Design, Analysis and Test of a Target Recognition Approach for the LDI Machine

For the Laser Direct Imaging (LDI) machine, out-of-focused-plane displacements, poor illumination, and target anomalies degrade the target recognition performance. The alignment accuracy or efficiency would be reduced. The lithography yield and production capacity decrease. This paper proposes a target recognition approach for the LDI machine. The performance degradation by three disturbances is investigated. First, a target recognition approach for an LDI machine was designed. A recognition hardware and a corresponding algorithm were combined and embedded into the LDI machine. Second, three typical disturbances during the target recognition procedure were analyzed. Generation principles of out-of-focused-plane displacements, poor illumination, and target anomalies were explained. A quantitative generation, excitation, and test system of three disturbances was developed. Third, the performance degradation of the proposed target recognition approach was tested. Experimental results demonstrate the performance degradation characteristics of the presented target recognition approach by three disturbances. Theoretical performance reestablishment methods against three disturbances were discussed. This paper contributes to developing a robust target recognition approach for the LDI machine.