Gas-introducing system and plasma CVD apparatus

• US 20060090700A1
• Filed: 10/28/2005
• Published: 05/04/2006
• Est. Priority Date: 10/29/2004
• Status: Active Grant

• Current Assignee: ASM Japan K.K. (ASM International NV)
• Original Assignee: ASM Japan K.K. (ASM International NV)
• Inventors: Matsumoto, Kazuya, Fukasawa, Yasushi, Satoh, Kiyoshi
• Granted Patent: US 7,718,004 B2
• Time in Patent Office: Days
• US Class Current: 118/715
• CPC Class Codes: C23C 16/4405 Cleaning of reactor or parts inside the reactor by using reactive gases
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/5096 Flat-bed apparatus
• CPC Class Codes: C23F 4/00 Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/3244 Gas supply means

Abstract

A gas-introducing system for plasma CVD and cleaning includes: a showerhead including a top plate with a gas inlet port and a shower plate; a rectifying plate installed in the interior space of the showerhead and dividing the interior space into an upper space and a lower space; a structure for inhibiting inactivation of active species of the activated cleaning gas at the rectifying plate; and a piping unit for connecting the gas inlet port of the showerhead to a remote plasma unit and a reaction gas introduction port.

Claims

1. A gas-introducing system for plasma CVD and cleaning, comprising:

a showerhead comprising a top plate with a gas inlet port though which a reaction gas or activated cleaning gas is to be introduced into an interior space of the showerhead, and a shower plate having multiple holes through which the reaction gas or activated cleaning gas is to be discharged into a reactor;

a rectifying plate installed in the interior space of the showerhead, dividing the interior space into an upper space and a lower space, and having multiple holes through which the upper space and the lower space are communicated;

a means for inhibiting inactivation of active species of the activated cleaning gas at the rectifying plate; and

a piping unit for connecting the gas inlet port of the showerhead to a remote plasma unit and a reaction gas introduction port.

2. The gas-introducing system according to claim 1, wherein the means is a material of the rectifying plate which is selected from a group consisting of sapphire and alumina ceramics with a purity of 99.95% or higher.

3. The gas-introducing system according to claim 2, wherein the rectifying plate has a surface roughness of about 0.5 μ

m or less.

4. The gas-introducing system according to claim 1, wherein the means is a structure wherein the piping unit comprises inner and outer pipes coaxially disposed, said inner pipe communicating the remote plasma unit and the lower space of the showerhead without exposing the active species of cleaning gas to the upper space of the showerhead, said outer pipe communicating the reaction gas introduction port and the upper space of the showerhead.

5. The gas-introducing system according to claim 4, wherein the inner pipe constitutes a straight downward passage of the active species of cleaning gas from the remote plasma unit which is opened to the lower space of the showerhead.

6. The gas-introducing system according to claim 1, wherein the holes of the rectifying plate have a size larger than that of the holes of the shower plate, and the number of the holes of the rectifying plate is less than that of the holes of the shower plate.

7. The gas-introducing system according to claim 1, wherein the rectifying plate has a thickness of about 3 mm to about 20 mm.

8. The gas-introducing system according to claim 1, wherein a distance between the rectifying plate and the top plate is about 1 mm to about 20 mm, and a distance between the rectifying plate and the shower plate is about 1 mm to about 20 mm.

9. The gas-introducing system according to claim 1, wherein the piping unit includes an insulating member which insulates the piping unit from the top plate.

10. The gas-introducing system according to claim 1, wherein the showerhead is connected to an RF power source.

11. The gas-introducing system according to claim 1, wherein the reactor is a reactor of a capacitively-coupled plasma CVD apparatus.

12. A self-cleanable plasma CVD processing apparatus comprising:

a reactor;

a susceptor provided inside the reactor to place a semiconductor substrate thereon;

the gas-introducing system of claim 1 wherein the showerhead is installed parallel to and facing the susceptor;

a remote plasma unit connected to the gas-introducing system to activate cleaning gas; and

at least one high-frequency power supply installed outside the reactor to supply power to the showerhead or the susceptor.

13. A self-cleanable plasma CVD processing apparatus comprising:

a reactor;

a susceptor provided inside the reactor to place a semiconductor substrate thereon;

a showerhead provided inside the reactor and installed in parallel with and facing the susceptor;

a rectifying plate installed in an interior space of the showerhead and having multiple through-holes, said rectifying plate being composed of a material selected from the group consisting of sapphire and alumina ceramics with a purity of 99.95% or higher;

at least one high-frequency power supply installed outside the reactor to supply power to the showerhead or the susceptor; and

a remote plasma discharge chamber installed outside the reactor to activate cleaning gas,

wherein the interior of the reactor is self-cleaned by the cleaning gas activated inside the remote plasma discharge chamber.

14. The apparatus according to claim 13, wherein the activated cleaning gas contains active fluorine species.

15. A self-cleanable plasma CVD processing apparatus comprising:

a reactor;

a susceptor provided inside the reactor to place a semiconductor substrate thereon;

a showerhead provided inside the reactor and installed in parallel with and facing the susceptor;

a rectifying plate installed in an interior space of the showerhead and having multiple through-holes;

at least one high-frequency power supply installed outside the reactor to supply power to the showerhead or the susceptor;

a remote plasma discharge chamber installed outside the reactor to activate cleaning gas;

a first pipe connecting the remote plasma discharge chamber with the reactor; and

a second pipe installed inside the first pipe coaxially with the first pipe, thereby forming a first channel inside the second pipe and a second channel between the first pipe and the second pipe,

wherein in film deposition, a reaction gas is diffused to the rectifying plate via the second channel and supplied from the showerhead, and in cleaning, the activated cleaning gas is supplied from the showerhead via the first channel without being diffused to the rectifying plate.

16. The apparatus according to claim 15, wherein the activated cleaning gas contains active fluorine species.

17. The apparatus according to claim 15, wherein the rectifying plate is composed of a material selected from the group consisting of alumina ceramics, sapphire, aluminum, aluminum alloy, aluminum nitride, and magnesium oxide.