Automated Transmission Electron Microscope Sample Preparation

Featured at Semicon West

FEI Company has developed new technology and control software for automated transmission electron microscope (TEM) sample preparation using a focused ion beam (FIB). To make sample preparation less labor-intensive, FEI has explored a range of automation techniques. The simplest technique is to mill the initial rough trenches on a number of samples in an unattended fashion. The next level is to use multiple beam current steps, including image recognition routines within the automation software to enable high-accuracy registration of the milling to the final section location. The third is to further allow these final steps to be completed under automatic control, enabling highly precise and repeatable sample preparation, including the preparation of multiple samples. Samples can be prepared in less than one hour each.

The FEI AutoFIB software links together a series of system states or settings in editable, text-based scripts. These scripts allow control of ion beam current, stage movement, gas injectors, as well as scan and milling parameters. The AutoFIB software has pattern recognition capability that can register the milling patterns to the required location within 15-30 nm without operator involvement. TEM examination has become an important tool for integrated circuit failure analysis, yield analysis, and process development. In these applications, sample preparation time and total analytical throughput is critical. TEM data supplements the information gained by examination with a scanning electron microscope. For example, accurate nanometer scale metrology is possible by using the silicon atom lattice spacing as a built-in calibration standard. High-resolution chemical analysis is also possible with energy-dispersive x-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS).

FEI Company, Contact: Pat Finney, 503-640-7500.