Wall-cooled gas-inlet element for a CVD reactor

1 . A gas inlet unit ( 1 ) for a chemical vapor deposition (CVD) reactor, comprising:

at least one gas distribution chamber ( 13 , 14 , 15 );

a cylindrical outer wall ( 10 ) that surrounds the at least one gas distribution chamber ( 13 , 14 , 15 );

a cylindrical base body ( 8 ) that, with the cylindrical outer wall ( 10 ) forms a gas outlet surface ( 11 ), into which open a plurality of gas outlet openings ( 12 ) originating in the at least one gas distribution chamber ( 13 , 14 , 15 );

at least one gas supply line ( 31 , 32 , 33 ) fluidly coupled to the at least one gas distribution chamber ( 13 , 14 , 15 );

a first coolant chamber ( 5 ) disposed adjacent to a top end of the cylindrical base body ( 8 ), wherein the first coolant chamber ( 5 ) comprises an annular volume;

a second coolant chamber ( 6 ) disposed adjacent to a bottom end of the cylindrical base body ( 8 );

a first coolant line and second coolant line ( 3 , 4 ), wherein the first coolant line ( 3 ) is an innermost pipe ( 30 ) of a plurality of nested pipes which form the at least one gas supply line ( 31 , 32 , 33 ), and wherein the first coolant chamber ( 5 ) surrounds the plurality of nested pipes in an annular manner; and

a cooling device that is fluidly connected to the first and second coolant lines ( 3 , 4 ) and the second coolant chamber ( 6 ) so as to convey a coolant through the cooling device, wherein the cooling device has a plurality of cooling channels ( 7 ) that are arranged in a uniform angular distribution in the cylindrical outer wall ( 10 ) between the second coolant chamber ( 6 ) and the first coolant chamber ( 5 ), the plurality of cooling channels ( 7 ) being spaced apart from one another, wherein each of the cooling channels ( 7 ) receives the coolant from the second coolant chamber ( 6 ), transports the coolant away from the second coolant chamber ( 6 ) and towards the first coolant chamber ( 5 ), and delivers the coolant into the first coolant chamber ( 5 ),

wherein each of the cooling channels ( 7 ) comprises a first opening ( 7 ′) to the first coolant chamber ( 5 ) and a second opening ( 7 ″) to the second coolant chamber ( 6 ), and

wherein the first and second openings face away from another and are each located in respective end surfaces ( 8 ′, 8 ″) of the cylindrical base body ( 8 ).

2 . The gas inlet unit ( 1 ) of claim 1 ,

wherein the cylindrical outer wall ( 10 ) consists of metal, and

wherein the plurality of cooling channels ( 7 ) comprises at least ten cooling channels ( 7 ) arranged parallel to one another.

3 . The gas inlet unit of claim 1 , wherein one of: the cooling channels ( 7 ) do not include any branching channels, the cooling channels ( 7 ) comprise branching channels that are disposed adjacent to one or more of the gas outlet openings ( 12 ), or the cooling channels ( 7 ) each has a constant circular, oval or polygonal cross-sectional area over its entire length.

4 . The gas inlet unit of claim 1 , wherein the first and second coolant chambers ( 5 , 6 ) are formed in part by end faces of the cylindrical base body ( 8 ) that face away from one another.

5 . The gas inlet unit of claim 1 ,

wherein the cooling channels ( 7 ) each run in a straight, curved, or serpentine line between the gas outlet openings ( 12 ) formed by radial bores in the cylindrical outer wall ( 10 ).

6 . The gas inlet unit of claim 5 ,

wherein the second coolant chamber ( 6 ) is separated from the at least one gas distribution chamber ( 15 ) by a separator plate ( 22 ).

7 . The gas inlet unit of claim 6 ,

wherein the first coolant line ( 3 ) opens into the second coolant chamber ( 6 ),

wherein the first coolant line ( 3 ) is formed by a pipe ( 30 ) that runs coaxially with an axis of the cylindrical base body ( 8 ), and

wherein the second coolant chamber ( 6 ) is formed in part by a closure element ( 23 ) having a wall that runs parallel to the separator plate ( 22 ).

8 . The gas inlet unit of claim 6 , wherein the first coolant chamber ( 5 ) is separated from the at least one gas distribution chamber ( 13 ) by an annular plate ( 16 ).

