Apparatus and process for integrated gas blending

Abstract

A system ( 10 ) for delivery of dilute fluid, utilizing an active fluid source ( 12 ), a diluent fluid source ( 14 ), a fluid flow metering device ( 24 ) for dispensing of one of the active and diluent fluids, a mixer ( 28 ) arranged to mix the active and diluent fluids to form a diluted active fluid mixture, and a monitor ( 42 ) arranged to sense concentration of active fluid and/or diluent fluid in the diluted active fluid mixture, and responsively adjust the fluid flow metering device ( 24 ) to achieve a predetermined concentration of active fluid in the diluted active fluid mixture. A pressure controller ( 38 ) is arranged to control flow of the other of the active and diluent fluids so as to maintain a predetermined pressure of the diluted active fluid mixture dispensed from the system. The fluid dispensed from the system then can be adjustably controlled by a flow rate controller, e.g., a mass flow controller, to provide a desired flow to a fluid-utilizing unit, such as a semiconductor process tool. An end point monitoring assembly is also described, for switching fluid sources ( 12, 15 ) to maintain continuity of delivery of the diluted active fluid mixture.

1 - 101 . (canceled) 
   
   
       102 . A system adapted for coupling with (i) an active fluid source of active fluid and (ii) a diluent fluid source of diluent fluid, and adapted for delivery of dilute fluid, the system including:
 a fluid flow metering device adapted to dispense one of the active and diluent fluids;   a mixer arranged to mix the active and diluent fluids to form a diluted active fluid mixture;   a monitor arranged to sense concentration of any of the active fluid and the diluent fluid in the diluted active fluid mixture;   a controller arranged to receive from the monitor a signal indicative of concentration of the active fluid and/or the diluent fluid in the diluted active fluid mixture, and to responsively adjust the fluid flow metering device to achieve a predetermined concentration of active fluid in the diluted active fluid mixture; and   a pressure controller disposed upstream of the mixer, arranged to sense and control pressure of the other of the active and diluent fluids, and configured to maintain at the mixer a predetermined pressure of said other of the active and diluent fluids.   
   
   
       103 . The system of  claim 102 , wherein the fluid flow metering device is arranged for dispensing the active fluid. 
   
   
       104 . The system of  claim 102 , wherein the pressure controller is arranged to control diluent fluid flow. 
   
   
       105 . The system of  claim 102 , wherein the monitor is arranged to sense concentration of the diluent fluid in the diluted active fluid mixture. 
   
   
       106 . The system of  claim 102 , wherein the pressure controller is arranged to control active fluid flow. 
   
   
       107 . The system of  claim 102 , coupled with a fluid-utilizing unit comprising a semiconductor or microelectronic device manufacturing tool, for flow of diluted active fluid mixture thereto. 
   
   
       108 . The system of  claim 107 , further comprising a flow controller disposed downstream of the mixer and arranged to provide a predetermined flow of diluted active fluid mixture to the fluid-utilizing unit. 
   
   
       109 . The system of  claim 107 , wherein the semiconductor or microelectronic device manufacturing tool comprises any of an ion implantation tool, a chemical vapor deposition tool, an epitaxial doping tool, and an etching tool. 
   
   
       110 . The system of  claim 102 , wherein the monitor is adapted to sense any of arsine, phosphine, hydrogen, nitrogen trifluoride, ammonia, nitrous oxide, tungsten hexafluoride, hydrogen chloride, chlorine, hydrogen bromide, diborane, methane, methane, ethylene, chloroform, propane, butane, sulfur hexafluoride, nitrogen, fluorine, ammonium fluoride, ammonium phosphate, ammonium hydroxide, boron trifluoride, boron trichloride, dichlorosilane, germane, tetrafluoromethane, trifluoromethane, difluoromethane, methyl fluoride, hexafluoroethane, pentafluoromethane, perfluoropropane, octafluorocyclobutane, nitric oxide, silane, silicon tetrachloride, silicon tetrafluoride, trichlorosilane, hydrogen selenide, and organometallic reagent gases. 
   
   
       111 . The system of  claim 102 , wherein the monitor comprises a thermopile infrared analyzer. 
   
   
       112 . The system of  claim 102 , wherein the monitor comprises a fluid monitoring device selected from the group consisting of spectrometric, spectroscopic, electrochemical, acoustic, thermal, photometric, chromatographic, colorimetric, surface acoustic wave (SAW), photonic and flame ionizer fluid monitors. 
   
