The present disclosure generally relates to an epitaxial chamber for processing of semiconductor substrates. In one example, the epitaxial chamber has a chamber body assembly. The chamber body assembly includes a lower window and an upper window, wherein chamber body assembly, the lower window and the upper window enclose an internal volume. A susceptor assembly is disposed in the internal volume. The epitaxial chamber also has a plurality of temperature control elements. The plurality of temperature control elements include one or more of an upper lamp module, a lower lamp module, an upper heater, a lower heater, or a heated gas passage.

A film growth process equipment including a main chamber and an illumination device is provided. The illumination device includes a light source, a transparent layer, and a van der Waals material layer. The transparent layer includes a light-emitting surface away from the light source. The van der Waals material layer has a defect concentration lower than 10.sup.12 cm.sup.2, and is disposed on the light-emitting surface of the transparent layer. The van der Waals material layer is formed as a portion of an inner surface of the main chamber.

A radiation shield and an assembly and a reactor including the radiation shield are disclosed. The radiation shield can be used to control heat flux from a susceptor heater assembly and thereby enable better control of temperatures across a surface of a substrate placed on a surface of the susceptor heater assembly.

A radiation shield and an assembly and a reactor including the radiation shield are disclosed. The radiation shield can be used to control heat flux from a susceptor heater assembly and thereby enable better control of temperatures across a surface of a substrate placed on a surface of the susceptor heater assembly.