In today’s semiconductor metrology labs, the wafer inspection tools, use high powered lasers to scan 200 mm and 300 mm silicon wafers to detect surface particles down to < 30 nanometers. When calibrating high laser power scanning systems, the size calibration is extremely important, in order to detect at 30 nm; and to accurately size particles across the size range. The size calibration using high powered lasers and traditional polystyrene latex sphere for calibrations may be difficult, as high laser power can shrivel the latex spheres. The solution is using silica particle, size standards at 20 nm, 30 nm, 50 nm, 100 nm, 500 nm, 1 µm and 2 µm. The advantage is that silica will not shrivel under the high laser power, thus consistently providing an accurate size peak for calibration; and the silica particles have a very close refractive index as compared to polystyrene latex particles. Silica Contamination Wafer Standards; Silica Particle Size Standards

silica particles