Gas box with cross-flow exhaust system
Gas boxes for providing semiconductor processing gases are provided that incorporate a cross-flow ventilation system that may effectively remove potentially leaking gases from within the gas box at significantly lower volumetric flow rates than are possible with conventional gas box ventilation systems.
1 . A gas box for a semiconductor processing apparatus, the gas box comprising:
a housing enclosing an interior volume;
a door; and
a plurality of first gas flow component assemblies located within the interior volume, wherein:
the plurality of first gas flow component assemblies are generally arranged along a first axis,
the housing has a first side with one or more inlet holes and a second side with one or more exhaust openings,
the housing has a third side that is substantially parallel to the first axis and generally interposed between the first side and the second side,
the housing has an opening in a side opposite the third side,
the door is mounted so as to be movable between an open state and a closed state,
the door, in the closed state, closes off the opening,
the third side has a plurality of cross-flow holes generally arranged along a second axis that is substantially parallel to the first axis, and
the one or more inlet holes, the one or more exhaust openings, and the plurality of cross-flow holes are configured such that when a) a negative pressure differential exists between the one or more exhaust openings and the one or more inlet holes and b) the one or more inlet holes and the plurality of cross-flow holes are fluidically connected with air, at least a first portion of the air is drawn from the one or more inlet holes, through the housing, and to the one or more exhaust openings in directions predominantly aligned with the first axis, and at least a second portion of the air is drawn from the plurality of cross-flow holes, past the first gas flow component assemblies and in a direction generally transverse to the first axis, and then to the one or more exhaust openings.
2 . The gas box of claim 1 , wherein:
the first gas flow component assemblies of each adjacent pair of one or more adjacent pairs of the first gas flow component assemblies have at least one corresponding cross-flow hole of the cross-flow holes interposed therebetween when viewed along a direction perpendicular to the third side.
3 . The gas box of claim 1 , wherein:
the first gas flow component assemblies of each adjacent pair of the first gas flow component assemblies have at least one corresponding cross-flow hole of the cross-flow holes interposed therebetween when viewed along a direction perpendicular to the third side.
4 . The gas box of claim 1 , wherein:
each of one or more of the first gas flow component assemblies has a portion thereof that overlaps with at least one corresponding cross-flow hole of the cross-flow holes when viewed along a direction perpendicular to the third side.
5 . The gas box of claim 1 , wherein:
each of the first gas flow component assemblies has a portion thereof that overlaps with at least one of the cross-flow holes when viewed along a direction perpendicular to the third side.
6 . The gas box of claim 1 , wherein:
each first gas flow component assembly includes a corresponding first gas flow component, second gas flow component, and first releasable fluidic fitting, and
the first gas flow component of each first gas flow component assembly is fluidically interposed between the second gas flow component of that first gas flow component assembly and the first releasable fluidic fitting of that first gas flow component assembly.
7 . The gas box of claim 6 , wherein, for each first gas flow component assembly of one or more of the first gas flow component assemblies, the cross-flow hole that is closest thereto is at a location interposed between the first gas flow component of that first gas flow component assembly and an end of the first releasable fluidic fitting of that first gas flow component assembly that is furthest from that first gas flow component when viewed from a direction perpendicular to the third side.
8 . The gas box of claim 6 , wherein, for at least one or more of the first gas flow component assemblies, the first gas flow component is a valve and the second gas flow component is a mass flow controller.
9 . The gas box of claim 8 , wherein:
there are at least two of the first gas flow component assemblies in which the first gas flow component is a valve and the second gas flow component is a mass flow controller, and
for each of the first gas flow component assemblies, the first gas flow component is a valve and the second gas flow component is a mass flow controller.
10 . The gas box of claim 8 , wherein the first gas flow component and the second gas flow component of each of the first gas flow component assemblies are, respectively, a valve and a mass flow controller.
11 . The gas box of claim 9 , wherein the mass flow controllers are, at least in part, spaced apart from the third side such that a gap is formed between at least part of each mass flow controller and the third side.
12 . The gas box of claim 11 , wherein at least one of the one or more inlet holes is positioned so as to overlap, at least in part, with the gap when viewed along the first axis.
13 . The gas box of claim 1 , wherein the gas box is configured such that each cross-flow hole is positioned so as to be in a location that appears, when viewed along a direction perpendicular to the third side, to be proximate to a releasable fluidic connection that is configured to conduct gas at a supra-atmospheric pressure during normal operation of the gas box.
14 . The gas box of claim 1 , wherein:
the one or more inlet holes have a total cross-sectional area of X,
the cross-flow holes have a total cross-sectional area of Y, and
X is between 4 and 5 times Y.
15 . The gas box of claim 1 , wherein:
the one or more inlet holes have a total open cross-sectional area of X,
the cross-flow holes have a total open cross-sectional area of Y,
the one or more exhaust openings have a total open cross-sectional area of Z, and
any other fluidic flow paths into or out of the gas box, when the door is in the closed state and the gas box is in a normal operational state and other than the one or more inlet holes, the cross-flow holes, and the one or more exhaust openings, have a total open cross-sectional area of less than 20% of X+Y.
16 . The gas box of claim 15 , wherein the other fluidic flow paths into or out of the gas box, when the door is in the closed state and the gas box is in a normal operational state and other than the one or more inlet holes, the cross-flow holes, and the one or more exhaust openings, have a total open cross-sectional area of less than 10% of X+Y.
17 . The gas box of claim 1 , wherein:
the first gas flow component assemblies of each adjacent pair of one or more adjacent pairs of the first gas flow component assemblies have at least one corresponding cross-flow hole of the cross-flow holes interposed therebetween when viewed along a direction perpendicular to the third side,
each first gas flow component assembly includes a corresponding first gas flow component, second gas flow component, and first releasable fluidic fitting, and
the first gas flow component of each first gas flow component assembly is fluidically interposed between the second gas flow component of that first gas flow component assembly and the first releasable fluidic fitting of that first gas flow component assembly.
18 . The gas box of claim 6 , wherein:
for each first gas flow component assembly of one or more of the first gas flow component assemblies, the cross-flow hole that is closest thereto is at a location interposed between the first gas flow component of that first gas flow component assembly and an end of the first releasable fluidic fitting of that first gas flow component assembly that is furthest from that first gas flow component when viewed from a direction perpendicular to the third side, and
for at least one or more of the first gas flow component assemblies, the first gas flow component is a valve and the second gas flow component is a mass flow controller.
19 . The gas box of claim 8 , wherein:
the first gas flow component and the second gas flow component of each of the first gas flow component assemblies are, respectively, a valve and a mass flow controller, And
the mass flow controllers are, at least in part, spaced apart from the third side such that a gap is formed between at least part of each mass flow controller and the third side.
20 . The gas box of claim 2 , wherein:
the one or more inlet holes have a total open cross-sectional area of X,
the cross-flow holes have a total open cross-sectional area of Y,
the one or more exhaust openings have a total open cross-sectional area of Z, and
any other fluidic flow paths into or out of the gas box, when the door is in the closed state and the gas box is in a normal operational state and other than the one or more inlet holes, the cross-flow holes, and the one or more exhaust openings, have a total open cross-sectional area of less than 20% of X+Y.