Sputter target for cathodic atomization to produce transparent, conductive layers

• US 5,480,532 A
• Filed: 11/09/1994
• Issued: 01/02/1996
• Est. Priority Date: 03/09/1994
• Status: Expired due to Term

• Current Assignee: Leybold Materials GmbH
• Original Assignee: Leybold Materials
• Inventors: Weigert, Martin, Schlott, Martin, Konietzka, Uwe, Vahlstrom, Shawn, Gehman, Bruce, Kutzner, Martin
• Primary Examiner(s): Weisstuch, Aaron
• Application Number:
  US08/336,769
• Time in Patent Office: 419 Days
• Field of Search: 204/192.29, 204/298.13, 501/126, 501/134, 264/65
• US Class Current: 204/298.13
• CPC Class Codes: C04B 35/01 based on oxide ceramics
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy

Abstract

A target for production of transparent electrically conductive layers by cathode sputtering is produced from indium oxide-tin oxide powder mixtures or coprecipitated indium oxide-tin oxide powders. A target with especially high mechanical strength consists of an oxide ceramic material into which metallic phase components have been incorporated in a uniform and finely distributed manner and which has a density of more than 96% of the theoretical density of indium oxide/tin oxide consisting purely of oxide.

Claims

1. Target for production of transparent electrically conductive coatings by cathode sputtering, said target consisting of

a matrix of indium oxide and tin oxide, said matrix having a theoretical density if consisting purely of said oxides, and

metallic phase components consisting of at least one of indium and tin, said components being less than 50 μ

m in size and distributed uniformly throughout said matrix, said target having a density of at least 96% of said theoretical density.

2. Target as in claim 1 wherein substantially all of said metal phase components are less than 10 μ

m in size.

3. Target as in claim 1 wherein said target has a fracture toughness of at least 1.5 MPa√

/m.

4. Process for production of a target for production of transparent electrically conductive coatings by cathode sputtering, said process comprising

providing a powder consisting of one of a mixture of indium oxide and tin oxide and co-precipitated indium oxide and tin oxide,

annealing said powder at temperatures below 1000°

C. in a reducing gas atmosphere so that metallic phase components of indium and tin less than 50 μ

m in size are formed uniformly throughout said powder, and

hot isostatic pressing said powder at temperatures above the melting points of said metallic phase components.

5. Process as in claim 4 wherein said annealing is performed so that metallic phase components less than 10 μ

m in size are formed.