Dielectric film

• US 5,225,286 A
• Filed: 06/12/1992
• Issued: 07/06/1993
• Est. Priority Date: 06/13/1991
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation), Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation)
• Inventors: Iida, Makio, Fujikawa, Hisayoshi, Taga, Yasunori
• Primary Examiner(s): Robinson, Ellis P.
• Assistant Examiner(s): Speer, Timothy M.
• Application Number:
  US07/897,818
• Time in Patent Office: 389 Days
• Field of Search: 174/250, 174/255, 106/286.1, 428/336, 428/469, 428/472, 428/688, 428/689, 428/697, 428/701, 428/702, 428/901, 428/917, 428/426, 428/432, 315/169.3, 357/2, 357/10, 357/17, 357/41, 357/63
• US Class Current: 428/426
• CPC Class Codes: H01L 28/40 Capacitors
• CPC Class Codes: H01L 29/513 the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• CPC Class Codes: Y10S 428/901 Printed circuit
• CPC Class Codes: Y10S 428/917 Electroluminescent
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A tantalum oxide dielectric film includes tantalum oxide (Ta₂ O₅) as a major component, and at least one oxide selected from the group consisting of yttrium oxide (Y₂ O₃), tungsten oxide (WO₃) and niobium oxide (Nb₂ O₅). This dielectric film exhibits a remarkably improved dielectric constant and insulation property because it is a composite oxide film in which Ta₂ O₅ is compounded with Y₂ O₃, WO₃ or Nb₂ O₅. For example, when the dielectric film is used as a capacitor film, the capacitor film exhibits a figure of merit, i.e., a product of a dielectric constant and an insulation property, approximately twice the silicon oxide (SiO₂) film which is used widely for the purpose at present.

Claims

1. A tantalum oxide dielectric film, consisting essentially of:

tantalum oxide (Ta₂ O₅) as a major component; and

one oxide selected from the group consisting of yttrium oxide (Y₂ O₃) and tungsten oxide (WO₃), wherein said tantalum oxide dielectric film contains yttrium or tungsten in an amount of 8 to 32 atomic % or 2 to 15 atomic %, respectively, relative to the sum of tantalum and yttrium/tungsten therein taken as 100 atomic %.

2. The tantalum oxide dielectric film according to claim 1, wherein said tantalum oxide dielectric film includes tungsten in an amount of 2 to 4 atomic % when the sum of tantalum and tungsten therein is taken as 100 atomic %.

3. The tantalum oxide dielectric film according to claim 1, wherein a thickness thereof is not more than 4000 angstroms.

4. The tantalum oxide dielectric film according to claim 3, wherein a thickness thereof falls in a range of 100 to 1000 angstroms.

5. The tantalum oxide dielectric film according to claim 4, wherein said thickness thereof falls in a range of 700 to 1000 angstroms.

6. The tantalum oxide dielectric film according to claim 1, wherein said tantalum oxide dielectric film is employed in an LSI circuit.

7. The tantalum oxide dielectric film according to claim 1, wherein said tantalum oxide dielectric film is employed in an EL display device.

8. The tantalum oxide dielectric film according to claim 1, wherein said tantalum oxide dielectric film is employed in an EC display device.