Nonvolatile semiconductor memory device and manufacturing method thereof, semiconductor device and manufacturing method thereof, and manufacturing method of insulating film

• US 7,955,995 B2
• Filed: 05/18/2007
• Issued: 06/07/2011
• Est. Priority Date: 05/26/2006
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kakehata, Tetsuya, Tanaka, Tetsuhiro, Asami, Yoshinobu
• Primary Examiner(s): CHAN, CANDICE
• Application Number:
  US11/802,093
• Publication Number:
  US 20080290393A1
• Time in Patent Office: 1,481 Days
• Field of Search: 438/795, 438/798
• US Class Current: 438/795
• 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 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/02183 the material containing tantalum, e.g. Ta2O5
• CPC Class Codes: H01L 21/0223 formation by oxidation, e.g. oxidation of the substrate
• CPC Class Codes: H01L 21/02255 formation by thermal treatment H01L21/02252 takes precedence; after treatment of an insulating film H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/02266 deposition by physical ablation of a target, e.g. sputtering, reactive sputtering, physical vapour deposition or pulsed laser deposition
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/3143 composed of alternated layers or of mixtures of nitrides and oxides or of oxinitrides, e.g. formation of oxinitride by oxidation of nitride layers
• CPC Class Codes: H01L 21/31612 on a silicon body
• CPC Class Codes: H01L 21/31637 Deposition of Tantalum oxides, e.g. Ta2O5
• CPC Class Codes: H01L 21/31645 Deposition of Hafnium oxides, e.g. HfO2
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66825 with a floating gate H01L29/6684 takes precedence
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• CPC Class Codes: H01L 29/7881 Programmable transistors with only two possible levels of programmation H01L29/7888 takes precedence
• CPC Class Codes: H10B 41/30 characterised by the memory core region
• CPC Class Codes: H10B 69/00 : Erasable-and-programmable ROM [EPROM] devices not provided for in groups H10B41/00 - H10B63/00, e.g. ultraviolet erasable-and-programmable ROM [UVEPROM] devices

Abstract

An object is to provide a technique to manufacture an insulating film having excellent film characteristics. In particular, an object is to provide a technique to manufacture a dense insulating film with a high withstand voltage. Moreover, an object is to provide a technique to manufacture an insulating film with few electron traps. An insulating film including oxygen is subjected to plasma treatment using a high frequency under the conditions where the electron density is 1×10¹¹ cm⁻³ or more and the electron temperature is 1.5 eV or less in an atmosphere including oxygen.

Claims

1. A method for manufacturing a nonvolatile semiconductor memory device comprising:

forming a semiconductor region;

forming a first insulating film including hydrogen over and in contact with the semiconductor region;

reducing a hydrogen content of the first insulating film by performing plasma treatment on the first insulating film in an atmosphere including oxygen;

forming a floating gate electrode over the first insulating film;

forming a second insulating film over the floating gate electrode;

forming a control gate electrode over the second insulating film; and

adding an impurity element to the semiconductor region.

2. The method for manufacturing the nonvolatile semiconductor memory device according to claim 1, further comprising:

performing plasma treatment on the second insulating film in an atmosphere including oxygen.

3. The method for manufacturing the nonvolatile semiconductor memory device according to claim 1, wherein plasma is excited by microwave.

4. The method for manufacturing the nonvolatile semiconductor memory device according to claim 2, wherein the first insulating film has a hydrogen concentration of 5×

10¹⁹ atoms/cm³ or less by a secondary ion mass spectrometry after reducing the hydrogen content and the second insulating film has a hydrogen concentration of 5×

10¹⁹ atoms/cm³ or less by a secondary ion mass spectrometry after performing plasma treatment.

5. The method for manufacturing the nonvolatile semiconductor memory device according to claim 1, wherein each of the first insulating film and the second insulating film is formed by a method selected from the group consisting of a CVD method, a sputtering method, and a thermal oxidation method.

6. The method for manufacturing the nonvolatile semiconductor memory device according to claim 1, wherein each of the first insulating film and the second insulating film comprises a material selected from the group consisting of a silicon oxide, silicon oxynitride, silicon nitride oxide, aluminum oxide, tantalum oxide, and hafnium oxide.

7. The method for manufacturing the nonvolatile semiconductor memory device according to claim 1, wherein the atmosphere including oxygen further includes a noble gas.

8. A method for manufacturing a semiconductor device comprising:

forming a semiconductor region;

forming a gate insulating film including hydrogen over and in contact with the semiconductor region;

reducing a hydrogen content of the gate insulating film by performing plasma treatment on the gate insulating film in an atmosphere including oxygen;

forming a gate electrode over the gate insulating film; and

adding an impurity element to the semiconductor region.

9. The method for manufacturing the semiconductor device according to claim 8, wherein plasma is excited by microwave.

10. The method for manufacturing the semiconductor device according to claim 8, wherein the gate insulating film has a hydrogen concentration of 5×

10¹⁹ atoms/cm³ or less by a secondary ion mass spectrometry after reducing the hydrogen content.

11. The method for manufacturing the semiconductor device according to claim 8, wherein the gate insulating film is formed by a method selected from the group consisting of a CVD method, a sputtering method, and a thermal oxidation method.

12. The method for manufacturing the semiconductor device according to claim 8, wherein the gate insulating film comprises a material selected from the group consisting of a silicon oxide, silicon oxynitride, silicon nitride oxide, aluminum oxide, tantalum oxide, and hafnium oxide.

13. The method for manufacturing the semiconductor device according to claim 8, wherein the atmosphere including oxygen further includes a noble gas.