   
       113 . The system of  claim 102 , wherein the fluid flow metering device comprises a device selected from the group consisting of mass flow controllers, micro-valves actuatable for dispensing low flow rates of active fluid from the active fluid source, and flowmeters coupled with flow control valves. 
   
   
       114 . The system of  claim 102 , wherein the fluid flow metering device comprises an electrically-responsive variable restricted flow orifice. 
   
   
       115 . The system of  claim 102 , wherein the fluid flow metering device comprises an electrically controlled variable restrictive flow orifice, said monitor is arranged to detect a control signal transmitted to the electrically-controlled variable restrictive flow orifice, and said monitor is arranged to responsively disable a source associated with said one of the active and diluent fluids when said electrical signal is at a value indicative of exhaustion or near-exhaustion of said source associated with said one of the active and diluent fluids. 
   
   
       116 . The system of  claim 102 , further comprising said active fluid source including a gas storage and dispensing vessel containing any of (A) a physical adsorbent medium sorptively retaining active gas, and from which active gas is desorbed for dispensing of active gas from the vessel; and (B) an interiorly disposed regulator for dispensing of active gas from the vessel at a pressure determined by set point of the regulator. 
   
   
       117 . A method for delivery of dilute fluid utilizing an active fluid source containing active fluid and a diluent fluid source containing diluent fluid, the method comprising:
 controllably dispensing one of the active fluid and diluent fluid from its associated fluid source at predetermined flow rate to a mixer;   dispensing to the mixer the other of the active fluid and diluent fluid from its associated fluid source, including sensing and controlling pressure of said other of the active and diluent fluid to maintain at the mixer a predetermined pressure of said other of the active and diluent fluid;   mixing the dispensed active fluid with dispensed diluent fluid in the mixer, to form a diluted active fluid mixture;   monitoring concentration of at least one of the active and diluent fluids in the diluted active fluid mixture; and responsively adjusting the dispensing rate of the fluid dispensed at predetermined flow rate, to maintain a predetermined concentration of active fluid in the diluted active fluid mixture; and   dispensing the diluted active fluid mixture for use in a fluid-utilizing process.   
   
   
       118 . The method of  claim 117 , wherein said use comprises manufacturing a semiconductor product. 
   
   
       119 . The method of  claim 117 , wherein the active fluid source comprises a fluid storage and dispensing vessel containing any of (1) a physical adsorbent medium having sorptive affinity for the active fluid and (2) a fluid pressure regulator. 
   
   
       120 . The method of  claim 117 , wherein said monitoring comprises use of a device selected from the group consisting of spectrometric, spectroscopic, electrochemical, acoustic, thermal, photometric, chromatographic, colorimetric, surface acoustic wave (SAW), photonic and flame ionizer fluid monitors. 
   
   
       121 . The method of  claim 117 , wherein said concentration monitoring comprises use of a thermopile infrared detector. 
   
   
       122 . The method of  claim 117 , wherein said controllable dispensing is performed with a variable flow control device, the method further comprising monitoring a characteristic of the variable flow control device and responsively terminating the blending of any of said active and diluent fluids when the monitored characteristic is indicative of approaching exhaustion of said active fluid source or diluent fluid source 
   
   
       123 . A system adapted for coupling with (a) an active fluid source of active fluid and (b) a diluent fluid source of diluent fluid, and for delivery of dilute fluid, the system including:
 a fluid flow metering device for dispensing of one of the active and diluent fluids;   a mixer arranged to mix the active and diluent fluids to form a diluted active fluid mixture;   a monitor arranged to sense concentration of any of active fluid and diluent fluid in the diluted active fluid mixture;   a controller arranged to receive from the monitor a signal indicative of concentration of any of active fluid and diluent fluid in the diluted active fluid mixture, and responsively adjust the fluid flow metering device to achieve a predetermined concentration of active fluid in the diluted active fluid mixture; and   at least one of:
 (I) a pressure controller disposed upstream of the mixer, arranged to sense and control pressure of the other of the active and diluent fluids, and configured to maintain at the mixer a predetermined pressure of said other of the active and diluent fluids; and 
 (II) an end point detector assembly arranged to determine when at least one of the active fluid source and diluent fluid source is empty or approaching an empty or near-empty condition, and to responsively disable such fluid source(s) from fluid dispensing. 
   
   
   
       124 . The system of  claim 123 , wherein the fluid flow metering device comprises an electrically-responsive variable restrictive flow orifice, and the end point detector assembly is arranged to monitor an electrical signal transmitted to the variable restrictive flow orifice, and to responsively terminate dispensing of at least one of the active fluid and diluting fluid. 
   
   
       125 . The system of  claim 123 , comprising both (I) and (II).