Gas inlet device for a CVD reactor
A gas distribution device has a plurality of gas inlet regions that are arranged above each other and can be adjusted by switching on or off respective valves. The gas inlet regions can also be adjusted by switching over one or more feed conduits through which process gases can be fed into respective gas distribution volumes of gas outlet zones. The respective gas distribution volumes are arranged above each other at several levels. Only one uniform process gas can exit into a process chamber through each of the gas inlet regions.
1 . A gas distribution device, comprising:
a plurality of gas inlet regions (E 1 to E 5 ), which are arranged on top of one another and from which process gases or a carrier gas are introduced into a process chamber ( 7 ) of a chemical vapor deposition (CVD) reactor;
a plurality of supply conduits ( 18 );
at least five gas outlet zones (Z 1 to Z 12 ) that are arranged on top of one another and respectively have a gas distribution volume ( 17 ), into which one of the supply conduits ( 18 ) for introducing a gas flow leads, wherein adjacent gas distribution volumes ( 17 , 17 ′, 17 ″) are separated from one another by a base ( 14 ), wherein each of the gas distribution volumes ( 17 ) has a gas outlet wall ( 11 ) with gas outlet openings ( 12 ), and wherein each of the gas inlet regions (E 1 to E 5 ) are formed by adjacent ones of the gas outlet walls ( 11 ); and
a matrix style gas mixing system comprising a plurality of gas conduits (L 1 to L 12 ) and a plurality of feed conduits (G 1 to G 4 ), wherein each of the supply conduits ( 18 ) is connected to one of the gas conduits (L 1 to L 12 ) of the matrix style gas mixing system, wherein each of the feed conduits (G 1 to G 4 ) is connected to a source of a process gas or an inert gas, wherein every one of the feed conduits (G 1 to G 4 ) intersects every one of the gas conduits (L 1 to L 12 ), and wherein at every intersection point between a respective one of the feed conduits (G 1 to G 4 ) and a respective one of the gas conduits (L 1 to L 12 ) a valve ( 20 ) is disposed.
2 . The gas distribution device of claim 1 , wherein the valves ( 20 ) are configured to connect a first group of the gas outlet zones (Z 1 , Z 2 , Z 11 , Z 12 ) to a first one of the feed conduits (G 1 ),
wherein the valves ( 20 ) are further configured to connect a second group of the gas outlet zones (Z 5 to Z 8 ) to a second one of the feed conduits (G 2 ), and
wherein the valves ( 20 ) are further configured to connect a third group of the gas outlet zones (Z 3 , Z 4 , Z 9 , Z 10 ) to either the first feed conduit (G 1 ) or the second feed conduit (G 2 ).
3 . The gas distribution device of claim 1 , wherein two of the gas outlet zones (Z 1 to Z 12 ) are fluidly connected to one another.
4 . The gas distribution device of claim 1 , further comprising a plurality of mass flow controllers ( 27 ), wherein a flow of each of the feed conduits (G 1 to G 4 ) is controlled by a respective one of the mass flow controllers ( 27 ).
5 . A method for feeding process gases into a process chamber ( 7 ) of a chemical vapor deposition (CVD) reactor, the method comprising:
feeding, by the gas distribution device of claim 1 , the process gases into the process chamber ( 7 ); and
adjusting respective heights of the gas inlet regions (E 1 to E 5 ) by fluidly connecting adjacent ones of the gas outlet zones (Z 1 to Z 12 ) with one another.
6 . A chemical vapor deposition (CVD) reactor, comprising:
a process chamber ( 7 ) with a ceiling ( 8 );
a susceptor ( 2 ) that is rotatable about a rotational axis and has pockets ( 5 ) that are open toward the process chamber ( 7 );
a plurality of substrate holders ( 4 ) respectively arranged in each of said pockets, wherein the process chamber ( 7 ) extends between the susceptor ( 2 ) and the ceiling ( 8 ) of the process chamber ( 7 ); and
a gas distribution device of claim 1 arranged in a center of the process chamber ( 7 ).