Patent ID: 6900413

Claim:
A heat treatment apparatus, comprising: a heating chamber enclosed in a processing tube; a plurality of heating elements positioned adjacent the heating chamber; a heating plate positioned adjacent the heating elements; a cooling chamber positioned adjacent to the heating chamber; and a wafer holder configured to move between the cooling chamber and the heating chamber, wherein the heating plate receives heat from the heating elements and re-radiates heat into the heating chamber, and where said heating plate has a mass and thermal conductivity configured to provide a thermal reservoir such that the temperature of a wafer to be processed is controlled by adjusting the temperature of the heating plate; a passageway positioned between the heating chamber and cooling chamber; and one or more shutters defining the size of the passageway and said shutters being movable between an open position where the wafer holder can pass through the passageway and an obstructing position which defines a passageway which is smaller than the passageway defined when the shutter is in the open position, where at least one of the one or more shutters includes two or more members positioned to define at least a portion of an air gap between adjacent members.