In our semiconductor Fab we're using a CD-SEM to measure some critical dimensions (down to .35µm). Up to now we did a gage R&R on a yearly basis on some specific products. The problem is, that this tool is used to measure a lot of different products, which all have their specific problems. Next to that, every product is measured several times during the process flow, with every time a different layer underneath. Because it's also time consuming for the operators, we can't do a gage R&R for all the products and for all the steps.
Is anyone aware of a method to use the process measurements to verify the reproducibility and repeatability of the tool ?
We have a standard wafer, which we measure on a weekly basis, but again this doesn't tell us everything about the tool.

Thanks.

Any comments on this one folks?