Dielectric film, its formation method, semiconductor device using the dielectric film and its production method

• US 20040113227A1
• Filed: 12/02/2003
• Published: 06/17/2004
• Est. Priority Date: 12/03/2002
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Ekisho Sentan Gijutsu Kaihatsu Center
• Original Assignee: Kabushiki Kaisha Ekisho Sentan Gijutsu Kaihatsu Center
• Inventors: Okamoto, Tetsuya, Azuma, Kazufumi, Goto, Masashi, Nakata, Yukihiko
• Application Number:
  US10/726,870
• Publication Number:
  US 20040113227A1
• Time in Patent Office: Days
• US Class Current: 257/506
• CPC Class Codes: H01L 21/0214 the material being a silicon oxynitride, e.g. SiON or SiON:H
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02238 silicon in uncombined form, i.e. pure silicon
• CPC Class Codes: H01L 21/02247 formation by nitridation, e.g. nitridation of the substrate
• CPC Class Codes: H01L 21/02252 formation by plasma treatment, e.g. plasma oxidation of the substrate after treatment of an insulating film by plasma H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/31662 of silicon in uncombined form
• CPC Class Codes: H01L 21/3185 of siliconnitrides
• CPC Class Codes: H01L 21/32105 Oxidation of silicon-containing layers
• CPC Class Codes: H01L 21/3211 Nitridation of silicon-containing layers

Abstract

A high-quality dielectric film is formed by generating plasma of a high electron density by a method such as diluting a rare gas or raising a frequency of a power supplier, and generating oxygen atoms or nitrogen atoms of a high density. The dielectric film contains silicon oxide in which the composition ratio of silicon and oxygen is between (1:1.94) and (1:2) both inclusive, silicon nitride in which the composition ratio of silicon and nitrogen is between (1:1.94) and (1:2) both inclusive, or silicon oxynitride in which the composition ratio of silicon and nitrogen is between (3:3.84) and (3:4) both inclusive.

Claims

1. A dielectric film formed directly or indirectly on at least a part of a glass substrate or a plastic substrate, comprising silicon oxide in a part at least in the direction of the film thickness, the composition ratio of silicon and oxygen being between 1:

1.94 and 1;

2 both inclusive.

4. A dielectric film according to any one of claims 1 through 3, wherein a silicon layer or a silicon compound layer is formed directly or indirectly on at least a part of said glass substrate or said plastic substrate, and wherein said dielectric film is formed on at least a part of said silicon layer or said silicon compound layer.

5. A dielectric film according to any one of claims 1 through 3, wherein said plastic substrate is made of polyimide resin, polyetherketone resin, polyethersulfone resin, polyetherimide resin, polyethylenenaphthalate resin or polyester resin.

6. A method of forming a dielectric film according to any one of claims 1 through 3, comprising steps of preparing a substrate having in the surface of a silicon layer formed directly or indirectly at least on a part of said glass substrate or said plastic substrate;

and processing the surface of said silicon layer in plasma having an electron density 3×

10¹¹ cm<sup>−

3</sup> or over formed by exciting a gas composed of at least one element constituting said dielectric film.

7. A method of forming the dielectric film according to claim 6, wherein said gas is composed of an oxygen molecule, or a molecular nitrogen or an ammonia molecule.

8. A method of forming the dielectric film according to claim 6, wherein said gas further contains a gas composed of a rare gas element, and wherein the partial pressure of said gas composed of the rare gas element is 90% or over of the total pressure.

9. A method of forming a dielectric film according to claim 8, wherein said rare gas element is argon, or xenon or krypton.

10. A method of forming a dielectric film according to claim 6, wherein said gas is an oxygen molecule, said rare gas element is xenon, and the energy of a light generated from said plasma is 8.8 eV or less.

11. A method of forming a dielectric film according to claim 6, wherein a frequency of a power supplier for generating said plasma is 2.45 GHz or over.

