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.

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.

Studies of the Coefficient of Thermal Expansion of Low-k ILD Materials by X-Ray Reflectivity

2006 ◽  
Vol 914 ◽  
Author(s):  
George Andrew Antonelli ◽  
Tran M. Phung ◽  
Clay D. Mortensen ◽  
David Johnson ◽  
Michael D. Goodner ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Chemical Vapor ◽  
Dielectric Materials ◽  
Free Standing ◽  
Dielectric Thin Films ◽  
X Ray ◽  
Chemical Vapor Deposited ◽  
Low K

AbstractThe electrical and mechanical properties of low-k dielectric materials have received a great deal of attention in recent years; however, measurements of thermal properties such as the coefficient of thermal expansion remain minimal. This absence of data is due in part to the limited number of experimental techniques capable of measuring this parameter. Even when data does exist, it has generally not been collected on samples of a thickness relevant to current and future integrated processes. We present a procedure for using x-ray reflectivity to measure the coefficient of thermal expansion of sub-micron dielectric thin films. In particular, we elucidate the thin film mechanics required to extract this parameter for a supported film as opposed to a free-standing film. Results of measurements for a series of plasma-enhanced chemical vapor deposited and spin-on low-k dielectric thin films will be provided and compared.

Thermal conductivity study of porous low K dielectric materials

1999 ◽  
Vol 565 ◽  
Author(s):  
Chuan Hu ◽  
Michael Morgen ◽  
Paul S. Ho ◽  
Anurag Jain ◽  
William. N. Gill ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Materials ◽  
Porous Films ◽  
Low Dielectric ◽  
Omega Method ◽  
3 Omega ◽  
Low Dielectric Constant Materials ◽  
Low K ◽  
Method Analysis

AbstractA quantitative characterization of the thermal properties is required to assess the thermal performance of low dielectric constant materials. Recently we have developed a technique based on the 3-omega method for measuring the thermal conductivity of porous dielectric thin films. In this paper we present the results on the measurements of thermal conductivity of thin porous films using this method. A finite element method analysis is used to evaluate the approximations used in the measurement. Two porosity-weighted thermal resistor models are proposed to interpret the results. By studying the dependence of the thermal conductivity on porosity, we are able to discuss the scaling rule of thermal conductivity. Additionally, a steady state layered heater model is used for evaluating the significance of introducing porous ILDs into an interconnect structure.

Characterization of chemical-vapor-deposited low-k thin films using x-ray porosimetry

2003 ◽  
Vol 82 (7) ◽  
pp. 1084-1086 ◽  
Author(s):  
Hae-Jeong Lee ◽  
Eric K. Lin ◽  
Barry J. Bauer ◽  
Wen-li Wu ◽  
Byung Keun Hwang ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor ◽  
X Ray ◽  
Chemical Vapor Deposited ◽  
Low K

Characterization of oxygen and nitrogen rapid thermal annealing processes for ultra-low-k SiCOH films

2008 ◽  
Vol 23 (3) ◽  
pp. 856-861 ◽  
Author(s):  
Sungwoo Lee ◽  
Donggeun Jung ◽  
Jaeyoung Yang ◽  
Jin-hyo Boo ◽  
Hyoungsub Kim ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Treatment Temperature ◽  
Ftir Analysis ◽  
Film Properties ◽  
The Fourier Transform ◽  
Low K

Rapid thermal annealing (RTA) processing under N2 and O2 ambient is suggested and characterized in this work for improvement of SiCOH ultra-low-k (k = 2.4) film properties. Low-k film was deposited by plasma-enhanced chemical vapor deposition (PECVD) with decamethylcyclopentasiloxane and cyclohexane precursors. The PECVD films were treated by RTA processing in N2 and O2 environments at 550 °C for 5 min, and k values of 1.85 and 2.15 were achieved in N2 and O2 environments, respectively. Changes in the k value were correlated with the chemical composition of C–Hx and Si–O related groups determined from the Fourier transform infrared (FTIR) analysis. As the treatment temperature was increased from 300 to 550 °C, the signal intensities of both the CHx and Si–CH3 peaks were markedly decreased. The hardness and modulus of the film processed by RTA have been determined as 0.44 and 3.95 GPa, respectively. Hardness and modulus of RTA-treated films were correlated with D-group [O2Si–(CH3)2] and T-group [O3Si–(CH3)] fractions determined from the FTIR Si–CH3 bending peak. The hardness and modulus improvement in this work is attributed to the increase of oxygen content in (O)x–Si–(CH3)y by rearrangement.

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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