I= DEPOSITION OF DIAMOND-LIKE CARBON AND TITANIUM NITRIDE FILMS USING PLASMA FOCUS DEVICE
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Title of Thesis
DEPOSITION OF DIAMOND-LIKE CARBON AND TITANIUM NITRIDE FILMS USING PLASMA FOCUS DEVICE

Author(s)
SHAISTA ZEB
Institute/University/Department Details
Department of Physics/ Quaid-i-azam University, Islamabad
Session
2007
Subject
Physics
Number of Pages
126
Keywords (Extracted from title, table of contents and abstract of thesis)
diamond-like carbon, titanium nitride films, plasma focus device, dlc films

Abstract
A 1.5 kJ Mather type dense plasma focus device charged at 18 kV is used for the deposition of hard coatings on different substrates. Amorphous diamond like carbon films are deposited on Si(100) substrates with high film deposition rates using different working gases. The graphite inserted at the anode tip is ablated by electron beams from the plasma focus and is used for the deposition of DLC films. Raman spectra of amorphous DLC films are characterized by two broad peaks centered around 1350 cm-I and 1550 cm-l known as D-band and G-band respectively. The peak intensity ratio (ID/ IG) and the peak position (D and G band) have been discussed for the investigation of diamond-like or amorphous carbon films. For amorphous carbon films the peak intensity ratio of the D-band to G-band (Io/IG) and the G-peak position in the Raman spectra are used to characterize the films deposited on silicon substrate placed at different axial and angular positions with respect to focus axis. The films deposited at different positions with different gas discharges possess varying content of Sp2 and Sp3 bonding network of carbon that change the properties of the films. Stress and sp2 cluster size present in the films are discussed with shift in G-peak position since higher sp2 content and growth stress shifts the G-peak position to higher frequencies. The peak intensity ratio lD/IG is related to sp3/sp2 ratio to estimate the four-fold carbon networks. Lower values of the peak intensity ratios lD/lG, as in case of nitrogen and neon plasma assisted OLC films, yield higher sp3/sp2 ratio corresponding to increased number of four-folded carbon network. Lower values of the peak intensity ratios lD/IlG, as in case of nitrogen and neon plasma assisted DLC films, yield higher sp3/sp2 ratio corresponding to increased number of four-folded carbon Sp3 network. EDX results show that higher carbon content is present on the substrates treated with methane plasma and a relatively lower with nitrogen plasma. The SEM micrographs show high thicknesses that indicate very high deposition rates (upto 3 um/shot in case of methane treated substrates). The films deposited in case of neon plasma are quite smooth and uniform while methane assisted films are less smooth. It is concluded that the alternation of deposition conditions results in the variation of the coating structure and the proportion of the Sp3 ISp2 -bonding, which change the band intensity ratio (ID lG) and G-peak position in the Raman spectra of the films.

It is observed that with the increasing number of focus shots the peak intensity ratio ID/lG markedly increases while the position of G-peak also shifts upward, which indicates the increase in size or number of Sp2 domains. This suggests that the conversion from sp3 carbon network to Sp2 bonding network takes place with increasing ion bombardment. For DLC films, Sp3 matrix controls the mechanical properties and 1t states of Sp2 clusters are responsible for the electronic structure and optical band gap. Thus with increasing ion dose the Sp2 bonded networks in the films tend to increase and come closer by forming small clusters. It is found that ion implantation is an alternative method of injection of thermal energy to modify the film properties in a highly controlled manner by the correct choice of ion species, ion energy and ion dose.

Polycrystalline, smooth and hard thin films of TiN are deposited on AISI-304 steel substrates in nitrogen plasma environment. The samples are treated at different axial and angular positions with varying focus shots. The structural and mechanical properties of the TiN films in terms of ion dose and substrate positions are investigated. The closer angular position yields higher hardness and more TiN content. At smaller distances from anode tip, the fabricated films exhibit more crystalline character as investigated by XRD analysis. The XRD patterns confirm the successful growth of TiN films and the formation of a new phase of iron chromium and nickel on the substrates. The content of titanium and nitrogen in films increases with the increasing number of focus shots.

Download Full Thesis
1638.44 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
133.68 KB
2 1 Introduction 1
182.62 KB
  1.1 Diamond-Like Carbon ( Dlc Deposition 2
  1.2 Titanium Nitride (Tin) Deposition 7
  1.3 Layout Of The Dissertation 12
  1.4 References 13
3 2 Film Deposition 18
283.85 KB
  2.1 Deposition Methods 18
  2.2 Plasma Focus System For Film Deposition 26
  2.3 Plasma Focus Operation 32
  2.4 References 36
4 3 Diagnostics And Characterization Techniques 39
268.09 KB
  3.1 Preliminary Plasma Focus Diagnostics 39
  3.2 Film Characterization 46
  3.3 References 60
5 4 Results And Discussion 62
686.27 KB
  4.1 Dlc Deposition In Neon Environment 63
  4.2 Dlc Deposition In Nitrogen Environment 77
  4.3 Olc Deposition In Methane Environment 86
  4.4 Dlc Deposition In Argon Environment 94
  4.5 References 105
6 5 Titanium Nitride Deposition 108
223.27 KB
  5.1 Experimental Details 109
  5.2 Ion-Beam Emission And Film Deposition 111
  5.3 Xrd Characterization 113
  5.4 Hardness Measurement 116
  5.5 Sem And Edx Analysis 118
7 6 Conclusions 123
26.36 KB
  6.1 Conclusions 123
  6.2 Suggestions For Future Work 126