Methods and apparatus for processing substrates are provided herein. In some embodiments, an apparatus for processing substrates includes a chamber body enclosing a processing volume, the chamber body comprising a chamber floor, a chamber wall coupled to the chamber floor, and a chamber lid removably coupled to the chamber wall, wherein at least one of the chamber floor, the chamber wall, and the chamber lid comprise passages for a flow of a thermal control media; a heater plate disposed adjacent to and spaced apart from the chamber floor; a sleeve disposed adjacent to and spaced apart from the chamber wall, the sleeve supported by the heater plate; and a first sealing element disposed at a first interface between the chamber wall and the chamber lid.