Patent ID: 7651569

Claim:
A furnace for semiconductor processing, comprising: a batch process chamber; a wafer boat configured to be accommodated in the batch process chamber; a pedestal for supporting the wafer boat in the batch process chamber, the pedestal comprising: insulating material disposed in an interior of the pedestal; an envelope with an internal gas volume, the envelope formed of quartz and defining exterior walls of the pedestal, a wall of the envelope comprising an exterior opening in gas communication with the internal gas volume, the exterior opening disposed in and opening to an interior volume of the batch process chamber, the exterior opening allowing gas communication between the internal gas volume of the pedestal and the interior volume of the batch process chamber; and a particulate filter forming an airtight seal with the exterior opening, the particulate filter disposed in a flow path of gas exiting the internal volume, wherein the particulate filter is formed of a material different from the insulating material.