Atomic layer deposition and characterization of thin oxide films for application in protective coatings
Date
2017-11-01
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Abstract
Erinevates toodetes kasutatavate materjalide eluea pikendamine ja koguste vähendamine on kaks tähtsat ülesannet, mille lahendamine võimaldab muuta väiksemaks ühiskonna ökoloogilist jalajälge. Kuna materjalid korrodeeruvad peaaegu kõigis keskkondades, siis selle tulemusena nende vastupidavus ning kasutusaeg vähenevad. See omakorda muudab lihtsalt kättesaadavate ja odavate materjalide kasutamise mõnede rakenduste puhul võimatuks. Üheks võimaluseks selliste materjalide eluiga pikendada ja neid seejuures ikkagi korrodeerivate keskkondades kasutada, on nende kaitsmine vastupidavamast materjalist katetega, mis isoleerivad kaitstavad materjalid neid hävitavast keskkonnast. Tänu tänapäevaste kõrgtehnoloogiliste seadmete üha keerukamale ehitusele ja detailide rangematele täpsusnõuetele on nende kaitsekatetega katmine traditsiooniliste meetoditega järjest keerulisem. Sellest tulenevalt on kasvanud vajadus uute senisest täpsemate tehnoloogiate järele. Käesolevas töös uuriti üliõhukeste kaitsekatete valmistamise võimalusi, kasutades selleks aatomkihtsadestamise meetodit, mis võimaldab kaitsekihi paksust ülitäpselt kontrollida. Uuringute käigus pandi kokku ja katsetati seadet, millega on võimalik sadestada kaitsekatteid ballooni-tüüpi kinniste anumate sisepinnale. Et arendada vastavaid sadestamismetoodeid ja parandada kaitsekatete omadusi, töötati välja uudsed lahendused TiO2 ja Al2O3 aatomkihtsadestamiseks tehnoloogilistes protsessides, milles lähteainesüsteemideks on vastavalt TiCl4-O3 ja AlCl3-O3. Töö käigus uuriti eelnimetatud meetoditega sadestatud kaitsekatete füüsikalisi ja keemilisi omadusi ning demontreeriti nende häid kaitseomadusi laialt kasutatava roostevaba terase pinnal.
Prolonging the lifetime and reducing the amount and cost of materials, used in different kind of products, are two big problems that have to be solved to decrease the ecological footprint of contemporary society. Corrosion is a process, which takes place in almost all environments and reduces the durability of materials, and sometimes makes impossible application of cheap and easily accessible materials. One of the possibilities to protect materials against corrosion is to add a barrier layer of a durable material on the top of a product to isolate it from environment and thereby increases its lifetime or make possible its application in more aggressive environments. However, due to and construction complexity of high-technology production, novel high-precision techniques are needed also for preparation of appropriate protective coatings. Therefore, need for corresponding studies is growing day by day. In this study, application of the atomic layer deposition method for deposition of thin precisely controlled protective coatings was investigated. During the studies novel atomic layer deposition equipment, which made possible deposition of protective coatings onto the inner surface of hermetic containers, was constructed and tested. Secondly, to advance the preparation methods and improve the properties of the protective coatings, atomic layer deposition processes based on new precursor combinations, TiCl4-O3 for deposition of TiO2 and AlCl3-O3 for deposition of Al2O, were developed and physical as well as chemical properties of coatings obtained in these processes were investigated. In the experiments, the potential of these coatings to protect surface of stainless steel was demonstrated.
Prolonging the lifetime and reducing the amount and cost of materials, used in different kind of products, are two big problems that have to be solved to decrease the ecological footprint of contemporary society. Corrosion is a process, which takes place in almost all environments and reduces the durability of materials, and sometimes makes impossible application of cheap and easily accessible materials. One of the possibilities to protect materials against corrosion is to add a barrier layer of a durable material on the top of a product to isolate it from environment and thereby increases its lifetime or make possible its application in more aggressive environments. However, due to and construction complexity of high-technology production, novel high-precision techniques are needed also for preparation of appropriate protective coatings. Therefore, need for corresponding studies is growing day by day. In this study, application of the atomic layer deposition method for deposition of thin precisely controlled protective coatings was investigated. During the studies novel atomic layer deposition equipment, which made possible deposition of protective coatings onto the inner surface of hermetic containers, was constructed and tested. Secondly, to advance the preparation methods and improve the properties of the protective coatings, atomic layer deposition processes based on new precursor combinations, TiCl4-O3 for deposition of TiO2 and AlCl3-O3 for deposition of Al2O, were developed and physical as well as chemical properties of coatings obtained in these processes were investigated. In the experiments, the potential of these coatings to protect surface of stainless steel was demonstrated.
Description
Väitekirja elektrooniline versioon ei sisalda publikatsioone
Keywords
aatomkihtsadestamine, õhukesed kiled, oksiidkiled, atomic layer deposition, thin films, oxide films