The Formation of TiN-Encapsulated Cu Interconnects

MRS Proceedings ◽

10.1557/proc-260-605 ◽

1992 ◽

Vol 260 ◽

Cited By ~ 2

Author(s):

Jian Li ◽

J. W. Strane ◽

S. W. Russell ◽

P. Chapman ◽

Y. Shacham-Diamand ◽

...

Keyword(s):

Stress Relaxation ◽

Tensile Stress ◽

Thermal Cycling ◽

Copper Film ◽

Alloy Film ◽

Ti Alloy ◽

Good Adhesion ◽

Adhesion Layer ◽

Fast Heating ◽

Copper Structure

ABSTRACTA TiN(0)-encapsulated copper structure was made by annealing a Cu-10 at%Ti alloy film evaporated on a SiO2/Si(100) substrate in N2 or NH3 ambiente. During thermal cycling, the tensile stress in the nitridated films is in the range of 200 to 800 MPa. The stress relaxation depends on the cooling cycle and the presence of interlayer between film and substrate. A fast heating rate (70°C/min.) to 550°C in an NH3 ambient can effectively suppress the formation of Cu3Ti and enhance the TiNχ(0) formation near the surface of the copper film. This self-encapsulated Cu structure exhibits good adhesion to SiO2 and oxidation resistance. A fully encapsulated Cu fine line structure can be achieved by annealing a Cu-10at%Ti alloy film in an Ar ambient at 550°C and then in an NH3 ambient at 550°C to form TiOχ/Ti5Si3 adhesion layer and TiN(O) layer, respectively.

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Isothermal Stress Relaxation in Al, Alcu and A1vpd Films

MRS Proceedings ◽

10.1557/proc-436-443 ◽

1996 ◽

Vol 436 ◽

Cited By ~ 1

Author(s):

J. P. Lokker ◽

J. F. Jongste ◽

G. C. A. M. Janssen ◽

S. Radelaar

Keyword(s):

Stress Relaxation ◽

Integrated Circuits ◽

Tensile Stress ◽

Thermal Cycling ◽

Mechanical Behavior ◽

Mechanical Stress ◽

Plasma Etching ◽

Isothermal Treatment ◽

Aluminum Metallization ◽

Curvature Measurements

AbstractMechanical stress and its relaxation in aluminum metallization in integrated circuits (IC) are a major concern for the reliability of the material. It is known that adding Cu improves the reliability but complicates plasma etching and increases corrosion sensitivity. The mechanical behavior of AlVPd, AlCu and Al blanket films is investigated by wafer curvature measurements. During thermal cycling between 50°C and 400°C the highest tensile stress is found in AlVPd. In a subsequent experiment, the cooling was interrupted at several temperatures to investigate the stress behavior during an eight hour isothermal treatment. Isothermal stress relaxation has been observed in the three types of films and is discussed.

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Isothermal Stress Relaxation In Al, AlCu and AlVPd Films

MRS Proceedings ◽

10.1557/proc-428-513 ◽

1996 ◽

Vol 428 ◽

Author(s):

J. P. Lokker ◽

J. F. Jongste ◽

G. C. A. M. Janssen ◽

S. Radelaar

Keyword(s):

Stress Relaxation ◽

Integrated Circuits ◽

Tensile Stress ◽

Thermal Cycling ◽

Mechanical Behavior ◽

Mechanical Stress ◽

Plasma Etching ◽

Isothermal Treatment ◽

Aluminum Metallization ◽

Curvature Measurements

AbstractMechanical stress and its relaxation in aluminum metallization in integrated circuits (IC) are a major concern for the reliability of the material. It is known that adding Cu improves the reliability but complicates plasma etching and increases corrosion sensitivity. The mechanical behavior of AIVPd, AlCu and Al blanket films is investigated by wafer curvature measurements. During thermal cycling between 50°C and 400°C the highest tensile stress is found in AIVPd. In a subsequent experiment, the cooling was interrupted at several temperatures to investigate the stress behavior during an eight hour isothermal treatment. Isothermal stress relaxation has been observed in the three types of films and is discussed.

