Shower plate having projections and plasma CVD apparatus using same

• US 20050183666A1
• Filed: 02/18/2005
• Published: 08/25/2005
• Est. Priority Date: 02/20/2004
• Status: Active Grant

• Current Assignee: ASM Japan K.K. (ASM International NV)
• Original Assignee: ASM Japan K.K. (ASM International NV)
• Inventors: Fukuda, Hideaki, Arai, Hiroki, Tsuji, Naoto, Morisada, Yoshinori, Kobayashi, Tamihiro
• Granted Patent: US 7,799,134 B2
• Time in Patent Office: Days
• US Class Current: 118/723.E
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/5096 Flat-bed apparatus
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/3244 Gas supply means

Abstract

A shower plate 122 has protrusions 22 formed on the front face used with a first electrode in a plasma CVD apparatus. A plane-surface portion 23 is left around apertures of gas inlet holes 21 formed in the shower plate 122. With protrusions 22 being formed, a surface area of the first electrode is increased.

Claims

1. A shower plate for plasma CVD comprising:

a base surface having multiple apertures for passing a gas therethrough; and

multiple protrusions each separately protruding from the base surface and being dispersed among the apertures.

2. The shower plate according to claim 1, wherein a surface area of the base surface and the protrusions is greater by at least 40% than a calculated surface area of the base surface if no protrusions are provided.

3. The shower plate according to claim 1, wherein a surface area when extending from the base surface and the protrusions by a sheath generated by plasma exposure is nearly or substantially equal to or greater than the surface area of the base surface and the protrusions.

4. The shower plate according to claim 1, wherein the base surface is constituted by a plane surface.

5. The shower plate according to claim 1, wherein the protrusions comprise multiple truncated pyramids, prismatic columns, cones, or cylindrical columns.

6. The shower plate according to claim 1, wherein the protrusions have an embankment shape.

7. The shower plate according to claim 1, wherein a width of each protrusion is larger than a diameter of each aperture.

8. The shower plate according to claim 1, wherein the width of each protrusion is about 1 mm or more and a distance between adjoining protrusions is about 2 mm or more.

9. The shower plate according to claim 5, wherein the number of the protrusions is more than half the number of the apertures.

12. A plasma CVD apparatus comprising:

a reaction chamber;

a showerhead provided in the chamber, which serves as an electrode and comprises the shower plate of claim 1 and a body member to which the shower plate is attached; and

a susceptor provided in the chamber, which serves as another electrode and is disposed parallel to the shower plate.

14. A plasma CVD method comprising:

placing a substrate on a susceptor disposed parallel to the shower plate of claim 1;

introducing a reaction gas through the shower plate;

generating a plasma between the susceptor and the shower plate by applying radio-frequency energy therebetween, wherein a sheath is formed over the shower plate, wherein a surface area of the sheath is nearly or substantially equal to or greater than a physical surface area of the shower plate; and

depositing a film on the substrate.

15. The plasma CVD method according to claim 14, wherein the film is selected from the group consisting of silicon nitride, silicon oxide, silicon oxynitride, low-dielectric-constant fluorine-doped silicon oxide, and low-dielectric-constant carbon-doped silicon oxide films.

10. A shower plate for plasma CVD comprising:

a base surface;

multiple protrusions protruding from the base surface, and

multiple apertures for passing a gas therethrough dispersed on a front face constituted by the base surface and the protrusions,

wherein a surface area of the base surface and the protrusions is greater by at least 40% than a calculated surface area of the base surface if no protrusions are provided, and wherein a surface area when extending from the base surface and the protrusions by a sheath generated by plasma exposure is nearly or substantially equal to or greater than the surface area of the base surface and the protrusions.

11. The shower plate according to claim 10, wherein the apertures are dispersed on the base surface, and the protrusions are dispersed among the apertures.

13. A plasma CVD apparatus comprising:

a reaction chamber;

a showerhead provided in the chamber, which serves as an electrode and comprises the shower plate of claim 10 and a body member to which the shower plate is attached; and

a susceptor provided in the chamber, which serves as another electrode and is disposed parallel to the shower plate.

16. A plasma CVD method comprising:

placing a substrate on a susceptor disposed parallel to the shower plate of claim 10;

introducing a reaction gas through the shower plate;

generating a plasma between the susceptor and the shower plate by applying radio-frequency energy therebetween, wherein a sheath is formed over the shower plate, wherein a surface area of the sheath is nearly or substantially equal to or greater than a physical surface area of the shower plate; and

depositing a film on the substrate.

17. The plasma CVD method according to claim 16, wherein the film is selected from the group consisting of silicon nitride, silicon oxide, silicon oxynitride, low-dielectric-constant fluorine-doped silicon oxide, and low-dielectric-constant carbon-doped silicon oxide films.