Analysis of the extended defects in 3C-SiC.pdf - Nelson Mandela ...

More documents

Recommendations

Info

6.1 Introduction 64 CHAPTER SIX EXPERIMENTAL DETAILS This chapter deals with the experimental procedures used in this investigation. Specifics on the growth process, ion implantation, annealing procedure and the TEM sample preparation are given. 6.2 CVD Growth of SiC The 3C-SiC used in this study was grown by NovaSiC in France using H2 as carrier gas and C3H8 (propane) and SiH4 (silane) as precursors on a silicon substrate. The layer deposition was carried out at 200 mbar. The first step of the process consisted of a carbonisation of Si at 1100 °C under a mixture of H2 and C3H8 and the second step was the epitaxial growth, performed at 1380 °C with a growth rate of 2 µm/h. 6.3 Proton Implantation in SiC To investigate the damage created by light ion bombardment in 3C-SiC the material was implanted with 400keV protons to a total dose of 2.2 × 10 16 over a 1cm diameter region. The 400 keV protons were generated by implanting the material with 800 keV H2 + ions which upon entering the material splits up into 400 keV H + . The implantation was done at NECSA (National Energy Corporation of South Africa). SRIM (Stopping Ranges of Ions in Matter) developed by Ziegler et al. (1985) was used to calculate the proton range. This software uses Monte Carlo methods to determine the ion range and defect production within the material.
6.3.1 Ion Range and Defect Production 65 Fig. 6.1. A plot of the ion distribution of 400 keV protons implanted into 3C-SiC obtained by using SRIM Fig. 6.1. shows a SRIM plot of the hydrogen ion distribution of 400 keV protons implanted into 3C-SiC. The plot shows a maximum concentration of ions at 2.87 µm. This is within the thickness of the SiC layer used for this study. Fig. 6.2. shows SRIM plots of the numbers of Si and C vacancies produced for displacement energies given by Heinisch et al. (2004) and Vladimirov et al. (1998).
Page 1 and 2:
Analysis of the Extended Defects in
Page 3 and 4:
My sincere thanks to the following
Page 5 and 6:
OPSOMMING Hierdie dissertasie hande
Page 7 and 8:
4.2.5. Two-Beam Scattering Matrix 4
Page 9 and 10:
Dedicated to my wife and parents
Page 11 and 12:
SUMMARY The dissertation focuses on
Page 13 and 14:
CONTENTS Chapter 1: INTRODUCTION 1
Page 15 and 16:
1 CHAPTER ONE INTRODUCTION Silicon
Page 17 and 18:
2.1. Introduction 3 CHAPTER TWO OVE
Page 19 and 20:
2.2.2 The Zinc-Blende Structure 5 T
Page 21 and 22:
2.3 Point Defects, Defect Migration
Page 23 and 24:
v m Em vm0 exp( ) (2.2) kT 9 wher
Page 25 and 26:
11 explained and the concept of par
Page 27 and 28: 13 Straight dislocations furthermor
Page 29 and 30: 2.5 Partial Dislocations and Slip 1
Page 31 and 32: 17 Fig. 2.13. The geometrical setup
Page 33 and 34: 19 extrinsic stacking faults are th
Page 35 and 36: 2.8 Twinning 21 Twinning is a proce
Page 37 and 38: 23 Fig. 2.20. The process of vacanc
Page 39 and 40: S n Td (3.2) 25 and is also referr
Page 41 and 42: 27 where a = a0(Z1 2/3 + Z2 2/3 ) -
Page 43 and 44: 29 Using this expression, curves of
Page 45 and 46: 31 As stated previously hard-sphere
Page 47 and 48: 33 where A is the atomic weight. Th
Page 49 and 50: 35 a vacancy dislocation loop if th
Page 51 and 52: 37 Fig. 4.1. (a) A wave incident on
Page 53 and 54: 39 Consider Fig. 4.2 which illustra
Page 55 and 56: 41 V0 is the mean inner potential o
Page 57 and 58: 43 beam left-hand side g' = 0 g' =
Page 59 and 60: 45 In addition another set of indep
Page 61 and 62: 47 When this is incorporated into t
Page 63 and 64: S ( s , z ) e T i Se ( / 0 )
Page 65 and 66: z0 z2 . xn cos and (4.47) D 1 proj
Page 67 and 68: 5.1 Introduction 53 CHAPTER FIVE LI
Page 69 and 70: 55 different orientations. The inte
Page 71 and 72: 57 Furthermore Pirouz et al. (1987)
Page 73 and 74: 59 intersection of the fault, the f
Page 75 and 76: 61 each nuclei because of the low s
Page 77: 63 (2000) found that subsequent ann
Page 81 and 82: 67 Fig. 6.3. Total number of displa
Page 83 and 84: 7.1 Introduction 69 CHAPTER SEVEN R
Page 85 and 86: Fig. 7.2. Simulated diffraction pat
Page 87 and 88: 73 Fig. 7.3. A HRTEM image of the S
Page 89 and 90: 75 Fig. 7.5. The stacking fault sel
Page 91 and 92: (Si/ni) 2 0.000018 0.000016 0.00001
Page 93 and 94: 79 may be concluded that the initia
Page 95 and 96: 81 Fig. 7.11. Bright field TEM micr
Page 97 and 98: 83 Fig. 7.12 which was obtained by
Page 99 and 100: 85 Fig. 7.13. Bright-field TEM micr
Page 101 and 102: 87 (a) (b) Fig. 7.15. The (a) exper
Page 103 and 104: 89 In the following paragraphs the
Page 105 and 106: Fig. 7.18. CBED pattern taken of th
Page 107 and 108: 93 Table 7.5. The measured paramete
Page 109 and 110: 7.4.2 Results 95 Fig. 7.22. Bright-
Page 111 and 112: 97 Twin platelets on {111} planes
Page 113 and 114: 99 REFERENCES Blumenau, A.T., Jones
Page 115 and 116: 101 Hull, D., Bacon, D.J. : (1984)
Page 117: 103 Smith, D.J., Jepps, N.W. and Pa
show all

Analysis of the extended defects in 3C-SiC.pdf - Nelson Mandela ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?