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Carbon film deposition using high power pulsed Nd : YAG laser
Author
Kang, Kim Hor
Supervisor
Lee, Paul Choon Keat
Abstract
Amorphous diamond-like carbon thin films have been deposited using the pulsed action of 1064 nrn Nd-YAG laser to ablate graphite target. The plasma plume that comes out fiom the target surface is condensed onto different substrate materials; silicon (100), microscope glass slides, and quartz crystal, at room as well as elevated temperatures, and thin films with varying degree diamond-like character were synthesized. Thickness of the films ranges between 600-24002. Raman spectroscopy was used to determine the degree of diamond-like character, i.e. the fraction of sp3 bonded carbon atoms within the films. Transparencies of films in the electromagnetic spectrum were measured using the Fourier Transform Infrared (FTIR) and the Ultraviolet-Visible (UVV) spectroscopies. Results showed that films have high sp3 bonding fraction (between 75% to 80%) and high transparency over a large portion of the IR and optical region. Tauc plots indicate optical bandgap energy of around 1 eV for films deposited at room temperature. Scanning from the Atomic Force Microscope revealed that films contain significant amount of micro particulates, and films deposited at room temperature showed smoother surface morphologies. Results showed that increased substrate-temperatures promote graphitization of the films, producing films with low sp3 bonding fraction. This results in films with higher electrical conductivity and higher optical absorbance. Hardness of the films was not accurately determined due to inadequate thickness of our deposited films.
Date Issued
2000
Call Number
TK7871.15.F5 Kan
Date Submitted
2000