The map of a wafer which was deposited with Silica spheres of various sizes for particle standards calibration. SPOT PROBLEMS QUICKLY. The Silica Leopard Contamination Standard (SLCS) is used for the calibration of instruments which size and detect particles over a range of values, on the surface of bare silicon wafers. Use this silica particle standards calibration to characterize particles common to your process. Silica Leopard Contamination Standard (SLCS) Product Description Utilizing spot depositions, VLSI Standards places distinct groups of silica spheres onto the surface of bare silicon wafers for silica particle standards calibration. Calibration standards are made containing a choice of 2 to 8 homogenous spots. VLSI Standards supplies Silica Contamination Standards with a variety of sphere sizes in the range of 32 nm up to 1.5 micron. Each spot is approximately 20 mm in diameter and contains up to 12,000. The Leopard Contamination Standard is designed for particle size standards calibration, and not particle count. Background contamination is kept at an extremely low level. Silica Contamination Standards (SCS) Product Specifications SEMI Specification Silicon Wafers 300 mm and 450 mm diameter silicon wafers Spots 2 to 8 Silica Spheres From 32 nm up to 1.5 micron* *Sizes in other ranges may be available. Please check with VLSI Standards.