JP2001085409A - Plasma treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma treatment device which can evenly supply a processing gas to the whole surface of a substrate to be treated, even when the substrate has a large area. SOLUTION: A plasma treatment device treats a substrate 7 by generating a plasma in a vacuum chamber 4 having a gas supplying section by impressing a high-frequency voltage upon the chamber 4, while a processing gas is supplied to the chamber 4. The gas-supplying section is constituted of a plurality of gas-supplying pipes 6b-6m, which are radially extended outward from a point above the center of the substrate 7 and each of which has a gas blowout hole 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus for processing a substrate by supplying a processing gas to a vacuum chamber having a gas supply unit and applying a high frequency voltage to generate plasma in the vacuum chamber. It is.

[0002]

2. Description of the Related Art Conventionally, a plasma processing apparatus utilizing high-frequency inductive coupling has been used in a dry etching apparatus, a CVD apparatus, or the like in a process of manufacturing a semiconductor element or a liquid crystal display element. 3 and 4 show a conventional plasma processing apparatus.

[0003] As shown in FIG.
A processing gas is supplied from a gas supply unit disposed in the vacuum chamber 4 to a substrate 7 disposed in the vacuum chamber 4, and a high-frequency voltage is applied from outside the vacuum chamber 4 to generate plasma inside the vacuum chamber 4. Then, the substrate 7 is processed. Vacuum chamber 4
A high-frequency induction coil 2 for generating plasma via a dielectric plate 3 and a first high-frequency power supply 1 connected thereto are provided on the upper side, and a pump 10 for evacuating the vacuum chamber 4 is provided on the lower side.
Are arranged.

An electrode 8 to which a high-frequency voltage is applied from a second high-frequency power supply 9 is disposed inside the vacuum chamber 4, and a substrate 7 is mounted on the electrode 8. The gas supply unit includes a gas supply port 5 provided on a side wall of the vacuum chamber 4 and a gas supply component 13 connected to the gas supply port 5 and connected to an inner surface of the vacuum chamber 4. FIG. 4 shows the configuration of the gas supply component 13. FIG. 4A is a plan view of the gas supply component 13 and FIG.
FIG. 2B is a side view of the gas supply component 13.

The gas supply component 13 comprises a gas supply pipe 13a for introducing a processing gas from the gas supply port 5 and a gas supply pipe 13b connected to the gas supply pipe 13b. The gas supply pipe 13b is larger than the outer shape of the substrate 7. A large number of gas blowing holes 12 are formed in the inner peripheral wall so as to be parallel to the substrate 7.
In the plasma processing apparatus configured as described above, when the substrate 7 is placed on the electrode 8, the vacuum chamber 4 is evacuated by the pump 10, and the processing gas is supplied from the gas supply port 5 through the gas introduction pipe 13 a. The pressure in the vacuum chamber 4 is low (10 mTorr to 100 mV) from the gas outlet 12 of the gas introduction pipe 13a.
Arbitrary processing gas is supplied until the state becomes about 0 mTorr).

Next, high-density plasma is generated by the high-frequency induction coil 2 and the first high-frequency power supply 1, and the substrate 7 is subjected to processing such as etching and film formation.

[0007]

However, in the above-described conventional plasma processing apparatus, a pressure loss occurs inside the gas supply pipe 13b, and a considerable decrease in the flow rate occurs at the gas outlet 12 far from the gas introduction pipe 13a. . This is not a problem when the size of the substrate 7 is as large as a semiconductor wafer (8 inches in diameter).
The gas introduction pipe 1 is also affected by the fact that b has a ring shape.
The gas flow rate is small in a portion far from the substrate 3a, and the gas supply amount has a remarkable variation in the central portion of the substrate 7, greatly affecting the uniformity of the processing speed in the substrate surface.

For example, this plasma processing apparatus is 550 m
When applied to the etching of an aluminum film as a dry etching apparatus corresponding to a substrate for a liquid crystal display device having a size of mx 670 mm, the etching rate varies, and the uniformity of the etching rate within the substrate surface is not ensured. Problems arise. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a plasma processing apparatus capable of uniformly supplying a processing gas to the entire surface even when processing a substrate having a large area.

[0009]

The plasma processing apparatus of the present invention is characterized in that the configuration of the gas supply unit is special. According to the present invention, even when a substrate having a large area is used, the processing gas can be uniformly supplied to the entire surface of the substrate, and the processing speed can be made uniform within the substrate surface.

