Applying the AVM system for run-to-run control: A preliminary study

In the PECVD process of solar-cell manufacturing, the sampling rate is less than 10%. However, run-to-run (R2R) control requires 100 % total inspection. To fulfill this requirement, numerous measurements are necessary, thus increasing production cycle time and cost. To resolve this problem, previous studies have proposed virtual metrology (VM). This paper describes how the R2R controller utilizes the VM value and batch information at the first run to calculate the suggestion value of the deposition time for the ensuing run to improve the process capability index (Cpk).