Effect of porosity and pore size on dielectric constant of organosilicate based low-k films: An analytical approach

Author(s):  
Alexander P. Palov ◽  
Ekaterina N. Voronina ◽  
Tatyana V. Rakhimova ◽  
Dmitri V. Lopaev ◽  
Sergey M. Zyryanov ◽  
...  
Author(s):  
Alexander Palov ◽  
Tatiana V. Rakhimova ◽  
Mikhail B. Krishtab ◽  
Mikhail R. Baklanov
Keyword(s):  

2000 ◽  
Vol 612 ◽  
Author(s):  
R. A. Donaton ◽  
B. Coenegrachts ◽  
E. Sleeckx ◽  
M. Schaekers ◽  
G. Sophie ◽  
...  

AbstractAURORA films, which have a Si-O-Si network with –CH3 terminations, were characterized and integrated into Cu single damascene structures. The relatively low carbon concentration (∼ 20%) and the very small pore size (∼ 0.6 nm) found could be advantageous during integration of AURORA. Integration of AURORA into Cu single damascene structures was successfully achieved. Suitable resist strip processes, which are critical for Si-O-C type materials, were developed, resulting in trenches with satisfactory profiles. After a complete single damascene process, a interline dielectric constant value of 2.7 was found for line spacing down to 0.25 µm.


2002 ◽  
Vol 716 ◽  
Author(s):  
A. Grill ◽  
V. Patel ◽  
K.P. Rodbell ◽  
E. Huang ◽  
S. Christiansen ◽  
...  

AbstractWe have shown previously that the dielectric constants of PECVD prepared SiCOH dielectrics can be extended to ultralow-k values of k=2.0. The reduction in the dielectric constants has been achieved by adding an organic precursor to the tetramethylcyclotetrasiloxane (TMCTS) used for the preparation of the SiCOH dielectric and annealing the films to remove the thermally less-stable organic CHx fractions from the films, thereby adding porosity and reducing the density of the films. To assess the effects of the reduction of the dielectric constant on other physical properties of the material, the density and composition of the films have been determined by RBS and FRES and the porosity has been measured by PAS/PALS, SAXS and ellipsometric porosimetry. In addition the films have been characterized structurally and topologically by TEM and AFM.It has been found that addition of the organic precursor reduces the Si fraction in the films, however, there is no direct correlation between dielectric constant and film composition. The dielectric constant and density decrease with increasing porosity in the films, which reaches values of 30-39% for k values of 2.05. The pore size increases with decreasing k, however the diameter remains below 5 nm for k=2.05. This is significantly smaller than the pore size typically found in porous spin-on films and may provide an integration advantage compared to spin-on films having similar k values.


1999 ◽  
Vol 565 ◽  
Author(s):  
Y. Shimogaki ◽  
S. W. Lim ◽  
E. G. Loh ◽  
Y. Nakano ◽  
K. Tada ◽  
...  

AbstractLow dielectric constant F-doped silicon oxide films (SiO:F) can be prepared by adding fluorine source, like as CF4 to the conventional PECVD processes. We could obtain SiO:F films with dielectric constant as low as 2.6 from the reaction mixture of SiH4/N2 O/CF4. The structural changes of the oxides were sensitively detected by Raman spectroscopy. The three-fold ring and network structure of the silicon oxides were selectively decreased by adding fluorine into the film. These structural changes contribute to the decrease ionic polarization of the film, but it was not the major factor for the low dielectric constant. The addition of fluorine was very effective to eliminate the Si-OH in the film and the disappearance of the Si-OH was the key factor to obtain low dielectric constant. A kinetic analysis of the process was also performed to investigate the reaction mechanism. We focused on the effect of gas flow rate, i.e. the residence time of the precursors in the reactor, on growth rate and step coverage of SiO:F films. It revealed that there exists two species to form SiO:F films. One is the reactive species which contributes to increase the growth rate and the other one is the less reactive species which contributes to have uniform step coverage. The same approach was made on the PECVD process to produce low-k C:F films from C2F4, and we found ionic species is the main precursor to form C:F films.


