WO2012090715A1 - Plasma treatment device - Google Patents

Abstract

Provided is a plasma treatment device which comprises: a gas supply chamber which is divided into a plurality of sections at the surface of a single substrate so that gas can be introduced independently into each section; and a second electrode which is shared by the sections of the gas supply chamber. Gas is brought to a plasma state and treatment is carried out on the substrate by supplying power to the second electrode while gas is supplied to the surface of the substrate from the gas supply chambers.

Description

Plasma processing equipment

The present invention relates to a plasma processing apparatus used for forming a semiconductor film.

A first electrode capable of holding the substrate and a second electrode disposed so as to face the first electrode are provided for performing processing such as film formation by plasma and etching on the substrate. A parallel plate type plasma processing apparatus is known.

In Patent Document 1, a plurality of film formation chambers each having a first electrode and a second electrode are continuously arranged, and film formation is performed in an optimal thermal atmosphere in each of the initial, intermediate, and final steps of film formation. A possible film forming apparatus is disclosed. In Patent Document 2, plasma generation means are provided independently in a plurality of film formation chambers, and a film can be formed by transporting a substrate to each film formation chamber via a common chamber. An apparatus is disclosed.

In these film forming apparatuses, as shown in FIG. 6, a gas supply chamber 14 is provided in the second electrode 12 disposed to face the first electrode 10, and a gas introduction pipe 16 is connected to the gas supply chamber 14. A gas for film formation or the like is supplied to the gas supply chamber 14 through the gas introduction pipe 16. In the gas supply chamber 14, as shown in the plan view of FIG. 7, a gas diffusion plate 18 having a large number of holes 18a formed in a plate-like member is disposed. The gas injection hole 12 a is also provided in the second electrode 12, and the gas introduced into the gas supply chamber 14 passes through the gas diffusion plate 18 and the second electrode 12, and the first electrode 10, the second electrode 12, Is supplied to the plasma generation space.

JP-A-8-176826 Japanese Patent No. 2918194

By the way, in the conventional film forming apparatus, the gas is uniformly dispersed in the gas supply chamber 14 by the gas diffusion plate 18 and is supplied from the second electrode 12 to the plasma generation space. However, as shown in FIG. 8, the flow rate of the gas supplied to the plasma generation space increases from the center to the end of the second electrode 12, and the gas supply amount per unit space is not uniform.

As shown by a broken line in FIG. 9, the gas pressure in the vicinity of the gas injection hole 12a of the second electrode 12 is substantially constant, whereas, as shown by a solid line in FIG. The gas pressure in the vicinity of the middle of the two electrodes 12 shows a distribution that decreases from the center to the end on the electrode plane, and it is considered that the larger the pressure difference, the more the gas supply amount per unit space.

As described above, when nonuniformity occurs in the gas supply amount in the plasma generation space, the plasma density also becomes nonuniform within the electrode surface, and the film formation and etching processing on the substrate also become nonuniform.

One aspect of the present invention is a plasma processing apparatus, which is divided into a plurality of parts on the surface of a single substrate, and can be independently introduced into each of the gas supply chamber and a common gas supply chamber. And supplying the electric power to the electrode unit while supplying the gas from each of the gas supply chambers to the surface of the substrate to process the gas on the substrate. Is a plasma processing apparatus.

According to the present invention, it is possible to provide a plasma processing apparatus with improved uniformity of plasma density distribution in the electrode plane.

It is a figure which shows the structure of the plasma processing apparatus in embodiment of this invention. It is an expanded section which shows the structure of the electrode part of the plasma processing apparatus in embodiment of this invention. It is a plane schematic diagram which shows arrangement | positioning of the gas supply chamber of the plasma processing apparatus in embodiment of this invention. It is a top view which shows the gas injection hole of the 2nd electrode of the plasma processing apparatus in embodiment of this invention. It is a plane schematic diagram which shows arrangement | positioning of the gas supply chamber of the plasma processing apparatus in embodiment of this invention. It is a figure which shows the structure of the conventional plasma processing apparatus. It is a top view which shows the hole of the gas diffusion plate in the conventional plasma processing apparatus. It is a figure which shows distribution of the gas supply amount in the conventional plasma processing apparatus. It is a figure which shows distribution of the gas pressure between the electrodes in the conventional plasma processing apparatus.

