Handbook of Silicon Based MEMS Materials and Technologies

6.7. Commercially Available Epitaxy Systems

The choice of a single wafer or batch processing approach for epitaxy is a compromise between film properties, productivity and cost. At first blush one might expect that productivity and cost are nearly synonymous. However, the yield to specifications for single wafer process tools is often higher than batch tools, particularly when exceptionally unforgiving film properties are specified. Further, some epi process tools can be purchased on a pre-owned basis for a much lower capital cost than a new tool, thus greatly reducing the cost-of-ownership (CoO) for processing due to a lower depreciation contribution compared to a new process tool. The reader is referred to the standard SEMATECH model for CoO ...