Characterization of PECVD ultralow dielectric constant porous SiOCH films using triethoxymethylsilane precursor and cinene porogen

Abstract

Ultralow dielectric-constant (k) SiOCH films were prepared from triethoxymethylsilane (MTES) and cinene (LIMO) by plasma-enhanced chemical vapor deposition (PECVD). By changing the mass flow rate ratio (MFRR) of LIMO/MTES, the properties of the low k films were investigated. In particular, the chemical composition and bonding structure of the deposited film were analyzed with the help of Fourier transforms infrared spectroscopy and x-ray photoelectron spectroscopy. It was revealed that the bonding configurations of O-Si-C 3 , O 2 -Si-C 2 , Si-C and C-C/C-H in the low-k film increased with increasing the MFRR of LIMO/MTES. Further, as the MFRR increased from 1.0 to 1.5, the k value decreased gradually to 2.3, and then increased again with a continuing increment of the MFRR. Such changes accorded with the evolvement of porosity within the film. In the case of our interested ultralow k film (k = 2.3) with a maximum porosity of 29.1%, it exhibited a very low leakage current density of 3.35 × 10 −9 A cm −2 at 1 MV cm −1 and 25 °C while maintaining good mechanical properties such as an Young's modulus of 4.26 GPa and a hardness of 0.41 GPa.

Characterization of the deposition behavior and changes in bonding structures of hexamethyldisiloxane and decamethylcyclopentasiloxane atmospheric plasma‐deposited films*

“…The assumption that the density is the same for all of the coatings is not necessarily a good assumption. Previous studies have shown that the porosity and density change with deposition conditions . Characterization of the rate of deposition by mass per area would be preferred.…”

“…FTIR spectra were obtained for films of various levels of W / FM and the absorbance values are shown in Figure for HMDSO and Figure for D5. The peaks assignments are summarized in Table and are based on published spectra for organosilicon materials and plasma‐deposited thin films . The absorbance spectra show the presence of Si–CH 3 groups.…”

“…Deconvolution of the Si–O–Si stretching and Si–CH 3 symmetric bending absorbance bands of the D5 deposited films for the following values of W / FM : (a) 83 kJ/g, (b) 245 kJ/g, (c) 842 kJ/g, (d) 1,757 kJ/g, (e) 3,434 kJ/g, and (f) 5,263 kJ/g. D5: decamethylcyclopentasiloxane; N: network structures; P: structures at pore surfaces; RC: ring and cage structures; S: stoichiometric SiO 2 , fully relaxed…”

“…Gaussian fits are used, which is commonly used for solid samples due to the lack of motion and a statistical distribution of environments . Table shows the peak assignments based on published literature that were used to evaluate the bonding structures and functional groups present in the films.…”

Ultralow‐k Amorphous Boron Nitride Based on Hexagonal Ring Stacking Framework for 300 mm Silicon Technology Platform

“…The results strongly indicate that the borazine-aBN films also offer superior Young's modulus (> 50 GPa), particularly at the region of k values<3, compared to other Si-and BC-based low-k materials. [8,11,12,[31][32][33][38][39][40] Recent atomistic simulation results also have shown that the Young's modulus increase with increasing the initial density of aBN microstructure is due to 80% sp 2 hybridization and 60% of atoms in hexagonal ring. [41] Therefore, we ascribe the superior mechanical strength of borazine-aBN films to the high density that originates from the matching stacking B-N hexagonal ring stucture.…”