Abstract: A reaction chamber assembly with a shutter system may be used in the processing of semiconductor substrates. The shutter system may facilitate gas flow control and temperature control within the reaction chamber assembly.

Abstract: Mixing of spent reactant gases with ambient air inside a semiconductor wafer fabrication facility is avoided and consequently corrosion of a scavenger box in a wafer fabrication facility is avoided. Repeatability of reaction gas results on wafers in a process tube is improved by maintaining precisely constant pressure in the wafer processing tube, which is operated close to ambient atmospheric pressure. This is accomplished by positioning an exhaust tube downstream from the wafers in the processing tube at a location that results in a uniform, repeatable reaction gas flow pattern between the wafers. Pressures at or near that point are measured by a differential manometer referenced to ambient atmospheric pressure to produce a pressure-indicating signal. The pressure indicating signal is electronically compared with a preset constant signal representative of the desired constant pressure at the pressure measurement point to produce an error signal.