[0010]

DETAILED DESCRIPTION OF THE INVENTION A plasma processing apparatus according to a first aspect of the present invention supplies a processing gas to a vacuum chamber having a gas supply unit and applies a high-frequency voltage to generate plasma in the vacuum chamber. In the plasma processing apparatus for processing a substrate, the gas supply unit includes a plurality of gas supply pipes whose front ends radially extend from a center point of the substrate toward an outer peripheral part, and a gas blowing hole is provided in the gas supply pipe. It is characterized by having been provided.

According to this structure, the gas is introduced into the gas supply section from the center of the substrate, and a plurality of gas supply pipes are installed radially from the center of the substrate. Variations in the flow rate of the supplied processing gas can be suppressed, and highly uniform gas can be supplied to the entire surface of the substrate. Hereinafter, a plasma processing apparatus of the present invention will be described based on specific embodiments.

3 and 4 showing the above-mentioned conventional example will be described with the same reference numerals. (Embodiment) FIGS. 1 and 2 show a plasma processing apparatus of the present invention. This embodiment differs from the above-described conventional example in that a gas supply unit having a special configuration is provided in order to enhance the processing uniformity of the substrate as compared with the conventional plasma processing apparatus.

A high-frequency induction coil 2 for generating plasma via a dielectric plate 3 and a first high-frequency power supply 1 connected to the coil 2 are provided above the vacuum chamber 4, and a pump 10 for evacuating the vacuum is provided below. Is provided. An electrode 8 to which a high-frequency voltage is applied from a second high-frequency power supply 9 is disposed inside the vacuum chamber 4, and a substrate 7 is mounted on the electrode 8.

A gas supply port 5 is provided on a side wall of the vacuum chamber 4, and a gas supply part 6 is connected to the gas supply port 5 from the inside of the vacuum chamber 4 as a gas supply unit. It is fixed to the vacuum chamber 4 by the bracket 11 configured. The gas supply component 6 includes a gas introduction pipe 6a extending from the gas supply port 5 to the center of the substrate 7 and bent at a right angle to the substrate surface side. It comprises a plurality of gas supply pipes 6b to 6m extending radially toward the outer periphery of the substrate 7, and a fixing ring 6n larger than the outer shape of the substrate 7 for fixing the distal ends of the gas supply pipes 6b to 6m. It is integrated. Each of the gas supply pipes 6b to 6m is provided with a plurality of gas blowing holes 12, and a processing gas is supplied from the gas introduction pipe 6a to the base ends of the gas supply pipes 6b to 6m.

FIG. 2 shows the details of the gas supply component 6. FIG.
2A is a plan view of the gas supply component 6 as viewed from the side facing the substrate 7, and FIG. 2B is a side view of the gas supply component 6. The gas supply pipes 6b to 6m have inner diameters of 1/8 to 3
Preferably, the length is about / 8 inch, and the length is such that the front end is outside the substrate 7. At least two or more gas outlet holes 12 are provided in each of the gas supply pipes 6b to 6m.
Are preferably formed at an equal pitch, and at least one or more of the gas blowing holes 12 is preferably outside the substrate 7. The gas blowing holes 12 are all formed in the same direction, and the hole diameter is about 0.5 to 3 mm.

The fixing ring 6n includes gas supply pipes 6b to 6b.
The fixing ring 6 n is fixed to the vacuum chamber 4 via the bracket 11.
By fixing the gas supply parts 6 to the vacuum chamber 4 in this manner, the radially arranged gas supply pipes 6b
The position of about 6 m and the positions of the gas supply component 6 and the vacuum chamber 4 are fixed, and the position and orientation of the hole of the pipe with respect to the substrate 7 are firmly fixed. When the gas supply component 6 is connected to the gas supply port 5, the gas blowout hole 12 and the substrate 7 are connected.
And are arranged so as to face each other.

In the gas supply component 6 configured as described above, the processing gas introduced from the gas supply port 5 is guided to above the center point of the substrate 7 by the gas introduction pipe 6a and further toward the surface side of the substrate 7. Since the gas is supplied at a right angle, the gas can be evenly distributed to the gas supply pipes 6b to 6m installed radially. In the plasma processing apparatus configured as described above, when the substrate 7 is placed on the electrode 8, the vacuum chamber 4 is evacuated by the pump 10, and the gas supply pipe 6 b is exhausted from the gas supply port 5 via the gas introduction pipe 6 a. A suitable pressure (10 mTorr to 1000 mT) is applied to the inside of the vacuum chamber 4 through the gas blowing holes 12 of up to 6 m.
(or about).

