COATED COPPER-CONTAINING POWDERS, METHODS AND APPARATUS FOR PRODUCING SUCH POWDERS, AND COPPER-CONTAINING DEVICES FABRICATED FROM SAME
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.