A method and apparatus for rapid thermal heat treatment of semiconductor and other substrates is provided. A number of heat lamps arranged in an array or other configuration produce light and heat radiation. The light and heat radiation is directed through a heat slot that forms a radiation beam of high intensity light and heat. The radiation beam is directed to a platen that includes multiple substrates. The apparatus and method include a controller that controls rotational and translational motion of the platen relative to the heat slot and also controls the power individually and collectively supplied to the heat lamps. A program is executed which maneuvers the platen such that all portions of all substrates receive the desired thermal treatment, i.e. attain a desired temperature for a desired time period.