A continuous chemical deposition reactor may be a stand-alone process system with a continuous semiconductor wafer flow. Basic subsystems in such a system may include a wafer handling, a reaction chamber, a gas flow system, a cooling system, and an electrical system.
The wafer handling system may include wafer loaders and unloaders, wafer carriers, and a track for moving a wafer through the reactor chambers. The semiconductor wafers are orientated to a known position so that pick-up devices may properly place the wafer in a carrier, which is indexed through the reactor system.
A basic reactor and process may be as follows. A semiconductor wafer is first picked-up by a wafer handing device. The wafer is then oriented prior to be loading onto a carrier which enters one end of the reactor through a port and is moved successively through the various chambers and out the other end of the reactor through another port.
Each semiconductor wafer is a round disk with a flat edge thereon, the flat edge being used to permit orientation of the wafer for placement in a carrier prior to transporting the wafer through the process reactor.
The reactor may not be physically closed, but has gas seals at each end and in between each chamber of the reactor. As an example, a reactor may include eight chambers in which the first chamber consists of a nitrogen seal, the second chamber is a preheat chamber, the next four chambers may be deposition chambers, then a cool-down chamber and the last chamber is a nitrogen seal.
A typical gas supply system may supply gases for two different deposition processes which may be directed into any of the deposition chambers.
Each chamber is effectively divided into two portions, a top portion and a bottom portion by the substrate carrier. The junctions between the chambers effectively isolate one chamber from the other by the flow of gases, or the exhaust gases from the chambers.