Introduction to radiation-resistant semiconductor devices and circuits

Effective Doping Concentration [cm -3 ]
10 14
10 13
10 12
10 11
10 10
10 9
10 8
10 11
N d0 = 10 13 cm -3
N d0 = 10 12 cm -3
10 12
above equations must be modified accordingly. Moderate resistivity n type material
(ρ = 1 to 5 kΩcm) used in large area tracking detectors is usually dominated by
donors.
Annealing of ionized acceptor states
After defect states are formed by irradiation, their electronic activity changes
with time. A multitude of processes contribute, some leading to beneficial
annealing, i.e. a reduction in acceptor-like states, and some increasing the acceptor
concentration. The third term in Eq. 4 describes the beneficial annealing (17),
where gs= 1.93⋅10 -2 cm -1 and τ (T)= (6⋅10 6 )⋅exp[-0.175(T-273.2)] s (to set the
scale, τ(0°C)= 70 d). The fourth term in Eq. 4
⎡
NY ( Φ , t1/2 , T ) = gYΦ
⋅⎢1− ⎣
10 13
Fluence [cm -2 ]
10 14
FIGURE 3. Calculated effective doping concentration vs. high-energy proton
fluence for silicon with initial donor concentrations N d0 of 10 12 and 10 13 cm -3 .
1 ⎤
1+
gYΦ ⋅ k( T ) ⋅
⎥
t ⎦
10 15
where for 1 MeV neutrons gY= (4.6±0.3)⋅10 -2 cm -1 and for 1 GeV protons values
of gY= (4.97±0.23)⋅10 -2 cm -1 (16) and (5.8±0.3)⋅10 -2 cm -1 (9) have been found. The
temperature dependent evolution is determined by
10
(5)
−
k T k e
Ea / kBT ( ) = 0 (6)