Rapid generation of nanoparticles from bulk solids at room temperature

• US 20070056465A1
• Filed: 03/03/2004
• Published: 03/15/2007
• Est. Priority Date: 03/06/2003
• Status: Abandoned Application

• Current Assignee: Rensselaer Polytechnic Institute
• Original Assignee: Rensselaer Polytechnic Institute
• Inventors: Dutta, Partha
• Application Number:
  US10/547,795
• Publication Number:
  US 20070056465A1
• Time in Patent Office: Days
• US Class Current: 106/3
• CPC Class Codes: B22F 1/054 Nanosized particles
• CPC Class Codes: B22F 1/145 Chemical treatment, e.g. passivation or decarburisation
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 9/16 using chemical processes
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 13/145 After-treatment of oxides or hydroxides, e.g. pulverising, drying, decreasing the acidity
• CPC Class Codes: C01B 19/007 Tellurides or selenides of metals C01B19/002 takes precedence
• CPC Class Codes: C01B 33/02 Silicon forming single crystals or homogeneous polycrystalline material with defined structure C30B
• CPC Class Codes: C01B 33/12 Silica; Hydrates thereof, e.g. lepidoic silicic acid
• CPC Class Codes: C01P 2004/52 highly monodisperse size distribution
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C08K 3/013 Fillers, pigments or reinforcing additives
• CPC Class Codes: C08K 9/02 Ingredients treated with inorganic substances
• CPC Class Codes: C09D 11/037 characterised by the pigment
• CPC Class Codes: C09D 11/322 Pigment inks
• CPC Class Codes: C09D 7/61 inorganic
• CPC Class Codes: C09D 7/62 modified by treatment with other compounds
• CPC Class Codes: C09D 7/67 Particle size smaller than 100 nm
• CPC Class Codes: C09D 7/70 characterised by shape, e.g. fibres, flakes or microspheres
• CPC Class Codes: C09G 1/02 : containing abrasives or grinding agents abrasives as such C09K3/14; polishing of semi-conductors H01L
• CPC Class Codes: C09K 3/1463 : Aqueous liquid suspensions
• CPC Class Codes: C30B 29/16 : Oxides
• CPC Class Codes: C30B 29/605 : Products containing multiple oriented crystallites, e.g. columnar crystallites
• CPC Class Codes: C30B 33/00 : After-treatment of single crystals or homogeneous polycrystalline material with defined structure C30B31/00 takes precedence
• CPC Class Codes: C30B 33/005 : Oxydation
• CPC Class Codes: C30B 7/00 : Single-crystal growth from solutions using solvents which are liquid at normal temperature, e.g. aqueous solutions from molten solvents C30B9/00; by normal or gradient freezing C30B11/00; under a protective fluid C30B27/00
• CPC Class Codes: G11B 11/007 : with reproducing by means directly associated with the tip of a microscopic electrical probe as defined in G11B9/14 details of heads G11B9/1409; disposition or mounting of heads G11B9/1418
• CPC Class Codes: G11B 5/712 : characterised by the surface treatment or coating of magnetic particles
• CPC Class Codes: G11B 5/82 : Disk carriers
• CPC Class Codes: H01F 1/0063 : in a non-magnetic matrix, e.g. granular solids granular films H01F10/007
• CPC Class Codes: H01F 1/405 : of IV type, e.g. Ge1-xMnx
• CPC Class Codes: Y10T 428/25 : Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/259 : Silicic material
• CPC Class Codes: Y10T 428/2991 : Coated
• CPC Class Codes: Y10T 428/2993 : Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]

Abstract

A plurality of nanoparticles are provided. The nanoparticles may have a metal oxide or a semiconductor oxide surface region and a metal or semiconductor core region and/or the nanoparticles may be uniformly doped. The nanoparticles are formed by grinding a bulk material to a powder and then etching the powder in a solution to a desired nanoparticle size.

