Development and characterization of a charge-coupled device detection system for ion microscopy

The construction of a prototype system capable of directly detecting and digitizing secondary-ion images using a charge-coupled device (CCD) is described. The CCD, alone, replaces the microchannel plate, fluorescent screen, and optical recording medium currently in use as the detection system on a CAMECA IMS-3f ion microanalyzer. Using the CCD as the image detector ensures that the secondary-ion signal is digitized in the most direct manner possible. A description of the hardware and image-acquisition process is given. Some of the first secondary-ion images to be detected using a CCD are presented, and the performance of the CCD as a detector of keV ions is evaluated. While preliminary trials appear promising, results indicate that the optimum efficiency is limited by the design of CCDs commercially available.