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Temperature Dependence of Stress Relaxation at the Copper/Polyimide Interface

MRS Proceedings ◽

10.1557/proc-79-351 ◽

1986 ◽

Vol 79 ◽

Cited By ~ 4

Author(s):

S. T. Chen ◽

C. H. Yang ◽

H. M. Tong ◽

P. S. Ho

Keyword(s):

Thin Film ◽

Stress Relaxation ◽

Thermal Cycling ◽

Temperature Dependence ◽

Room Temperature ◽

Copper Film ◽

Interfacial Stress ◽

Film Stress ◽

Cross Sectional ◽

Cu Film

AbstractA Cu/polyimide thin film couple prepared on a thin quartz reed has been used to study interfacial stress relaxation during thermal cycling between room temperature and 400 °C. The polyimide thickness varies from 0 (no polyimide at all) to 10.5μm while the Cu thickness was fixed at 0.53μm. The average copper film stress has been calculated from the curvature of the quartz reed. The information clarifies the relation between the polyimide thickness and the average Cu film stress. The Cu/polyimide interfacial morphology after thermal cycling has also been examined using the cross sectional TEM technique. The results suggest that the interfacial stress is partially released through the deformation of polyimide near the Cu/polyimide interface.

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Stress Relaxation and the Formation of Silicides in the Process of the Crystallization of NI-NB Films on SI

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088804 ◽

1991 ◽

Vol 49 ◽

pp. 898-899

Author(s):

N. Rozhanski ◽

V. Lifshitz

Keyword(s):

Thin Films ◽

Stress Relaxation ◽

Integrated Circuits ◽

Direct Evidence ◽

Alloy Film ◽

Diffusion Barriers ◽

Effective Barrier

Thin films of amorphous Ni-Nb alloys are of interest since they can be used as diffusion barriers for integrated circuits on Si. A native SiO2 layer is an effective barrier for Ni diffusion but it deformation during the crystallization of the alloy film lead to the appearence of diffusion fluxes through it and the following formation of silicides. This study concerns the direct evidence of the action of stresses in the process of the crystallization of Ni-Nb films on Si and the structure of forming NiSi2 islands.

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Evolution of the microstructure of Cu(Ti)/SiO2 layers annealed in NH3

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100138634 ◽

1995 ◽

Vol 53 ◽

pp. 452-453

Author(s):

J. Liu ◽

N. D. Theodore ◽

D. Adams ◽

S. Russell ◽

T. L. Alford ◽

...

Keyword(s):

Thermal Stability ◽

Titanium Nitride ◽

Large Scale ◽

Standard Procedure ◽

Alloy Film ◽

Electron Beam Evaporation ◽

Copper Metallization ◽

Nominal Composition ◽

Ti Alloy ◽

Thermally Grown

Copper-based metallization has recently attracted extensive research because of its potential application in ultra-large-scale integration (ULSI) of semiconductor devices. The feasibility of copper metallization is, however, limited due to its thermal stability issues. In order to utilize copper in metallization systems diffusion barriers such as titanium nitride and other refractory materials, have been employed to enhance the thermal stability of copper. Titanium nitride layers can be formed by annealing Cu(Ti) alloy film evaporated on thermally grown SiO2 substrates in an ammonia ambient. We report here the microstructural evolution of Cu(Ti)/SiO2 layers during annealing in NH3 flowing ambient.The Cu(Ti) films used in this experiment were prepared by electron beam evaporation onto thermally grown SiO2 substrates. The nominal composition of the Cu(Ti) alloy was Cu73Ti27. Thermal treatments were conducted in NH3 flowing ambient for 30 minutes at temperatures ranging from 450°C to 650°C. Cross-section TEM specimens were prepared by the standard procedure.

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