A vacuum thermal annealing device is provided having a temperature control for use with various materials, such as semiconductor substrates. A vacuum is used to remove air and outgas residual materials. Heated gas is injected planar to a substrate as pressure is quickly raised. Concurrent with the heated gas flow, a chamber wall heater is turned on and maintains a temperature for a proper annealing time. Upon completion of the annealing process, the chamber wall heater shuts down and air is forced around the chamber wall heater. Additionally, cool gas replaces the heated gas to cool the substrate.