Capacitor and semiconductor device including dielectric and N-type semiconductor

• US 8,513,773 B2
• Filed: 01/09/2012
• Issued: 08/20/2013
• Est. Priority Date: 02/02/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Takemura, Yasuhiko
• Primary Examiner(s): Soward, Ida M
• Application Number:
  US13/346,172
• Publication Number:
  US 20120193759A1
• Time in Patent Office: 589 Days
• Field of Search: 257/300, 257/407, 257/E27.042, 257/532
• US Class Current: 257/532
• CPC Class Codes: H01L 21/84 the substrate being other than a semiconductor body, e.g. being an insulating body
• CPC Class Codes: H01L 27/0207 Geometrical layout of the components, e.g. computer aided design; custom LSI, semi-custom LSI, standard cell technique
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H01L 27/1207 combined with devices in contact with the semiconductor body, i.e. bulk/SOI hybrid circuits
• CPC Class Codes: H01L 28/91 made by depositing layers, e.g. by depositing alternating conductive and insulating layers
• CPC Class Codes: H10B 12/033 the capacitor extending over the transistor
• CPC Class Codes: H10B 12/05 Making the transistor
• CPC Class Codes: H10B 12/482 Bit lines
• CPC Class Codes: H10B 41/20 characterised by three-dimensional arrangements, e.g. with cells on different height levels
• CPC Class Codes: H10B 41/70 the floating gate being an electrode shared by two or more components

Abstract

A capacitor that has an electrode of an n-type semiconductor that is provided in contact with one surface of a dielectric, has a work function of 5.0 eV or higher, preferably 5.5 eV or higher, and includes nitrogen and at least one of indium, tin, and zinc. Since the electrode has a high work function, the dielectric can have a high potential barrier, and thus even when the dielectric is as thin as 10 nm or less, a sufficient insulating property can be maintained. In particular, a striking effect can be obtained when the dielectric is formed of a high-k material.

Claims

1. A capacitor comprising:

a dielectric; and

an n-type semiconductor provided in contact with one surface of the dielectric,

wherein the n-type semiconductor includes nitrogen and at least one of indium, tin, and zinc, and

wherein the n-type semiconductor has a work function of 5.0 eV or higher.

2. The capacitor according to claim 1, wherein the n-type semiconductor has a work function of 5.5 eV or higher.

3. The capacitor according to claim 1, wherein the dielectric includes at least one material selected from the group consisting of strontium titanate, lead titanate, barium strontium titanate, lead zirconate, barium zirconate, tantalum oxide, strontium bismuth titanate, titanium oxide, zirconium oxide, hafnium oxide, aluminum oxide, yttrium oxide, lanthanum oxide, zirconium silicate, and hafnium silicate.

4. The capacitor according to claim 1, wherein the dielectric is an oxide of at least one metal selected from the group consisting of strontium, titanium, barium, zirconium, lead, tantalum, bismuth, hafnium, aluminum, yttrium, and lanthanum, which is included at 50% or higher of metal elements constituting the dielectric.

5. The capacitor according to claim 1, wherein the thickness of the n-type semiconductor is from 4 nm to 10 nm.

6. The capacitor according to claim 1, wherein the n-type semiconductor includes nitrogen at a concentration of from 5 at. % to 50 at. %.

7. A semiconductor device comprising:

a dielectric;

an n-type semiconductor provided in contact with one surface of the dielectric; and

a conductive material provided on another surface of the dielectric opposite to the n-type semiconductor,

wherein the n-type semiconductor includes nitrogen and at least one of indium, tin, and zinc, and

wherein the n-type semiconductor has a work function of 5.0 eV or higher.

8. The semiconductor device according to claim 7, wherein the n-type semiconductor has a work function of 5.5 eV or higher.

9. The semiconductor device according to claim 7, wherein the dielectric includes at least one material selected from the group consisting of strontium titanate, lead titanate, barium strontium titanate, lead zirconate, barium zirconate, tantalum oxide, strontium bismuth titanate, titanium oxide, zirconium oxide, hafnium oxide, aluminum oxide, yttrium oxide, lanthanum oxide, zirconium silicate, and hafnium silicate.

10. The semiconductor device according to claim 7, wherein the dielectric is an oxide of at least one metal selected from the group consisting of strontium, titanium, barium, zirconium, lead, tantalum, bismuth, hafnium, aluminum, yttrium, and lanthanum, which is included at 50% or higher of metal elements constituting the dielectric.

11. The semiconductor device according to claim 7, wherein the thickness of the n-type semiconductor is from 4 nm to 10 nm.

12. The semiconductor device according to claim 7, wherein the n-type semiconductor includes nitrogen at a concentration of from 5 at. % to 50 at. %.

13. A semiconductor device comprising:

an insulator;

an n-type semiconductor film provided on a side surface of the insulator; and

a dielectric film formed over the n-type semiconductor film,

wherein the n-type semiconductor film includes nitrogen and at least one of indium, tin, and zinc, and

wherein the n-type semiconductor film has a work function of 5.0 eV or higher.

14. The semiconductor device according to claim 13, wherein the n-type semiconductor film has a work function of 5.5 eV or higher.

15. The semiconductor device according to claim 13, wherein the dielectric film includes at least one material selected from the group consisting of strontium titanate, lead titanate, barium strontium titanate, lead zirconate, barium zirconate, tantalum oxide, strontium bismuth titanate, titanium oxide, zirconium oxide, hafnium oxide, aluminum oxide, yttrium oxide, lanthanum oxide, zirconium silicate, and hafnium silicate.

16. The semiconductor device according to claim 13, wherein the dielectric film is an oxide of at least one metal selected from the group consisting of strontium, titanium, barium, zirconium, lead, tantalum, bismuth, hafnium, aluminum, yttrium, and lanthanum, which is included at 50% or higher of metal elements constituting the dielectric film.

17. The semiconductor device according to claim 13, wherein the thickness of the n-type semiconductor film is from 4 nm to 10 nm.

18. The semiconductor device according to claim 13, wherein the n-type semiconductor film includes nitrogen at a concentration of from 5 at. % to 50 at. %.