Measuring the scatter distribution of PSL spheres on Si wafers using a fast calibrated CMOS photodetector array

A major problem of in situ surface characterization with angle-resolved light scatter (ARS) measurements is the fast and accurate detection of surface defects with respect to industrial applications. The paper deals with a specific application - the angle resolved scatter measurements on PSL particles on Si wafers (spheres with a particle diameter 5 micrometers , 10 micrometers ) by using a calibrated CMOS photo detector array (CPDA). In the first part of the paper a short overview about the development of ARS sensors will be outlined. In the second part of the paper the experimental setup of the ARS sensor and its components will be discussed. The ARS sensor consists of a CPDA and a data acquisition system which allows ARS measurements in 32887 different angles, in an intensity range of 7 decades and an acquisition speed of up to 10 million angles per second. In the third part of the paper the PSL particle detection on Si- wafers will be considered. Experimental data will be presented and compared with simulated scatter data. In the last part of the paper the results will be summarized, the applicability of the ARS sensor will be discussed with respect to specific applications, and further design stages to improve the sensor performance will be outlined.