Characterization of plasma polymers from tetramethylsilane, octamethylcyclotetrasiloxane, and methyltrimethoxysilane

Abstract

SynopsisThe products in inductively coupled plasma excited in organosilicic compounds were studied on chemical structures by spectroscopic methods. Plasma-polymerized tetrar,dhylsilane (PA) contains not only Si-CH, groups but also Si-H groups on IR and ?%NMR analyses. 13C-NMR spectrum of PA reveals that the crosslinked structure of PA is mainly constructed of CH, and CH groups. Plasma-polymerized octamethylcyclotetrasiloxane (PD, ) is composed of Si-CH, andSi-0 groups. 13C-and ?Si-NMR spectra of PD, point out the highly preservation of the structural units similar to the monomer. These data of PD, suggest that PD, is formed from the ring-opening polymerization by cleavages of Si-0 bonds. 13C-NMR spectrum of poly[methyltrimethoxysilane] (PT) indicates the existence of CH,-0 groups, meanwhile its 29Si-NMR analysis concludes that F'T is chiefly c o m p a d of the structural units similar to the monomer. The surface analyses by XPS of PA, PD,, and F'T suggest that these organosilicic plasma polymers resemble their starting materials.have proven valuable to the study of the chemical structures of the plasma polymers.6-8 We have studied the chemical structures of the plasma-polymerized organosilicic compounds (tetramethylsilane, octamethylcyclotetrasiloxane, and methyltrimethoxysilane) by IR, XPS, and high-resolution solid-state NMR.

Chemical Bonding Structure of Low Dielectric Constant Si:O:C:H Films Characterized by Solid-State NMR

“…This observation is consistent with the observation of relative featureless XPS spectra in previous studies of plasma enhanced CVD organosilicon materials. 16,17 A shift of ϩ1.0 eV in binding energy was observed going from sample 5 to sample 6 on both O 1s and C 1s scans, which was partly due to a charging effect. Taking into account this charging effect in the Si 2p scan, a resulting shift of ϩ0.5 eV in binding energies was measured going from sample 5 to sample 6 attributed to a change in chemical structure, a shift to higher binding energies being significant of a higher level of oxidation.…”

Hot-Filament Chemical Vapor Deposition of Organosilicon Thin Films from Hexamethylcyclotrisiloxane and Octamethylcyclotetrasiloxane

“…Typical chemical shifts reported in the literature for organosilicon CVD films are included in Table IV. 20,32,[46][47][48][49] As suggested by the data in this table, films deposited by other CVD methods commonly show a wide variety of bonding environments, including the presence of M, D, T, and Q groups as well as their hydrogenated analogs. 32,49,50 By contrast, only two primary peaks were observed in these HFCVD films.…”

Adhesion Improvement between Epoxy and Stainless Steel Using a Silane Coupling Agent in an Atmospheric Plasma Process

“…[27][28][29][30] Atmospheric plasma deposition of siloxane films has already been described in literature where most of the studies deal with the chemical characterization, the structure, and the functional properties of the deposited siloxane film. [31][32][33][34][35] Some studies are also carried out to investigate the plasma polymerization mechanisms of the organosilicon compounds. [36][37][38][39] Generally, these deposited films are described as branched, highly cross-linked, insoluble in nature, pinhole free, and highly adhesive to most of the substrates.…”