An apparatus for heat treating semiconductor wafers is disclosed. The
apparatus includes a heating device which contains an assembly of light
energy sources for emitting light energy onto a wafer. The light energy
sources can be placed in various configurations. In accordance with the
present invention, tuning devices which are used to adjust the overall
irradiance distribution of the light energy sources are included in the
heating device. The tuning devices can be either active sources of light
energy or passive sources which reflect, refract or absorb light energy.
For instance, in one embodiment, the tuning devices can comprise a lamp
spaced from a focusing lens designed to focus determined amounts of light
energy onto a particular location of a wafer being heated.
