Development of mechanical characterization methods for thin films and interfaces: “God created matter, surfaces were invented by devil” – Wolfgang Pauli

Jussi Aav

Development of mechanical characterization methods for thin films and interfaces: “God created matter, surfaces were invented by devil” – Wolfgang Pauli

Julkaisun otsikon käännös: Mekaanisten karakterisointimenetelmien kehitys ohutkalvoille ja rajapinnoille

Jussi Aav

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Ohutkalvojen ja pinnoitteiden todennäköisesti tärkein ominaisuus on niiden adheesio käytettyyn substraattiin. Jotta voidaan havaita adheesioon liittyviä ongelmia mahdollisimman nopeasti, on erittäin tärkeää ymmärtää kiinnipysyvyyteen vaikuttavat tekijät. Lisäksi tarvitaan soveltuvia kvantitatiivisia karakterisointimenetelmiä, jotta voidaan rakentaa luotettavia laitteita. Monissa perinteisissä testausmenetelmissä substraattiin kohdistetaan merkittävää kuormitusta, joka voi johtaa ongelmiin, kuten substraatin hajoamiseen ennen pinnoitteen irtoamista erityisesti hauraiden substraattien tapauksessa. Yhä ohuempien pinnoitteiden ja näiden rajapintojen mekaanisten ominaisuuksien karakterisointi on haastavaa ja näiden tutkimiseksi tarvitaan menetelmäkehitystä. Tässä väitöskirjassa esitellään kolme pinnoitteiden ja rajapintojen mekaanista mittausmenetelmää, joissa substraattiin kohdistuva kuormitus on minimoitu. Menetelmät soveltuvat erityisesti atomikerroskasvatettujen (ALD) pinnoitteiden tutkimiseen: (i) Mikroelektromekaanisia menetelmiä (MEMS) hyödyntävä palkki-kuormitettu rakkulakoe, jossa ohutkalvon kuormitus tapahtuu takaapäin substraatissa olevan reiän läpi, (ii) mikrorobotiikka hyödyntävä ohutkalvon sisään upotettujen mikropallojen sivuttainen kuormituskoe ja (iii) yhdistetty nanonaarmutus- ja pyyhkäisevä nanokulutuskoe, jossa substraattiin kohdistuvan kuormituksen vuorovaikutustilavuus on minimoitu. Adheesion ja koheesion suhde kilpailevina prosesseina ohutkalvojen ja substraatin murtuessa osoitetaan: kun systeemiä kuormitetaan, energia vapautuu sieltä missä vastustus on pienin. Tämä tapahtuu joko (i) plastisena muodonmuutoksena, (ii) pinnoitteen murtumisena tai (iii) delaminaationa. Usein systeemiin kohdistettu kuormitus relaksoituu yhdistelmänä näitä kolmea mekanismia ellei joku mekanismi ole dominoiva. Esitellyt karakterisointimenetelmät ovat enimmäkseen geneerisiä ja niitä voidaan soveltaa lähes minkä tahansa materiaalien välisten rajapintojen ja mekaanisten ominaisuuksien, kuten adheesion, tutkimiseen tietyin rajoituksin. Näiden menetelmien kvantitatiivinen luonne mahdollistaa ohutkalvojen ja rajapintojen ominaisuuksien syvällisemmän ymmärryksen, jotta voidaan kehittää parempia pinnoitteita sekä näitä hyödyntävien tuotteiden ja prosessien laatua. Väitöskirjan tärkein anti on uusien potentiaalisten ja monipuolisten tutkimusmenetelmien esittely. Erityisesti MEMS testirakenteet joko yksinään tai yhdistettynä mikroroboottisiin testausjärjestelmiin voivat olla ratkaisu kehitettäessä uusia räätälöityjä mekaanisia karakterisointimenetelmiä täyttämään teollisuuden ja tutkimuksen nykyisiä ja tulevia tarpeita.

