Adhesion and reliability of copper interconnects with Ta and TaN barrier layers

2000 ◽  
Vol 15 (1) ◽  
pp. 203-211 ◽  
Author(s):  
Michael Lane ◽  
Reinhold H. Dauskardt ◽  
Nety Krishna ◽  
Imran Hashim
Keyword(s):  
Quantitative Data ◽  
Copper Interconnects ◽  
Interface Fracture ◽  
Copper Metallization ◽  
Interfacial Chemistry ◽  
Adhesive Properties ◽  
Barrier Layers ◽  
Metal Plasma ◽  
Cu Interconnect ◽  
Metal Layers

With the advent of copper metallization in interconnect structures, new barrier layers are required to prevent copper diffusion into adjacent dielectrics and the underlying silicon. The barrier must also provide adequate adhesion to both the dielectric and copper. While Ta and TaN barrier layers have been incorporated for these purposes in copper metallization schemes, little quantitative data exist on their adhesive properties. In this study, the critical interface fracture energy and the subcritical debonding behavior of ion-metal-plasma sputtered Ta and TaN barrier layers in Cu interconnect structures were investigated. Specifically, the effects of interfacial chemistry, Cu layer thickness, and oxide type were examined. Behavior is rationalized in terms of relevant reactions at the barrier/dielectric interface and plasticity in adjacent metal layers.

Effect of Nitrogen Content on Interfacial Adhesion of the Ta/SiO2Interface

1999 ◽  
Vol 564 ◽  
Author(s):  
Michael Lane ◽  
Reiner Dauskardt ◽  
Nety Krishna ◽  
Imran Hashim
Keyword(s):  
Quantitative Data ◽  
Interfacial Adhesion ◽  
Silicon Oxide ◽  
Interface Fracture ◽  
Copper Metallization ◽  
Interfacial Chemistry ◽  
Adhesive Properties ◽  
Barrier Layers ◽  
Nitrogen Contents ◽  
Diffusion Properties

AbstractWith the advent of copper metallization in interconnect structures, new barrier layers are required to prevent copper diffusion into the adjacent dielectrics as well as the underlying silicon. These barriers must not only prevent interdiffusion but also provide adequate adhesion to both the dielectric and copper. Ta and TaN have received considerable attention as barrier layers in copper metallization schemes. While much has been reported on their diffusion properties, little or no quantitative data exists on their adhesive properties. We present data on both the interface fracture energy and the subcritical debonding of ionmetal- plasma sputtered Ta and TaN films on thermal silicon oxide. Data is also presented showing the significant effect of interfacial chemistry, particularly varying nitrogen contents at the TaN/SiO2interface.

Plasticity contributions to interface adhesion in thin-film interconnect structures

2000 ◽  
Vol 15 (12) ◽  
pp. 2758-2769 ◽  
Author(s):  
Michael Lane ◽  
Reinhold H. Dauskardt ◽  
Anna Vainchtein ◽  
Huajian Gao
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Fracture Energy ◽  
Fracture Resistance ◽  
Work Of Adhesion ◽  
Interface Fracture ◽  
Cohesive Stress ◽  
Wide Range ◽  
Macroscopic Fracture ◽  
Metal Layers

The effects of plasticity in thin copper layers on the interface fracture resistance in thin-film interconnect structures were explored using experiments and multiscale simulations. Particular attention was given to the relationship between the intrinsic work of adhesion, Go, and the measured macroscopic fracture energy, Gc. Specifically, the TaN/SiO2 interface fracture energy was measured in thin-film Cu/TaN/SiO2 structures in which the Cu layer was varied over a wide range of thickness. A continuum/FEM model with cohesive surface elements was employed to calculate the macroscopic fracture energy of the layered structure. Published yield properties together with a plastic flow model for the metal layers were used to predict the plasticity contribution to interface fracture resistance where the film thickness (0.25–2.5 μm) dominated deformation behavior. For thicker metal layers, a transition region was identified in which the plastic deformation and associated plastic energy contributions to Gc were no longer dominated by the film thickness. The effects of other salient interface parameters including peak cohesive stress and Go are explored.