12. A method of forming a dielectric film according to claim 6, wherein said glass substrate or said plastic substrate is heated at a temperature between 90°

C. and 400°

C. both inclusive.

2. A dielectric film formed directly or indirectly on at least a part of a glass substrate or a plastic substrate, comprising silicon nitride in a part at least in the direction of the film thickness, the composition ratio of silicon and nitrogen being between 3:

3.84 and 3;

4 both inclusive.

3. A dielectric film formed directly or indirectly on at least a part of a glass substrate or a plastic substrate, comprising silicon oxide in which the composition ratio of silicon and oxygen is between 1:

1.94 and 1;

2 both inclusive, or silicon oxynitride in which the composition ratio of silicon and nitrogen being between 3;

3.84 and 3;

4 both inclusive, in a part at least in the direction of the film thickness.

13. A semiconductor device having a dielectric film formed on at least a part of a silicon layer formed directly or indirectly on at least a part of a glass substrate or a plastic substrate, said dielectric film comprising silicon oxide in which the composition ratio of silicon and oxygen is between 1:

1.94 and 1;

2 both inclusive in a part at least in the direction of the film thickness.

16. A semiconductor device according to any one of claims 13 through 15, wherein said dielectric film constitues a part of a gate dielectric layer relative to the direction of the thickness of the gate dielectric layer.

17. A semiconductor device according to any one of claims 13 through 15, wherein said plastic substrate is made of polyimide resin, polyetheretherketone resin, polyethersulfone resin, polyetherimide resin, polyethylenenaphthalate resin or polyester resin.

18. A method of producing a semiconductor device according to any one of claims 13 through 15, comprising steps of:

preparing a substrate having a silicon layer formed directly or indirectly on at least a part of said glass substrate or said plastic substrate; and

processing the surface of said silicon layer in plasma having an electron density of 3×

10¹¹ cm<sup>−

3</sup> or over formed by exciting a gas composed of at least one element constituting said dielectric film.

19. A method of producing a semiconductor device according to claim 18, wherein said gas is composed of an oxygen molecule, or a molecular nitrogen or an ammonia molecule.

20. A method of producing the semiconductor device according to claim 18, wherein said gas further contains a gas composed of a rare gas element, and wherein the partial pressure of the rare gas element is 90% or over of the total pressure.

21. A method of producing the semiconductor device according to claim 20, wherein said rare gas element is argon, or xenon or krypton.

22. A method of producing a semiconductor device according to claim 20, wherein said gas is an oxygen molecule, said rare gas element is xenon, and the energy of a light generated from the plasma is 8.8 eV or less.

23. A method of producing the semiconductor device according to claim 18, wherein a frequency of a power supplier for generating said plasma is 2.45 GHz or over.

24. A method of producing the semiconductor device according to claim 18, wherein said glass substrate or said plastic substrate is heated at a temperature between 90°

C. and 400°

C., inclusive.

25. A method of producing the semiconductor device according to claim 18, wherein said dielectric film is a gate dielectric layer of a thin film transistor.

14. A semiconductor device having a dielectric film formed on at least a part of a silicon layer formed directly or indirectly on at least a part of a glass substrate or a plastic substrate, said dielectric film comprising silicon nitride in which the composition ratio of silicon and nitrogen is between 3:

3.84 and 3;

4 both inclusive in a part at least in the direction of the film thickness.

15. A semiconductor device having a dielectric film formed on at least a part of a silicon layer formed directly or indirectly on at least a part of a glass substrate or a plastic substrate, said dielectric film comprising silicon oxynitride having silicon oxide in which the composition ratio of silicon and oxygen is between 1:

1.94 and 1;

2 both inclusive in a part at least in the direction of the film thickness or silicon nitride in which the composition ratio of silicon and nitrogen is between 3;

3.84 and 3;

4 both inclusive in a part at least in the direction of the film thickness.