Atomic layer deposition apparatus with point of use generated reactive gas species

Abstract

An apparatus for atomic layer deposition preventing mixing of a precursor gas and input gas is disclosed. From the apparatus a flow of the input gas is provided over a surface of the workpiece wherein a beam of the electromagnetic radiation is directed into the input gas in close proximity to the surface of the workpiece, but spaced a finite distance therefrom. The input gas is dissociated by the beam producing a high flux point of use generated reactive gas species that reacts with a surface reactant formed on the surface of the workpiece by a direct flow of the precursor gas flown from the dispensing unit. The surface reactant and reactive gas species react to form a desired monolayer of a material on the surface of the workpiece.

1 . An apparatus for chemically treating a surface of a workpiece comprising: 
 a first gas port which exposes the surface of the workpiece to a precursor gas;    a second gas port which provides an input gas over the surface of the workpiece in a direction away from said precursor gas; and    a third gas port which prevents mixing of said input gas and precursor gas.    
   
   
       2 . The apparatus of  claim 1  further comprising a fourth gas port which provides a transmission gas.  
   
   
       3 . The apparatus of  claim 1  further comprising evacuation ports which evacuates at least said purge gas.  
   
   
       4 . The apparatus of  claim 1  wherein said first and said second ports are provided by a dispensing unit.  
   
   
       5 . The apparatus of  claim 1  wherein said first, said second, and said third ports are provided by a dispensing unit.  
   
   
       6 . The apparatus of  claim 1  further comprising evacuation ports which evacuates at least said purge gas, and wherein said first, said second, said third, and said evacuation ports are provided by a dispensing unit.  
   
   
       7 . The apparatus of  claim 1  further comprising a fourth gas port which provides a transmission gas, and evacuation ports which evacuates at least said purge gas, and wherein said first, said second, said third, said fourth, and said evacuation ports are provided by a dispensing unit.  
   
   
       8 . The apparatus of  claim 1  further comprising a source configured to converge a beam of electromagnetic radiation in the input gas in close proximity to the surface of the workpiece, but spaced a finite distance therefrom, and to dissociate the input gas into a high flux of generated reactive gas species.  
   
   
       9 . The apparatus of  claim 1  further comprising a reaction chamber for containing said gases.  
   
   
       10 . An apparatus for chemically treating a surface of a workpiece comprising: 
 a supply of an input gas;    a supply of a precursor gas;    a supply of a purge gas;    a dispenser unit configured to 
 expose the surface of the workpiece to the precursor gas,  
 provide the input gas over the workpiece in a direction away from the precursor gas, and  
 provide the purge gas between the precursor gas and the input gas to prevent mixing of the precursor and the input gas; and  
   a source configured to converge a beam of electromagnetic radiation in the input gas in close proximity to the surface of the workpiece, but spaced a finite distance therefrom, and to dissociate the input gas into a high flux of generated reactive gas species.    
   
   
       11 . The apparatus of  claim 10  further configured to evacuate at least said purge gas.  
   
   
       12 . The apparatus of  claim 10  further comprising a supply of transmission gas.  
   
   
       13 . The apparatus of  claim 10  further configured to cause relative motion between the surface of the workpiece, said dispenser unit, and the beam.  
   
   
       14 . The apparatus of  claim 10  further comprising a chamber for containing the workpiece and the gases during treating, said chamber having a window transparent to the electromagnetic radiation.  
   
   
       15 . The apparatus of  claim 10  wherein the electromagnetic radiation is ultraviolet radiation.  
   
   
       16 . The apparatus of  claim 10  further comprising optics to focus the beam.  
   
   
       17 . The apparatus of  claim 10  further comprising optics to focus the beam and expand a cross sectional dimension of the beam.  
   
   
       18 . The apparatus of  claim 10  wherein the finite distance is measured by a mean-free-path length of the generated reactive gas species.  
   
   
       19 . The apparatus of  claim 10  wherein the dispenser unit includes a nozzle connected to the supply of input gas to provide a laminar flow across the surface of the workpiece.  
   
   
       20 . The apparatus of  claim 10  further configured to heat and cool the workpiece.  
   
   
       21 . The apparatus of  claim 10  further comprising a chamber for containing the workpiece and the gases during treating, the chamber having a window transparent to the electromagnetic radiation, a workpiece temperature sensor for measuring the temperature of the workpiece during treating; a pressure sensor for measuring the gas pressures in the chamber during treating, and a gas sensor for monitoring at least generated reactive gas species.  
   
   
       22 . The apparatus of  claim 10  further comprising at least one mixing chamber.  
   
   
       23 . The apparatus of  claim 10  further comprising a controller adapted to control the chemical treatment according to a selected set of reaction parameters.  
   
   
       24 . The apparatus of  claim 10  further comprising a monitor adapted to monitor completion of the chemical treatment.  
   
   
       25 . The apparatus of  claim 10  further comprising a beam dump adapted to absorb reflected energy of the beam.  
   
   
       26 . The apparatus of  claim 10  wherein said dispenser unit is one of a plurality of dispenser units and the beam is one of a plurality of beams.