In Situ Study of Barrier Layers Using Spectroscopic Ellipsometry and Mass Spectroscopy of Recoiled Ions

2000 ◽  
Vol 619 ◽  
Author(s):  
Y. Gao ◽  
A.H. Mueller ◽  
E.A. Irene ◽  
O. Auciello ◽  
A.R. Krauss ◽  
...  
Keyword(s):  
Real Time ◽  
Mass Spectroscopy ◽  
Spectroscopic Ellipsometry ◽  
Nitrogen Concentration ◽  
Random Access ◽  
Copper Interconnects ◽  
Access Memory ◽  
Barrier Layers ◽  
The Stability

ABSTRACTAn in situ study of barrier layers using spectroscopic ellipsometry (SE) and Time-of-Flight (ToF) mass spectroscopy of recoiled ions (MSRI) is presented. First the formation of copper silicides has been observed by real-time SE and in situ MSRI in annealed Cu/Si samples. Second TaSiN films as barrier layers for copper interconnects were investigated. Failure of the TaSiN layers in Cu/TaSiN/Si samples was detected by real-time SE during annealing and confirmed by in situ MSRI. The effect of nitrogen concentration on TaSiN film performance as a barrier was also examined. The stability of both TiN and TaSiN films as barriers for electrodes for dynamic random access memory (DRAM) devices has been studied. It is shown that a combination of in situ SE and MSRI can be used to monitor the evolution of barrier layers and detect the failure of barriers in real-time.

Modeling of Thermo-Mechanical Stresses in Copper Interconnect/Low-k Dielectric Systems

2005 ◽  
Author(s):  
Y.-L. Shen
Keyword(s):  
Structural Integrity ◽  
Temperature Response ◽  
Future Generation ◽  
Interface Fracture ◽  
Deformation Pattern ◽  
Barrier Layers ◽  
Copper Interconnect ◽  
On Chip ◽  
Interconnect Systems ◽  
Low K

Systematic finite element analyses are carried out to model the thermomechanical stresses in on-chip copper interconnect systems. Constitutive behavior of encapsulated copper films, determined by experimentally measuring the stress-temperature response during thermal cycling, is used in the model for predicting stresses in copper interconnect/low-k dielectric structures. Various combinations of oxide and polymer-based low-k dielectric schemes are considered. The evolution of stresses and deformation pattern in the dual-damascene copper, barrier layers, and the dielectrics is seen to have direct connections to the structural integrity of contemporary and future-generation devices. In particular, stresses experienced by the thin barrier layers and the mechanically weak low-k dielectrics are critically assessed. A parametric analysis on the influence of low-k material properties is also conducted. Practical implications in reliability issues such as voiding, interface fracture, electromigration and dielectric failure are discussed.

European Copper Interconnection Project

MRS Bulletin ◽  
1994 ◽  
Vol 19 (8) ◽  
pp. 75-75
Author(s):  
J. Torres
Keyword(s):  
Dielectric Material ◽  
Low Cost ◽  
Deep Submicron ◽  
Copper Metallization ◽  
Copper Interconnection ◽  
Low Temperature Processing ◽  
Circuit Fabrication ◽  
On Chip ◽  
Metal Layers ◽  
Interesting Area

Multilevel metallization is becoming an increasingly interesting area of research as circuit fabrication technologies are scaled down to deep submicron dimensions. The mainstream of today's interconnection technology is AlSiCu metallization. Al-based solutions, however, seem to be limited in resistivity as well as in electromigration performance. Because of its low electrical resistivity and its resistance to electromigration, copper is considered to be a promising new solution for on-chip interconnections. The performance of copper would allow its use in wiring with very small linewidths, as required for ULSI circuits. Before considering copper metallization in ULSI processing, however, major problems still have to be overcome.Taking into account these considerations, a European project is now devoted to the evaluation of copper-based metallization for ULSI applications. The project, Copper Interconnection (COIN), associates the efforts of seven European partners.The objectives of COIN are to evaluate and develop a set of optimized solutions which demonstrate to our industrial partners the interest of using on-chip copper metallization. High deposition rates, low temperature processing, thermal stability, reliability, and low cost are the main goals.The COIN project is devoted to an exploratory study concerning the major issues to be addressed in order to reach the above targets. The choice is to limit, for as long as possible, the modifications of existing multilevel metallization (MLM) structures to a simple replacement of the aluminum by copper interconnection levels. The refractory metal layers in MLM structures (TiSi2, Ti, TiN, W) will be maintained in the copper metallization scheme as will the use of SiO2 as the dielectric material. Another consideration in our approach is the possibility of achieving this substitution with minimum modification to existing fabrication lines. Thus, processes for copper deposition and copper patterning will be developed using existing machines and machine concepts for as long as possible.

