Patent ID: 7351057

Claim:
A furnace for semiconductor processing, comprising: a reaction chamber at least partially delimited by a vertically-extending process tube sized and shaped to accommodate a plurality of vertically separated semiconductor substrates, the process tube provided with a feed for gas and the process tube further having an open end, wherein walls of the process tube proximate the open end are free of passages for exhausting gas; and a process tube closure configured to reversibly seal against the process tube to close off the open end, the closure comprising: a first door plate having one or more gas exhaust openings, the gas exhaust openings disposed proximate a lateral center of the first door plate and configured to exhaust gases from the reaction chamber, wherein surfaces of the closure define one or more gas exhaust channels below an upper surface of the door plate, the one or more gas exhaust channels configured to communicate gas from the gas exhaust openings to a gas exhaust apparatus configured for removing gases from the reaction chamber.