How to get consistent processing results? Control of parameters and checks done often with built in test structures and metrology.

Items which get overlooked during the control process are often the glassware/plastic supplies provied at the fumehoods for general use. One of the processing groups had issues pop-up in their processing due to cross-contamination from the glassware/plastic containers they were using. (e.g. using the same container to develop photoresit and etch later.) This issue relapsed 10 years later due to loss of knowledge in the same group for fabricating the a generations-later device.

It is especially important for very fine features to provide your own glassware and be consitent about what the use is for each individual container. Rinsing a container with DI water three times does not clean well enough to keep cross contaimnation away.