Competing Initial Reactions at Transition-Metal/Silicon Interfaces

1985 ◽  
Vol 54 ◽  
Author(s):  
G. W. Rubloff
Keyword(s):  
Low Temperature ◽  
Transition Metal ◽  
Diffusion Processes ◽  
Uniform Motion ◽  
Ion Scattering ◽  
Interfacial Chemistry ◽  
Reaction Behavior ◽  
Temperature Deposition ◽  
Surface Diffusion Processes ◽  
Metal Layers

ABSTRACTThe process of suicide formation by contact reaction at metal/Si interfaces normally involves rather uniform motion of the growth fronts which separate metal, suicide, and Si regions, as has been observed for suicide growth in many transition-metal/Si systems. At lower temperatures, however, the reaction behavior can be complicated significantly by the presence of other material reactions which may compete with interfacial suicide formation. For refractory metals, strong interfacial mixing over considerable depth (∼ 100 Å or more) is observed at temperatures too low for the normal inlerlacial suicide formation process to contribute; the highly nonuniform character of this reaction, as shown by ion scattering and TEM studies, suggests that other material reactions (e.g., grain boundary diffusion) must dominate the interfacial chemistry at low temperature. In a similar way, anomalous and nonuniform reaction behavior during the low temperature deposition of initial transition metal layers on Si apparently involves surface diffusion processes which are faster than inlerlacial suicide formation.

scholarly journals Формирование омических контактов к слою алмазоподобного углерода, осажденному на диэлектрическую алмазную подложку

2020 ◽  
Vol 54 (9) ◽  
pp. 865
Author(s):  
А.И. Охапкин ◽  
П.А. Юнин ◽  
Е.А. Архипова ◽  
С.А. Краев ◽  
С.А. Королев ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Layer Thickness ◽  
Sheet Resistance ◽  
Thermal Annealing ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Contact Resistivity ◽  
Diamond Like Carbon ◽  
Adhesive Properties ◽  
Metal Layers

In this paper describes the process of manufacturing ohmic contacts to diamond-like carbon (DLC) layer by depositing of Au/Mo/Ti metal layers. Contacts had good mechanical and adhesive properties. Their contact resistivity ranged from 1.4 ∙ 10-4 to 6.4 ∙ 10-5 Ohm ∙ cm2 depending on the DLC layer thickness. The temperature dependence of the films sheet resistance was studied. It is shown that thin DLC layers provide better ohmic contact characteristics due to their more uniform graphitization during thermal annealing.

Characteristics of the Oxidation Barrier Layers for Copper Metallization

1994 ◽  
Author(s):  
K.-I. Lee ◽  
K.-I. Min ◽  
S.-K. Joo ◽  
K.-G. Rha ◽  
W.-S. Kim
Keyword(s):  
Copper Metallization ◽  
Barrier Layers

Sub-Quarter Micron Metallization Using Ionized Metal Plasma Technology

1998 ◽  
Vol 514 ◽  
Author(s):  
Fusen Chen ◽  
Zheng Xu ◽  
Ashok Sinha
Keyword(s):  
Film Stress ◽  
Copper Metallization ◽  
Plasma Technology ◽  
Bias Power ◽  
Tin Film ◽  
Metal Plasma ◽  
Layer Deposition ◽  
Process Pressure ◽  
Ecr Source

ABSTRACTIonized Metal Plasma (IMP) technology has been developed for liners and wetting layer deposition of sub-quarter-micron devices. Numerical modeling showed the unique advantages of IMP source over ECR source and long throw sputtering in enhancing bottom coverage. Ti and TiN bottom coverage up to 70% were demonstrated on 0.18μm contact holes. The deposition rate, uniformity, bottom coverage and film stress were optimized by tuning RF and DC powers, process pressure and bias power. In situ TiSi2 were formed in high aspect ratio contacts by depositing IMP Ti at an elevated temperature. The precisely controlled microstructure of IMP TiN film enabled low temperature aluminum planarization. The extendibility to 0.13μm technology node was demonstrated, and the application in copper metallization was revealed.

Sign in / Sign up

Export Citation Format

Share Document