Study of radiation damage in silicon detectors for high ... - F9

More documents

Recommendations

Info

8 1. IntroductionForward SCTBarrel SCTPixel DetectorsTRTFigure 1.3: Schematic layout of the ATLAS Inner Detector (ID).This work presents results obtained by the study of radiation induced defects ofsilicon bulk under controlled conditions. Biasing voltage and temperature were controlledduring and after irradiations. Irradiation ux was varied from about 10 8 to few times10 15 n/cm 2 s to search for a ux eect on defect creation. Frequent measurements ofreverse current and full depletion voltage were performed during and immediately after theirradiation to provide better insight into fast defect annealing. Finally, abias dependentdefect annealing was discovered, resulting in about two times higher full depletion voltageof the biased samples after the end of benecial annealing.Radiation damage caused in silicon detectors can be separated to damage to siliconbulk and surface damage. The latter is mainly due to xed positive charges, collected atthe border between the semiconductor and the oxide. It increases the conductivity of thesurface, giving rise to surface currents. Surface damage can also distort the eld belowthe surface structures, thus changing the operation properties of a detector. It dependsconsiderably on detector design and manufacturing, which have been well studied andunderstood. Thus the surface damage seems to be manageable. Bulk damage, on theother hand, is much less understood. It causes an increase of the leakage current and ofthe eective dopant concentration. This results in increased operation voltage, increasednoise due to leakage current and increased power consumption and therefore heat. Allthose eects signicantly inuence the operational capability ofa silicon detector.Due to the interaction of radiation (n, p, , e, etc.)with silicon atoms the
1. Introduction 9R(cm)Z(cm)Figure 1.4: Flux in the inner detector cavity in units of 1 MeV equivalent neutrons per cm 2per year [6].R(cm)Z(cm)Figure 1.5: Flux of charged hadrons in the inner detector cavity percm 2 per year [6].periodic structure of the lattice is destroyed locally, i.e. silicon atoms are dislocated. Adislocated atom is called an interstitial atom, whereas the lattice site, being empty, iscalled a vacancy. The interstitials and vacancies form defect complexes which establishenergy levels in the band gap. Most of the defect complexes contain impurity atoms e.g.carbon and oxygen. Since the detector operation is foreseen to last 10 years, the long termbehaviour of bulk properties (eective doping concentration, reverse current) is of majorconcern. Understanding which type of defect causes the deterioration of performance is
Page 1: UNIVERSITY OF LJUBLJANAFACULTY OF M
Page 5: Najprej gre moja zahvala delovnima
Page 8 and 9: PovzetekSevalne poskodbe v siliciju
Page 10 and 11: 3.5 Measurement Setup, Methods and
Page 13 and 14: 1IntroductionSilicon detectors play
Page 15: 1. Introduction 7Figure 1.2: Schema
Page 19 and 20: 2Operation and Radiation Damage of
Page 21 and 22: 2. Operation and Radiation Damage o
Page 43 and 44: 3Irradiation Facility3.1 The Reacto
Page 45 and 46: 3. Irradiation Facility 373.3 Irrad
Page 47 and 48: 3. Irradiation Facility 39Fission p
Page 49 and 50: 3. Irradiation Facility 413.4 Irrad
Page 51 and 52: 3. Irradiation Facility 43Figure 3.
Page 53 and 54: 3. Irradiation Facility 45Figure 3.
Page 55 and 56: 3. Irradiation Facility 47the inuen
Page 57 and 58: 3. Irradiation Facility 49width of
Page 59 and 60: 3. Irradiation Facility 51The full
Page 61 and 62: 3. Irradiation Facility 53percent.
Page 63 and 64: 4Time Development of DefectsIn this
Page 65 and 66: 4. Time Development ofDefects 57* F
Page 67 and 68:
4. Time Development ofDefects 59val
Page 69 and 70:
4. Time Development ofDefects 61for
Page 71 and 72:
4. Time Development ofDefects 63Fig
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
4. Time Development ofDefects 79An
Page 89 and 90:
5Dose Rate Dependence5.1 Motivation
Page 91 and 92:
5. Dose Rate Dependence 83Figure 5.
Page 93 and 94:
5. Dose Rate Dependence 85Figure 5.
Page 95 and 96:
5. Dose Rate Dependence 87could be
Page 97 and 98:
6Inuence of Bias VoltageIt was a ge
Page 99 and 100:
6. Inuence of Bias Voltage 91energy
Page 101 and 102:
6. Inuence of Bias Voltage 93Figure
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
6. Inuence of Bias Voltage 99that t
Page 109 and 110:
6. Inuence of Bias Voltage 101(abou
Page 111 and 112:
6. Inuence of Bias Voltage 103Figur
Page 113 and 114:
7Comparison with Other GroupsWhile
Page 115 and 116:
7. Comparison with Other Groups 107
Page 117 and 118:
8ConclusionsA systematic study of r
Page 119 and 120:
8. Conclusions 111Implications for
Page 121 and 122:
9Povzetek doktorskega dela9.1 UvodS
Page 123 and 124:
9. Povzetek doktorskega dela 115Ski
Page 125 and 126:
9. Povzetek doktorskega dela 117sre
Page 127 and 128:
9. Povzetek doktorskega dela 1199.2
Page 129 and 130:
9. Povzetek doktorskega dela 121Sli
Page 131 and 132:
9. Povzetek doktorskega dela 123Ce
Page 133 and 134:
Page 135 and 136:
9. Povzetek doktorskega dela 127Cep
Page 137 and 138:
9. Povzetek doktorskega dela 129Mer
Page 139 and 140:
9. Povzetek doktorskega dela 131Sam
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
9. Povzetek doktorskega dela 1379.6
Page 147 and 148:
10Appendix: List of Symbols and Abb
Page 149 and 150:
10. Appendix: List of Symbols and A
Page 151 and 152:
References[1] J. Straver et al., Nu
Page 153 and 154:
[27] A.M. Ougang et al.: Dierential
Page 155 and 156:
[57] M. Huhtinen et al, HU-SEFT-R-1
Page 158:
Izjavljam, da je disertacija rezult
show all

Study of radiation damage in silicon detectors for high ... - F9

Create successful ePaper yourself

Delete template?

Save as template?