Angled implantation for removal of thin film layers

• US 20090057788A1
• Filed: 10/24/2008
• Published: 03/05/2009
• Est. Priority Date: 12/01/2005
• Status: Abandoned Application

• Current Assignee: Jack Kavalieros, Justin K. Brask, Justin S. Sandford, Matthew V. Metz, Michael L. Hattendorf
• Original Assignee: Jack Kavalieros, Justin K. Brask, Justin S. Sandford, Matthew V. Metz, Michael L. Hattendorf
• Inventors: Kavalieros, Jack, Brask, Justin K., Metz, Matthew V., Hattendorf, Michael L., Sandford, Justin S.
• Application Number:
  US12/288,944
• Publication Number:
  US 20090057788A1
• Time in Patent Office: Days
• US Class Current: 257/412
• CPC Class Codes: H01L 21/26586 characterised by the angle between the ion beam and the crystal planes or the main crystal surface
• CPC Class Codes: H01L 21/28114 characterised by the sectional shape, e.g. T, inverted-T
• CPC Class Codes: H01L 21/31111 by chemical means
• CPC Class Codes: H01L 21/31155 by ion implantation
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• CPC Class Codes: H01L 29/42376 characterised by the length or the sectional shape
• CPC Class Codes: H01L 29/495 the conductor material next to the insulator being a simple metal, e.g. W, Mo H01L29/4908, H01L29/4983 take precedence
• CPC Class Codes: H01L 29/4958 with a multiple layer structure
• 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
• 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: H01L 29/66545 using a dummy, i.e. replacement gate in a process wherein at least a part of the final gate is self aligned to the dummy gate

Abstract

Embodiments of the invention provide a device with a reverse-tapered gate electrode and a gate dielectric layer with a length close to that of the gate length. In an embodiment, this may be done by altering portions of a blanket dielectric layer with one or more angled ion implants, then removing the altered portions of the blanket dielectric layer.

Claims

1. A semiconductor device, comprising:

a substrate;

a gate dielectric layer on the substrate, the gate dielectric layer having a length;

a gate electrode on the gate dielectric layer, the gate electrode having a gate length adjacent the gate dielectric layer, the gate electrode having reverse-tapered sidewalls so the gate electrode has an intermediate length further from the gate dielectric layer than the gate length, the intermediate length being greater than the gate length; and

wherein the length of the gate dielectric layer is between about 120% and about 85% of the gate length.

2. The device of claim 1, wherein at least a portion of the gate electrode sidewalls has a sidewall angle between the gate electrode sidewalls and a top surface of the substrate, the sidewall angle being between about eighty-five degrees and about seventy-five degrees.

3. The device of claim 1, wherein the gate electrode includes a work function metal gate layer comprising a first metal and a second metal gate layer comprising a second metal different than the first metal on the work function metal gate layer.

4. The device of claim 3, wherein the work function metal gate layer is conformal to the bottom and sidewalls and has a thickness between about 50 angstroms and about 100 angstroms.

5. The device of claim 1, wherein the length of the gate dielectric layer is between about 105% and about 97% of the gate length.

6. The device of claim 1, wherein the gate length is between about 18 nanometers and about 22 nanometers and the length of the gate dielectric layer is between about 23.2 nanometers and about 17.4 nanometers.

7. The device of claim 1, wherein the gate dielectric layer has a footing less than or equal to about six angstroms on each side.

8. The device of claim 1, wherein the gate dielectric layer has an undercut less than or equal to about three angstroms on each side.