Coated copper-containing powders, methods and apparatus for producing such powders, and copper-containing devices fabricated from same

Abstract

Copper powder batches including coated copper-containing particles and methods for producing the same. The coated copper-containing particles having have a small particle size, narrow size distribution and a spherical morphology. The present invention is also directed to devices incorporating the coated copper-containing particles.

1 . A method for making coated copper-containing particles, the method comprising: 
 preparing particles comprising a copper-containing material, as prepared the particles are dispersed in a flowing aerosol stream; and    after the preparing and while the particles are in the aerosol stream, processing the particles, wherein the processing comprises forming a coating on the particles, the coating comprising a coating material that is different than the copper-containing material.    
     
     
         2 . The method of  claim 1 , wherein the coating has an average thickness of not greater than 100 nanometers.  
     
     
         3 . The method of  claim 1 , wherein the coating has an average thickness of not greater than 50 nanometers.  
     
     
         4 . The method of  claim 3 , wherein the coating has an average thickness of at least 5 nanometers.  
     
     
         5 . The method of  claim 1 , wherein the coated copper-containing particles have a weight average particle size in a range of from 0.1 μm to 5 μm.  
     
     
         6 . The method of  claim 1 , wherein the coating material is an inorganic compound.  
     
     
         7 . The method of  claim 1 , wherein the coating material is a metal phase.  
     
     
         8 . The method of  claim 7 , wherein the metal phase is an elemental metal.  
     
     
         9 . The method of  claim 7 , wherein the metal phase comprises a noble metal.  
     
     
         10 . The method of  claim 9 , wherein the noble metal is platinum.  
     
     
         11 . The method of  claim 9 , wherein the noble metal is gold.  
     
     
         12 . The method of  claim 7 , wherein the metal phase is selected from the group consisting of elemental silver and silver alloys.  
     
     
         13 . The method of  claim 1 , wherein the coating material is a metal oxide.  
     
     
         14 . The method of  claim 13 , wherein the metal oxide is selected from the group consisting of ZrO 2 , SiO 2 , B 2 O 5 , TiO 2 , Cu 2 O, CuO, Bi 2 O 3 , V 2 O 5 and Al   2 O 3 .  
     
     
         15 . The method of  claim 1 , wherein the coating material is a dielectric compound.  
     
     
         16 . The method of  claim 15 , wherein the dielectric compound is selected from the group consisting of titanates, silicates, aluminates and tantalates.  
     
     
         17 . The method of  claim 15 , wherein the dielectric compound is selected from the group consisting of barium titanate, neodymium titanate, magnesium titanate, calcium titanate, lead titanate and strontium titanate.  
     
     
         18 . The method of  claim 15 , wherein the dielectric compound is selected from the group consisting of a zirconate and a niobate.  
     
     
         19 . The method of  claim 15 , wherein the dielectric compound is selected from the group consisting of magnesium zirconate and calcium zirconate.  
     
     
         20 . The method of  claim 1 , wherein the coating material is a non-metallic compound.  
     
     
         21 . The method of  claim 20 , wherein the non-metallic compound is a boride.  
     
     
         22 . The method of  claim 1 , wherein the coating material is an organic compound.  
     
     
         23 . The method of  claim 1 , wherein the coating material is polymethylmethacrylate.  
     
     
         24 . The method of  claim 1 , wherein the coating material is polystyrene.  
     
     
         25 . The method of  claim 1 , wherein the coating material is a surfactant.  
     
     
         26 . The method of  claim 1 , wherein the coating material is hydrophobic.  
     
     
         27 . The method of  claim 1 , wherein the coating material is hydrophilic.  
     
     
         28 . The method of  claim 1 , wherein the coating is a monolayer coating.  
     
     
         29 . The method of  claim 1 , wherein the forming comprises chemical vapor deposition.  
     
     
         30 . The method of  claim 1 , wherein the forming comprises physical vapor deposition.  
     
     
         31 . The method of  claim 1 , wherein the forming comprises gas-to-particle conversion.  
     
     
         32 . The method of  claim 1 , wherein the forming comprises contacting the copper-containing particles with a reactive gas composition.  
     
