Remote ICP torch for semiconductor processing

Abstract

Chemical generators and methods are described for generating a desired chemical species at or near a point of use such as the chamber of a reactor in which a workpiece such as a semiconductor wafer is to be processed. The chemical species is generated by dissociating precursor materials to create free radicals, and combining the free radicals, alone or in combination with other materials, to form the chemical species. An inductively coupled plasma preferably performs such dissociation.

1 . An apparatus for semiconductor processing comprising: a tube having a chamber, a first inlet providing access to the chamber, and an outlet providing fluidic connectivity between the chamber and a reactor chamber for semiconductor processing; and a connector configured to provide turbulence in a flow of a first precursor material being admitted into the chamber through the first inlet so as to be uniformly distributed while flowing through the chamber.  
     
     
         2 . The apparatus according to  claim 1  further comprising a coil disposed concentrically around the tube so as to generate an inductively coupled plasma in the chamber from the precursor material when energized.  
     
     
         3 . The apparatus according to  claim 2  wherein the coil is energized by radio frequency power.  
     
     
         4 . The apparatus according to  claim 3  wherein the radio frequency power oscillates at approximately 27.12 MHz.  
     
     
         5 . The apparatus according to  claim 2  wherein the tube further has a second inlet providing access to the chamber, and the coil is aligned with the tube such that the first inlet is on a high voltage side of the coil and the second inlet is on a grounded side of the coil so as to result in free radicals generated from the first precursor material flowing through the first inlet to combine with molecules of a second material flowing through the second inlet to form a desired chemical species.  
     
     
         6 . The apparatus according to  claim 5  wherein the first precursor material is oxygen, the second material is hydrogen, and the desired chemical species is steam H 2 O.  
     
     
         7 . The apparatus according to  claim 1  wherein the connector provides fluidic connectivity between a source of the first precursor material and the first inlet.  
     
     
         8 . The apparatus according to  claim 7  wherein the connector is fluidically connected to the source of the first precursor material through a delivery hose line.  
     
     
         9 . The apparatus according to  claim 1  wherein the connector has an inner wall against which all molecules of the first precursor material collide before being admitted into the chamber through the first inlet.  
     
     
         10 . The apparatus according to  claim 9  wherein the connector is L-shaped.  
     
     
         11 . The apparatus according to  claim 1  further comprising a ground strap contacting the tube so as to inhibit plasma generation in the chamber beyond the ground strap.  
     
     
         12 . An apparatus for semiconductor processing comprising: a tube having a chamber, first and second inlet ports providing access to the chamber, and an open end providing access from the chamber to a reactor chamber for semiconductor processing; and a coil disposed concentrically around the tube and aligned such that the first inlet port is on a high voltage side of the coil and the second inlet port is on a low voltage side of the coil so as to generate an inductively coupled plasma in the chamber when energized that results in free radicals generated from a first precursor material flowing through the first inlet port to combine with molecules of a second material flowing through the second inlet port to form a desired chemical species.  
     
     
         13 . The apparatus according to  claim 12  wherein the inductively coupled plasma is generated such that it does not extend to the second inlet port.  
     
     
         14 . The apparatus according to  claim 12  wherein the first precursor material is oxygen, the second material is hydrogen, and the desired chemical species is steam.  
     
     
         15 . The apparatus according to  claim 12  further comprising a third inlet port providing access to the chamber on a side of the tube approximately opposite from the first inlet port on the high voltage side of the coil so as to admit additional of the first precursor material into the chamber.  
     
     
         16 . The apparatus according to  claim 12  further comprising a fourth inlet port providing access to the chamber on a side of the tube approximately opposite from the second inlet port on the ground side of the'coil so as to admit additional of the second material into the chamber.  
     
     
         17 . The apparatus according to  claim 12  further comprising a ground strap contacting the tube so as to inhibit plasma generation in the chamber beyond the ground strap.  
     
     
         18 . An apparatus for semiconductor processing comprising: a tube having a chamber, an inlet providing access to the chamber, and an outlet providing fluidic connectivity to a reactor chamber for processing semiconductors; means for generating a plasma in the chamber; and a ground strap contacting the tube so as to inhibit plasma generation in the chamber beyond the ground strap.  
     
     
         19 . The apparatus according to  claim 18  further comprising a coil disposed concentrically around the tube so as to generate an inductively coupled plasma when energized.  
     
     
         20 . The apparatus according to  claim 19  wherein~the coil is energized by a radio frequency generator through a matching network.  
     
     
         21 . The apparatus according to  claim 19  wherein the ground strap is positioned on the tube on a ground side of the coil.  
     
     
         22 . The apparatus according to  claim 21  wherein the ground strap includes copper material.  
     
     
         23 . An apparatus for semiconductor processing comprising: a first free radical source for generating a first type of free radicals from a first precursor material and providing the first type of free radicals to a reactor chamber, and a second free source for generating a second type of free radicals from a second precursor material and providing the second type of free radicals to the reactor chamber for combination with the first type of free radicals to form a desired chemical species for processing semiconductors in the reactor chamber.  
     
     
         24 . The apparatus according to  claim 23  wherein the first free radical source comprises: a first tube having a first chamber; and a first coil disposed concentrically around the first tube so as to generate a first inductively coupled plasma generating the first type of free radicals from the first precursor material when energized.  
     
     
         25 . The apparatus according to  claim 24  wherein the second free radical source comprises: a second tube having a second chamber; and a second coil disposed concentrically around the second tube so as to generate a second inductively coupled plasma generating the second type of free radicals from the second precursor material when energized.  
     
     
         26 . The apparatus according to  claim 24  wherein the first coil is coupled to a first radio frequency generator through a first matching network.  
     
     
         27 . The apparatus according to  claim 26  wherein the second coil is coupled to the first radio frequency generator through the first matching network.  
     
     
         28 . The apparatus according to  claim 26  wherein the second coil is coupled to a second radio frequency generator through a second matching network.  
     
     
         29 . The apparatus according to  claim 26  wherein the second coil is coupled to the first radio frequency generator through a third matching network.