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A series of epoxy resins containing various trifluoromethyl groups were synthesized and thermally cured with diaminodiphenylmethane (DDM) and aminophenyl sulfone (DDS). All epoxy resins exhibited excellent thermal stability with the glass transition temperatures of above 128 °C and 5% weight loss temperatures of above 300 °C. DDS-cured epoxy resins possessed higher thermal stability than that of DDM-cured epoxy resins, while DDM-cured epoxy resins showed better mechanical, dielectric, and hydrophobic properties. Additionally, DDM-cured epoxy resins with different locations and numbers of trifluoromethyl groups showed flexural strength in the range of 95.55~152.36 MPa, flexural modulus in the range of 1.71~2.65 GPa, dielectric constant in the range of 2.55~3.05, and water absorption in the range of 0.49~0.95%. These results indicate that the incorporation of trifluoromethyl pendant groups into epoxy resins can be a valid strategy to improve the dielectric and hydrophobic performance.

Colorless and transparent polymer films and sheets with good high-temperature resistance and low dielectric constant (low-Dk) and low dissipation factors (low-Df) features are highly desired in advanced optoelectronic integrated circuits (OEIC) fabrications. In the current work, a series of semi-alicyclic polyimide (PI) powders were first prepared by the onestep high-temperature polycondensation of an alicyclic dianhydride, hydrogenated 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (HBPDA) and aromatic diamines which were beneficial for endowing the derived PI films with low-Dk features, including 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) for PI-1, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (BDAF) for PI-2, and 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene (BAOFL) for PI-3. Then, the derived PI powders were fabricated into colorless films and light-colored sheets, respectively. The freestanding flexible and tough PI films showed excellent optical transparency with the ultraviolet (UV) cutoff wavelength (λcut) lower than 300 nm, the optical transmittance higher than 85% at the wavelength of 400 nm, yellow indices (b*) lower than 1.0, and haze values lower than 1.2%. The hot-processed PI sheets also exhibited light colors. The PI films and sheets showed good thermal stability with the glass transition temperatures (Tg) higher than 220 °C. More importantly, the derived semi-alicyclic PI sheets showed Dk and Df values as low as 2.56 and 0.008 at 1 MHz, respectively.

The sintering and dielectric properties of (1 − x)Li2Mg0.95Co0.05SiO4 + xTiO2 ceramics created by the solid state reaction method were investigated. X-ray diffraction and energy-dispersive X-ray spectroscopy were used to obtain phase composition of the ceramics, and scanning electron microscopy was used to observe their microstructure. A network analyzer was used to measure dielectric properties, while mechanical, simultaneous-thermal, and dynamic mechanical analyzers were used to obtain mechanical and chemical properties. Li2Mg0.95Co0.05SiO4 (LMCS) and TiO2 co-exist in the composite system. TiO2 addition resulted in decreasing grain size and crystallite size, increasing starting temperature of shrinkage, increasing activation energy, and increasing elasticity and stiffness. A 4%/volume addition of TiO2 and sintering at 1075 °C changed the LMCS τf to 1.57 ppm/°C and resulted in dielectric properties of er = 6.33 and Q × f = 17,000 GHz (16 GHz) with a relative density equals to 96.13%.

The substitution properties of Mn2+ to Zn2+ for Zn3B2O6 ceramic was probed at the atomic scale using the first principle calculation, involving the bond properties, electron density, and formation energy. All samples were synthesized through the solid–state reaction method, and the variation of macro performance, like sintering and dielectric properties, was discussed in detail. The sintering property was characterized by the differential-thermal & thermo-mechanical analyzer and scanning electron microscopy, the dielectric property was characterized by the Network Analyzer, and the phase formation was verified by the X-ray dispersive spectroscopy. Three sites in the Zn3B2O6 crystal are available for Mn2+ to be occupied, and the substitution process for the Zn3 site has the lowest formation energy. The ion-substitution in ZnO4 tetrahedron results in the change of the electron distribution and bond property. The dielectric performance of Zn3B2O6 ceramic has been improved, and the microstructure has been densified at 900 °C, yielding values of er = 6.58, Q×f = 88,100 GHz (15 GHz), relative density = 96.7%, and τf = −56.5 ppm/°C as x = 0.04. Additionally, the activation energy has been decreased and the densification window shifts forward slightly.

In the rapidly growing area of high-frequency communications, polyimide films with ultralow dielectric constant and dielectric loss, adequate insulating strength, and recyclability are in high demand. Using a synthesized soluble fluorinated polyimide, a series of recyclable porous dielectric films with varying porosities were fabricated in this study through nonsolvent-induced phase separation. By manipulating the mass ratio of the binary solvent used to dissolve the polyimide, the shape, size, and size distribution of the pores generated throughout the polyimide matrix can be accurately regulated. The porosity and average pore size of the as-prepared porous films were adjustable between 71% and 33% and between 9.31 and 1.00 μm, respectively, which resulted in a variable dielectric constant of 1.51–2.42 (100 kHz) and electrical breakdown strength of 30.3–119.7 kV/mm. The porous sPI film with a porosity rate of 48% displayed a low dielectric constant of 2.48 at 10 GHz. Coupled with their superior thermal stability, mechanical characteristics, and recyclability, these porous polyimide films are highly promising for constructing high-frequency microelectronic devices.

