Novel Low-k Dual-phase Materials Prepared by PECVD

2000 ◽  
Vol 612 ◽  
Author(s):  
Alfred Grill ◽  
Vishnubhai Patel

AbstractDielectric materials based on Si, C., O, H (SiCOH) have been demonstrated previously with dielectric constants of about 2.8. This value could be potentially further reduced by increasing/introducing porosity in the SiCOH films. Depositing multiphase films containing at least one thermally unstable phase and annealing the films to remove this labile phase from the material could create the enhanced porosity. Dual-phase materials, SiCOH-CH, have been prepared in the present study by PECVD from mixtures of a SiCOH precursor with a hydrocarbon. The films have been characterized as-deposited and after thermal anneals of up to 4 hours at 400°C. The atomic composition of the films has been determined by RBS and FRES analysis and their optical properties have been determined by FTIR and n&k measurements. Metal-insulator-silicon structures have been used to measure the electrical properties of the dual-phase films. After an initial anneal at 400°C, accompanied by a significant loss of CH and some SiH species and a thickness loss of up to 50%, the films stabilized. Depending on the deposition conditions and concentration of the CH precursor in the feed gas, the dielectric constant decreased by 10-15% during the stabilization anneal and reached values as low as 2.4. These initial results indicate the possibility to further reduce the dielectric constant of PECVD produced SiCOH films and the potential to incorporate such films in the interconnect structures of future ULSI chips.

2010 ◽  
Vol 1249 ◽  
Author(s):  
George Andrew Antonelli ◽  
Gengwei Jiang ◽  
Mandyam Sriram ◽  
Kaushik Chattopadhyay ◽  
Wei Guo ◽  
...  

AbstractOrganosilicate materials with dielectric constants (k) ranging from 3.0 to 2.2 are in production or under development for use as interlayer dielectric materials in advanced interconnect logic technology. The dielectric constant of these materials is lowered through the addition of porosity which lowers the film density, making the patterning of these materials difficult. The etching kinetics and surface roughening of a series of low-k dielectric materials with varying porosity and composition were investigated as a function of ion beam angle in a 7% C4F8/Ar chemistry in an inductively-coupled plasma reactor. A similar set of low-k samples were patterned in a single damascene scheme. With a basic understanding of the etching process, we will show that it is possible to proactively design a low-k material that is optimized for a given patterning. A case study will be used to illustrate this point.


2009 ◽  
Vol 421-422 ◽  
pp. 69-72
Author(s):  
Jie Shen ◽  
Wen Chen ◽  
Jing Zhou ◽  
Jie Zhu ◽  
Qiong Lei

The relationship between the character of the B-site cation–oxygen bond and the microwave dielectric properties in perovskites dielectric materials was studied in this paper. The atomic net charge of CaTiO3 (CT) and Ca(Zn1/3Nb2/3)O3 (CZN) was calculated respectively. The calculating result implies that the covalency of B-O bonds in CZN is stronger than that in CT. This predicted that the dielectric constant and loss of the ceramics will decrease after CZN incorporated in CT. To confirme the prediction, (1-x)CT-xCZN microwave dielectric ceramics were prepared by solid state reaction method with ZnNb2O6 as precursor. The structure analysis in terms of tolerance factor gives an identical result as calculation. The microwave dielectric properties, such as dielectric constants, Q×f values and τf were studied as a function of composition. With x increasing from 0.2 to 0.8, the dielectric constant linearly decreases from 109 to 49.37, the Q×f value increases from 8,340 to 13,200 GHz, and τf decreases from 321 to -18 ppm/°C. The properties trends are consistent with the previous calculation results, and confirm the relationship between the character of B-O bond and dielectric properties.


2004 ◽  
Vol 812 ◽  
Author(s):  
Jung-Won Kang ◽  
Byung Ro Kim ◽  
Gwi-Gwon Kang ◽  
Myung-Sun Moon ◽  
Bum-Gyu Choi ◽  
...  

