Process of forming an electronic device including forming a gate electrode layer and forming a patterned masking layer

• US 7,737,018 B2
• Filed: 02/06/2007
• Issued: 06/15/2010
• Est. Priority Date: 02/06/2007
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Mathew, Leo, Trivedi, Vishal P., Thean, Voon-Yew
• Primary Examiner(s): CHAUDHARI, CHANDRA P
• Application Number:
  US11/671,748
• Publication Number:
  US 20080188067A1
• Time in Patent Office: 1,225 Days
• Field of Search: 438/551, 438/552, 438/592, 438/657, 438/923, 257/E21.2
• US Class Current: 438/592
• CPC Class Codes: H01L 21/2652 Through-implantation
• CPC Class Codes: H01L 21/28123 Lithography-related aspects, e.g. sub-lithography lengths; Isolation-related aspects, e.g. to solve problems arising at the crossing with the side of the device isolation; Planarisation aspects
• CPC Class Codes: H01L 21/32139 using masks
• CPC Class Codes: H01L 29/4966 the conductor material next to the insulator being a composite material, e.g. organic material, TiN, MoSi2 H01L29/4908, H01L29/4983 take precedence

Abstract

A process of forming an electronic device can include forming a gate electrode layer and forming a patterned masking layer. In a first aspect, a process operation is performed before removing substantially all of a lower portion of the gate electrode layer. In a second aspect, a gate dielectric layer is formed prior to forming the gate electrode layer, and a portion of the gate dielectric layer is exposed after removing the patterned masking layer and prior to forming another masking layer. A portion of the gate electrode layer remains covered during a process where some or all of the portion would be otherwise removed or consumed. By forming the electronic device using such a process, damage to the gate electrode structure while performing subsequent processing can be significantly reduced.

Claims

1. A process of forming an electronic device comprising:

forming a gate electrode layer over a substrate, wherein forming the gate electrode layer includes;

forming a first electrode layer over the substrate and having a first composition and a first thickness; and

forming a second electrode layer after forming the first electrode layer and having a second composition different from the first composition and having a second thickness greater than the first thickness;

forming a patterned masking layer including a masking member and an opening, wherein;

the masking member overlies a first region of the substrate; and

the opening overlies a second region of the substrate;

removing an upper portion of the gate electrode layer to form a lower portion of the gate electrode layer overlying the second region of the substrate that includes the first electrode layer and a remaining portion of the second electrode layer, wherein the lower portion of the gate electrode layer has a third thickness greater than the first thickness;

performing a process operation other than removing substantially all of the lower portion of the gate electrode layer; and

removing substantially all of the lower portion of the gate electrode layer overlying the second region of the substrate to form a gate electrode overlying the first region of the substrate, wherein removing substantially all of the lower portion of the gate electrode layer is performed after performing the process operation.

2. The process of claim 1, wherein:

the first electrode layer includes a metal-containing material; and

the second electrode layer includes a semiconductor material.

3. The process of claim 2, wherein the first electrode layer sets the work function of the subsequently formed gate electrode.

4. The process of claim 2, wherein performing the process operation includes forming another layer, removing another layer, introducing a dopant, or any combination thereof.

5. The process of claim 2, wherein forming the patterned masking layer is performed using a lithographic process capable of printing a feature at a resolution limit, wherein:

the masking member has a width as least as wide as the resolution limit; and

the gate electrode corresponding with the masking member has a width less than the resolution limit.

6. The process of claim 2, wherein performing the process operation includes ion implanting through the remaining portion of the second electrode layer.

7. The process of claim 6, wherein ion implanting through the remaining portion includes performing a source/drain implant and an extension implant at substantially a same time.

8. The process of claim 1, wherein performing the process operation includes:

reacting a surface of the second electrode layer to form a surface layer; and

removing the surface layer.

9. The process of claim 8, wherein reacting the surface of the second electrode layer includes forming an oxide, forming a nitride, forming an oxynitride, or any combination thereof.

10. The process of claim 8, wherein reacting the surface of the second electrode layer includes exposing the second electrode layer to steam.