2003 ◽  
Vol 766 ◽  
Author(s):  
Jin-Heong Yim ◽  
Jung-Bae Kim ◽  
Hyun-Dam Jeong ◽  
Yi-Yeoul Lyu ◽  
Sang Kook Mah ◽  
...  

AbstractPorous low dielectric films containing nano pores (∼20Å) with low dielectric constant (<2.2), have been prepared by using various kinds of cyclodextrin derivatives as porogenic materials. The pore structure such as pore size and interconnectivity can be controlled by changing functional groups of the cyclodextrin derivatives. We found that mechanical properties of porous low-k thin film prepared with mCSSQ (modified cyclic silsesquioxane) precursor and cyclodextrin derivatives were correlated with the pore interconnection length. The longer the interconnection length of nanopores in the thin film, the worse the mechanical properties of the thin film (such as hardness and modulus) even though the pore diameter of the films were microporous (∼2nm).


Author(s):  
Swati Gupta ◽  
Anil Gaikwad ◽  
Ashok Mahajan ◽  
Lin Hongxiao ◽  
He Zhewei

Low dielectric constant (Low-[Formula: see text]) films are used as inter layer dielectric (ILD) in nanoelectronic devices to reduce interconnect delay, crosstalk noise and power consumption. Tailoring capability of porous low-[Formula: see text] films attracted more attention. Present work investigates comparative study of xerogel, aerogel and porogen based porous low-[Formula: see text] films. Deposition of SiO2 and incorporation of less polar bonds in film matrix is confirmed using Fourier Transform Infra-Red Spectroscopy (FTIR). Refractive indices (RI) of xerogel, aerogel and porogen based low-[Formula: see text] films observed to be as low as 1.25, 1.19 and 1.14, respectively. Higher porosity percentage of 69.46% is observed for porogen-based films while for shrinked xerogel films, it is lowered to 45.47%. Porous structure of low-[Formula: see text] films has been validated by using Field Emission Scanning Electron Microscopy (FE-SEM). The pore diameters of porogen based annealed samples were in the range of 3.53–25.50 nm. The dielectric constant ([Formula: see text]) obtained from RI for xerogel, aerogel and porogen based films are 2.58, 2.20 and 1.88, respectively.


2000 ◽  
Vol 612 ◽  
Author(s):  
M.R. Baklanov ◽  
K.P. Mogilnikov

AbstractEllipsometric porosimetry (EP) is a simple and effective method for the characterization of the porosity (volume of both open and close pores), average pore size, specific surface area and pore size distribution (PSD) in thin porous films deposited on top of any smooth solid substrat e. Because a laser probe is used, small surface area can be analyzed. Therefore, EP can be used on patterned wafers and it is compatible with microelectronic technology. This method is a new version of adsorption (BET) porosimetry. In situ ellipsometry is used to determine the amount of adsorptive which adsorbed/condensed in the film. Change in refractive index is used to calculate of the quantity of adsorptive present in the film. EP also allows the study of thermal stability, adsorption and swelling properties of low-K dielectric films. Room temperature EP based on the adsorption of vapor of some suitable organic solvents and method of calculation of porosity and PSD is discussed. Examination of the validity of Gurvitsch rule for various organic adsorptives (toluene, heptane, carbon tetrachloride and isopropyl alcohol) has been carried out to assess the reliability of measurements of pore size distribution by the ellipsometric porosimetry.


2006 ◽  
Vol 914 ◽  
Author(s):  
Hanan Assaf ◽  
E. Ntsoenzok ◽  
M-O. Ruault ◽  
S. Ashok

AbstractThermally-grown 220nm-thick silicon oxide layers were implanted at room temperature with 300keV Xe at doses ranging from 0.5 to 5x1016Xe/cm2. As-implanted samples exhibit bubbles in silicon oxide for all doses. Annealing at T≤400°C results in the disappearance of bubbles from SiO2 layer for the dose of 1x1016Xe/cm2. But for the higher doses of 3.5 and 5x1016Xe/cm2, the bubbles are very stable and remain in the sample even after very high thermal annealing. Capacitance measurements show a strong decrease in the dielectric constant k of the implanted SiO2 sample from 4 (reference sample) to 1.5.


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