A conformal doping process for FinFET devices on a semiconductor substrate which includes NFET fins and PFET fins. A first screw is received within the screw feeding adaptor and held at a driving position near the distal end of the screw path by applying a distal partial vacuum within the screw feeding adaptor. The selected at least one search area corresponds to the at least one reference macroblock. The image processing circuit is connected to the first data interface, receives the image signals, converts the image signals into corresponding gray scale voltages, and outputs the gray scale voltages. A mis-match between the computed hash value and the entirety hash value contained in the data set indicates that less than the entirety of the data set is being presented, and the rendering is prohibited. Accordingly, when a confidential document is color-erased, the stamp image develops color, and when the color-erased confidential document again develops color, it can not be read.