Development of an In-line Minority-Carrier Lifetime Monitoring Tool for Process Control during Fabrication of Crystalline Silicon Solar Cells. Final Technical Report

摘要

The objective of this subcontract over its two-phase, two-year duration was to design and develop improvements to the existing Sinton Consulting R&D minority-carrier lifetime testers. The improvements enable the possibilities for performing various in-line diagnostics on crystalline silicon wafers and cells for solar cell manufacturing lines. This facilitates manufacturing optimization and improved process control. The scope of work for Phase I was to prototype industrial applications for the improved instruments. A small-sample-head version of the instrument was designed and developed in this effort. This new instrument was complemented by detailed application notes detailing the productive use of minority-carrier lifetime measurements for process optimization and routine process control. In Phase II, the results from the first year were applied to design new instruments for industrial applications. These instruments were then characterized and documented. We report here on four new instruments, each optimized for a specific application as demanded by industrial customers. The documentation for these instruments was very technical and involved considerable R&D. Applications were developed that applied the latest in R&D on industrial silicon materials. By investigating the compromises that would be necessary to measure industrial material directly without the sample preparation that is commonly done for good research, we were able to develop several very innovative applications that can now be done directly in the production line for process control.