“amere et sapere vix deo conceditur”
Appendix A: SEM Images
and Raman Spectra from MWCVD Diamond Films
This appendix presents data pertinent to the results
chapters of this thesis. Thus the data
in this chapter does not present a coherent ‘story’ on it’s own, but should be
referred to by the reader when reading the results chapters of this thesis.
A.1 Effect of
Deposition Time
Conditions kept constant for the growth runs where
the effect of deposition time on diamond film thickness and morphology was
studied (Section 4.2.1) are given in Table A.1. SEM micrograph images of films grown for increasing lengths of
time are shown in Figs. A.1-A.4
Constant Conditions |
Old Substrate Holder (OSH) |
Microwave power (W) |
1000 |
Substrate temperature (K) |
1073 |
Pressure (Torr) |
30 |
Input CH4 mole
fraction (%) |
0.72 |
Table A.1 Constant conditions used for MWCVD diamond
film growth, whilst increasing the deposition time. The substrate temperature given here is that measured by the
thermocouple in the substrate holder.
Figure A.1a & b: 1.5 hours growth (Sample MW88).
Figure A.2
6.0 hours growth (MW88). Figure
A.3 13.0 hours growth (MW88).
Figure A.4 18.7 hours
growth (MW88).
Figures A.1-A.4: SEM images of CVD diamond films grown under
the conditions given in Table A.1. A
representative Raman spectrum of the film in Fig. A.1a is shown in
Fig. A.1b.
A.2 Effect of CH4
mole fraction in H2 feed
Constant
Conditions |
Old Substrate Holder (OSH) |
New Substrate Holder (NSH) |
Microwave power (W) |
1000 |
1000 |
Substrate temperature (K) |
1073 |
973 |
Pressure (Torr) |
30 |
30 |
Growth Time (hours) |
6.0 |
6.0 |
Table A.2 Constant
conditions used for MWCVD diamond film growth whilst varying the mole fraction
of CH4 in the H2 feed gas.
Figure A.5 0.36% input CH4 mole fraction
(OSH, MW44).
Figure A.6 0.54% input CH4 mole fraction
(OSH, MW59).
Figure A.7 0.72% input CH4 mole fraction
(OSH, MW32).
Figure A.8 1.08% input CH4 mole fraction
(OSH, MW 47).
Figure A.9 1.44% input CH4
mole fraction (OSH, MW46).
Figure A.10 1.80% input CH4
mole fraction (OSH, MW48).
Note to Figs. A.5-A.10: Raman
spectra for CVD diamond films with increasing input CH4 were
presented in chapter 4 (Fig. 4.3).
Figure A.11a & b: 0.36% input
CH4 mole fraction (NSH, MW112)
Figure A.12a & b: 0.72%
input CH4 mole fraction (NSH, MW97)
Figure A.13a & b: 1.08%
input CH4 mole fraction (NSH, MW102)
Figure A.14a & b: 1.44%
input CH4 mole fraction (NSH, MW100)
Figure A.15a & b: 2.16%
input CH4 mole fraction (NSH, MW103)
A.3 Variation of applied Microwave Power
Constant
Conditions |
Old Substrate Holder (OSH) |
New Substrate Holder (NSH) |
Input CH4 mole
fraction (%) |
0.72 |
0.72 |
Substrate temperature (K) |
1073 |
973 |
Pressure (Torr) |
30 |
30 |
Growth Time (hours) |
6.0 |
6.0 |
Table A.3 Constant
conditions used for MWCVD diamond film growth whilst varying the microwave
power level used to sustain the plasma.
Figure A.16a & b:
800 W (OSH, MW41).
Figure A.17a & b:
900 W (OSH, MW55).
Figure A.18a & b:
1100 W (OSH, MW56).
Figure A.19: 1200 W (OSH,
MW83).
Figure A.20a & b:
600 W (NSH, MW111).
Figure A.21a & b:
800 W (NSH, MW110).
Figure A.22a & b:
900 W (NSH, MW113).
Figure A.23a & b:
1100 W (NSH, MW115).
Figure A.24a & b:
1200 W (NSH, MW109).
A.4 Effect of CVD Reactor Pressure
Constant Conditions |
Old Substrate Holder (OSH) |
New Substrate Holder (NSH) |
Input CH4 mole
fraction (%) |
0.72 |
0.72 |
Substrate temperature (K) |
1073 |
973 |
Microwave Power (W) |
1000 |
1000 |
Growth Time (hours) |
6.0 |
6.0 |
Table A.4 Constant
conditions used for MWCVD diamond film growth whilst varying the reactor
pressure.
Figure A.25a & b:
20 Torr (OSH, MW33).
Figure A.26a & b:
25 Torr (OSH, MW58).
Figure A.27a & b:
35 Torr (OSH, MW60).
Figure A.28a & b:
40 Torr (OSH, MW34).
Figure A.29a & b:
50 Torr (OSH, MW37).
Figure A.30a & b:
20 Torr (NSH, MW106).
Figure A.31a & b:
40 Torr (NSH, MW105).
Figure A.32a & b:
55 Torr (NSH, MW104).
A.5 Effect of substrate holder vertical
position
Figure A.33 SEM image of CVD diamond film grown using a
pressure of 30 Torr, 700°C substrate temperature,
1000 W microwave power, 0.72% CH4/H2. 6 hours
growth, using the new substrate holder positioned at Z = 23 mm
(Sample MW120).
A.5 Effect of Substrate Temperature
Constant Conditions |
Both Substrate Holders |
Input [CH4] (%) |
0.72 |
Pressure (Torr) |
30 |
Microwave Power (W) |
1000 |
Growth Time (hours) |
6.0 |
Table A.5 Constant conditions used for growth of CVD
diamond films whilst examining the effect of substrate temperature.
Figure A.34a & b: 700°C (OSH, MW53).
Figure A.35a & b: 750°C (OSH, MW35).
Figure A.36a & b: 775°C (OSH, MW57).
Figure A.37a & b: 850°C (OSH, MW36).
Figure A.38: 383°C (NSH, MW125).
Figure A.39a & b: 550°C (NSH, MW107).
Figure A.40a & b: 600°C (NSH, MW101).
Figure A.41: 625°C (NSH, MW114).
Figure A.42a & b: 650°C (NSH, MW98).
Figure A.43a & b: 750°C (NSH, MW99).