Apparatus and method for thermal treatment of substrates

The aim of the invention is to provide an economical and homogenous thermal treatment for substrates. To this end, the inventive device and method for thermally treating substrates, especially semiconductor wafers, comprise at least one heating device for heating at least one substrate by electromagnetic radiation. Said heating device comprises at least two arc lamps, the radiation characteristics for each arc lamp being controlled individually, and the electromagnetic radiation of the arc lamps contributing essentially to the power density of the electromagnetic radiation of the heating device.