Automatic supervision system on the ion beam map for ion implantation

Abstract

An automatic supervision system using an ion beam map generated by an ion implantation machine during an ion implantation process a feature extraction circuit and a data converter. The feature extraction circuit receives a beam current signal and a display blanking signal from the ion implantation machine, and extract features of the ion beam map. The data converter is coupled to the feature extraction circuit and converts the features into indexes indicative of the alignment and symmetry of beam maps. The data converter also compares the indexes to index values or symptoms of known abnormal ion beam scanning, which allows the data converter to recognize abnormal ion beam scanning and indicate the proper corrective action to adjust the ion beam scanning. Thus, the two-dimensional beam map recognition analysis is reduced to a one-dimensional feature analysis, thereby simplifying the beam map recognition process. This simplified beam recognition process allows the automatic supervision system to achieve real time control of the ion beam scanning process, thereby reducing faulty implantation.