Abstract: A heating apparatus has an upper heating element and a lower hotplate. As part of the process of making integrated circuits, the heating apparatus is preheated using both the upper heating element and the hotplate. A substrate, which may be a semiconductor substrate or a photolithography mask, is then inserted into the preheated heating apparatus. Typically, the purpose of the heating is to cure the photoresist that is on the substrate and has already been exposed to a desired pattern. By having both the top heating element and the hotplate active during the preheating and during the curing, the photoresist is cured uniformly, which improves the pattern in the photoresist that occurs after a solvent has been applied to perform the selective removal of the photoresist in accordance with the exposed pattern. Subsequent use of the substrate results in integrated circuits made from semiconductor substrates.