Radiative Modeling In Rapid Thermal Processing For Accurate Wafer Temperature Measurement

Radiative Modeling in Rapid Thermal Processing for Accurate Wafer Temperature Measurement

Time-consuming. The reverse Monte Carlo method can reduce tremendously the computation time. The reflection direction can be generated by the closed-form BRDF models or by directly tracing the light ray consecutively between the micro-facets of rough surface and between multi-layers inside wafers using geometrical optics. The latter idea has been extended to explore radiative properties, such as emissivity, reflectivity, transmissivity, and BRDF, of opaque or semitransparent materials. The simulation results showed that for non-diffuse wafers the true effective emissivity (defined in this work) should be used, instead of the hemispherical effective emissivity, to correct the thermometer readings, especially when the wafer is specularly reflective with an emissivity of 0.5 and less. The numerical aperture of the LPRT and the wafer-to-shield distance may be optimized to improve the accuracy of LPRT.

Advanced Short-time Thermal Processing for Si-based CMOS Devices 2

Advances in Rapid Thermal Processing