Atomic layer deposition of metal and metal chalcogenide thin films and nanolaminate composites.
by Christian Volkmann
Date of Examination:2017-11-23
Date of issue:2018-04-09
Advisor:Prof. Dr. Sven Schneider
Referee:Prof. Dr. Dietmar Stalke
Referee:Dr. Inke Siewert
Referee:Prof. Dr. Selvan Demir
Referee:Prof. Dr. Guido Clever
Referee:Prof. Dr. Thomas Waitz
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EnglishThe construction of a novel “hot and cold wall, cross laminar flow multiple substrate atomic layer deposition reactor” is presented including a LabView based control program and an user-optimized graphical user interface. The chamber was successfully tested by the improvement of three different materials with respect to growth rates and impurity content by well chosen depositional parameter (AlOx, Pt and Ir). The synthesis of a new multilayer system is introduced by forming nanolaminates made with alternating platinum and aluminium oxide ALD. Theses structures were probed by transient temperature-dependent reflectivity (TTR) and Rydberg atom tagging (RAT), respectively. The outstanding decrease in heat conductivity as well as the possibility of the formation of a super thin isolation layer on metals for atom scattering purposes were proven with these techniques. Deposition experiments aiming for cobalt or cobalt oxide thin films using a new kind of precursor design within the elusive ALD procedure are discussed. Thin films are presented with growth rates comparable to the literature values, being very small. However, the examination of this procedure revealed a possible decomposition pathway prohibiting ALD. Beyond that, an ALD strategy is investigated to generate thin tantalum oxide and the still unreported sulphide films with outstanding qualities, such as lowest roughness, unequalled mild deposition temperature and sufficient growth rates.
Keywords: Atomic Layer Deposition; Thin Film; Sandwich layer; ALD; Reactor design