9 . The gas inlet unit of claim 8 ,

wherein the separator plates ( 20 , 21 , 22 ) are connected to annular lands ( 17 , 18 , 19 ),

wherein the annular lands ( 17 , 18 , 19 ) comprise respective openings for attachment to a corresponding one of the separator plates ( 20 , 21 , 22 ),

wherein the openings have respective diameters that differ from one another,

wherein the respective diameters of the annular lands ( 19 ) become progressively smaller away from the first end surface ( 8 ′) of the cylindrical base body ( 8 ), and

wherein respective radially inward edges of the annular lands ( 17 , 18 , 19 ) form steps ( 34 ), to which geometrically complementary stepped edges of the separator plates ( 20 , 21 , 22 ) are attached.

10 . The gas inlet unit ( 1 ) of claim 9 , wherein the annular lands ( 17 , 18 , 19 ) and the cylindrical base body ( 8 ) both comprise a first material.

11 . The gas inlet unit ( 1 ) of claim 9 , wherein at least one of:

the separator plates ( 20 , 21 , 22 ) consist of quartz or metal, or

the separator plates ( 20 , 21 , 22 ) are welded to the annular lands ( 17 , 18 , 19 ).

12 . The gas inlet unit of claim 1 ,

wherein the at least one gas distribution chamber ( 13 , 14 , 15 ) comprises a plurality of gas distribution chambers ( 13 , 14 , 15 ) arranged one on top of another in an axial direction of the cylindrical base body ( 8 ), and are separated from one another by respective separator plates ( 20 , 21 , 22 ), and

wherein the at least one gas supply line ( 31 , 32 , 33 ) is fluidly coupled to each of the plurality of gas distribution chambers ( 13 , 14 , 15 ).

13 . The gas inlet unit of claim 12 ,

wherein the at least one gas supply line comprise a plurality of gas supply lines ( 31 , 32 , 33 ) that are formed by respective volumes between mutually facing surfaces of a plurality of pipes ( 27 , 28 , 29 , 30 ) that are arranged coaxially with respect to one another, and

wherein the separator plates ( 20 , 21 , 22 ) each have a central opening through which the plurality of pipes ( 28 , 29 , 30 ) protrude.

14 . The gas inlet unit of claim 1 ,

wherein the at least one gas distribution chamber ( 13 , 14 , 15 ) comprises a plurality of gas distribution chambers ( 13 , 14 , 15 ), the gas inlet unit further comprising pressure barriers ( 24 ) arranged in at least one of the gas distribution chambers ( 13 , 14 , 15 ),

wherein the pressure barriers ( 24 ) have an annular shape,

wherein the pressure barriers ( 24 ) are arranged around the at least one gas supply line ( 31 , 32 , 33 ), and have passage openings ( 35 ) for feeding gas into the plurality of gas distribution chambers ( 13 , 14 , 15 ),

wherein the pressure barriers ( 24 ) are formed by tubular elements that have respective edges ( 24 ′) facing away from one another,

wherein the respective edges ( 24 ′) engage in respective recesses ( 25 , 26 ) of separator plates ( 20 , 21 , 22 ), and

wherein the separator plates ( 20 , 21 , 22 ) separate the plurality of gas distribution chambers ( 13 , 14 , 15 ) in an axial direction.

15 . The gas inlet unit ( 1 ) of claim 14 ,

wherein the pressure barriers ( 24 ) consist of metal, and

wherein the pressure barriers ( 24 ) are welded to the separator plates ( 20 , 21 , 22 ) or are welded to an annular plate ( 16 ) which forms part of the first coolant chamber ( 5 ).

16 . A gas inlet device for feeding one or more process gases into a process chamber ( 37 ) of a chemical vapor deposition (CVD) reactor, the gas inlet device comprising:

the gas inlet unit ( 1 ) of claim 1 ;

a housing of the CVD reactor; and

a holder ( 2 ) for holding the gas inlet unit ( 1 ) of claim 1 ,

wherein the holder ( 2 ) is attached to the housing of the CVD reactor, and

wherein the at least one gas supply line ( 31 , 32 , 33 ), the first coolant line ( 3 ), and the second coolant line ( 4 ) pass through the housing of the CVD reactor.

17 . A chemical vapor deposition (CVD) reactor, comprising:

the gas inlet unit ( 1 ) of claim 1 ;

a process chamber ( 37 );

a cover plate forming a ceiling ( 36 ) of the process chamber ( 37 ); and

a susceptor ( 38 ) forming a floor of the process chamber ( 37 ),

wherein the process chamber ( 37 ) surrounds the gas inlet unit ( 1 ), and

wherein the gas inlet unit ( 1 ) extends between the cover plate and the susceptor ( 38 ).