Charge Collection in CVD Diamond
description
Transcript of Charge Collection in CVD Diamond
Charge Collection in CVD Diamond
R. KassParis – Nov. 22, 2012 35
R. KassParis – Nov. 22, 2012 40
Radiation Damage - Basics
Charge trapping the only relevant radiation damage effect NIEL scaling questionable a prioriEgap in diamond 5 times larger than in Si Many processes freeze out Typical emission times order of months Like Si at 300/5 = 60 K – Boltzmann factor A rich source of effects and (experimental) surprises !
Radiation induced effect Diamond Operational
consequence Silicon Operational consequence
Leakage current
small &decreases none I/V = αΦ
α ~ 4x10-17 A/cm
HeatingThermal runaway
Space charge ~ none noneΔNeff ≈ -βΦ
β ~ 0.015 cm-1
Increase of full depletion
voltage
Charge trapping Yes Charge loss
Polarization
1/τeff = βΦβ ~ 5-7x10-16
cm2/ns
Charge lossPolarization
t
thttteff
vPN
)1(1
Summary of RD42 Test Beam Resultsfor CVD Diamond
R. KassParis – Nov. 22, 2012 41
Particle Energy Relative k
p 24GeV 1.0
800MeV 1.6-1.8
70MeV 2.5-2.8
25MeV 4.0-5.0
π 200MeV 2.5-3.0
k is relative damage constant