     
         33 . The method of  claim 1 , wherein the forming comprises reaction at elevated temperature of a precursor selected from the group consisting of metal acetates, metal chlorides, metal alkoxides and metal halides.  
     
     
         34 . The method of  claim 1 , wherein the forming comprises reaction of SiCl 4 .  
     
     
         35 . The method of  claim 1 , wherein the forming comprises reaction of Si(OEt) 4 .  
     
     
         36 . The method of  claim 1 , wherein the forming comprises reaction of Mg(O 2 CCH 3 ) 2 .  
     
     
         37 . The method of  claim 1 , wherein the forming comprises reacting an organic or inorganic molecule with a surface of the particles to form the coating.  
     
     
         38 . The method of  claim 1 , wherein the forming comprises reacting a surface of the particles with a functionalized organo silane compound.  
     
     
         39 . The method of  claim 38 , wherein the functionalized organo silane compound is a halo-silane.  
     
     
         40 . The method of  claim 38 , wherein the functionalized organo silane compound is an amino-silane.  
     
     
         41 . The method of  claim 38 , wherein the functionalized organo silane compound is hexamethyidisilazane.  
     
     
         42 . The method of  claim 38 , wherein the functionalized organo silane compound is trimethylsilylchloride.  
     
     
         43 . The method of  claim 1 , wherein the forming comprises condensing a volatile coating material on the particles.  
     
     
         44 . The method of  claim 43 , wherein the volatile coating material is selected from the group consisting of PbO, MoO 3  and V 2 O 5 .  
     
     
         45 . The method of  claim 1 , wherein the preparing comprises forming the particles in a thermal reactor.  
     
     
         46 . The method of  claim 45 , wherein the thermal reactor is a furnace reactor.  
     
     
         47 . The method of  claim 45 , wherein the thermal reactor is a flame reactor.  
     
     
         48 . The method of  claim 45 , wherein the thermal reactor is a plasma reactor.  
     
     
         49 . The method of  claim 1 , comprising: 
 prior to the preparing, generating the aerosol stream, the aerosol stream as generated comprising droplets of flowable medium comprising liquid and a copper-containing precursor; and    the preparing comprising removing at least a portion of the liquid from the droplets.    
     
     
         50 . The method of  claim 49 , wherein the precursor is dissolved in the liquid in the droplets.  
     
     
         51 . The method of  claim 50 , wherein the precursor is a copper salt.  
     
     
         52 . The method of  claim 49  wherein, during the generating, the droplets are formed by a spray nozzle.  
     
     
         53 . The method of  claim 49 , wherein: 
 the generating comprises sweeping away with carrier gas the droplets from a reservoir of the flowable medium ultrasonically energized by a plurality of ultrasonic transducers underlying the reservoir.    
     
     
         54 . The method of  claim 53 , comprising: 
 after the forming, cooling the aerosol stream, the cooling comprising passing the aerosol through a perforated conduit while introducing a quench gas into the perforated conduit through openings in a wall of the perforated conduit.    
     
     
         55 . A method for making a copper-containing product feature, the method comprising: 
 making the coated copper-containing particles according to  claim 1;  and    after the making, processing the coated copper-containing particles to make a feature of a product comprising copper from the coated copper-containing particles.    
     
     
         56 . The method of  claim 55 , wherein the product is a microelectronic device.  
     
     
         57 . The method of  claim 55 , wherein the product is a multilayer ceramic.  
     
     
         58 . The method of  claim 57 , wherein the feature is a conductive trace.  
     
     
         59 . The method of  claim 58 , wherein the conductive trace has a line width of less than 25 μm.  
     
     
         60 . The method of  claim 55 , wherein the product is a multilayer ceramic capacitor and the feature is an internal electrode of the multi-layer ceramic capacitor.  
     
     
         61 . The method of  claim 60 , wherein the internal electrode has an average thickness of not greater than 2 μm.  
     
     
         62 . The method of  claim 55 , wherein the product is a flat panel display.  
     
     
         63 . The method of  claim 62 , wherein the flat panel display is a plasma display panel.  
     
     
         64 . The method of  claim 63 , wherein the feature is an electrode of the plasma display panel.  
     
     
         65 . The method of  claim 63 , wherein the feature is a bus line of the plasma display panel.