Effect of terminal methyl groups concentration on properties of organosilicate glass low dielectric constant films

Abstract

Surfactant-templated organosilicate glass (OSG) based low-k films are deposited by using tetraethyl orthosilicate/methyltriethoxysilane (TEOS/MTEOS) mixture with different ratio and spin-on technology with the goal of understanding the effects of terminal methyl groups on chemical and structural properties. It is shown that despite of constant surfactant concentration these films have quite different properties when the changing of CH3/Si ratio. The most important changes are related to change of their hydrophilicity, change of mechanical properties, the pore size and to the shift of Si–CH3 peak position in Fourier transform infrared (FTIR) spectra. The films are becoming hydrophobic if they are deposited from sols with CH3/Si ratio higher than 0.2. The Young’s modulus gradually decreases with increasing the terminal methyl groups concentration in the films. The pore size increases with concentration of methyl groups and changes from cylindrical to ink-bottle shape. The nature of SiCH3 peak shift is explained by using molecular mechanics simulation. It is shown that the reason of this shift is change of dπ–pπ hybridization in Si–O–Si bonds, which is affected by presence of CH3 group.

Charge Transport Mechanism and Trap Origin in Methyl‐Terminated Organosilicate Glass Low‐κ Dielectrics

“…This composition was chosen to provide a compromise between the dielectric constant and Young's modulus. [ 9 ] The 203 nm thick films with refractive index 1.246 (±0.004) and a full porosity of ≈43% were used for electric measurements.…”

“…[ 7,8 ] Carbon‐bridged films also need to contain a certain amount of terminal groups to provide sufficient hydrophobicity to low‐κ films that are introduced by the precursor optimization or by additional silylation after the deposition. [ 9 ] The porogen removal occurs through the polymer fragmentation with the formation of volatile species, but the process should be sufficiently gentle to avoid significant destruction of SiCH 3 bonds in the matrix. UV photons may also have negative impacts on the electrical properties of the films.…”

Synthesis of Bioactive Glasses SiO2-Al2O3-MgO-K2CO3-CaO-MgF2 -CNT: Structural, Mechanical and Biological Properties

“…The observed bands in the region 1200-1250 cm -1 are attributed to the stretching vibrations of O-Si-O in the glassy network [73]. The various counts of NBO in the SiO4 tetrahedral were observed due to the wavenumbers in the region 840-1250 cm -1 [74].…”

“…However, the band noticed at 915 cm -1 revealed the vibrations of Si-O - [75,76]. A low intensity transmission band was also observed at ~840 cm -1 that assigned to the bending vibrations of H-Si-O [73]. Moreover, it is gradually lifted near to the higher wavenumber side as increasing the content of CNT.…”

Evaluation of Mechanical Properties of Porous OSG Films by PFQNM AFM and Benchmarking with Traditional Instrumentation

“…Terminal Si–CH 3 groups incorporated into the OSG matrix replace a part of bridging oxygen atoms and provide hydrophobic properties necessary for prevention of moisture adsorption. However, they also decrease the matrix density and cross-linkage of Si atoms, reducing the mechanical strength and stiffness. ,, The Young’s modulus ( E ) of low- k dielectrics should be E > 6 GPa to meet the requirements of the presently used integration and packaging technologies, so advanced ultralow- k materials must be in a balance between the low- k value and mechanical strength. , Thus, control of mechanical properties of low- k materials is an important part of interconnect technology.…”