11. The process of claim 8, wherein after removing the upper portion of the gate electrode layer, the gate electrode layer includes an electrode portion overlying the first region of the substrate, wherein the electrode portion includes a wall having a first roughness prior to reacting the surface of the second electrode layer and a second roughness after removing the surface layer, and the second roughness is less than the first roughness.

12. A process of forming an electronic device comprising:

forming a gate dielectric layer over a substrate;

forming a gate electrode layer over the gate dielectric layer, wherein forming the gate electrode layer comprises;

forming a metal-containing electrode layer on the gate dielectric layer; and

forming a semiconductor layer over the metal-containing layer, wherein the semiconductor layer includes an end-point marker;

forming a patterned masking layer, wherein an exposed portion of the gate electrode layer lies within an opening in the patterned masking layer;

etching the exposed portion of the gate electrode layer, wherein etching the exposed portion of the gate electrode layer includes;

exposing the end-point marker;

detecting the exposed end-point marker;

generating a control signal in response to detecting the exposed end-point marker; and

ending etching the exposed portion of the gate electrode layer in response to the control signal;

removing the patterned masking layer after etching the exposed portion of the gate electrode layer and before exposing the gate dielectric layer; and

exposing a portion of the metal-containing electrode layer after removing the patterned masking layer;

exposing a portion of the gate dielectric layer before forming another patterned masking layer, wherein exposing the portion of the gate dielectric layer is performed after exposing the portion of the metal-containing electrode layer.

13. The process of claim 12, wherein removing the patterned masking layer includes removing a hard mask layer, removing an anti-reflective coating layer, removing a resist layer, or any combination thereof.

14. The process of claim 12, wherein forming the gate dielectric layer includes forming the gate dielectric layer having a dielectric constant greater than 8.0.

15. The process of claim 12, wherein etching the exposed portion of the gate electrode layer is performed using a timed etch process.

16. A process of forming an electronic device comprising:

forming a gate dielectric layer over a substrate;

forming a metal-containing layer on the gate dielectric layer, wherein the metal-containing layer has a first thickness;

forming a semiconductor layer over the substrate after forming the metal-containing layer, wherein the semiconductor layer has a second thickness greater than the first thickness;

forming a patterned masking layer including a masking member and an opening, wherein;

the masking member overlies a first region of the substrate; and

the opening overlies a second region of the substrate, and an exposed portion of the semiconductor layer lies between the opening and the substrate;

removing most of the exposed portion of the semiconductor layer to form a remaining portion of the semiconductor layer overlying the second region of the substrate, wherein substantially all of the metal-containing layer remains covered by the semiconductor layer;

removing the patterned masking layer;

oxidizing the remaining portion of the semiconductor layer to form a surface layer, wherein oxidizing the semiconductor layer is performed using steam;

introducing a dopant through the metal-containing layer and into the substrate;

removing the surface layer; and

removing remaining portions of the semiconductor layer and the metal-containing layer overlying the second region of the substrate to form a gate electrode over the first region of the substrate, wherein the gate electrode includes the metal-containing layer and the semiconductor layer.

17. The process of claim 16, wherein:

removing most of the exposed portion of the semiconductor layer is performed such that the remaining portion of the semiconductor layer has, from a cross-sectional view, a curved taper; and

introducing the dopant is performed such that an extension region and a source/drain region is formed within the second region of the substrate, wherein the extension region is covered by the curved taper of the semiconductor layer, and a source/drain region lies away from the curved taper.

18. The process of claim 16, wherein:

after removing most of the exposed portion of the semiconductor layer, the semiconductor layer includes a wall having a first roughness; and

after removing the surface layer, the wall has a second roughness less than the first roughness.

19. The process of claim 16, wherein the metal-containing layer includes platinum, palladium, iridium, molybdenum, osmium, ruthenium, rhenium, tantalum, titanium or any combination thereof.

20. The process of claim 16, wherein the metal-containing layer includes a material that dissolves in an acidic or a peroxide solution.