SUNNYVALE, Calif.—An automated SEM/TEM sample preparation technology for semiconductor processes promises to speed productivity and increase reliable and contamination-free samples.
The EM2, from automated sample preparation systems developer Sela Ltd. (www.sela.com), has been designed to automatically produce a less than 20-µm thin sample for SEM (scanning electron microscopy) or TEM (transmission electron microscopy) tools—a quality-control process that is becoming increasingly vital in diagnosing and controlling production problems as semiconductor device features become smaller and film interfaces become more critical.
EM2, which features a cryo-cooled dry-sawing process (no water or chemicals), prepares specimens of crystalline or amorphous materials for cross-section and plan view without technician intervention and hand-polishing that can lead to contamination.
With the EM2 system, Sela says a semiconductor sample is automatically mounted on a support grid and then loaded in a holder, ready within twenty-five minutes for final thinning at electron transparency in FIB (focused ion beam) or SEM workstations. Output samples can then be mounted onto a TEM-compatible stub, allowing for multiple reworking of the specimen.
Sela claims that manual techniques to produce the same results typically require extended processing times, Sela Ltd.'s EM2 technology is an automated sample preparation system designed to automatically produce a contamination-free < 20-µm thin sample for SEM (scanning electron microscopy) or TEM (transmission electron microscopy) equipment used in determining quality of semiconductor processes.and that the success rate in producing a thin, accurate, and undamaged sample depends upon the experience of the sample operator.
Sela's automated tools for SEM sample preparation, however, apply a sequence of precisely controlled cleaving operations that are designed to yield a finished sample that doesn't require polishing—a process that can introduce contaminants. Targeted submicron accuracy is obtained through a high-resolution optical microscope, resulting in two mirror-image cross-sections—half of the target on each side—with contamination-free surfaces.