Precursor material delivery system with thermal enhancements for atomic layer deposition

Abstract

A precursor delivery system includes a flow path from a precursor container to a reaction space of a thin film deposition system, such as an atomic layer deposition (ALD) reactor. At least a portion of the flow path may be formed in one or more blocks of thermally conductive material forming an elongate thermally conductive body extending from the precursor container toward the reaction space. In some embodiments, a heater is thermally associated with the thermally conductive body to inhibit condensation of precursor vapor in the flow path. A high conductivity particle filter having inertial traps is preferably included for filtering particles from the precursor material. The particle filter preferably include a filter passage including turns and inertial traps adjacent the turns. In some embodiments, the filter passage and the inertial traps may be formed in the thermally conductive body between the precursor container and the reaction space.

1 . A precursor material delivery system for delivering pulses of precursor vapor to a reaction space of a thin film deposition system, comprising: 
 a precursor container for holding precursor vapor;    one or more blocks of thermally conductive material forming an elongate thermally conductive body extending from the precursor container toward the reaction space, in use, the body having formed therein at least a portion of a flow path for the precursor vapor that extends from the precursor container to the reaction space, in use;    a pulse control device operably interposed in the flow path between the precursor container and the reaction space, in use, for selectively releasing pulses of precursor vapor toward the reaction space via the flow path; and    a heater thermally associated with the thermally conductive body to thereby inhibit the precursor vapor from condensing in the flow path.    
   
   
       2 . The system of  claim 1 , wherein the heater creates a positive temperature gradient along the flow path.  
   
   
       3 . The system of  claim 1 , further comprising a high conductivity particle filter interposed in the flow path between the precursor container and the reaction space, the high conductivity particle filter including at least one inertial trap adjacent the flow path for filtering particles from the precursor material without significantly restricting flow of the pulses through the flow path.  
   
   
       4 . The system of  claim 3 , in which the high conductivity particle filter further includes: 
 an inlet coupled to an upstream portion of the flow path;    an outlet coupled to a downstream portion of the flow path;    a filter passage in communication with the inlet and the outlet, the filter passage including multiple turns between the inlet and the outlet; and    in which the inertial trap communicates with the filter passage and is positioned in proximity to one of the turns so that the inertia of the particles causes the particles to travel into the trap as the precursor material flows through the filter passage through said turn, thereby preventing the particles from passing into the reaction space.    
   
   
       5 . The system of  claim 4 , in which at least some of the turns of the filter passage form a spiral.  
   
   
       6 . The system of  claim 4 , in which at least some of the turns of the filter passage are defined by a series of baffles between the inlet and the outlet.  
   
   
       7 . The system of  claim 1 , in which internal surfaces of the thermally conductive body bordering the flow path are passivated.  
   
   
       8 . The system of  claim 7 , in which a passivation of the internal surfaces is selected from a group consisting of oxides, nitrides, and mixtures thereof.  
   
   
       9 . The system of  claim 1 , in which a passivation of the internal surfaces is selected from a group consisting of Al 2 O 3 , ZrO 2 , HfO 2 , TiO 2 , Ta 2 O 5 , Nb 2 O 5 , AlN, HfN, TiN, TaN, NbN, AlC, ZrC, HfC, TiC, TaC, NbC, and mixtures thereof.  
   
   
       10 . The system of  claim 1 , further comprising means for vaporizing the precursor material upstream from the reaction space.  
   
   
       11 . The system of  claim 10 , in which the means for vaporizing includes a vacuum source coupled to the precursor container via a vacuum flow path.  
   
   
       12 . The system of  claim 10 , in which the means for vaporizing includes a heater thermally associated with the precursor container.  
   
   
       13 . The system of  claim 1 , in which the pulse control device includes a pulse valve.  
   
   
       14 . The system of  claim 13 , in which the pulse control device includes a diffusion barrier operably connected to the flow path downstream from the pulse valve for preventing leakage from the pulse valve from reaching the reaction space.  
   
   
       15 . The system of  claim 1 , in which the pulse control device includes an inert gas valve operably coupled to the flow path.  
   
   
       16 . The system of  claim 1 , further comprising a staging volume formed in the thermally conductive body and interposed in the flow path downstream from the precursor container and upstream from the reaction space for holding at least one dose of precursor material, the staging volume being selectively isolatable from the precursor container and selectively isolatable from the reaction space.  
   
   
       17 . The system of  claim 16 , in which the staging volume is sufficiently large so that the release of a single pulse of the precursor material from the staging volume causes a pressure inside the staging volume to decrease no more than 50 percent.  
   
   
       18 . The system of  claim 16 , in which: 
 the precursor container is formed in a first block of thermally conductive material; and    the staging volume is formed in a second block of thermally conductive material separable from the first block.    
   
   
       19 . The system of  claim 18 , further comprising an isolation valve interposed in the flow path between the precursor container and the staging volume for selectively isolating the staging volume from the precursor container.  
   
   
       20 . The system of  claim 18 , further comprising a shut-off valve interposed in the flow path between the precursor container and the isolation valve, the precursor container and the shut-off valve detachable as a unit from the second block to enable the precursor material to be replenished.  
   
   
       21 . The system of  claim 1 , further comprising one or more temperature sensors coupled to the thermally conductive body.  
   
   
       22 . The system of  claim 21 , further comprising an automatic controller responsive to the temperature sensor.  
   
   
       23 . The system of  claim 1 , in which the thin film deposition system comprises an atomic layer deposition system.  
   
   
       24 . A method of delivering pulses of a precursor vapor to a reaction space in a thin film deposition system, comprising: 
 providing a supply of precursor material;    forming at least a portion of a flow path in a thermally conductive body comprised of one or more blocks of thermally conductive material, the flow path extending from the supply of precursor material to the reaction space;    vaporizing at least a portion of the precursor material to form a precursor vapor;    selectively releasing pulses of the precursor vapor through the flow path and toward the reaction space; and    heating the thermally conductive body to inhibit condensation of the precursor vapor in the flow path.    
   
   
       25 . The method of  claim 24 , further comprising establishing a positive temperature gradient in the flow path that increases toward the reaction chamber.  
   
   
       26 . The method of  claim 24 , further comprising filtering parties from the precursor vapor as it passes through the flow path.  
   
   
       27 . The method of  claim 26 , in which the filtering of particles includes directing the precursor vapor through a filter passage having multiple turns, at least one of the turns being positioned in proximity to an inertial trap in communication with the filter passage so that inertia of particles carried into the filter passage by the precursor vapor causes the particles to travel into the trap as the precursor vapor flows through said turn.  
   
   
       28 . The method of  claim 24 , further comprising: 
 accumulating at least one dose of the precursor vapor in a staging volume located downstream in the flow path from the supply of precursor material and upstream from the reaction space; and    selectively isolating the staging volume from the supply of precursor material.    
   
   
       29 . The method of  claim 28 , further comprising accumulating multiple doses of the precursor vapor in the staging volume.  
   
   
       30 . The method of  claim 28 , in which the supply of precursor material is stored in a precursor container, and the step of vaporizing at least a portion of the precursor material includes drawing a vacuum inside the precursor container.  
   
   
       31 . The method of  claim 28 , in which the supply of precursor material is stored in a precursor container, and further comprising detaching the precursor container from the staging volume to allow the supply of precursor material to be replenished.  
   
   
       32 . The method of  claim 24 , in which the thin film deposition system comprises an atomic layer deposition system.