When the inside of the vacuum chamber 4 is maintained at a constant pressure, high-frequency power is applied to the high-frequency induction coil 2 by the first high-frequency power supply 1 to generate high-density plasma. A high-frequency power source is applied to the substrate to control the energy of ions incident on the substrate 7. When the high-density plasma is generated, the substrate 7 placed on the electrode 8 is treated with the reaction gas.

The reaction gas supplied to the substrate 7 is first introduced from the gas introduction pipe 6a to a position above the center point of the substrate 7 by the gas supply component 6 as described above, and then supplied to the radial gas supply pipes 6b to 6m. Therefore, variation in the flow rate of gas blown out from the gas blowing holes 12 can be suppressed as compared with the related art, and even when the substrate 7 having a large area is used, a highly uniform gas can be supplied to the entire surface of the substrate 7.

For example, this plasma processing apparatus is 550
When applied to the etching of an aluminum film as a dry etching device corresponding to a substrate for a liquid crystal display device having a size of mm × 670 mm and using Cl ₂ and BCl ₃ as reaction gases, the etching rate can be made more uniform than before. Enhanced. In the above description, the gas supply part 6 in which the gas introduction pipe 6a, the gas supply pipes 6b to 6m, and the fixing ring 6n are integrated has been described as an example, but the material constituting each part may be the same. Further, composites of different materials may be used.

The materials constituting the gas supply component 6 include:
Although a metal such as SUS316 is preferable, the present invention is not limited to this. For example, a configuration using ceramics such as quartz, alumina, silicon nitride, and aluminum nitride is also possible. Further, the number of gas supply pipes, the diameter of the pipes, the diameter of the gas discharge holes, the positions of the holes, the direction of the holes, and the like are not limited to those described above, but include the pressure loss of the processing gas and the size of the vacuum chamber 4. The size may be determined in consideration of the size and the like of the substrate 7 to be processed. The diameter may be reduced, the diameter of the pipe may be gradually increased, or the holes may be integrated in a direction parallel to the substrate 7 to be processed.

Also, a case where a rectangular substrate is used as the substrate 7 to be processed and the shapes of the vacuum chamber 4, gas supply components 6, electrodes 8 and the like are rectangular has been described as an example, but the present invention is not limited to this. For example, when processing a circular substrate such as in the case of manufacturing a semiconductor device, it is easier to configure the vacuum chamber, gas supply parts, electrodes, and the like in a circular shape because of the configuration of the apparatus. is there.

[0023]

As described above, according to the plasma processing apparatus of the present invention, the gas supply section comprises a plurality of gas supply pipes whose tips extend radially from the center of the substrate toward the outer periphery. Since the gas supply pipe is provided with gas outlet holes, the uniformity of gas can be supplied to the entire substrate even if the substrate has a large area by suppressing the variation in the gas flow rate from each gas outlet hole. Plasma processing with high uniformity of processing speed in the inside can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view and a side view of the gas supply component according to the embodiment of the present invention as viewed from below.

FIG. 3 is a diagram showing a configuration of a conventional plasma processing apparatus.

FIG. 4 is a plan view and a side view of a gas supply component in a conventional plasma processing apparatus as viewed from below.

[Explanation of symbols]

 Reference Signs List 4 Vacuum chamber 5 Gas supply port 6 Gas supply part 6a Gas introduction path 6b-6m Gas introduction pipe 6n Fixing ring 7 Substrate 12 Gas outlet

Continued on the front page (72) Inventor Kiyohiko Takagi 1006 Kazuma Kadoma, Kazuma, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. (reference) 4K030 CA06 EA05 EA06 FA04 KA46 LA18 4K057 DA11 DB05 DD01 DE01 DG07 DG08 DG13 DG16 DM05 DM37 DN02 5F004 AA01 BA04 BB18 BB28 BC03 BD04 CA02 DA04 DA11 DB09 5F045 AA08 BB02 EB02 EF08 EH14

Claims (1)

[Claims] 1. A plasma processing apparatus for supplying a processing gas to a vacuum chamber having a gas supply unit and applying a high-frequency voltage to generate plasma in the vacuum chamber and process a substrate, wherein the gas supply unit comprises: A plasma processing apparatus comprising: a plurality of gas supply pipes each of which has a front end radially extending from a center point of a substrate toward an outer peripheral portion, wherein the gas supply pipes are provided with gas blowing holes.