Plasma processing system and surface processing method

• US 20030066487A1
• Filed: 09/30/2002
• Published: 04/10/2003
• Est. Priority Date: 09/28/2001
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Suzuki, Nobumasa
• Granted Patent: US 6,884,318 B2
• Time in Patent Office: Days
• US Class Current: 118/723MW
• CPC Class Codes: C23C 16/511 using microwave discharges
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• 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 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/31612 on a silicon body
• CPC Class Codes: H01L 21/3185 of siliconnitrides
• CPC Class Codes: H01L 21/67069 for drying etching

Abstract

To provide a plasma processing system capable of introducing a uniform microwave into a plasma processing chamber irrespective of conditions, and a surface processing method using the same. A plasma processing system in which air in a plasma processing chamber is exhausted by an exhaust unit, a microwave is supplied to the plasma processing chamber through an annular waveguide which is bored to be provided at predetermined intervals in a circumferential direction on the same plane facing a surface to be processed of an object to be processed on the plasma processing chamber side to generate plasma within the plasma processing chamber, wherein the annular waveguide is separated into two layers of an input side waveguide and an output side waveguide, and the slots are bored to be provided between these waveguides at predetermined intervals in a circumferential direction.

Claims

1. A plasma processing system in which gas is introduced into a plasma processing chamber, and a microwave is supplied to said plasma processing chamber through an annular waveguide having a plurality of slots provided at predetermined intervals in a circumferential direction on the same plane facing a surface to be processed of an object to be processed on the plasma processing chamber side to generate the plasma within said plasma processing chamber,

wherein said annular waveguide includes an input side waveguide and an output side waveguide, and said slots are bored to be provided between said waveguides at predetermined intervals in a circumferential direction.

2. A plasma processing system according to claim 1, wherein the microwave is introduced through introduction ports which are provided at predetermined intervals in a circumferential direction with a center of said annular waveguide as an axis into said input side waveguide.

3. A plasma processing system according to claim 2, wherein the distributed microwaves are introduced through said introduction ports, and the microwave is distributed by an H distributor when one circumferential length of said input side waveguide is odd number multiples of the wavelength inside the waveguide of the microwave, while the microwave is distributed by an E distributor when one circumferential length of said input side waveguide is even number multiples of the waveguide inside the waveguide of the microwave, and each of the predetermined intervals at which said introduction ports are provided is 180 degrees.

4. A plasma processing system according to any one of claims 1 to 3, wherein the microwave to be introduced into said input side waveguide is introduced through a rectangular waveguide, and an inner cross section of said input side waveguide is the same dimensions as those of said rectangular waveguide.

5. A plasma processing system according to claim 1, wherein said slots provided between said waveguides two by two are provided radially and when the central radii of said waveguides are respectively r_g2 and r_g1, the central radius r_s2 of each of said slots is expressed by the following approximate expression:

r_s2≡

(r_g2+r_g1)/2

6. A plasma processing system according to claim 1, wherein the central radius r_g1 of said output side waveguide is substantially equal to the central radius r_s1 of each of said slots provided on the side of said plasma processing chamber, and when the number of loops of a surface standing wave excited between the adjacent slots two by two is n_l, the wavelength of the surface wave is λ

_s, and the magnification of one circumferential length of said output side waveguide to the wavelength inside the waveguide of the microwave in said output side waveguide is ng, the central radius rgg1 is expressed by the following approximate expression;

r_g1≅

n₁λ

_s/2 tan[(π

/2n_g)][1+cos(π

/n_g)]

7. A plasma processing system according to claim 1, wherein when the wavelength inside the waveguide in said output side waveguide is λ

g1, the length ls1 of each of said slots between said waveguides is expressed by the following approximate expression;

Isl≅

λ

_g1/4

8. A plasma processing system according to claim 1, wherein a dielectric window is provided between said annular waveguide and said plasma processing chamber, and the main constituent of said dielectric window is aluminum nitride.

9. A plasma processing system according to claim 1, further comprising high-frequency bias applying means for applying a high frequency bias to substrate supporting means for supporting said object to be processed within said plasma processing chamber.

10. A surface processing method of processing the surface to be processed of said object to be processed, which uses said plasma processing system as defined in claim 1.

11. A surface processing method according to claim 10, wherein the surface processing is any one of etching, ashing, CVD, doping, oxidation and nitriding processing.

12. A manufacturing method of an element comprising surface processing of the surface to be processed of said object to be processed for forming the element using said plasma processing system as defined in claim 1.

13. A manufacturing method of an element according to claim 10, wherein the surface processing is any one of etching, ashing, CVD, doping, oxidation and nitriding processing.