To activate implanted dopants at the surface of a semiconductor wafer, a laser pulse may be used. Assume that the wafer can be treated as semi-infinite and that its thermal diffusivity is 0.25 cm2/s.

If the wafer is initially at 25 °C and a laser pulse supplies enough energy to heat the top 0.4 μm of the wafer to 950 °C, what is the greatest temperature that will be reached 5 μm beneath the surface due to thermal conduction of heat into the wafer?