Collection of charge carriers, generated by 2 MeV protons, in n(+)p diodes with buried conductive layers, formed by high-energy B+ implantation, has been investigated using nuclear microprobe (i.e., focused ion beam) induced current-measurement. Suppression efficiency of generated charge carriers was found to depend on the implantation dose for buried wells. About 20% of carriers generated by an incident ion beam could be suppressed by formation of a buried layer, while the suppression rate by the buried layers was increased to about 60% by lowering the applied reverse bias down to 1 V.