Claims

1-52. -52. (canceled)

53. A plurality of nanoparticles, wherein:

the nanoparticles have an average size below about 100 nm with a size standard deviation of less than 60 percent of the average nanoparticle size determined by photon correlated spectroscopy (PCS) method; and

the nanoparticles comprise ceramic, metal or uniformly doped semiconductor nanoparticles.

54. The nanoparticles of claim 53, wherein the nanoparticles have an average size between about 2 nm and about 10 nm with a size standard deviation of between about 10 and about 25 percent of the average nanoparticle size determined by photon correlated spectroscopy (PCS) method.

55. The nanoparticles of claim 53, wherein the nanoparticles comprise uniformly doped semiconductor nanoparticles.

56. The nanoparticles of claim 55, wherein the nanoparticles comprise silicon nanoparticles uniformly doped with a suitable Group III or Group V dopants.

57. The nanoparticles of claim 53, wherein:

the nanoparticles comprise uniformly doped nanoparticles;

each uniformly doped nanoparticle has a dopant concentration that varies by less than 5% throughout its volume; and

the uniformly doped nanoparticles have an average dopant concentration that varies by less than 5% among the nanoparticles.

58. The nanoparticles of claim 53, wherein the nanoparticles are capable of being suspended in water without substantial agglomeration and substantial precipitation on container surfaces for at least 30 days.

59. The nanoparticles of claim 53, wherein the nanoparticles comprise ceramic or metal nanoparticles.

60. The nanoparticles of claim 59, wherein the nanoparticles comprise ceramic nanoparticles.

61. The nanoparticles of claim 60, wherein the nanoparticles comprise uniformly doped ceramic nanoparticles.

62. The nanoparticles of claim 59, wherein the nanoparticles comprise metal nanoparticles.

63. The nanoparticles of claim 62, wherein the nanoparticles comprise uniformly alloyed metal nanoparticles.

64. A method of making nanoparticles, comprising combining a powder having particles of a first size with an etching liquid to etch the particles of the first size to nanoparticles having a second size smaller than the first size.

65. The method of claim 64, further comprising:

providing a bulk material; and

grinding the bulk material into the powder having particles of the first size.

66. The method of claim 65, wherein the step of grinding comprises placing a chunk of the bulk material on an abrasive film and moving the chunk and the abrasive film relative to each other to grind the bulk material into the powder.

67. The method of claim 65, wherein the step of grinding comprises ball milling the bulk material.

68. The method of claim 65, wherein the bulk material comprises a uniformly doped semiconductor bulk material.

69. The method of claim 68, wherein the bulk material comprises at least a portion of a silicon wafer uniformly doped with suitable Group III or Group V dopants.

70. The method of claim 64, wherein the particles comprise semiconductor particles.

71. The method of claim 64, wherein the particles comprise ceramic particles.

72. The method of claim 64, wherein the particles comprise pure metal or metal alloy particles.

73. The method of claim 64, wherein:

the nanoparticles have an average size of 50 nm or less; and

the method is conducted at a temperature below 100 C.

74. The method of claim 64, wherein the step of combining the powder with the etching liquid comprises combining the powder with the etching liquid in a solution.

75. The method of claim 74, wherein:

the solution comprises an aqueous solution;

the etching liquid comprises HCl, KOH, HF or NaOH; and

the step of combining the powder with the etching liquid in a solution comprises providing the powder into water followed by providing the etching liquid into the water.

76. The method of claim 64, further comprising incorporating the nanoparticles into an article of manufacture.

77. A polishing or grinding pad comprising a pad material and nanoparticles attached to a surface of the pad material.

78. The pad of claim 77, wherein:

the pad comprises a polishing pad; and

the nanoparticles comprise silicon, silicon dioxide or silicon nitride nanoparticles.

79. A chemical mechanical polishing method, comprising:

placing a device to be polished onto a first surface of the polishing pad of claim 77;

providing a chemical mechanical polishing fluid onto the first surface of the polishing pad; and

chemically mechanically polishing the device.

80. The method of claim 79, wherein:

the polishing fluid contains nanoparticles;

the polishing fluid is provided to the pad prior to placing the device onto the first surface of the pad; and

the device comprises a semiconductor device.