Sub-atmospheric pressure delivery of liquids, solids and low vapor pressure gases

Abstract

A delivery system and method for vaporizing and delivery of vaporized solid and liquid precursor materials at sub-atmospheric pressures between a heatable vaporization vessel and a processing tool. The system includes a pressure regulator internally positioned within the vaporization vessel and in fluid communication with a downstream mass flow controller to maintain a consistent flow of vaporized source material. The system further comprises introducing a carrier/diluent gas for diluting the vaporized source material before entry into the processing tool. A venturi is positioned directly upstream of the processing tool and provides for mixing of the carrier gas with the vaporized source material while providing the negative pressure required to open the gas pressure regulator within the vaporization vessel.

1 . A method for delivering a vaporized source material to a processing tool, the method comprising: 
 a) heating a source material in a vaporization vessel to generate a vaporized source material;    b) releasing the vaporized source material through a gas pressure regulator, wherein the pressure regulator is positioned within the vaporization vessel and pre-set to release the vaporized source material at a sensed sub-atmospheric pressure level downstream from the vaporization vessel;    c) flowing the vaporized source material to a downstream processing tool via a connecting line;    d) adjusting the flow rate of the vaporized source material by passing through a mass flow controller positioned upstream from the processing tool; and    e) introducing a carrier/diluent gas to the connecting line for diluting the vaporized source material before delivery into the processing tool.    
     
     
         2 . The method according to  claim 1 , wherein the source material is a member selected from the group consisting of decaborane, hafnium tetrachloride, zirconium tetrachloride, indium trichloride, metalorganic β-diketonate complexes, tungsten hexafluoride, cyclopentadienylcycloheptatrienyl-titanium (C p TiCht), aluminum trichloride, titanium iodide, cyclooctatetraenecyclo-pentadienyltitanium, biscyclopentadienyltitaniumdiazide, trimethyl gallium, trimethyl indium, aluminum alkyls like trimethylaluminum, triethylaluminum, trimethylamine alane, dimethyl zinc, tetramethyl tin, trimethyl antimony, diethyl cadmium and tungsten carbonyl.  
     
     
         3 . The method according to  claim 1 , wherein the gas pressure regulator is interiorly disposed in the vaporization vessel.  
     
     
         4 . The method according to  claim 1 , wherein the gas pressure regulator is set at a predetermined sub-atmospheric pressure ranging from about 300 Torr to about 800 Torr.  
     
     
         5 . The method according to  claim 1 , wherein the pressure in the processing tool is maintained at a sub-atmospheric pressure ranging from about 1×10 −2  Torr to about 760 Torr.  
     
     
         6 . The method according to  claim 1 , further comprising effecting a vacuum in the connecting line between the pressure regulator and processing tool by connecting a vacuum generating means thereto.  
     
     
         7 . The method according to claims  1 , further comprising sensing the pressure in the processing tool with a pressure sensor.  
     
     
         8 . The method according to  claim 7  further comprising communicatively linking the pressure sensor to a central processing unit for inputting sensed ambient pressure values.  
     
     
         9 . The method according to  claim 8 , further comprising linking the mass flow controller to the central processing unit for adjusting the flow of the released gas into the processing tool relative to the sensed pressure in the processing tool.  
     
     
         10 . The method according to  claim 9 , wherein releasing the gas through the gas pressure regulator and flowing the discharged gas through a mass flow controller is effected without a carrier gas.  
     
     
         11 . A vapor delivery system for vaporization and sub-atmospheric delivery of a vaporized source material, comprising: 
 a) a heatable vaporization vessel for holding and heating a vaporizable source material;    b) a pressure regulator positioned within the heatable vaporization vessel, wherein the gas pressure regulator is preset to open and release vaporized source material from the heatable vaporization vessel when sensing a downstream subatmospheric pressure level equal to or lower than a preset pressure level;    c) a processing tool positioned downstream and in fluid communication with the gas pressure regulator; and    d) a venturi positioned downstream of the heatable vaporization vessel to provide negative pressure to open the pressure regulator.    
     
     
         12 . A vapor delivery system for vaporization and sub-atmospheric delivery of a vaporized source material, comprising: 
 a) a vaporization vessel enclosing an interior volume, wherein the vessel includes a heating means for vaporizing a source material, a fill port for introducing source material and an outlet port for discharged vaporized source material;    b) a gas pressure regulator positioned within the vaporization vessel, wherein the gas pressure regulator is set to release vaporized source material at a predetermined subatmospheric pressure;    c) a processing tool positioned downstream from the vaporization vessel;    d) at least one connecting vapor line positioned between the vaporization vessel and processing tool and in fluid communication therewith; and    e) a mass flow controller in fluid communication with the connecting vapor line to establish a flow rate of the discharged vaporized source material into the downstream processing tool; and    f) a vacuum pump communicatively connected to the connecting vapor line and positioned to maintain pressure within the connecting vapor line at a pressure sufficient to release vaporized source material from the vaporization vessel through the gas pressure regulator.    
     
     
         13 . The vapor delivery system according to  claim 12 , wherein the connecting vapor line is heated.  
     
     
         14 . The vapor delivery system according to  claim 12 , wherein the connecting vapor line is unheated.  
     
     
         15 . The vapor delivery system according to  claim 12 , wherein the gas pressure regulator is set at a predetermined sub-atmospheric pressure ranging from about 300 Torr to about 600 Torr.  
     
     
         16 . The vapor delivery system according to  claim 12 , wherein the pressure in the processing tool is maintained at a sub-atmospheric pressure from about 1×10 −2  Torr to about 400 Torr.  
     
     
         17 . The vapor delivery system according to  claim 12 , wherein the source material is a member selected from the group consisting of decaborane, hafnium tetrachloride, zirconium tetrachloride, indium trichloride, metalorganic β-diketonate complexes, tungsten hexafluoride, cyclopentadienylcycloheptatrienyl-titanium (C p TiCht), aluminum trichloride, titanium iodide, cyclooctatetraenecyclo-pentadienyltitanium, biscyclopentadienyltitaniumdiazide, trimethyl gallium, trimethyl indium, aluminum alkyls like trimethylaluminum, triethylaluminum, trimethylamine alane, dimethyl zinc, tetramethyl tin, trimethyl antimony, diethyl cadmium and tungsten carbonyl.  
     
     
         18 . The vapor delivery system according to  claim 12 , further comprising at least one pressure sensor communicatively connected to the connecting line.  
     
     
         19 . The vapor delivery system according to  claim 18 , wherein the at least one pressure sensor is communicatively linked to a central processing unit for input of sensed pressure values.  
     
     
         20 . The vapor delivery system according to  claim 18 , wherein the central processing unit is communicatively linked to the mass flow controller for adjustment of flow relative to the sensed pressure in the connecting line.