Patent ID: 8555920

Claim:
A flow rate ratio variable type fluid supply apparatus, comprising: (a) a flow rate control system, wherein the flow rate control system supplies gas of a flow rate Q; (b) a plurality of first flow diverting pipe passages connected to the flow rate control system so that gas of flow rate Q is diverted to the plurality of first flow diverting pipe passages, wherein each first flow diverting pipe passage is supplied with a prescribed flow rate of diverted gas so that gas of flow rate Q is supplied to a chamber through a plurality of outlets; (c) at least one first orifice member installed on at least one of the plurality of first flow diverting pipe passages, wherein each first orifice member comprises a first orifice formed therein having a first opening area, and any first flow diverting pipe passages that does not have a first orifice member installed forms a second flow diverting pipe passage to which a plurality of branch pipe passages are connected in parallel, wherein the plurality of outlets consists of the outlets of the plurality of first flow diverting pipe passages and the outlets of the second flow diverting pipe passages so that the gas of flow rate Q is supplied to a plurality of positions in the chamber through the plurality of outlets; (d) a plurality of second orifice members installed on the plurality of branch pipe passages, wherein each second orifice member comprises a second orifice formed therein having a second opening area; and (e) a plurality of open/close valves installed on all, or some of the plurality of branch pipe passages so that gas of flow rate Q is diverted and flows to the plurality of first flow diverting pipe passages with a flow rate ratio for each first flow diverting pipe passage that is equivalent to the ratio of the respective first opening area of the corresponding first orifice member on the corresponding first flow diverting pipe passage and a total opening area of all flow-passable second orifices, wherein the total opening area is the sum of the second opening areas of those second orifice members that are flow-passable, and wherein the flow rate ratio is regulated by an open/close operation of the open/close valves installed on the branch pipe passages.