The Correlation of Adhesion Strength with Barrier Structure in Cu Metallization

AbstractAdhesion strength in sputter-deposited Cu thin films on various types of barrier layers was investigated by scratch test. The barrier layers were Ta1-xNx with varied nitrogen concentration of 0, 0.2, 0.3, and 0.5. Microstructure observation by TEM indicated that each layer consists of mixed phases of β;-Ta, bcc-TaN0.1, hexagonal-TaN, and fcc-TaN, depending on the nitrogen concentration. A sulfur- containing amorphous phase was also present discontinuously at the Cu/barrier interfaces in all samples. Scratch test showed that delamination occurred at the Cu/barrier interface and that the overall adhesion strength increased with increasing the nitrogen concentration. A good correlation was found between the measured adhesion strength and the composing phases in the barrier layer.

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Stress, Microstructure and Temperature Stability of Reactive Sputter Deposited Ta(N) Thin Films

MRS Proceedings ◽

10.1557/proc-594-427 ◽

1999 ◽

Vol 594 ◽

Cited By ~ 1

Author(s):

K. D. Leedy ◽

M. J. O'Keefe ◽

J. T. Grant

Keyword(s):

Thin Films ◽

Photoelectron Spectroscopy ◽

Nitrogen Concentration ◽

Temperature Stability ◽

Microstructural Characterization ◽

Tantalum Nitride ◽

X Ray ◽

Nitrogen Concentrations ◽

Sputter Deposited ◽

Temperature Exposure

AbstractInterest in tantalum nitride thin films for use as diffusion barriers in Cu-based microelectronic interconnects merits the study of tantalum nitride thin film properties as a function of deposition conditions and elevated temperature exposure. In this investigation, the influence of nitrogen content and post deposition annealing on the stress, microstructure and resistivity of Ta(N) films was analyzed. Ta(N) thin films were deposited by reactive dc magnetron sputtering of a Ta target in Ar/N2 gas mixtures. With an increasing N2 to Ar flow ratio, the as-deposited crystal structure of the films changed from ß-Ta to bcc Ta with N in solid solution to TaN0.1 to Ta2N and finally to TaN. The as-deposited Ta(N) stress, grain size and resistivity of the films were found to be strongly dependent on the phase(s) present. Films with less than 20 at. % nitrogen concentration displayed large compressive stress increases during 650°C anneals in flowing N2. Phase transformations to Ta2N occurred after 650°C anneals in films with nitrogen concentrations from ∼ 15 to 25 at. %. Microstructural characterization using transmission electron microscopy and x-ray diffraction, and chemical analysis by x-ray photoelectron spectroscopy and Auger electron spectroscopy of the Ta(N) films were used to identify the as-deposited and transformed phases.

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Adhesion Strength of CuCr Alloy Films to Polyimide

MRS Proceedings ◽

10.1557/proc-390-55 ◽

1995 ◽

Vol 390 ◽

Cited By ~ 3

Author(s):

E. C. Ahn ◽

Jin Yu ◽

I. S. Park

Keyword(s):

Thin Films ◽

Adhesion Strength ◽

Hold Time ◽

Peel Strength ◽

Alloy Layer ◽

Polyimide Films ◽

Alloy Films ◽

Cr Content ◽

Sputter Deposited

ABSTRACTIn the present work, CuCr alloys with varying Cr content were sputter deposited on polyimide films, and the metal/polyimide thin films were maintained under 85° C/85%R.H. (T/H) conditions for the reliability measurements. Results showed that the peel strength without T/H treatments increased proportionally with the Cr content in the CuCr alloy layer(x) up to 17 at. %, and then saturated. Among the samples studied, the peel strength decreased with hold time under T/H conditions for all the cases, but most drastically for the sample with x=8.5. The very poor peel strength of that sample (x=8.5) was attributed to the occurrence of interfacial failures which were thought to take place along Cr-oxide/polyimide interfaces.

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Investigation on diffusion barrier properties of reactive sputter deposited TiAlxNyOz thin films for Cu metallization

Thin Solid Films ◽

10.1016/s0040-6090(03)01384-1 ◽

2004 ◽

Vol 449 (1-2) ◽

pp. 6-11 ◽

Cited By ~ 18

Author(s):

H.C. Kim ◽

T.L. Alford

Keyword(s):

Thin Films ◽

Diffusion Barrier ◽

Barrier Properties ◽

Cu Metallization ◽

Sputter Deposited

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Micro-Scratch Analysis on Adhesion between Thin Films and PES Substrate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.26-28.1153 ◽

2007 ◽

Vol 26-28 ◽

pp. 1153-1156

Author(s):

Sang Hyuk Lee ◽

Bo Hyun Seo ◽

Jong Hyun Seo

Keyword(s):

Thin Films ◽

Adhesion Strength ◽

Indium Tin Oxide ◽

Metal Layer ◽

Dissimilar Materials ◽

Scratch Test ◽

Flexible Display ◽

Aluminum Metal ◽

Film Adhesion ◽

Film Polymer

In flexible display, reliability of the thin film/polymer interface is an important issue because adhesion strength dissimilar materials is often inherently poor, and residual stresses arising from thermal mismatches or pressure exerted by vaporized moisture often lead to delaminations of interfaces. In the present study we deposited various thin films such as silicon nitride (SiNx), aluminum metal layer, and indium tin oxide on polyether sulphone (PES) substrate. The film adhesion was determined by micro-scratch test. The adhesion strength, presented by the critical load, Lc, when the film starts to delaminate, was determined as a function of plasma pretreated on PES substrate.

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Characterization of reactive phase formation in sputter-deposited Ni/Al multilayer thin films using TEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100167469 ◽

1996 ◽

Vol 54 ◽

pp. 1000-1001

Author(s):

G. Lucadamo ◽

K. Barmak ◽

C. Michaelsen

Keyword(s):

Thin Films ◽

Phase Formation ◽

Dark Field ◽

Nickel Layer ◽

Multilayer Thin Films ◽

Cross Sectional ◽

Dark Field Imaging ◽

Transmission Electron ◽

Sputter Deposited ◽

Constant Heating

The subject of reactive phase formation in multilayer thin films of varying periodicity has stimulated much research over the past few years. Recent studies have sought to understand the reactions that occur during the annealing of Ni/Al multilayers. Dark field imaging from transmission electron microscopy (TEM) studies in conjunction with in situ x-ray diffraction measurements, and calorimetry experiments (isothermal and constant heating rate), have yielded new insights into the sequence of phases that occur during annealing and the evolution of their microstructure.In this paper we report on reactive phase formation in sputter-deposited lNi:3Al multilayer thin films with a periodicity A (the combined thickness of an aluminum and nickel layer) from 2.5 to 320 nm. A cross-sectional TEM micrograph of an as-deposited film with a periodicity of 10 nm is shown in figure 1. This image shows diffraction contrast from the Ni grains and occasionally from the Al grains in their respective layers.

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TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100167561 ◽

1996 ◽

Vol 54 ◽

pp. 1020-1021

Author(s):

F. Ma ◽

S. Vivekanand ◽

K. Barmak ◽

C. Michaelsen

Keyword(s):

Thin Films ◽

Solid State ◽

Stoichiometric Composition ◽

Analytical Electron Microscopy ◽

Grain Structure ◽

Solid State Reactions ◽

Multilayer Thin Films ◽

X Ray Diffraction ◽

X Ray ◽

Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

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