3D Pattern Effects in RTA Radiative vs Conductive Heating

Most studies on emissivity effects present during fast radiative heating of wafers generally focus on variation of the optical properties of the substrate across the wafer, within die, etc. This is usually well described by considering the differences in emissivity of the films or patterns that are present on the wafer. However, the absorption of radiation also varies when areas with different topography are present on the wafer and/or die. In the latter case, the effective emissivity varies between areas with different topographies, even though the deposited films are identical everywhere. This is because structures with large aspect ratios have a tendency to absorb radiation more efficiently than structures with less pronounced topographies, see fig. 1.