SHOWERHEAD-COOLER SYSTEM OF A SEMICONDUCTOR-PROCESSING CHAMBER FOR SEMICONDUCTOR WAFERS OF LARGE AREA

• US 20150214009A1
• Filed: 01/25/2014
• Published: 07/30/2015
• Est. Priority Date: 01/25/2014
• Status: Active Grant

• Current Assignee: Yuri Glukhoy
• Original Assignee: Yuri Glukhoy
• Inventors: GLUKHOY, Yuri
• Granted Patent: US 9,484,190 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C23C 16/4404 Coatings or surface treatment on the inside of the reaction chamber or on parts thereof
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/45572 Cooled nozzles
• CPC Class Codes: C23C 16/45585 Compression of gas before it reaches the substrate
• CPC Class Codes: C23C 16/50 using electric discharges generation and control of plasma in discharge tubes for surface treatment H01J37/32, H01J37/34
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• CPC Class Codes: C23C 16/509 using internal electrodes
• CPC Class Codes: C23C 16/5096 Flat-bed apparatus
• 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
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01J 37/32477 characterised by the means for protecting vessels or internal parts, e.g. coatings

Abstract

Proposed is a showerhead-cooler system of a semiconductor-processing chamber with uniform distribution of plasma density. The showerhead has a plurality of through gas holes that are coaxial with respective channels of the gas-feeding cooler plate. On the gas inlet side, the though passages of the showerhead are provided with unequal conical nozzles characterized by a central angle that decreases from the peripheral part of the showerhead to the showerhead center. Such design provides uniformity of plasma density. Furthermore, in order to protect the walls of the nozzle and the walls of the gas holes from erosion that may be caused by the hollow-cathode phenomenon, these areas are coated with a thin protective coating that is resistant to electrical breakdown and chemical corrosion.

Claims

1. A showerhead-cooler system of a semiconductor-processing chamber of a CCP plasma processing apparatus intended for plasma processing of objects comprising:

a showerhead having a plurality of through gas holes;

a gas-feeding cooler plate that is connected to an RF power supply, has electrical contact with the showerhead, and forms with the showerhead a gas-accumulation reservoir that communicates with the through gas holes of the showerhead;

a gas-feeding cooler plate being connected to the source of a working gas and has a plurality of through gas-feeding passages that communicate with the gas-accumulating reservoir;

a showerhead having a front side that faces the semiconductor-processing chamber, a back side that faces the cooler plate, a peripheral portion, which is in said electrical contact with the cooler plate, and a central area which is in the center of the showerhead;

on the back side of the showerhead the through gas holes of the showerhead having conical nozzles with a cone angle θ

that decreases in the direction from the peripheral portion to the central area of the showerhead.

2. The showerhead-cooler system of claim 1, wherein the cone angle of each nozzle decreases in the direction from the peripheral portion to the central area of the showerhead from 120°

to 0°

.

3. The showerhead-cooler system of claim 1, wherein said showerhead is provided with an intermediate portion that is located between the peripheral portion and the central area and wherein the cone angle of the conical nozzles linearly decreases in the direction to the central area.

4. The showerhead-cooler system of claim 3, wherein the cone angle of each nozzle decreases in the direction from the peripheral portion to the central area of the showerhead from 120°

to 0°

.

5. The showerhead-cooler system of claim 1, wherein the surfaces of the conical nozzles and at least a part of the walls of the gas holes in the area adjacent to the conical nozzles have a protective coating resistant to electrical breakdown and chemical corrosion.

6. The showerhead-cooler system of claim 5, wherein the protective coating is selected from the group consisting of silicon carbide and yttrium oxide coating.

7. The showerhead-cooler system of claim 6, wherein the cone angle of each nozzle decreases in the direction from the peripheral portion to the central area of the showerhead from 120°

to 0°

, the through gas-feeding passages of the cooler plate being coaxial with the gas holes of the showerhead.

8. The showerhead-cooler system of claim 1, wherein the object is a semiconductor wafer.

9. The showerhead-cooler system of claim 8, wherein the wafer has a diameter of 450 mm.

10. The showerhead-cooler system of claim 9, wherein the surfaces of the conical nozzles and at least a part of the walls of the gas holes in the area adjacent to the conical nozzles have a protective coating resistant to electrical breakdown and chemical corrosion.

11. The showerhead-cooler system of claim 10, wherein the protective coating is selected from the group consisting of silicon carbide and an yttrium oxide coating.

12. The showerhead-cooler system of claim 11, wherein the cone angle of each nozzle decreases in the direction from the peripheral portion to the central area of the showerhead from 120°

to 0°

.

13. The showerhead-cooler system of claim 1, wherein the object is a semiconductor wafer, each through gas hole has a diameter d_H, a length I_H, and is located at a predetermined radial distance R from the center of the showerhead, and wherein the following relationship exists between the cone angle θ

of the conical nozzle of a through gas hole and a radial distance R of the gas hole from the showerhead center,

(1+bR)=[1−

1/{1−

[(2I_H tan θ

)/d_H]}⁴]<sup>−

1/2</sup> 

 

(1)

where “

b”

is a coefficient that depends on the parameters of the plasma process.

14. The showerhead-cooler system of claim 2, wherein the object is a semiconductor wafer, each through gas hole has a diameter d_H, a length I_H, and is located at a predetermined radial distance R from the center of the showerhead, and wherein the following relationship exists between the cone angle θ

of the conical nozzle of a through gas hole and a radial distance R of the gas hole from the showerhead center,

(1+bR)=[1−

1/{1−

[(2I_H tan θ

)/d_H]}⁴]<sup>−

1/2</sup> 

 

(1)

where “

b”

is coefficient that depends on the parameters of the plasma process.

15. The showerhead-cooler system of claim 3, wherein the object is a semiconductor wafer, each through gas hole has a diameter d_H, a length I_H, and is located at a predetermined radial distance R from the center of the showerhead, and wherein the following relationship exists between the cone angle θ

of the conical nozzle of a through gas hole and a radial distance R of the gas hole from the showerhead center,

(1+bR)=[1−

1/{1−

[(2I_H tan θ

)/d_H]}⁴]<sup>−

1/2</sup> 

 

(1)

where “

b”

is a coefficient that depends on the parameters of the plasma process.

16. The showerhead-cooler system of claim 7, wherein the object is a semiconductor wafer, each through gas hole has a diameter d_H, a length I_H, and is located at a predetermined radial distance R from the center of the showerhead, and wherein the following relationship exists between the cone angle θ

of the conical nozzle of a through gas hole and a radial distance R of the gas hole from the showerhead center,

(1+bR)=[1−

1/{1−

[(2I_H tan θ

)/d_H]}⁴]<sup>−

1/2</sup> 

 

(1)

where “

b”

is a coefficient that depends on the parameters of the plasma process.

17. The showerhead-cooler system of claim 13, wherein the wafer has a diameter of 450 mm.

18. The showerhead-cooler system of claim 14, wherein the wafer has a diameter of 450 mm.

19. The showerhead-cooler system of claim 15, wherein the wafer has a diameter of 450 mm.

20. The showerhead-cooler system of claim 16, wherein the wafer has a diameter of 450 mm.