FIG. 1 is a schematic view showing a plasma processing apparatus 100 according to an embodiment of the present invention. As shown in FIG. 1, the plasma processing apparatus 100 has a parallel structure in which a first electrode 22 and a second electrode 24 are disposed in a vacuum chamber 20 so as to face each other. The vacuum chamber 20 has an exhaust port 20 a on the side, and the exhaust port 20 a is connected to a vacuum exhaust system 28 via an exhaust flow rate adjustment valve 26. In the present embodiment, the vacuum exhaust equipment 28 is constituted by a turbo molecular pump (TMP) 28a and an oil rotary pump (RP) 28b. However, the present invention is not limited to this, and other exhaust pumps may be used. Good. The first electrode 22 is an anode electrode, and the second electrode 24 is a cathode electrode.

The area of the opposing surfaces of the first electrode 22 and the second electrode 24 is, for example, about 600 mm × about 600 mm. The substrate 102 has a rectangular shape of about 400 mm × about 300 mm, for example.

The first electrode 22 has a substrate holding portion for holding the substrate 102 to be formed or etched on the side facing the second electrode 24. When processing such as film formation or etching is performed by plasma, the substrate 102 is fixed to the substrate holding portion of the first electrode 22.

The first electrode 22 may include a heating / cooling mechanism (not shown) for keeping the substrate 102 at a predetermined temperature. By providing the heating / cooling mechanism, the substrate 102 can be heated to a desired temperature when processing such as film formation or etching on the substrate 102 by plasma is performed.

The second electrode 24 is provided with a gas supply chamber 32 as shown in the enlarged sectional view of FIG. In the present embodiment, a plurality of independent gas supply chambers 32 are provided. A gas introduction pipe 34 is connected to each gas supply chamber 32, and a gas for film formation or the like is supplied to the gas supply chamber 32 through the gas introduction pipe 34.

In the present embodiment, each of the gas supply chambers 32 is divided into a frame shape from the center of the second electrode 24 as shown in the schematic plan view of FIG.

Each gas introduction pipe 34 connected to the gas supply chamber 32 is provided with a gas pressure regulator 36 as shown in FIGS. The gas pressure adjuster 36 is provided to adjust the pressure of the gas supplied from the gas supply unit (gas cylinder) 30. In the present embodiment, a gas pressure regulator 36 is provided in each of the gas introduction pipes 34. The gas pressure adjuster 36 includes a pressure sensor that measures the pressure in the gas introduction pipe 34 and a flow rate adjustment valve that adjusts the flow rate of the gas according to the pressure measured by the pressure sensor. Thereby, the pressure of the gas introduced into each of the gas supply chambers 32 can be controlled independently.

Further, each of the gas supply chambers 32 may be provided with a gas diffusion plate 32a. As shown in FIG. 7, the gas diffusion plate 32 a is a member in which a large number of holes are formed in a plate-like member, and in order to uniformly distribute the gas introduced into the gas supply chamber 32 in the gas supply chamber 32. Is provided.

On the other hand, the second electrode 24 is provided in common to the plurality of gas supply chambers 32. In the present embodiment, one plate-like second electrode 24 is provided in common so as to cover all the gas supply chambers 32. Further, the second electrode 24 is provided with a gas injection hole 24a as shown in FIG. The gas introduced into each of the gas supply chambers 32 is supplied to the plasma generation space between the first electrode 22 and the second electrode 24 through the gas diffusion plate 32 a and the second electrode 24.

During film formation or etching, the substrate 102 to be processed is disposed on the first electrode 22, and the vacuum chamber 20 is evacuated by the evacuation equipment 28. Thereafter, a gas to be converted into plasma is supplied from the gas supply unit 30 to the plasma generation space between the first electrode 22 and the second electrode 24, and high-frequency power is applied between the first electrode 22 and the second electrode 24. . As a result, the supplied gas is turned into plasma, and film formation and etching are performed on the substrate 102.

