Hitachi Introduces First Optical Shallow Defect Analyzer Designed to Find Defects in Silicon Wafers

Hitachi Scientific Instruments has made available their new Optical Shallow Defect Analyzer, the OSDA-2000. It is designed to non-destructively detect and measure defects as small as 0.02µm inside the silicon wafer and 0.05µm on the silicon wafer surface prior to circuitry fabrication. Typical defects found include grown-in defects, stacking faults, oxygen precipitation, Crystal Originated Particles (COPs), polishing and process induced damage, defects in epitaxial layer, slip lines, haze and surface particles.

"Using defective wafers can cause problems serious enough to result in device failure," said Mr. Hideo Naito, assistant director for Electron Microscope Systems Group. "For example, crystal defects near the surface and shallow region of silicon wafers have been found to cause such problems as gate oxide breakdown, degradation of P-N junctions, or inferior refresh function capability of DRAMs. The OSDA-2000 ensures that only high quality wafers will be used to handle the demands of integrating increasingly miniaturized Large Scale Integrated Circuits (LSIs). This is critical to improving high production yield of LSIs, minimizing process damage and ensuring continued development of next generation LSIs."

The OSDA-2000 also provides far greater performance than traditional optical-based defect analyzers. For example, the OSDA-2000 finds defects as small as 0.02µm while providing the depth information necessary to distinguish between shallow-and-small and deep-and-large defects. It also features a 0.5µm measurement range with depth information and 5µm maximum detectable depth. Depth resolution is ±0.1µm.

The OSDA-2000 finds defects by irradiating two laser beams of different wavelengths onto a silicon wafer surface. Then, the OSDA detects with high sensitivity the scattered light created by the crystal defects inside of the silicon wafer.