Epitaxial silicon devices for dosimetry applications

A straightforward improvement of the efficiency and long term stability of silicon dosimeters has been obtained with a $n^{+}\text{-}p$ junction surrounded by a guard-ring structure implanted on an epitaxial $p$ -type Si layer grown on a Czochralski substrate. The sensitivity of devices made on $50\text{-}\mu \mathrm{m}$ -thick epitaxial Si degrades by only 7% after an irradiation with $6\mathrm{MeV}$ electrons up to $1.5\mathrm{kGy}$ , and shows no significant further decay up to $10\mathrm{kGy}$ . These results prove the enhanced radiation tolerance and stability of epitaxial diodes as compared to present state-of-the-art Si devices.