AbstractSpin-on Low-K materials are potentially very attractive as interconnection materials in a wide range of semiconductor structures. In this work, new organic-inorganic hybrid materials synthesized by vinylsilane polymerization were proposed. According to compositions and additional fabrications, dielectric constants of these materials were evaluated to be 2.3∼3.1. The hardness was 2.0GPa after 430°C curing. These materials had good adhesion strength such that fracture toughness on silicon wafer was 0.22 MPam0.5 without any adhesion promoters. This result indicates that these organicinorganic hybrid materials are very promising candidates for low-K dielectrics.


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.


1996 ◽  
Vol 443 ◽  
Author(s):  
A. Grill ◽  
V. Patel ◽  
K.L. Saenger ◽  
C. Jahnes ◽  
S.A. Cohen ◽  
...  

AbstractA variety of diamondlike carbon (DLC) materials were investigated for their potential applications as low-k dielectrics for the back end of the line (BEOL) interconnect structures in ULSI circuits. Hydrogenated DLC and fluorine containing DLC (FDLC) were studied as a low-k interlevel and intralevel dielectrics (ILD), while silicon containing DLC (SiDLC) was studied as a potential low-k etch stop material between adjacent DLC based ILD layers, which can be patterned by oxygen-based plasma etchingIt was found that the dielectric constant (k) of the DLC films can be varied between >3.3 and 2.7 by changing the deposition conditions. The thermal stability of these DLC films was found to be correlated to the values of the dielectric constant, decreasing with decreasing k. While DLC films having dielectric constants k>3.3 appeared to be stable to anneals of 4 hours at 400 °C in He, a film having a dielectric constant of 2.7 was not, losing more than half of its thickness upon exposure to the same anneal. The stresses in the DLC films were found to decrease with decreasing dielectric constant, from 700 MPa to about 250 MPa. FDLC films characterized by a dielectric constant of about 2.8 were found to have similar thermal stability as DLC films with k >3.3. The thermally stable FDLC films have internal stresses <300 MPa and are thus promising candidates as a low-k ILD.For the range of Si contents examined (0-9% C replacement by Si), SiDLC films with a Si content of around 5% appear to provide an effective etch-stop for oxygen RIE of DLC or FDLC films, while retaining desirable electrical characteristics. These films showed a steady state DLC/SiDLC etch rate ratio of about 17, and a dielectric constant only about 30% higher than the 3.3 of DLC.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4827
Author(s):  
Nianmin Hong ◽  
Yinong Zhang ◽  
Quan Sun ◽  
Wenjie Fan ◽  
Menglu Li ◽  
...  

Since the application of silicon materials in electronic devices in the 1950s, microprocessors are continuously getting smaller, faster, smarter, and larger in data storage capacity. One important factor that makes progress possible is decreasing the dielectric constant of the insulating layer within the integrated circuit (IC). Nevertheless, the evolution of interlayer dielectrics (ILDs) is not driven by a single factor. At first, the objective was to reduce the dielectric constant (k). Reduction of the dielectric constant of a material can be accomplished by selecting chemical bonds with low polarizability and introducing porosity. Moving from silicon dioxide, silsesquioxane-based materials, and silica-based materials to porous silica materials, the industry has been able to reduce the ILDs’ dielectric constant from 4.5 to as low as 1.5. However, porous ILDs are mechanically weak, thermally unstable, and poorly compatible with other materials, which gives them the tendency to absorb chemicals, moisture, etc. All these features create many challenges for the integration of IC during the dual-damascene process, with plasma-induced damage (PID) being the most devastating one. Since the discovery of porous materials, the industry has shifted its focus from decreasing ILDs’ dielectric constant to overcoming these integration challenges. More supplementary precursors (such as Si-C-Si structured compounds), deposition processes (such as NH3 plasma treatment), and post porosity plasma protection treatment (P4) were invented to solve integration-related challenges. Herein, we present the evolution of interlayer dielectric materials driven by the following three aspects, classification of dielectric materials, deposition methods, and key issues encountered and solved during the integration phase. We aim to provide a brief overview of the development of low-k dielectric materials over the past few decades.