Julkaisun otsikon käännös	Mekaanisten karakterisointimenetelmien kehitys ohutkalvoille ja rajapinnoille
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Koskinen, Jari, Vastuuprofessori Koskinen, Jari, Ohjaaja
Kustantaja	Aalto University
Painoksen ISBN	978-952-60-8654-5
Sähköinen ISBN	978-952-60-8655-2
Tila	Julkaistu - 2019
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

mekaaniset karakterisointimenetelmät
ohutkalvot
pinnoitteet
rajapinnat
ALD

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-60-8655-2

OtaNano
Rissanen, A. (Manager)
Aalto-yliopisto
Laitteistot/tilat: Facility
OtaNano Nanofab
Repo, P. (Manager) & Rissanen, A. (Other)
OtaNano
Laitteistot/tilat: Facility
OtaNano Nanomikroskopiakeskus
Seitsonen, J. (Manager) & Rissanen, A. (Other)
OtaNano
Laitteistot/tilat: Facility

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@phdthesis{1b7e76a2bc5b43119dc3fd3043b31529,

title = "Development of mechanical characterization methods for thin films and interfaces: “God created matter, surfaces were invented by devil” – Wolfgang Pauli",

abstract = "Probably the most important thin film characteristic is its' adhesion to the used substrate. It is very important to understand the fundamental mechanics of adhesion-related failures, and by having suitable characterization methods to detect any problems as early as possible. Tailored or correctly conducted quantitative analysis of adhesion is required for building reliable devices. In many conventional test methods significant loading to the substrate is applied which can result in problems especially with brittle substrates where the substrate can break before the film is delaminated. The characterization of interfacial mechanical properties of increasingly thinner films is challenging with many practical shortcomings and thus method development is needed. In this thesis, three measurement methods where the loading to the substrate is minimized are presented and demonstrated for the interfacial and mechanical testing of especially atomic layer deposited (ALD) thin films. (i) Microelectromechanical system (MEMS) test chip assisted shaft-loaded blister testing through a hole in the substrate to the backside of the thin film, (ii) microrobotic manipulation of embedded microspheres using lateral loading mostly to the thin film and to the interface and (iii) a combination of nanoscratch and scanning nanowear for minimized interaction volume of loading to the substrate. The relationship between adhesion and cohesion as competing processes during film/substrate failure is shown. When the film-interface-substrate system is under loading the energy will dissipate through the path of least resistance. This will happen either (i) through plastic deformation of the coating/substrate, (ii) film fracture (decohesion) or (iii) delamination (de-adhesion) of the film. Usually, however the energy is dissipated as a combination of these three different mechanisms, unless some of the mechanisms is dominant in the energy release. The presented characterization methods are mostly generic, and can be applied for the evaluation of mechanical and interfacial properties, such as adhesion, between practically any materials of choice with some limitations. Compared to some of the existing methods, the quantitative nature of these characterization methods enables a more in-depth possibility for the analysis, understanding, tuning and improvement of the properties of the thin films and processes aiding in maintaining and improving product and process quality. The main outcome of this thesis is that the authors have demonstrated the potential and versatility of especially the MEMS test structures and microrobotic testing systems, either on their own or as a combination as a solution to developing new tailored interfacial and mechanical characterization methods for current and future needs of research and the industry.",

keywords = "mechanical characterization, thin films, interfaces, ALD, mekaaniset karakterisointimenetelm{\"a}t, ohutkalvot, pinnoitteet, rajapinnat, ALD, mechanical characterization, thin films, interfaces, ALD",

author = "Jussi Aav",

year = "2019",

language = "English",

isbn = "978-952-60-8654-5",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "136",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Development of mechanical characterization methods for thin films and interfaces

