Commercial SiC device processing: Status and requirements with respect to SiC based power devices

Abstract

SiC power devices have been commercially available since 2001. In the meantime the standard wafer diameter increased from 2″ to 3″ and a lot of processes which are needed for SiC device technology and which have not been standard in Si device fabrication (e.g. rapid thermal annealing of metal layers, stepper lithography for 3″ etc.) have now found a place in the list of common processes. On the other hand there are still processing issues or process steps that are not yet solved satisfactorily or not yet fulfilling the standards set in the production of Si devices. After a short introduction about the application and market of SiC power devices the paper will present a brief status of today’s productive SiC device processing. This part will mainly focus on Schottky diode manufacturing which is currently the only SiC power device produced in significant amounts. In a second part the paper will focus on remaining issues like wafering, availability of defect density monitoring, ohmic contact formation, high quality substrates and epi, oxidation, and post implantation annealing. All topics will be related to the needs resulting from an industrial point of view concerning process stability, influence on device costs, quality and on commercialization. The paper concludes that the major tasks to be attacked are the quality and price of substrates and epitaxial layers . Other technical issues are ranked behind those.