GROUPING METHOD OF IMAGE FRAGMENTS OF ADJACENT DISLOCATION ETCH PITS OF THE SEMICONDUCTOR WAFER

An increase in production volumes of gallium arsenide semiconductor devices determines the need for better control of dislocations of semiconductor wafer. The grouping method of image fragments of adjacent dislocation etch pits of the semiconductor wafer is proposed in the article. Adjacent fragments will be allocated in the pre-binarized image of wafer surface, which contains adjacent fragments of etch pits of dislocation loops after treatment by the described method. Improved methods for determining the loop line width determines the edge line width of etch pits of suspected dislocations, given the variability of their display in the binarized image. The current loop line width is compared to the reference line width of the dislocation loop. The grouping method of image fragments of adjacent dislocation etch pits of the semiconductor wafer defines recovery of loop lines branching, takes into account various options of line adjacency and determines the direction of further recovery of loop line of dislocation etch pits. A step by step description of the method is given.

A New, Ultrafast Technique for Mapping Dislocation Density in Large-area, Single-crystal and Multicrystalline Si Wafers

We describe a new technique for rapidly measuring average dislocation density and for mapping dislocation distribution of crystalline and multicrystalline silicon wafers. The wafer is etched in Sopori etch and the light scattered by dislocation etch pits is used to statistically count the pits. We also describe a unique arrangement for wafer illumination and measurement of scattered light that allows each dislocation map to be generated very rapidly—typically in less than 20 ms. The measurement system is now commercially available and has capabilities for measuring many other physical parameters of wafers and solar cells