In the present article, a simple technique is provided for the fabrication of a polymer electrolyte system composed of polyvinyl chloride (PVC) and doped with varying content of ammonium iodide (NH4I) salt using solution-casting methodology. The influences of NH4I on the structural, electrochemical, and electrical properties of PVC have been investigated using X-ray diffraction, electrochemical impedance spectroscopy (EIS), and dielectric properties. The X-ray study reveals the amorphous nature of the polymer–salt complex. The EIS measurement revealed an ionic conductivity of 5.57 × 10−10 S/cm for the electrolyte containing 10 wt.% of salt. Our hypothesis is provided, which demonstrated the likelihood of designing highly resistive solid electrolytes using the concept of a polymer electrolyte. Here, the results showed that the resistivity of the studied samples is not dramatically decreased with increasing NH4I. Bode plots distinguish the decrease in resistance or impedance with increasing salt contents. Dielectric measurements revealed a decrease in the dielectric constant with the increase of NH4I content in the PVC polymer. The relaxation time and dielectric properties of the electrolytes confirmed their non-Debye type behavior. This pattern has been validated by the existence of an incomplete semicircle in the Argand plot. Insulation materials with low εr have found widespread applications in electronic devices due to the reduction in delay, power dissipation, and crosstalk. In addition, an investigation of real and imaginary parts of electric modulus leads to the minimized electrode polarization being reached.

Variations in the crystal structure, electron density and formation energy of Mn2+ doped LiZnPO4 ceramic were discussed in accordance with the first principle calculation. The sintering and microwave dielectric properties of the doped ceramics were investigated through the solid-state reaction experiment. Characterisation methods included X-ray diffraction, scanning electron microscopy, X-ray spectroscopy, network analysis, thermomechanical analysis and simultaneous thermal analysis. The bond length and bond population of oxygen-cation in the zinc group changed. The moderate substitution of Mn2+ to Zn2+ could densify the microstructure, improve the dielectric properties and modify the sintering property of the LiZnPO4 ceramic. The LiZn0.96Mn0.04PO4 ceramic sintered at 825 °C had er = 5.57, Q × f = 77,900 GHz at 15 GHz, τf = −80.54 ppm/°C and relative density = 97.8%. Therefore, the sintering and microwave dielectric properties of the LiZnPO4 ceramic could be improved by Mn2+ substitution.

High-performance composites with a resin matrix are urgently required for electronic packaging due to their low dielectric constant, outstanding high temperature resistance, excellent corrosion resistance, light weight and easy molding. In this work, hollow-glass-microsphere (HGM)-filled fluorinated-phthalonitrile (PBDP) composites, with filler contents ranging from 0 to 35.0 vol.%, were prepared in order to modify the dielectric properties of the phthalonitrile. Scanning electron microscopy (SEM) observations indicate that the modified HGM particles were uniformly dispersed in the matrix. The PBDP/27.5HGM-NH2 composite demonstrates a low dielectric constant of 1.85 at 12 GHz. The 5% thermogravimetric temperature (T5) of composites with silanized HGM filler (481–486 °C) is higher than the minimum packaging-material requirements (450 °C). In addition, the heat-resistance index (THRI) of PBDP/HGM-NH2 composites reached as high as 268 °C. the storage modulus of PBDP/HGM-NH2 composites were significantly increased to 1283 MPa at 400 °C, an increase by 50%, in comparison to that of PBDP phthalonitrile resin (857 MPa). The excellent dielectric and thermal properties of the present composites may pave a way for comprehensive applications in electronic packaging and thermal management for energy systems.

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.

A novel poly(arylene ether nitrile) terminated with hydroxyl groups (PEN&ndash, OH) was synthesized successfully. The effects of heat-treatment temperature on the thermal properties, mechanical properties, and dielectric properties of the PEN&ndash, OH films were studied in detail. Due to the cross-linking reaction occurring, at high temperature, among the nitrile groups on the side of the PEN&ndash, OH main chain to form a structurally stable triazine ring, the structure of materials changes from a linear structure to a bulk structure. Thus, the thermal properties and mechanical properties were improved. In addition, the occurrence of cross-linking reactions can reduce the polar groups in the material, leading to the decrease of dielectric constant. As the heat-treatment temperature increased, the glass-transition temperature increased from 180.6 &deg, C to 203.6 &deg, C, and the dielectric constant decreased from 3.4 to 2.8 at 1 MHz. Proper temperature heat-treatment could improve the tensile strength, as well as the elongation, at the break of the PEN&ndash, OH films. Moreover, because of the excellent adhesive property of PEN&ndash, OH to copper foil, a double-layer flexible copper clad laminate (FCCL) without any adhesives based on PEN&ndash, OH was prepared by a simple hot-press method, which possessed high peel strength with 1.01 N/mm. Therefore, the PEN&ndash, OH has potential applications in the electronic field.

