Design of a computerized low temperature EBIC system

A system to perform low temperature Electron Beam Induced Current Imaging (EBIC) is detailed. To aid in the analysis of semiconductor materials, EBIC imaging analysis is used to locate and identify electrically active defects. Low temperature EBIC relies on lowered carrier diffusion lengths in the semiconductor to enhance the carrier trapping abilities of defects, thus improving EBIC image contrast. This cold-stage EBIC system is designed for use with minimal modifications to an existing scanning electron microscope (SEM), in this case a Cambridge model S-200. A feature of the system is a PowerMac desktop computer with a National Instruments high-speed data acquisition (D/A) card, used to control the stage temperature and to acquire data. The goal of this project is to build a complete low temperature EBIC system that will allow quantitative analysis by recording actual EBIC currents. Work began on the system in January, 1995, and is still underway as of early August. This paper discusses the design of the system and results to date