Tool for imaging and device modification

Description:

Focused ion beam (FIB)-based systems provide a versatile tool for performing work at the nanoscale. They can be used to selectively remove material from substrates and to direct write insulator and metal patterns while providing a high resolution inspection system, comparable to that achieved in the scanning electron microscope. These features have made FIB instruments a staple in failure analysis labs and semiconductor foundries alike.

CNF has recently installed a donated FEI 611 FIB system. This tool uses a high brightness Ga liquid metal ion source coupled with a double lens focusing system to produce an intense beam of ions capable of being focused to a 40 nm diameter spot. It is capable of milling a variety of metals, semiconductors and insulators and depositing SiOx and Pt. The system is equipped with a vacuum load lock to enable rapid transfer of samples up to 6" in diameter. 8" wafers can be loaded directly into the chamber.

The tool is also equipped with a computer controlled eucentric 5-axis motorized stage. A Kleindiek micromanipulator system is also contained inside the specimen chamber to provide in situ probing capabilities of samples. This micromanipulator can also be used to remove thin cross sectional samples for use in transmission electron microscopes. The micromanipulator combined with the deposition capabilities can also be used to repair damaged MEMS structures.

Results:

Example of a cross section performed in the FEI 611 at CNF. In these micrographs, a multilayer interconnect structure was cross sectioned using the FIB. Following inspection in the FIB, the sample was removed and imaged in the Hitachi S4700. This underscores the usefulness of the FEI 611 in preparing cross-sectional samples for electron microscopy.