Low-Dielectric Constant SiO(F,C) Films for ULSI Interconnections Prepared by CF4 Plasma Ion Implantation

1998 ◽  
Vol 511 ◽  
Author(s):  
Yuanzhong Zhou ◽  
Shu Qin ◽  
Chung Chan ◽  
Paul K. Chu

ABSTRACTPlasma ion implantation (PII) doping technique has been utilized to prepare a new lowdielectric constant (low k) material SiO(F,C). Fluorine and carbon were implanted into SiO2 films by CF4 PII using an ICP plasma reactor. The effective dielectric constant of the films was significantly reduced after PH doping. An analysis of a double layer model indicated that a high quality dielectric layer with a dielectric constant down to 2.8 can be achieved by an optimized PII process. Contrasting to other conventional low-k material techniques, PII process also improved bulk resistivity and electrical field breakdown strength. The improvement possibly resulted from adding carbon into the films. The etching effect of CF4 PII could be beneficial to planarization and gap filling of dielectric interlayer.

2002 ◽  
Vol 716 ◽  
Author(s):  
Alok Nandini ◽  
U. Roy ◽  
A. Mallikarjunan ◽  
A. Kumar ◽  
J. Fortin ◽  
...  

AbstractThin films of low dielectric constant (κ) materials such as Xerogel (ĸ=1.76) and SilkTM (ĸ=2.65) were implanted with argon, neon, nitrogen, carbon and helium with 2 x 1015 cm -2 and 1 x 1016 cm -2 dose at energies varying from 50 to 150 keV at room temperature. In this work we discuss the improvement of hardness as well as elasticity of low ĸ dielectric materials by ion implantation. Ultrasonic Force Microscopy (UFM) [6] and Nano indentation technique [5] have been used for qualitative and quantitative measurements respectively. The hardness increased with increasing ion energy and dose of implantation. For a given energy and dose, the hardness improvement varied with ion species. Dramatic improvement of hardness is seen for multi-dose implantation. Among all the implanted ion species (Helium, Carbon, Nitrogen, Neon and Argon), Argon implantation resulted in 5x hardness increase in Xerogel films, sacrificing only a slight increase (∼ 15%) in dielectric constant.


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.


RSC Advances ◽  
2015 ◽  
Vol 5 (82) ◽  
pp. 66511-66517 ◽  
Author(s):  
Albert S. Lee ◽  
Sung Yeoun Oh ◽  
Seung-Sock Choi ◽  
He Seung Lee ◽  
Seung Sang Hwang ◽  
...  

Low dielectric constant poly(methyl)silsesquioxane spin-on-glass resins incorporating a cyclic precursor exhibited exceptional mechanical properties to withstand CMP processes.


2002 ◽  
Vol 124 (4) ◽  
pp. 362-366 ◽  
Author(s):  
Christopher L. Borst ◽  
Dipto G. Thakurta ◽  
William N. Gill ◽  
Ronald J. Gutmann

Successful integration of copper and low dielectric constant (low-k) materials is dependent on robust chemical-mechanical planarization (CMP) during damascene patterning. This process includes the direct removal of copper and interaction of the copper slurry with the underlying dielectric. Experiments were designed and performed to examine the CMP of two low-k polymers from Dow Chemical Company, bis-benzocyclobutene (BCB*, k=2.65) and “silicon-application low-k material” (SiLK* resin, k=2.65) with both acidic slurries suitable for copper damascene patterning and a KH phthalate-based model slurry developed for SiLK. Blanket polymer films were polished in order to determine the interactions that occur when copper and liner materials are removed by the damascene CMP process. Removal rates were obtained from material thickness measurements, post-CMP surface topography from AFM scans, and post-CMP surface chemistry from XPS measurements. Physically based wafer-scale models are presented which are compatible with the experimental results.


1999 ◽  
Vol 565 ◽  
Author(s):  
Paul A. Kohl ◽  
Agnes Padovani ◽  
Michael Wedlake ◽  
Dhananjay Bhusari ◽  
Sue Ann ◽  
...  

AbstractPreviously, the fabrication of air-gap structures for electrical interconnections was demonstrated using a sacrificial polymer encapsulated in conventional dielectric materials. The air-gaps were formed by thermally decomposing the sacrificial polymer and allowing the by-products to diffuse through the encapsulating dielectric. The diffusivity of the polymer decomposition products is adequate at elevated temperatures to allow the formation of air-gaps. This process was extended to form low dielectric constant, porous silica from commercially available methylsilsesquioxane (MSQ) by the addition of the sacrificial polymer to the MSQ. The porous MSQ film was thermally cured followed by decomposition of the NB at temperatures above 400°C. The dielectric constant of the MSQ was lowered from 2.7 to 2.3 by creating 70 nm pores in the MSQ. The voids created in the MSQ appeared to exhibit a closed-pore structure.


2005 ◽  
Vol 863 ◽  
Author(s):  
Alok Nandini ◽  
U. Roy ◽  
Zubin P. Patel ◽  
H. Bakhru

AbstractLow-κ dielectrics have to meet stringent requirements in material properties in order to be successfully integrated. A particularly difficult challenge for material development is to obtain a combination of low dielectric constant with good thermal and mechanical properties. Incorporation of low dielectric constant materials such as porous silica based materials as a replacement to conventional dielectrics like SiO2 and use of Cu metallization schemes has become a necessity as critical dimensions of devices decrease. This paper is focused on the challenges in developing materials with low dielectric constant but strong thermo mechanical properties. Thin films of Ultra-Low materials such as porous Methyl Silsesquioxane (MSQ) (κ=2.2) were implanted with argon 1 × 1016 cm-2 dose at energies varying from 20 to 50 keV at room temperature. This work shows that the surface hardness of the porous films can be improved five times as compared to the as-deposited porous films by implanting Ar with 1 × 1016 cm-2 doses at 20 keV, sacrificing only a slight increase (∼9%) in dielectric constant (e.g., from 2.2 to 2.4). The hardness persists after 4500C annealing. In this current work, an ion implantation strategy was pursued to create a SiO2-like surface on MSQ. The effects of implantation parameters on the barrier property and bulk stability of MSQ were then studied. The results reveal one possible route to attain the “zero barrier thickness” requirement for interconnects systems.


RSC Advances ◽  
2015 ◽  
Vol 5 (60) ◽  
pp. 48898-48907 ◽  
Author(s):  
Vaithilingam Selvaraj ◽  
K. P. Jayanthi ◽  
Thatchanamurthy Lakshmikandhan ◽  
Muthukaruppan Alagar

Scheme shows the synthesis of a cardanol-based polybenzoxazine composite for low-dielectric constant applications.


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