The response of Si p-n junction diodes to proton irradiation

In this paper the response of Si junction diodes to 10 MeV proton irradiation in the fluence range 5 x 10(9) cm(-2) to 4 x 10(11) cm(-2) is described. In particular, the impact on the peripheral and areal leakage current density and on the recombination lifetime is studied for diodes processed on different silicon substrate types. It is shown that in general the different damage coefficients for p-type Si are slightly lower than for n-type Si. Furthermore, p-type Czochralski (Cz) Si is harder for the lowest fluence range studied (< 2 x 10(10) cm(-2)) compared with float-zone Si. A marked effect of the pretreatment used is also observed: internally gettered Cz wafers are overall more radiation hard than non-gettered substrates. The electrical diode results are discussed in view of the microscopic defect behaviour revealed by deep level transient spectroscopy. Finally, from temperature-dependent lifetime measurements, it is observed that in the irradiated wafers, the recombination lifetime in the temperature range -50 degrees C to 200 degrees C is governed by a shallow recombination centre in both n- and p-type silicon.