBTDET) as precursor and hydrogen plasma as the reducing agent at a temperature of 250°C. Auger electron spectrometry, X-ray photoelectron spectrometry, and X-ray diffraction analyses indicate that the deposited films are carbide rich, and possess electrical resistivity as low as 250νΔcm, significantly lower than that of tantalum nitride deposited by conventional ALD or CVD using TBTDET and ammonia. PEALD Ta(C)N also possesses a strong resistance to oxidation, and possesses diffusion barrier properties superior to those of thermally grown TaN.

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