Apparatus and method for evenly flowing processing gas onto a semiconductor wafer
AssigneeApplied Materials, Inc.
InventorThomas P.H.F. Wendling
Life of this patent
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Abstract
A semiconductor processing apparatus with a chamber, a wafer holder and a processing gas inlet pipe is provided with an impeller fixed within the inlet pipe. As gas flows through slots in the impeller, the gas is directed into a plurality of generally horizontal streams beneath the impeller which cause a swirling whirlpool-like motion of the gas in a lower portion of the pipe. As the swirling gas flows out of an exit-end of the pipe, centrifugal forces cause the gas immediately to flow outward within the chamber so that on passing down onto a wafer the gas flows uniformly across a surface of the wafer.
Claims14
A semiconductor processing apparatus comprising;
- a chamber;
- a wafer support member within the chamber;
- a gas inlet pipe for flowing processing gas down into a top part of the chamber at an exit-end of the pipe;
- and
- an impeller mounted within the pipe above the exit-end thereof, the impeller directing the gas flowing down within the pipe into a plurality of lateral secondary gas streams rotating beneath the impeller to cause a swirling whirlpool-like motion of the gas.
Semiconductor apparatus useful to control processing gas flowing onto a wafer held within the chamber, the apparatus comprising:
- a chamber having an upper portion and a lower portion;
- a platform for holding a wafer for the processing thereof within the chamber;
- a gas pipe for flowing processing gas down through an exit-end thereof into the upper portion of the chamber;
- and
- an impeller which comprises a plurality of fan-like blades radiating from a center to an outer rim, the blades being circumferentially spaced and overlapping each other with a front edge of one blade being beneath and ahead of a rear edge of the next blade and so on, there being respective spaces between the blades where they overlap, the spaces between the blades forming secondary gas passageways for directing respective streams of gas laterally beneath the impeller into a rotational swirling motion, the impeller being fixed within the gas pipe above its exit-end, such that when the swirling gas beneath the impeller flows into the upper portion of the chamber internal forces cause the gas to flow outward across the chamber and then down evenly onto and over a wafer on the platform.
A method of evenly spreading processing gas onto and over the surface of a semiconductor wafer, the method comprising the steps of:
- flowing a stream of processing gas in a pipe downward toward a wafer being held in a chamber;
- generating a whirlpool-like laterally swirling motion in the gas stream;
- and
- using internal forces within the swirling gas to cause it on entering the chamber to flow immediately outward within the chamber and then down evenly onto and over a wafer within the chamber.
Dependencies are inferred from the claim text.