Thermal cycle reliability of stacked via structures with copper metallization and an organic low-k dielectric

Author(s):  
R.G. Filippi ◽  
J.F. McGrath ◽  
T.M. Shaw ◽  
C.E. Murray ◽  
H.S. Rathore ◽  
...  
1999 ◽  
Vol 565 ◽  
Author(s):  
N. Ariel ◽  
M. Eizenberg ◽  
E. Y. Tzou

AbstractIn order to achieve better performance of devices, the interconnects RC delay time, the limiting factor of the device speed today, must be reduced. This calls for a new interconnect stack: lower resistivity Copper and low k materials (k<3) as dielectrics.Fluorinated amorphous carbon (a-F:C) prepared by HDP- CVD is an attractive candidate as a low-k material. In this work we have studied the film, its stability and its interface with Copper metallization. The high density plasma CVD process resulted in a film which contains C and F at a ratio of 1:0.6 as determined by Nuclear Reactions Analysis. XPS analysis of the Cls transition indicated four types of bonds: C-C, C-CF, CF, and CF2. X-ray diffraction as well as high resolution TEM analyses proved that the film was amorphous at least up to 500°C anneal. For various applications, the advantage of adding a thin bi-layer of a-SiC/SiOx for adhesion promotion purposes was demonstrated. In addition, the interface of a-F:C and the adhesion promoter layer with Ta, TaN and Cu was studied. No interdiffusion was observed by SIMS after 400°C annealing. 500°C annealing caused F outdiffusion from the film and Cu diffusion into the adhesion promoter layer.


2002 ◽  
Vol 716 ◽  
Author(s):  
Ilanit Fisher ◽  
Wayne D. Kaplan ◽  
Moshe Eizenberg ◽  
Michael Nault ◽  
Timothy Weidman

AbstractThe success of future gigascale integrated circuits (IC) chip technology depends critically upon the reduction of the interconnects RC delay time. This calls for the development of new low dielectric constant (low-k) insulators, and for work on their integration with lower resistivity copper metallization.A porous silica based film prepared by surfactant templated self-assembly spin-on deposition (SOD) is an attractive candidate as a low-k material. In this research we have studied the structure, chemical composition and bonding of the film and its interface with copper metallization. The decomposition and vaporization of the surfactant in the last step of film deposition resulted in a film with an amorphous structure, as determined by XRD and TEM analysis. Its high porosity (35-58%) was confirmed by XRR and RBS measurements. XPS analysis of the Si2p transition indicated three types of bonding: Si-O, O-Si-C and Si-C. The bonding characteristics were also investigated by FTIR analysis. The effect of a hydrogen plasma post-treatment process on the film topography and bonding was determined by AFM and XPS, respectively. It was found that direct H2 plasma exposure significantly affected the surface roughness of the film and type of chemical bonding. The structure and properties of various PECVD deposited capping layers were also studied, as was the interface between the porous dielectric and Ta, TaxN and Cu (PVD deposited films) after annealing at 200-700°C in vacuum environment for 30 min. At temperatures up to 500°C, no significant diffusion of Cu or Ta into the porous film was detected, as determined by RBS. No copper penetration was detected up to 700°C, according to AES and SIMS analysis. However, at 700°C copper dewetting occurred when it was deposited directly on the porous silica based film.


2007 ◽  
Author(s):  
Hiraku Ishikawa ◽  
Toshihisa Nozawa ◽  
Takaaki Matsuoka ◽  
Akinobu Teramoto ◽  
Masaki Hirayama ◽  
...  

2009 ◽  
Vol 2009.6 (0) ◽  
pp. 51-52
Author(s):  
Yukihiro KUMAGAI ◽  
Hiroyuki OHTA ◽  
Masahiko Fujisawa ◽  
Takeshi Iwamoto ◽  
Aakihiko Ohsaki

1999 ◽  
Vol 564 ◽  
Author(s):  
N. Ariel ◽  
M. Eizenberg ◽  
E. Y. Tzou

AbstractIn order to achieve better performance of devices, the interconnects RC delay time, the limiting factor of the device speed today, must be reduced. This calls for a new interconnect stack: lower resistivity Copper and low k materials (k<3) as dielectrics.Fluorinated amorphous carbon (a-F:C) prepared by HDP- CVD is an attractive candidate as a low-k material. In this work we have studied the film, its stability and its interface with Copper metallization. The high density plasma CVD process resulted in a film which contains C and F at a ratio of 1:0.6 as determined by Nuclear Reactions Analysis. XPS analysis of the C Is transition indicated four types of bonds: C-C, C-CF, CF, and CF2. X-ray diffraction as well as high resolution TEM analyses proved that the film was amorphous at least up to 500°C anneal. For various applications, the advantage of adding a thin bi-layer of a-SiC/SiOx for adhesion promotion purposes was demonstrated. In addition, the interface of a-F:C and the adhesion promoter layer with Ta, TaN and Cu was studied. No interdiffusion was observed by SIMS after 400°C annealing. 500°C annealing caused F outdiffusion from the film and Cu diffusion into the adhesion promoter layer.


2000 ◽  
Vol 612 ◽  
Author(s):  
F. Lanckmans ◽  
S. H. Brongersma ◽  
I. Varga ◽  
H. Bender ◽  
E. Beyne ◽  
...  

AbstractThe adhesion between several materials implemented in Cu/low-k integration is studied. Adhesion issues at different interfaces are important with regard to the reliability of back-end processing. Layered test structures are processed to study different interfaces. A tangential shear tester allows quantifying the adhesion force at the interface and provides a relative measurement to compare various materials. Failed interfaces are analyzed using auger electron spectroscopy (AES) and scanning electron microscopy (SEM). Among all studied structures, the strongest interface is seen between a barrier (Ti(N), Ta(N), WxN) and Cu. A weaker interface proves to be between a low-k dielectric and Cu. However, the presence of a barrier increases the adhesion. The weakest interface occurs between an oxide cap and the low-k material, with a lower adhesion when the low-k material is fluorinated. The low-k/cap oxide interface forms a critical issue with regard to Cu/low-k integration processing such as chemical mechanical polishing (CMP). All test structures show no significant degradation of the adhesion after a thermal cycle up to 400°C.


2006 ◽  
Vol 504 (1-2) ◽  
pp. 243-247 ◽  
Author(s):  
K.C. Aw ◽  
N.T. Salim ◽  
W. Gao ◽  
Z. Li
Keyword(s):  

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