Heat treatment apparatus having a thin light-transmitting window

摘要

A quartz window decreases an amount of absorption of heat from a heat source while maintaining a pressure difference between the pressure inside a process chamber and an atmospheric pressure. The process chamber defines a process space for processing an object to be processes. A placement stage is provided in the process chamber so as to place the object to be processed thereon. A gas supply part which supplies to the process chamber a process gas for processing the object to be processed. The quartz window is provided as a part of the process chamber so that the quartz window is opposite to the object to be processed placed on the placement stage. A heating unit has a heat radiation lamp provided on an opposite side of the process chamber with respect to the light-transmitting window. The quartz window constitutes a convex lens part which is formed on a periphery of the quartz window and protrudes into the process space.