Chemical Bonding, Permittivity and Elastic Properties in Locally Modified Organosilicate Glass

2006 ◽  
Vol 914 ◽  
Author(s):  
Ehrenfried Zschech ◽  
Heiko Stegmann ◽  
Patrick Hoffmann ◽  
Dieter Schmeisser ◽  
Pavel Potapov ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Energy Loss ◽  
Electron Energy ◽  
Chemical Bonding ◽  
Effective Permittivity ◽  
Compositional Analysis ◽  
Electrical Performance ◽  
Near Surface ◽  
Electron Energy Loss ◽  
Low K

AbstractChanging local electronic polarizability and chemical bonding in OSG in such a way that the effective permittivity - and consequently the electrical performance of the Cu/low-k structure - deteriorates only slightly and that adhesion and stiffness are improved significantly is an extremely challenging task [1], [2]. As the interconnect line spacings continue to shrink, optimization of the electrical and mechanical properties of the ILD material becomes increasingly important for Cu/low-k integration since the effect of thin regions that have been modified by special treatments on the effective material properties, e. g. keff, increases. Composition and chemical bonding, changed by plasma or beam treatments, effect the materials properties significantly. Plasma processes for resist stripping, trench etching and post-etch cleaning remove C and H containing molecular groups from the near-surface layer of OSG. Electron-beam interaction with OSG changes the chemical bonding in the low-k material. In this paper, the effect of chemical bonding on permittivity and elastic modulus is studied. Compositional analysis and chemical bonding characterization of structured ILD films with nanometer resolution is done with electron energy loss spectroscopy (EELS). The fine structure near the C-K electron energy loss edge, allows to differentiate between C-H, C-C, and C-O bonds, and consequently, between individual low-k materials and their modifications. Dielectric permittivity changes are studied based on VEELS (valence EELS) measurements and subsequent Kramers-Kronig analysis. The elastic modulus is determined with atomic force microscopy (AFM) in force modulation (FM) mode. Nanoindentation was applied as a complementary technique to obtain reference data.

scholarly journals Characterization of Chemical Bonding in Low-K Dielectric Materials for Interconnect Isolation: A XAS and EELS Study

2006 ◽  
Vol 914 ◽  
Author(s):  
Patrick Hoffmann ◽  
Dieter Schmeisser ◽  
Hans-Juergen Engelmann ◽  
Ehrenfried Zschech ◽  
Heiko Stegmann ◽  
...  
Keyword(s):  
Energy Loss ◽  
Chemical Bonding ◽  
Compositional Analysis ◽  
Chemical Vapor ◽  
Dielectric Materials ◽  
Total Electron ◽  
Near Surface ◽  
Patterned Films ◽  
Low K

AbstractThe use of low dielectric constant materials in the on-chip interconnect process reduces interconnect delay, power dissipation and crosstalk noise. To achieve the requirements of the ITRS for 2007-2009 minimal sidewall damage from etch, ash or cleans is required. In chemical vapor deposited (CVD) organo-silicate glass (OSG) which are used as intermetal dielectric (IMD) materials the substitution of oxygen in SiO2 by methyl groups (-CH3) reduces the permit-tivity significantly (from 4.0 in SiO2 to 2.6-3.3 in the OSG), since the electronic polarizability is lower for Si-C bonds than for Si-O bonds.However, plasma processing for resist stripping, trench etching and post-etch cleaning removes C and H containing molecular groups from the near-surface layer of OSG. Therefore, compositional analysis and chemical bonding characterization of structured IMD films with nanometer resolution is necessary for process optimization.OSG thin films as-deposited and after plasma treatment are studied using X-ray absorp-tion spectroscopy (XAS) and electron energy loss spectroscopy (EELS). In both techniques, the fine structure near the C1s absorption or energy loss edge, respectively, allows to identify C-H, C-C, and C-O bonds. This gives the opportunity to differentiate between individual low-k mate-rials and their modifications. The O1s signal is less selective to individual bonds. XAS spectra have been recorded for non-patterned films and EELS spectra for patterned structures. The chemical bonding is compared for as-deposited and plasma-treated low-k materials. The Fluo-rescence Yield (FY) and the Total Electron Yield (TEY) recorded while XAS measurement are compared. Examination of the C 1s near-edge structures reveal a modified bonding of the re-maining C atoms in the plasma-treated sample regions.

