what is the role of measurement metrology in process control

METROLOGY = the measurement layer that tells you whether your process is working. It's the EYES of the fab: you measure film thickness, uniformity, composition, and defects, and use that data to CONTROL the process — if a parameter drifts out of spec, you catch it and correct before it becomes a yield problem. The feedback loop: measure → compare to spec → adjust/correct → measure again. WHY IT'S YOUR EDGE: you're a metrology person (ellipsometry SME, ICP-OES, GCMS). The one-line frame: 'Process control is a feedback loop, and metrology is what closes it — you can't control what you can't measure, so the measurement is where process control starts.' This is a direct, rare match to the role — say it confidently. It pairs with Lessons 53, 68, 69, and the drift lessons (60).