Pk. Bhatnagar et al., FAST-NEUTRON IRRADIATION FOR FABRICATION OF NARROW FORWARD VOLTAGE P-I-N-DIODES, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 329(3), 1993, pp. 467-469
Wide base p-i-n diodes show an increase in the forward voltage V(f) at
a constant current when exposed to neutrons. The change in V(f) is a
measure of neutron dose. Variation in V(f) with neutron dose is linear
but has different slopes for regions below 2.5 Gy and above it. In or
der to use a single electronic reader instrument for measuring a chang
e in V(f), there is a requirement of fabricating diodes of unique V(f)
, which is not always possible due to minor deviation in the quality o
f wafer used. A method of exposing diodes to neutrons has been used to
arrive at desired narrow V(f) for the p-i-n diodes produced in differ
ent batches. Further the raw p-i-n diodes when exposed to about 2.5 Gy
neutrons, before using them for dosimetry, need a readout instrument
for simple amplification as the neutron response of the diodes give on
ly one slope beyond 2.5 Gy.