Topsil GlobalWafers A/S, a world-leading supplier of ultrapure silicon used in various energy-efficient power components, is committed to delivering top-tier products to its customers. To ensure the quality of their silicon, Topsil sought ways to enhance their confidence in the absence of crystal deviations that could potentially impact material properties.
The crystal structure of silicon can be affected by deviations, some of which have no impact on material properties, such as vacancies. On the other hand, there are deviations like interstitial atoms that can have negative effects on the material's properties. Interstitials are atoms located in positions within the crystal lattice that are typically empty in a perfect silicon crystal. Silicon wafers containing interstitial atoms can become conductive instead of being insulators, rendering them unsafe for use in the intended devices. Topsil GlobalWafers A/S offers ultrapure silicon without interstitials, as determined by standard electrical property measurements. However, these methods solely assess the electrical properties and not the crystal structure itself.
To address this concern, Topsil explored the use of X-ray topography, an imaging technique that provides contrast differences in images when deviations are present within a single crystal, including crystalline vacancies and interstitial atoms. This technique requires high-quality X-rays available at specialized facilities known as synchrotrons, which can present challenges in terms of access and selection. With over 50 synchrotrons worldwide, each with its own capabilities and specialties, navigating the process can be complex. Acting as a synchrotron mediator, the Danish Technological Institute offers expertise and assistance in synchrotron utilization, ranging from experiment design to measurements and data analysis.
Consequently, Topsil GlobalWafers A/S collaborated with the Danish Technological Institute to facilitate X-ray topography analysis for their ultrapure silicon. Ane Baden, a project leader at Topsil, expressed their satisfaction with this collaboration, stating that working with the Danish Technological Institute enabled them to delve into synchrotron analysis and investigate their material in greater depth. The process of initiating synchrotron analysis can be intimidating for companies due to the necessary knowledge of different facility capabilities, sample documentation requirements, and data interpretation. By partnering with the Danish Technological Institute, Topsil overcame these hurdles, minimized potential errors resulting from inexperience, and reduced the overall time from idea to results. As a result, Topsil GlobalWafers A/S now possesses an additional tool for detailed exploration of interstitials, vacancies, and perfect silicon on a wafer level, surpassing the level of detail previously achievable.
The successful collaboration between Topsil GlobalWafers A/S, the Danish Technological Institute, and the utilization of the European Synchrotron Radiation Facility (ESRF) were instrumental in accomplishing this work.
