Applied Surface Science, Vol.184, No.1-4, 455-459, 2001
Triode structure of ion detector based on 6H-SiC epitaxial films
The possibility of the approximate to 10(2) times inner amplification of signals in SiC-based detectors of short-range ions was shown. Detector was realized by growth of p-type epilayers on base of 6H-n(+) -SiC substrate. Doping level in the films was 2.8 x 10(15) cm(-3), thickness approximate to 10 mum. Ni Schottky diodes were formed on films surface by magnetron sputtering. Final detector has n-p-n(+)-like structure. Detector parameters were investigated in regime of "floating base". alpha -Particles from Cm-244 with energy 5.8 MeV was used and investigated the increasing of the signal (Q) with increasing applied voltage (U). The superlinear growing of Q with significant (tens of times) amplification of the introduced by a-particle nonequilibrium charge was found. Irradiated structure was equal to phototriode which allows to use the results of Grinberg [Solid State Phys. 1 (1959) 31], obtained for transport of the introduced in base charge at delta -like voltage pulses on emitter-base junction. Using model from Grinberg [Solid State Phys. 1 (1959) 31], approximation of the experimental dependence Q(U) gives value for electron diffusion lengths in base of 5.9 mum.
Keywords:triode structure;alpha-spectrometry;amplification;spectrum width;radiation hardness;diffusion length