Probing of near surface semiconductor layers by electron energy loss spectroscopy

1990 ◽  
Vol 54-55 ◽  
pp. 1163-1172 ◽  
Author(s):  
T.S. Jones ◽  
M.Q. Ding ◽  
N.V. Richardson ◽  
C.F. McConville ◽  
M.O. Schweitzer
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Near Surface ◽  
Electron Energy Loss

The dielectric response of low-k interlayer dielectric material characterized by electron energy loss spectroscopy

2014 ◽  
Vol 187 ◽  
pp. 23-28 ◽  
Author(s):  
Pradeep K. Singh ◽  
Jan M. Knaup ◽  
Sven Zimmermann ◽  
Steffen Schulze ◽  
Stefan E. Schulz ◽  
...  
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Dielectric Response ◽  
Dielectric Material ◽  
Interlayer Dielectric ◽  
Electron Energy Loss ◽  
Low K

scholarly journals Structural Analysis of Patterned low-k Film by Electron Energy Loss Spectroscopy (EELS)

Materia Japan ◽  
2009 ◽  
Vol 48 (12) ◽  
pp. 637-637
Author(s):  
Yuji Otsuka ◽  
Naohiko Kawasaki ◽  
Yumiko Shimizu ◽  
Shinichi Ogawa
Keyword(s):  
Structural Analysis ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Electron Energy Loss ◽  
Low K

Application of Low-k Liner for Stress and Capacitance Control in Cu-TSV

2013 ◽  
Vol 2013 (1) ◽  
pp. 000017-000021
Author(s):  
C. S. Tan ◽  
L. Zhang ◽  
H.Y. Li ◽  
W. Yoo
Keyword(s):  
Elastic Modulus ◽  
Structural Reliability ◽  
Coefficient Of Thermal Expansion ◽  
Effective Permittivity ◽  
Chemical Vapor ◽  
Parasitic Capacitance ◽  
Effective Dielectric Constant ◽  
Near Surface ◽  
Compliant Layer ◽  
Low K

Through silicon via (TSV) is commonly fabricated by high aspect ratio deep silicon etching, lining with dielectric layer for electrical isolation and super-conformal filing with copper. It has been reported that Cu-TSV can exert thermo-mechanical stress on Si due to coefficient of thermal expansion (CTE) mismatch. This stress can result in undesired device mobility variation and structural reliability. In addition, TSV parasitic capacitance has the most predominant impact on the circuit operation. It is therefore imperative to reduce the TSV stress and capacitance. One solution is to use low-k dielectric as the liner since it has much lower elastic modulus and effective permittivity. In this work, low-k dielectric is successfully integrated in TSV as a liner. The implications on TSV stress, capacitance and leakage current are discussed. Due to its smaller elastic modulus (~7.2 GPa), the selected low-k carbon-doped oxide acts as a compliant layer to cushion the Cu-TSV stress on the Si compared with conventional oxide (75 GPa) by plasma enhanced chemical vapor deposition. This effectively reduces the near-surface compressive stress in Si by >25% compared with the conventional liner which is more rigid. Since the low-k liner has an effective dielectric constant of ~2.8, it is found that the integration of the low-k liner reduces the TSV capacitance by ~26% as compared with the conventional oxide liner. In summary, this work has provided evidence of the technical merits of a low-k material to mitigate the undesired Cu-TSV induced stress in the surrounding Si and the related parasitic capacitance.

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