A method for manufacturing a substrate having a cavity is disclosed. A voltage on each vertical signal line in the state where the signal accumulated in a corresponding photodiode has been transferred to a corresponding floating diffusion, can be used as a comparison voltage of each column. Following attachment of the polymer, still-existing epoxy groups on the polymer may then cross-link the polymer to form a unified anchoring layer on the surface. In another aspect of the invention, the datum is assigned to the target level in accordance with the target data type. The second organic layer forms a blanket layer over the first organic layer.