Evaluation of Si(Li) detectors by a combination of the copper plating method and X-ray analytical microscopy

Copper mapping for copper-plated lithium-ion compensated Si(Li) wafers was performed by a microbeam X-ray fluorescence method. Positional distribution of copper across a cross section of the Si(Li) wafers treated at 120 degre esC for 20 h with no bias applied after complete compensation clearly showe d deviation from those that did not undergo the thermal treatment. The surf ace-barrier detectors fabricated from the thermally treated wafers were fou nd to have better energy resolution both for conversion electrons from Bi-2 07 and for cx-particles from Am-241. Correlation between the performance of the Si(Li) detectors and the lithium distribution in the intrinsic region was studied on the basis of the experimental results.