Polimerização por plasma de éter e ésteres orgânicos: caracterização e possíveis usos em microeletrônica. / Plasma polymerization of ethyl ether and ethyl or methyl acetate: film caracterization and microeletronic uses.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The aim of this work is to characterize thin films obtained by plasma polymerization of ethyl ether, ethyl or methyl acetate. The films were tested for adsorption of polar organic compounds in order to evaluate their use for sensors or preconcentrators manufacturing. It was tried plasma polymerization of pure reactants and mixtures of ethyl ether with oxygen, acetone, methyl or ethyl acetate. For all reactants and mixtures films were obtained on silicon and peeling did not occur during one year of observation. Measurements of profilemeter, infrared spectroscopy, contact angle for drop of water, 2-propanol and acetone aqueous solutions were used to determine deposition rate, polar species and hydrophilic or organophilic character, respectively. For ethyl ether the films show a deposition rate between 80 and 300 Å/min and high OH relative intensity. Water contact angles were approximately 75º for all films, therefore the surfaces are hydrophilic. Oxygen addition to the plasma favors ethyl ether oxidation, increase in CO relative intensity and water contact angle. Acetone addition favors rise not only in CO relative intensity and water contact angle but also in particle formation. Deposition on closed chamber mode favors the increase of deposition rate and OH formation but the diminish on water contact angle. Mixture with methyl or ethyl acetate turns the system complex and difficult to control. The acetates process window acetates were narrow but presented higher deposition rates, from 160 A/min to 510 A/min, and lower water contact angles, from 54 º to 68º. Infrared spectroscopy shows the same species found for ethyl ether deposition. Deposition on closed chamber mode increases deposition rate and decreases the water contact angle. Ethyl acetate plasmas show high deposition rate but low water contact angle values when compared to methyl acetate. The deposition rates and water contact angles lie between 350 and 1200 A/min and 61º and 72º, respectively. Infrared spectroscopy shows the same species found on ethyl ether deposition but co presents high relative intensity. Deposition on closed chamber mode not only rises the deposition rate and CO relative intensity but also lowers the water contact angle. Contact angle measurements for 2-propanol and acetone aqueous solution show the surface is organophilic and show bigger affinity for 2-propanol aqueous solution. Deposition on aluminum lines deposited on silicon shows conformal deposition for all films. Quartz crystal measurements show the films adsorb polar organic compounds. Plasma deposited ethyl ether, methyl or ethyl acetate films on plasma deposited hexametyldisilazane substrates showed a continuous film that easily stress, although peeling was not observed. Deposition on poly(methyl methacrylate) showed good adhesion for all films. These films are also hydrophilic and organophilic. Micromachinned microchannels showed the possibility of adsorption and preconcentrators development.

ASSUNTO(S)

plasma organic compound preconcentrators polimerização plasma compostos orgânicos polymerization pré-concentradores

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