Tantalum silicide capacitor

• US 4,589,056 A
• Filed: 10/15/1984
• Issued: 05/13/1986
• Est. Priority Date: 10/15/1984
• Status: Expired due to Term

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Stimmell, James B.
• Primary Examiner(s): Hix, L. T.
• Assistant Examiner(s): Lee, Douglas S.
• Application Number:
  US06/660,991
• Time in Patent Office: 575 Days
• Field of Search: 361/433, 361/311, 361/314, 361/315, 29/570, 29/569 R, 29/25.42, 148/1.5, 148/171, 148/172, 148/173, 156/625, 156/653, 156/652, 357/23.6, 357/49
• US Class Current: 361/311
• CPC Class Codes: H01G 4/008 Selection of materials
• CPC Class Codes: H01G 4/10 Metal-oxide dielectrics H01G4/085 takes precedence
• CPC Class Codes: H01L 28/40 Capacitors
• CPC Class Codes: Y10T 29/435 Solid dielectric type

Abstract

A high capacitance/low leakage capacitor for use in a dynamic RAM cell fabricated from a metal silicide or metal silicide/poly capacitor plate structure, with formation of an anodic metal/silicon/oxygen insulating film over that structure.

Claims

1. A capacitor for an integrated circuit comprising:

a first electrically conductive layer composed of a silicide bearing material;

a dielectric layer disposed over said first electrically conductive layer, said dielectric layer including oxides of said silicide components whereby said dielectric layer comprises a compound of metal, silicon and oxygen; and

a second electrically conductive layer disposed over said dielectric layer.

2. The capacitor of claim 1 wherein said dielectric layer comprises an oxidized portion of said first electrically conductive region.

3. The capacitor of claim 2 wherein said first electrically conductive region is composed of the silicide of an anodizable metal.

4. The capacitor of claim 3 wherein said first electrically conductive region is composed of the silicide of one of the group of valve metals including tantalum, niobium, zirconium, or titanium.

5. The capacitor of claim 1 wherein said first electrically conductive region comprises tantalum silicide.

6. The capacitor of claim 1 wherein said second electrically conductive layer comprises one of polycrystalline silicon, aluminum or a silicide.

7. The capacitor of claim 6 wherein said second electrically conductive layer comprises polycrystalline silicon and is doped with an impurity to increase electrical conductivity.