Technological progress in electron microscopy has made it possible to analyze physical structures at the atomic level. As if in step with that progress, structural control at the nanometer level has become essential for sophistication of products in various areas. The Analysis Technology Research Center therefore positions nanostructural analysis as a core technology for providing support to research and development activities.

I am primarily in charge of analyzing compound semiconductor devices. Among other subjects, I deal with many concerning the analysis of semiconductor lasers used in optical communications. Semiconductor lasers have a nanometer-level structure. A change in their atomic arrangement affects product characteristics, and eventually reliability. My task is to observe the status of the structure inside a semiconductor laser, to detect defects, and to propose remedies.

Analysis techniques are not solely for the purpose of observing objects. Disturbed atomic arrangements and structural abnormalities are indicative of the true situation and provide hints toward clarifying the reason for a phenomenon and toward finding a remedy for improvement. I believe that the mission of the Center is to present the reason and remedy to the research and development staff, as well as to the production departments in order to shed light on the path toward product quality improvement and sophistication.

Pre-treatment techniques applied to samples are highly significant for obtaining proper analysis results. The challenge is to form a thin film that allows electron beams to pass through it, while ensuring that the sample retains its structure. Furthermore, inside the semiconductor laser there are degraded spots, which are not easily detected by external viewing. We therefore took on the challenge of developing a new technique and succeeded. This technique allows us to detect degradation in semiconductor lasers and to form a thin film 100 nanometers or less in thickness precisely including the degraded spot.

It was a great achievement that we were able to contribute to improving production processes and semiconductor product quality, as a consequence of gaining experience in the above-mentioned techniques. Another problem was reliability of laser powered for an extended time. Regarding this problem, we could identify the point causing defects, by developing an analysis technique using transmission electron microscopy for crystal defects. Furthermore, we were able to clarify the mechanism of a process leading to characteristic degradation.

Sumitomo Electric has a continuous manufacturing system that bridges the departments engaged in materials research and development, and the departments that produces products in volume. This system is highly beneficial to analysis engineers like ourselves, because extensive knowledge of the materials, structures, processes etc. handled in the Company is required for conducting analyses. Engineers frequently get together and hold discussions in a cross-departmental manner. In addition, we visit the production site in some cases. By this means we can obtain hints regarding innovative analysis techniques.

The importance of nanometer-level structural analysis continues to increase over a wide range of Sumitomo Electric’s business areas, including semiconductors and materials such as carbides used for cutting tools. I hope that analysis technology, in which we specialize, will back up Sumitomo Electric’s entire manufacturing capacity and contribute to the development of new products and to improved product quality.