Material for electronic device and process for producing the same

• US 7,560,396 B2
• Filed: 03/31/2003
• Issued: 07/14/2009
• Est. Priority Date: 03/29/2002
• Status: Expired due to Fees

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Sasaki, Masaru, Ozaki, Shigenori, Sugawara, Takuya
• Primary Examiner(s): Lindsay, Jr.; Walter L
• Assistant Examiner(s): Lee; Cheung
• Application Number:
  US10/509,662
• Publication Number:
  US 20060046503A1
• Time in Patent Office: 2,297 Days
• Field of Search: 438/776, 438/777, 438/513, 257/E21.302
• US Class Current: 438/786
• CPC Class Codes: H01L 21/0214 the material being a silicon oxynitride, e.g. SiON or SiON:H
• 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 21/02332 into an oxide layer, e.g. changing SiO to SiON
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/28202 in a nitrogen-containing ambient, e.g. nitride deposition, growth, oxynitridation, NH3 nitridation, N2O oxidation, thermal nitridation, RTN, plasma nitridation, RPN
• CPC Class Codes: H01L 21/3144 on silicon
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material

Abstract

An electronic device material comprising at least an electronic device substrate and a silicon oxynitride film disposed on the substrate is provided. The silicon oxynitride film is characterized by containing nitrogen atoms in a large amount in the vicinity of the oxynitride film surface when the nitrogen content distribution in the thickness direction of the silicon oxynitride film is examined by SIMS (secondary ion mass spectrometry) analysis. By virtue of this constitution, an electronic device material comprising an oxynitride film having an excellent effect of preventing penetration of boron and having excellent gate leak properties can be obtained.

Claims

1. A process for treating a substrate by plasma nitridation, comprising:

providing the substrate having an oxide film thereon; and

irradiating plasma having an electron temperature of 0.5 to 2.0 eV on the oxide film using a mixed gas comprising argon gas and nitrogen gas to form an oxynitride film, wherein

the plasma is irradiated on the oxide film at a temperature of 250 to 500°

C. and under a pressure of 7 to 260 Pa,

a nitrogen atom content in the oxynitride film has a distribution such that the maximum value Ns of the nitrogen atom content in the oxynitride film at a surface of the oxynitride film opposite a surface facing the substrate is 10 to 40 atomic percent, and the maximum value Nb of the nitrogen atom content in the oxynitride film at the surface facing the substrate side is 0 to 10 atomic percent,

the ratio Ns/Nb is 2 or more, and

the oxynitride film has an electrical film thickness from 1.0 to 2.5 nm.

2. A process according to claim 1, wherein the plasma is generated using microwave irradiation by using a plane antenna member having a plurality of slots.

3. A process according to claim 1, wherein the oxide film is formed by plasma processing or thermal oxidation.

4. A process for treating a substrate by plasma nitridation, comprising:

forming an oxide film on the substrate; and

irradiating plasma on the oxide film using a mixed gas comprising argon gas and nitrogen gas to form an oxynitride film, wherein

the plasma is irradiated on the oxide film at a temperature of 250 to 500°

C. and under a pressure of 7 to 260 Pa,

a nitrogen atom content in the oxynitride film has a distribution such that the maximum value Ns of the nitrogen atom content in the oxynitride film at a surface of the oxynitride film opposite a surface facing the substrate is 10 to 40 atomic percent, and the maximum value Nb of the nitrogen atom content in the oxynitride film at the surface facing the substrate side is 0 to 10 atomic percent,

the ratio Ns/Nb is 2 or more, and

the oxynitride film has an electrical film thickness from 1.0 to 2.5 nm.

5. A process according to claim 4, wherein the plasma is generated using microwave irradiation by using a plane antenna member having a plurality of slots.

6. A process according to claim 4, wherein the ratio Ns/Nb is 4 or more.

7. A process for forming a gate oxynitride film, comprising:

providing a substrate having an oxide film thereon; and

irradiating plasma having density of 1×

10¹⁰ to 5×

10¹²/cm³ and an electron temperature of 0.5 to 2.0 eV on the oxide film using a mixed gas comprising argon gas and nitrogen gas to form the oxynitride film, wherein

the plasma is irradiated on the oxide film at a temperature of 250 to 500°

C. and under a pressure of 7 to 260 Pa,

a nitrogen atom content in the oxynitride film has a distribution such that the maximum value Ns of the nitrogen atom content in the oxynitride film at a surface of the oxynitride film opposite a surface facing the substrate is 10 to 40 atomic percent, and the maximum value Nb of the nitrogen atom content in the oxynitride film at the surface facing the substrate side is 0 to 10 atomic percent,

the ratio Ns/Nb is 2 or more, and

the oxynitride film has an electrical film thickness from 1.0 to 2.5 nm.

8. A process according to claim 7, wherein the plasma is generated using microwave irradiation by using a plane antenna member having a plurality of slots.