Transistor having an etch stop layer including a metal compound that is selectively formed over a metal gate, and method therefor

• US 20080157365A1
• Filed: 12/27/2006
• Published: 07/03/2008
• Est. Priority Date: 12/27/2006
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Sharma, Ajay, Ott, Andrew, King, Sean
• Granted Patent: US 8,120,114 B2
• Time in Patent Office: Days
• US Class Current: 257/750
• CPC Class Codes: H01L 21/2807 the final conductor layer next to the insulator being Si or Ge or C and their alloys except Si
• CPC Class Codes: H01L 21/28079 the final conductor layer next to the insulator being a single metal, e.g. Ta, W, Mo, Al
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence
• CPC Class Codes: H01L 21/7685 the layer covering a conductive structure H01L21/76849 takes precedence
• CPC Class Codes: H01L 21/76856 by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 21/76886 Modifying permanently or temporarily the pattern or the conductivity of conductive members, e.g. formation of alloys, reduction of contact resistances
• CPC Class Codes: H01L 21/76888 By rendering at least a portion of the conductor non conductive, e.g. oxidation

Abstract

In one aspect, an apparatus may include a metal gate of a transistor. An etch stop layer may be selectively formed over the metal gate. The etch stop layer may include a metal compound. An insulating layer may be over the etch stop layer. A conductive structure may be included through the insulating layer to the metal gate. Methods of making such transistors are also disclosed.

Claims

1. An apparatus comprising:

a metal gate of a transistor;

an etch stop layer selectively over the metal gate, wherein the etch stop layer comprises a metal compound;

an insulating layer over the etch stop layer;

a conductive structure through the insulating layer to the metal gate.

2. The apparatus of claim 1, wherein the metal compound comprises a compound of a metal and one or more of oxygen, nitrogen, carbon, and boron.

3. The apparatus of claim 2, wherein the metal compound comprises an oxide of a metal, a nitride of a metal, a carbide of a metal, a boride of a metal, or a combination thereof.

4. The apparatus of claim 1, wherein the metal compound comprises a metal that is capable of forming a passivating oxide, a metal capable of forming a passivating nitride, a metal capable of forming a passivating carbide, or a combination thereof.

5. The apparatus of claim 1, wherein the metal comprises aluminum, chromium, molybdenum, nickel, titanium, tungsten, tantalum, or a combination thereof.

6. The apparatus of claim 1, wherein a thickness of the etch stop layer ranges from 5 to 50 nanometers.

7. The apparatus of claim 1, wherein the metal compound comprises a metal that is the same as a metal of a top surface of the metal gate.

8. The apparatus of claim 1, wherein the etch stop layer has a bottom surface that extends below a top surface of a sidewall spacer of the metal gate.

9. The apparatus of claim 1, wherein the metal compound comprises a metal tat is different than a metal of a top surface of the metal gate.

10. The apparatus of claim 1, wherein the etch stop layer has a bottom surface that is substantially aligned with a top surface of a sidewall spacer of the metal gate, and wherein the etch stop layer has a top surface that extends above the top surface of the sidewall spacer.

11. The apparatus of claim 1, omitting a blanket deposited etch stop layer over a top surface of an insulating layer in which the metal gate is disposed.

12-20. -20. (canceled)

21. An apparatus comprising:

a metal gate of a transistor;

an etch stop layer directly on the metal gate, wherein the etch stop layer comprises an oxide of a metal, a nitride of a metal, a carbide of a metal, or a combination thereof.

22. The apparatus of claim 21, wherein the metal is the same as a metal of a top surface of the metal gate.

23. The apparatus of claim 21, wherein the metal is different than a metal of a top surface of the metal gate.