An experimental .r-y measurement system is described that was designed for the high-speed. high-precision measurements required in integrated circuit manufacturing and for optical measurement applications in which a sufficiently large data base is required for statistical process analysis. The technology for this experimental system differs considerably from that of conventional optical measuring systems in current use and utilizes a computer for data acquisition. manipulation and evaluation. The system, utilizing the edge detection principle, presently operates at a measuring speed of 2.5 cm/s. An analysis gives both the short-term and the long-term precision of the system. The standard deviation for the short-term precision is 0.038 iuc:

Measurement precision is in general determined by the instrument performance, the environmental conditions, and last but not least by economical considerations (measuring time, workload etc.). The influence of all three parameters which as of today limits the overall precision of industrial measurements can be drastically reduced by the aid of computers. Their data handling capabilities in terms of speed, capacity, and numerical data analysis allow to either increase the number of measurements and/or to evaluate the measurement data more thoroughly. In both cases the measurement precision will be increased beyond the instrument capabilities in conventional terms. The constraints of the environmental and the economical conditions can be overcome by increasing the speed of the measurement. Examples will be given for opto-electronic measurement principles applied to measurement tasks in integrated circuit manufacturing.