Plasma surface treatment system and plasma surface treatment method

• US 20040259380A1
• Filed: 03/17/2004
• Published: 12/23/2004
• Est. Priority Date: 03/26/2003
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Samukawa, Seiji, Fukuda, Seiichi
• Granted Patent: US 7,000,565 B2
• Time in Patent Office: Days
• US Class Current: 438/776
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• 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 21/28185 with a treatment, e.g. annealing, after the formation of the gate insulator and before the formation of the definitive gate conductor
• 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

Abstract

A plasma surface treatment system for irradiating a surface of a substrate to be treated with a nitrogen plasma excited by a high-frequency electric field to introduce nitrogen into the surface of the substrate comprises a pulse modulator for pulse modulation of the high-frequency electric field. By applying the high-frequency electric field in a pulsed form, it is possible to realize a nitriding by which the peak of nitrogen concentration is located at a shallower position and a desired nitrogen concentration can be obtained.

Claims

1. A plasma surface treatment system for irradiating a surface of a substrate to be treated with a nitrogen plasma excited by a high-frequency electric field to introduce nitrogen into said surface of said substrate, wherein

said system comprises a pulse modulator for pulse modulation of said high-frequency electric field.

2. A plasma surface treatment system as set forth in claim 1, wherein

said pulse modulator is a pulse modulator capable of controlling the high-frequency electric field application time at the time of pulse modulation of said high-frequency electric field.

3. A plasma surface treatment system as set forth in claim 1, wherein

said pulse modulator is a pulse modulator capable of controlling the high-frequency electric field stop time at the time of pulse modulation of said high-frequency electric field.

4. A plasma surface treatment system as set forth in claim 1, wherein

an electrode having apertures for mitigating vacuum ultraviolet rays is provided between said nitrogen plasma excited by said high-frequency electric field and said substrate to be treated.

5. A plasma surface treatment method for irradiating a surface of a substrate to be treated with a nitrogen plasma excited by a high-frequency electric field to introduce nitrogen into said surface of said substrate, wherein

a high-frequency electric field undergoing pulse modulation is used as said high-frequency electric field.

6. A plasma surface treatment method as set forth in claim 5, wherein

the high-frequency electric field application time is controlled at the time of pulse modulation of said high-frequency electric field.

7. A plasma surface treatment method as set forth in claim 5, wherein

the high-frequency electric field stop time is controlled at the time of pulse modulation of said high-frequency electric field.

8. A plasma surface treatment method as set forth in claim 5, wherein

nitrogen atomic and molecular ions accelerated from said nitrogen plasma excited by said high-frequency electric field are implanted into said surface of said substrate to be treated through an electrode having apertures.

9. A plasma surface treatment method as set forth in claim 5, wherein

the discharge sustention time at the time of pulse modulation of said high-frequency electric field is in the range of from 5 to 50 μ

sec.

10. A plasma surface treatment method as set forth in claim 5, wherein

the duty ratio at the time of pulse modulation of said high-frequency electric field is in the range of from 5 to 50%.