2011 ◽  
Vol 110-116 ◽  
pp. 5380-5383
Author(s):  
Tejas R. Naik ◽  
Veena R. Naik ◽  
Nisha P. Sarwade

Scaling down the integrated circuits has resulted in the arousal of number of problems like interaction between interconnect, crosstalk, time delay etc. These problems can be overcome by new designs and by use of corresponding novel materials, which may be a solution to these problems. In the present paper we try to put forward very recent development in the use of novel materials as interlayer dielectrics (ILDs) having low dielectric constant (k) for CMOS interconnects. The materials presented here are porous and hybrid organo-inorganic new generation interlayer dielectric materials possessing low dielectric constant and better processing properties.


Author(s):  
M. A. Zulkifeli ◽  
S. N. Sabki ◽  
S. Taking ◽  
N. A. Azmi ◽  
S. S. Jamuar

<p>A Metal-Insulator-Metal (MIM) capacitor with high capacitance, high breakdown voltage, and low leakage current is aspired so that the device can be applied in many electronic applications. The most significant factors that affect the MIM capacitor’s performance is the design and the dielectric materials used. In this study, MIM capacitors are simulated using different dielectric materials and different number of dielectric layers from two layers up to seven layers.  The effect of the different dielectric constants (<em>k</em>) to the performance of the MIM capacitors is also studied, whereas this work investigates the effect of using low-<em>k</em> and high-<em>k</em> dielectric materials. The dielectric materials used in this study with high-<em>k</em> are Al<sub>2</sub>O<sub>3</sub> and HfO<sub>2</sub>, while the low-<em>k</em> dielectric materials are SiO<sub>2</sub> and Si<sub>3</sub>N<sub>4</sub>. The results demonstrate that the dielectric materials with high-<em>k</em> produce the highest capacitance. Results also show that metal-Al<sub>2</sub>O<sub>3</sub> interfaces increase the performance of the MIM capacitors. By increasing the number of dielectric layers to seven stacks, the capacitance and breakdown voltage reach its highest value at 0.39 nF and 240 V, respectively.</p>


2017 ◽  
Vol 751 ◽  
pp. 390-396
Author(s):  
Oratai Jongprateep ◽  
Nicha Sato ◽  
Jednupong Palomas ◽  
Pongsakorn Jantaratana

It has been generally accepted that doping of dielectric materials could significantly contribute to compositional and microstructural evolution, which consequently lead to alteration in dielectric properties. In this study, the effects of adding magnesium (Mg) at 5,10 and 20at% on the chemical composition, microstructure and dielectric constant of calcium titanate (CaTiO3) synthesized by solid state reaction was assessed. Chemical composition analysis using an X-ray diffraction technique CaTiO3 doped with 5 at% Mg has been found to contain a single phase whereas samples doped with 10 and 20 at% Mg both exhibited apparent secondary phase (MgO). Microstructural examination however, revealed that no significant variation in particle size, grain size and density were evident among the samples of different Mg contents. Average dielectric constants obtained from the entire samples ranged from 245.9 to 387.6 (at 1 MHz) and the sample with the highest dielectric constant was that doped with 5 at% Mg. Enhancement of dielectric constant in the samples with the lowest level of Mg doping has been attributed largely to the homogeneity of its chemical composition.


2005 ◽  
Vol 880 ◽  
Author(s):  
Mark Johnson ◽  
Zijian Li ◽  
Yushan Yan ◽  
Junlan Wang

AbstractWith the semiconductor technologies continuously pushing the miniaturization limits, there is a growing interest in developing novel low dielectric constant (low-k) materials to replace traditional dense SiO2 based insulators. In order to survive the multi-step integration process and provide reliable material and structure for the desired integrated circuit (IC) functions, the new low-k materials have to be mechanically strong and stable. Thus the material selection and mechanical characterization are vital in the successful development of next generation low-k dielectrics. A new class of low-k dielectric materials, nanoporous pure-silica zeolite, is prepared in thin films using IC compatible spin coating process and characterized using depth sensing nanoindentation technique. The elastic modulus measurements of the zeolite thin films are found to be significantly higher than that of other porous silicates with similar porosity and dielectric constants. Correlations of the mechanical, microstructural and electrical properties are discussed in detail.


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