In spite of the progress that has made so far in the recent years regarding the synthesis of bio-based polymers and in particular polyesters, only few references address the optimisation of these new reactions with respect to conversion and reaction time. Related to this aspect, we here describe the transesterification reaction of two different acetalised galactarate esters with a model aliphatic diol, 1,6-hexanediol. The kinetics of these two apparently similar reactions is compared, with a focus on the conversion while varying the concentration of a di-butyltin oxide catalyst (DBTO), respectively, the used N2 flow-rate. During the first stage of polymerisation, the molecular weight of the end-products is more than doubled when using a 250 mL/min flow as opposed to an almost static N2 pressure. Additionally, the resulted pre-polymers are subjected to further polycondensation and the comparison between the obtained polyesters is extended to their thermal, mechanical and dielectrical characterisation. The influence of the acetal groups on the stability of the polyesters in acidic conditions concludes the study.

The effects of catalyst HF concentration on the dielectric and electrical properties of SiOF films are discussed. From the current density-voltage and capacitance-voltage curves, we observed that the film catalyzed with the special concentration of HF (the ratio of HF/H2O = 1/5) shows good moisture resistance, low leakage current (10-11 A/cm2 at 1 MV/cm) and high breakdown field (6 MV/cm), which can be explained by the results of Fourier transform infrared spectra. The dielectric constant value is also very low and reaches about 1.75 after annealing at the temperature of 450?C. Therefore, the concentration of HF catalyst is an important factor in the sol-gel process.

This paper presents the synthesis, properties and potential applications of new polymers containing 1, 3, 4-oxadiazole rings, tacking into account the requirements of the modern technologies. Two classes of polymers containing oxadiazole rings were approached: polyamides and polyimides. All the polymers were characterized with respect to the identification of their chemical structure, solubility, molecular weights, film forming ability, thermal, dielectric and optical properties, and the behaviour of polyoxadiazole films upon irradiation with pulsed KrF laser. All the properties were discussed in correlation with their chemical structure and compared with those of related polymers.

application/pdf, 3,5-Dimethyladamantyl unit-containing semi-alicyclic poly(o-hydroxy amide), precursor polymer of the polybenzoxazole, of high molecular weight was synthesized by the low-temperature solution polycondensation of 5,7-dimethyladamantane-1,3-dicarbonyl chloride with N,N',O,O'-tetrakis(trimethylsilyl)-substituted 4,4'-diamino-3,3'-dihydroxybiphenyl. Subsequent thermal cyclodehydration of the precursor polymer at 300°C successfully afforded the polybenzoxazole with high molecular weight. The poly(o-hydroxy amide) dissolved in polar aprotic solvents, whereas the polybenzoxazole was insoluble in any organic medium tested. The polybenzoxazole was stable up to around 400°C under nitrogen and had a low dielectric constant of 2.866. The mechanical properties of the polybenzoxazole film were excellent, its tensile strength, elongation at break, and tensile modulus were 110 MPa, 6%, and 3.3 GPa, respectively.

A method is provided for producing a porogen-residue-free ultra low-k film with porosity higher than 50% and a high elastic modulus above 5 GPa. The method starts with depositing a SiCOH film using Plasma Enhanced Chemical Vapor Deposition (PE-CVD) or Chemical Vapor Deposition (CVD) onto a substrate and then first Perfonning an atomic hydrogen treatment at elevated wafer temperature in the range of 200 C up to 350 C to remove all the porogens and then performing a UV assisted thennal curing step. status: published

The solution to the problem of increased resistance-capacitance (RC) delay in the present day ULSI is to use porous low-k dielectric films (k = 2.0) along with Copper interconnects. There are a number of issues with Cu/low-k integration, such as Cu diffusion in the porous low-k film, moisture penetration, and damage during backend processing steps like etching and photoresist ashing. Water vapor is introduced into the low-k layer during ashing of the photo resist, which raises the k value to typically above 3. We have successfully addressed all these issues in the case of hydrogen silsesquioxane (HSQ) (k = 2.8) with the help of a non-plasma-based hot-wire-induced chemical-vapor process (HWCVP). With the help of this process, we have also been successful in developing an ultra-thin hydrogenated amorphous silicon-carbon-based barrier layer that completely avoids copper diffusion and shows a higher resistance to electromigration.