Here, in this embodiment, a plurality of gas supply chambers 32 are provided for one second electrode 24, that is, one substrate 102, and the pressure of the gas supplied to the gas supply chamber 32 can be controlled independently. . Thereby, the pressure of each gas supply chamber 32 can be controlled so that the flow rate of the gas supplied to the plasma generation space over the entire second electrode 24 is uniform.

Specifically, it is preferable to control so that the pressure in each gas supply chamber 32 decreases from the center to the end of the second electrode 24. As a result, the gas pressure in the vicinity of the gas injection hole 24a of the second electrode 24 also shows a distribution that decreases from the center to the end, and the gas pressure in the vicinity of the middle between the first electrode 22 and the second electrode 24 is also Since the distribution decreases from the central portion toward the end portion, the pressure difference becomes substantially constant in the electrode plane, and the gas supply amount per unit space is made uniform.

Thus, in the plasma processing apparatus 100, the plasma density in the plasma generation space can be made more uniform, and the film formation and etching on the substrate 102 can be made more uniform.

In the present embodiment, the gas supply chamber 32 is divided into a frame shape from the center of the second electrode 24 as shown in FIG. 3, but the present invention is not limited to this, and the unit of the plasma generation space The gas supply amount per space may be made uniform. For example, as shown in the schematic plan view of FIG. 5, the gas supply chamber 32 may be divided into a lattice shape.

Further, the shapes of the first electrode 22 and the second electrode 24 are not limited to a square, and may be other shapes such as a rectangle or a circle. Furthermore, it is also preferable that the gas diffusion plate 32a has a different number of holes and different hole diameters for each gas supply chamber 32 so that the gas pressure in the chamber becomes more uniform for each gas supply chamber 32. In addition, a plurality of gas diffusion plates 32 a may be provided in one gas supply chamber 32.

In the present embodiment, the gas is supplied through the gas supply chamber 32. However, a gas injection hole may be provided in the gas introduction pipe 34, and the gas may be supplied directly from the gas introduction pipe 34. In this case, a plurality of gas introduction pipes 34 are provided, and a gas pressure regulator 36 is provided in each gas introduction pipe 34. And it is suitable to supply gas, adjusting the pressure in each gas introduction pipe 34 so that the amount of gas supply per unit space of plasma generation space may become uniform.

In this embodiment, the rectangular substrate 102 having a size of about 400 mm × about 300 mm is used. However, the substrate 102 having a side exceeding 1000 mm (1 m), and the first electrode 22 and the second electrode 24 corresponding to the substrate 102 may be used. Good. The larger the substrate, the greater the effect of non-uniform film formation and etching on the substrate. By increasing the uniformity of the plasma density distribution, non-uniformity of film formation or etching in the central region and end region of a large substrate can be suppressed.

10 1st electrode, 12 2nd electrode, 12a gas injection hole, 14 gas supply chamber, 16 gas introduction pipe, 18 gas diffusion plate, 18a hole, 20 vacuum chamber, 20a exhaust port, 22 1st electrode, 24 2nd electrode , 24a gas injection hole, 26 exhaust flow adjustment valve, 28 vacuum exhaust equipment, 30 gas supply unit, 32 gas supply chamber, 32a gas diffusion plate, 34 gas introduction pipe, 36 gas pressure regulator, 100 plasma processing apparatus, 102 substrate .

Claims (4)

A plasma processing apparatus,
A gas supply chamber that is divided into a plurality of surfaces of one substrate and into which gas can be independently introduced;
An electrode portion provided in common in the gas supply chamber;
With
The plasma processing is characterized in that the gas is converted into plasma by supplying electric power to the electrode portion while supplying the gas from each of the gas supply chambers to the surface of the substrate, and processing is performed on the substrate. apparatus. The plasma processing apparatus according to claim 1,
The plasma processing apparatus, wherein the gas is introduced into the gas supply chamber at an equal pressure. The plasma processing apparatus according to claim 1 or 2,
The electrode part has the gas injection port,
The plasma processing apparatus according to claim 1, wherein at least one of a size, a shape, and an arrangement pattern of the gas injection port is different for each gas supply chamber. The plasma processing apparatus according to claim 1 or 2,
A plasma processing apparatus, wherein a semiconductor layer included in a photoelectric conversion unit that converts incident light into electricity is formed on the substrate.

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