Low K Mesoporous Silica Films Through Template-Based Processing

1996 ◽  
Vol 443 ◽  
Author(s):  
P.J. Bruinsma ◽  
N.J. Hess ◽  
J.R. Bontha ◽  
J. Liu ◽  
S. Baskaran

AbstractLow dielectric-constant mesoporous silica films were prepared by condensation of a silicate network around surfactant micellar structures. Adherent, porous films 0.5–1.0 μm in thickness, and containing an ordered assemblage of ≈2 nm diameter pores were synthesized by spin-coating water/ethanol-based solutions containing a silica precursor and surfactant template. In this paper, film deposition conditions are described, and film thickness, porosity, refractive index and dielectric constant measured by ellipsometry are presented. Using a coating solution containing tetraethyl orthosilicate (TEOS) and a cationic cetyltrimethylammonium chloride (CTAC) surfactant template, the film porosity and dielectric properties were controlled over a wide range by adjusting the CTAC/TEOS molar ratio. With the CTAC/TEOS ratio between 0.1 and 0.15, the pores were highly ordered in hexagonal arrays after heat treatment at 550 °C. With a CTAC/TEOS ratio of 0.21, films with a pore volume of ≈64% (≈36 vol% silica) could be synthesized. The measured index of refraction for these highly porous films at 500 nm wavelength was 1.16, indicating that these films are potentially useful as low K interlayer dielectrics.

2008 ◽  
Vol 47-50 ◽  
pp. 973-976 ◽  
Author(s):  
Yi He Zhang ◽  
Qing Song Su ◽  
Li Yu ◽  
Hong Zheng ◽  
Hai Tao Huang ◽  
...  

A sol-gel process was used to prepare polyimide-silica hybrid films from the polyimide precursors and TEOS in N,N- dimethyl acetamide, then the hybrid film was treated with hydrofluoric acid to remove the dispersed silica particles, leaving pores with diameters between 80nm to 1µm, depending on the size of silica particles. The structure and dielectric constant of the hybrid and porous films were characterized by FTIR,SEM. The porous films displayed relatively low dielectric constant compared to the hybrid polyimide-silica films.


2005 ◽  
Vol 875 ◽  
Author(s):  
B.R. Kim ◽  
J. M. Son ◽  
J.W. Kang ◽  
K.Y. Lee ◽  
K.K. Kang ◽  
...  

AbstractDecreasing the circuit dimensions is driving the need for low-k materials with a lower dielectric constant to reduce RC delay, crosstalk, and power consumption. In case of spin-on organosilicate low-k films, the incorporation of a porogen is regarded as the only foreseeable route to decrease dielectric constant of 2.2 or below by changing a packing density. In this study, MTMS-BTMSE copolymers that had superior mechanical properties than MSSQ were blended with decomposable polymers as pore generators. While adding up to 40 wt % porogen into MTMS:BTMSE=100:50 matrix, optical, electrical, and mechanical properties were measured and the pore structure was also characterized by PALS. The result confirmed that there existed a tradeoff in attaining the low dielectric constant and desirable mechanical strength, and no more pores than necessary to achieve the dielectric objective should be incorporated. When the dielectric constant was fixed to approximately 2.3 by controlling BTMSE and porogen contents simultaneously, the thermo-mechanical properties of the porous films were also investigated for the comparison purpose. Under the same dielectric constant, the increase in BTMSE and porogen contents led to improvement in modulus measured by the nanoindentation technique but deterioration of adhesion strength obtained by the modified edge lift-off test.


2004 ◽  
Vol 462-463 ◽  
pp. 311-315 ◽  
Author(s):  
Suzhu Yu ◽  
Terence K.S. Wong ◽  
Xiao Hu ◽  
Kantisara Pita

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.


ChemInform ◽  
2001 ◽  
Vol 32 (10) ◽  
pp. no-no
Author(s):  
Seana Seraji ◽  
Yun Wu ◽  
Michael Forbess ◽  
Steven J. Limmer ◽  
Tammy Chou ◽  
...  

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