Monitoring and qualification using comprehensive surface haze information

Haze, the low frequency signal of light scattering, is already accessible in most fabs and contains very useful surface information. It can be used as a proxy for other metrology tools to measure thickness, reflectivity, roughness, defects,...and can be integrated in SPC tests for the equipment (given examples are W, Ta, oxide, small particles, surface treatments and sealing defects). When combined with particle measurements, it provides a full map and has very short process time. Also the calibration of the light scattering tools with haze reference wafers is addressed.