T2 - “God created matter, surfaces were invented by devil” – Wolfgang Pauli

AU - Aav, Jussi

PY - 2019

Y1 - 2019

N2 - Probably the most important thin film characteristic is its' adhesion to the used substrate. It is very important to understand the fundamental mechanics of adhesion-related failures, and by having suitable characterization methods to detect any problems as early as possible. Tailored or correctly conducted quantitative analysis of adhesion is required for building reliable devices. In many conventional test methods significant loading to the substrate is applied which can result in problems especially with brittle substrates where the substrate can break before the film is delaminated. The characterization of interfacial mechanical properties of increasingly thinner films is challenging with many practical shortcomings and thus method development is needed. In this thesis, three measurement methods where the loading to the substrate is minimized are presented and demonstrated for the interfacial and mechanical testing of especially atomic layer deposited (ALD) thin films. (i) Microelectromechanical system (MEMS) test chip assisted shaft-loaded blister testing through a hole in the substrate to the backside of the thin film, (ii) microrobotic manipulation of embedded microspheres using lateral loading mostly to the thin film and to the interface and (iii) a combination of nanoscratch and scanning nanowear for minimized interaction volume of loading to the substrate. The relationship between adhesion and cohesion as competing processes during film/substrate failure is shown. When the film-interface-substrate system is under loading the energy will dissipate through the path of least resistance. This will happen either (i) through plastic deformation of the coating/substrate, (ii) film fracture (decohesion) or (iii) delamination (de-adhesion) of the film. Usually, however the energy is dissipated as a combination of these three different mechanisms, unless some of the mechanisms is dominant in the energy release. The presented characterization methods are mostly generic, and can be applied for the evaluation of mechanical and interfacial properties, such as adhesion, between practically any materials of choice with some limitations. Compared to some of the existing methods, the quantitative nature of these characterization methods enables a more in-depth possibility for the analysis, understanding, tuning and improvement of the properties of the thin films and processes aiding in maintaining and improving product and process quality. The main outcome of this thesis is that the authors have demonstrated the potential and versatility of especially the MEMS test structures and microrobotic testing systems, either on their own or as a combination as a solution to developing new tailored interfacial and mechanical characterization methods for current and future needs of research and the industry.

AB - Probably the most important thin film characteristic is its' adhesion to the used substrate. It is very important to understand the fundamental mechanics of adhesion-related failures, and by having suitable characterization methods to detect any problems as early as possible. Tailored or correctly conducted quantitative analysis of adhesion is required for building reliable devices. In many conventional test methods significant loading to the substrate is applied which can result in problems especially with brittle substrates where the substrate can break before the film is delaminated. The characterization of interfacial mechanical properties of increasingly thinner films is challenging with many practical shortcomings and thus method development is needed. In this thesis, three measurement methods where the loading to the substrate is minimized are presented and demonstrated for the interfacial and mechanical testing of especially atomic layer deposited (ALD) thin films. (i) Microelectromechanical system (MEMS) test chip assisted shaft-loaded blister testing through a hole in the substrate to the backside of the thin film, (ii) microrobotic manipulation of embedded microspheres using lateral loading mostly to the thin film and to the interface and (iii) a combination of nanoscratch and scanning nanowear for minimized interaction volume of loading to the substrate. The relationship between adhesion and cohesion as competing processes during film/substrate failure is shown. When the film-interface-substrate system is under loading the energy will dissipate through the path of least resistance. This will happen either (i) through plastic deformation of the coating/substrate, (ii) film fracture (decohesion) or (iii) delamination (de-adhesion) of the film. Usually, however the energy is dissipated as a combination of these three different mechanisms, unless some of the mechanisms is dominant in the energy release. The presented characterization methods are mostly generic, and can be applied for the evaluation of mechanical and interfacial properties, such as adhesion, between practically any materials of choice with some limitations. Compared to some of the existing methods, the quantitative nature of these characterization methods enables a more in-depth possibility for the analysis, understanding, tuning and improvement of the properties of the thin films and processes aiding in maintaining and improving product and process quality. The main outcome of this thesis is that the authors have demonstrated the potential and versatility of especially the MEMS test structures and microrobotic testing systems, either on their own or as a combination as a solution to developing new tailored interfacial and mechanical characterization methods for current and future needs of research and the industry.

KW - mechanical characterization

KW - thin films

KW - interfaces

KW - ALD

KW - mekaaniset karakterisointimenetelmät

KW - ohutkalvot

KW - pinnoitteet

KW - rajapinnat

KW - ALD

KW - mechanical characterization

KW - thin films

KW - interfaces

KW - ALD

M3 - Doctoral Thesis

SN - 978-952-60-8654-5

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

Development of mechanical characterization methods for thin films and interfaces: “God created matter, surfaces were invented by devil” – Wolfgang Pauli

Abstrakti

Tutkimusalat

Pääsy asiakirjaan

Sormenjälki

Laitteet

OtaNano

OtaNano Nanofab

OtaNano Nanomikroskopiakeskus

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