Amorphous silicon/crystalline silicon heterojunctions in nuclear radiation detector fabrication

Application of amorphous silicon/crystalline silicon heterojunctions formed by RF sputter deposition and plasma enhanced chemical vapor deposition to the fabrication of nuclear radiation detectors is described. The performance of these heterojunctions as blocking contacts on high-resistivity p-type and n-type single crystal silicon and on lithium-ion compensated silicon (Si(Li)), which are commonly used in silicon detector fabrication, is presented. It is shown that an aluminum/amorphous-silicon contact on Si(Li) x-ray detectors results in about a factor of two reduction in the background counts when compared to a normal gold barrier contact.