Conductive exotic-nitride barrier layer for high-dielectric-constant material electrodes

• US 5,679,980 A
• Filed: 12/19/1996
• Issued: 10/21/1997
• Est. Priority Date: 08/01/1994
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Summerfelt, Scott R.
• Primary Examiner(s): Thomas, Tom
• Assistant Examiner(s): WILLIAMS, ALEXANDER O
• Application Number:
  US08/770,066
• Time in Patent Office: 306 Days
• Field of Search: 257/751, 257/758, 257/759, 257/741, 257/744, 257/748, 257/293
• US Class Current: 257/751
• CPC Class Codes: H01L 21/28568 the conductive layers comprising transition metals H01L21/28518 takes precedence
• CPC Class Codes: H01L 28/75 comprising two or more layers, e.g. comprising a barrier layer and a metal layer

Abstract

A preferred embodiment of this invention comprises an oxidizable layer (e.g. TiN 50), a conductive exotic-nitride barrier layer (e.g. Ti-Al-N 34) overlying the oxidizable layer, an oxygen stable layer (e.g. platinum 36) overlying the exotic-nitride layer, and a high-dielectric-constant material layer (e.g. barium strontium titanate 38) overlying the oxygen stable layer. The exotic-nitride barrier layer substantially inhibits diffusion of oxygen to the oxidizable layer, thus minimizing deleterious oxidation of the oxidizable layer.

Claims

1. A microelectronic structure comprising:

an oxidizable layer, wherein said oxidizable layer is substantially conductive and unoxidized;

a conductive nitride layer overlying said oxidizable layer, said conductive nitride selected from the group consisting of;

titanium aluminum nitride, Zr nitride, Hf nitride, Y nitride, Sc nitride, La nitride, other rare earth nitrides, N deficient Al nitride, doped Al nitride, Mg nitride, Ca nitride, Sr nitride, Ba nitride, and combinations thereof;

a conductive oxygen stable layer overlying and adjacent said conductive nitride layer; and

a layer of a high-dielectric-constant material overlying said oxygen stable layer, whereby the conductive nitride layer substantially inhibits diffusion of oxygen to the oxidizable layer.

2. The structure of claim 1, wherein said conductive nitride layer is partially oxidized.

5. The structure of claim 1, wherein said conductive oxygen stable layer is platinum.

6. The structure of claim 1, wherein said conductive oxygen stable layer is selected from the group consisting of ruthenium, ruthenium dioxide, and combinations thereof.

3. The structure of 1, said structure further comprising an upper electrode overlying said high-dielectric-constant material layer.

4. The structure of claim 3, wherein said upper electrode is selected from the group consisting of:

tungsten, tungsten nitride, titanium, titanium nitride, ruthenium dioxide, YBa₂ Cu₃ O_7-x, platinum, palladium, rhodium, gold, iridium, silver, and combinations thereof.