Abstract: Exemplary embodiments provide a controller system and method to control etch critical dimensions (CDs) during semiconductor manufacturing processes when the etch elements cannot be manipulated to control such end. The controller system includes a photo CD controller and an etch CD controller. The photo CD controller includes a first feedback loop that correlates a measured photo CD of a photo-processed semiconductor product back to the photo-process. The etch CD controller calculates a CD bias from the measured photo CD, a measured etch CD of a further etch-processed semiconductor product, and manufacturing targets for the photo CD and the etch CD. The CD bias is then fed back to the photo CD controller as a device-level CD-offset to adjust the target photo CD, which modifies the photo-process and generates the etch CD on the target etch CD. This automated etch CD control can be used for error corrections for product-to-product variations.