Optical thin films prepared by ion-assisted and ultrasound-assisted deposition.

Persistent Link:
http://hdl.handle.net/10150/184577
Title:
Optical thin films prepared by ion-assisted and ultrasound-assisted deposition.
Author:
Hwangbo, Chang Kwon.
Issue Date:
1988
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Optical, electrical, and microstructural effects of Ar ion bombardment and Ar incorporation on thermally evaporated Ag and Al thin films were investigated. The results show that as the momentum supplied to the growing films by the bombarding Ar ions per arriving metal atom increases, refractive index at 632.8 nm increases and extinction coefficient decreases, lattice spacing expands, grain size decreases, electrical resistivity increases, and trapped Ar increases slightly. In Ag films, stress reverses from tensile to compressive; in AI films compressive stress increases. In both films, the change in optical constants can be explained by variation in void volume. The reversal of stress from tensile to compressive in Ag films requires a threshold level of momentum. The increase in electrical resistivity is related to the increase in the void fraction, decrease in the grain size, and increase in trapped Ar in both types of films. Many of these properties correlate well with the momentum transferred, suggesting that the momentum is an important physical parameter in describing the influence of ion beams on growing thin films and determining the characteristics of thin metal films prepared by ion-assisted deposition (IAD). With a low energy ion beam, the Ar concentration in IAD Ag films was negligible. When the bombarded film thickness was less than 5 nm, the electrical resistivity of IAD Ag films tended to decrease slightly from that of the non-IAD film. Using the Bruggeman effective medium theory, a formula for the void fraction at any given wavelength was derived. We investigated optical properties, stoichiometry, chemical bonding states, and structure of aluminum oxynitride thin films prepared by reactive ion-assisted deposition. Variations of optical constants and chemical bonding states are related to the stoichiometry. We found that our amorphous aluminum oxynitride film is not simply a mixture of aluminum oxide and nitride but a compound. A rugate filter using a step-index profile of aluminum oxynitride films was fabricated by nitrogen ion beam bombardment of a growing Al film with backfilled oxygen pressure as the sole variable. The effects of ultrasound-assisted deposition (UAD) on the optical properties of ZrO₂, Ta₂O₅, and MgF₂ films were investigated. UAD is likely to induce oxygen and fluoride deficiencies in oxide and fluoride films and increase the packing density of films.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Thin films -- Research.; Optical films -- Research.; Ion bombardment -- Research.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Optical Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Macleod, H. Angus

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleOptical thin films prepared by ion-assisted and ultrasound-assisted deposition.en_US
dc.creatorHwangbo, Chang Kwon.en_US
dc.contributor.authorHwangbo, Chang Kwon.en_US
dc.date.issued1988en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractOptical, electrical, and microstructural effects of Ar ion bombardment and Ar incorporation on thermally evaporated Ag and Al thin films were investigated. The results show that as the momentum supplied to the growing films by the bombarding Ar ions per arriving metal atom increases, refractive index at 632.8 nm increases and extinction coefficient decreases, lattice spacing expands, grain size decreases, electrical resistivity increases, and trapped Ar increases slightly. In Ag films, stress reverses from tensile to compressive; in AI films compressive stress increases. In both films, the change in optical constants can be explained by variation in void volume. The reversal of stress from tensile to compressive in Ag films requires a threshold level of momentum. The increase in electrical resistivity is related to the increase in the void fraction, decrease in the grain size, and increase in trapped Ar in both types of films. Many of these properties correlate well with the momentum transferred, suggesting that the momentum is an important physical parameter in describing the influence of ion beams on growing thin films and determining the characteristics of thin metal films prepared by ion-assisted deposition (IAD). With a low energy ion beam, the Ar concentration in IAD Ag films was negligible. When the bombarded film thickness was less than 5 nm, the electrical resistivity of IAD Ag films tended to decrease slightly from that of the non-IAD film. Using the Bruggeman effective medium theory, a formula for the void fraction at any given wavelength was derived. We investigated optical properties, stoichiometry, chemical bonding states, and structure of aluminum oxynitride thin films prepared by reactive ion-assisted deposition. Variations of optical constants and chemical bonding states are related to the stoichiometry. We found that our amorphous aluminum oxynitride film is not simply a mixture of aluminum oxide and nitride but a compound. A rugate filter using a step-index profile of aluminum oxynitride films was fabricated by nitrogen ion beam bombardment of a growing Al film with backfilled oxygen pressure as the sole variable. The effects of ultrasound-assisted deposition (UAD) on the optical properties of ZrO₂, Ta₂O₅, and MgF₂ films were investigated. UAD is likely to induce oxygen and fluoride deficiencies in oxide and fluoride films and increase the packing density of films.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectThin films -- Research.en_US
dc.subjectOptical films -- Research.en_US
dc.subjectIon bombardment -- Research.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorMacleod, H. Angusen_US
dc.identifier.proquest8906388en_US
dc.identifier.oclc701928348en_US
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