JPH11350118A - Film forming equipment - Google Patents

Abstract

(57) [Problem] To provide a film forming apparatus for uniformly supplying a process gas into a vacuum chamber. A pedestal (16) for holding a substrate (12) is provided in a vacuum chamber (14).
A disk-shaped target 18 made of a material to be deposited on the surface of the substrate 12 is arranged to face the pedestal 16. Further, a gas supply pipe 10 made of a porous ceramic for introducing a process gas for plasma generation into the inside is arranged in a substantially annular shape along the upper edge of the vacuum chamber 14, that is, along the outer peripheral surface of the packing plate 20. A substantially annular and air-permeable auxiliary shield 22 similar to the shield 13 for shutting off a substantially annular gas flow so as to sandwich the gas supply pipe 10.
Is arranged. The supply process gas leaked from the surface of the gas supply pipe 10 is uniformly supplied into the shield 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a film forming apparatus such as a sputtering apparatus, and more particularly to a means for supplying a process gas into a vacuum chamber of such a film forming apparatus.

[0002]

2. Description of the Related Art An important step in a semiconductor device manufacturing process is a thin film deposition process. This thin film deposition process usually includes a physical vapor deposition (PVD) method such as vacuum evaporation or sputtering.
D) and chemical vapor deposition (Chemical Vapor Deposition =
CVD) is used.

FIG. 2 shows an example of the sputtering apparatus. The apparatus comprises a shield 13 between a substrate 11 such as a semiconductor wafer disposed in a vacuum chamber 14 and a target 18 made of a deposition material disposed thereon from a nozzle 11 provided in an upper part of the vacuum chamber 1. The process gas is supplied directly to the internal space. And
The process gas is turned into plasma, and positive ions, usually argon ions, in the gas are made to collide with the surface of the target 18 serving as a cathode, and target atoms sputtered therefrom are deposited on the substrate 12 on the anode side to form a film.

[0004]

However, in this type of apparatus, since only one or two nozzles 11 are usually provided in the vacuum chamber 14, the concentration distribution of the process gas in the shield 13 is not sufficient. Become uniform. When the gas concentration becomes non-uniform, for example, in the case of reactive sputtering, the reactivity between the reactive gas and the sputtered particles varies depending on the position in the shield 13, and therefore, the deposition rate and the film quality of the film deposited on the substrate 12. Is different depending on the position.

Increasing the number of nozzles is not a practical solution because it becomes difficult to secure airtightness in the chamber 1 and to control the flow rate of process gas between the nozzles.

In view of the above problems, an object of the present invention is to provide a film forming apparatus for uniformly supplying a process gas into a vacuum chamber.

[0007]

In order to solve the above-mentioned problems, a film forming apparatus of the present invention is a film forming apparatus for depositing a film on a substrate, and supports a vacuum chamber and a substrate in the vacuum chamber. Support means, and a gas supply pipe which is arranged annularly in the vacuum chamber and supplies a process gas to a space on the substrate through a number of ventilation holes provided in the pipe wall. And

According to this configuration, the large number of ventilation holes provided in the tube wall of the supply tube are annularly arranged around the substrate supported by the support means in the vacuum chamber. Therefore, the process gas supplied from these ventilation holes is supplied almost uniformly to the space above the substrate.

This supply pipe is arranged in a substantially circular ring shape,
In addition, it is preferable that it is arranged coaxially with the substrate supported by the support means. By making the supply pipe a substantially circular ring, the process gas is uniformly dispersed to the center of the ring.

Further, the supply pipe is preferably made of a porous ceramic. According to this, the process gas is supplied substantially uniformly from the entire outer surface of the ceramic supply pipe, so that the uniformity of the process gas concentration in the chamber is further enhanced.

It is preferable that a substantially annular, air-permeable auxiliary shield is further provided above the supply pipe in the vacuum chamber. As a result, part of the process gas passes through the auxiliary shield and is sent from the upper portion of the vacuum chamber to the space above the substrate.

It is preferable that the auxiliary shield has a mesh structure. By employing a mesh structure, uniform air permeability can be ensured.

Further, the auxiliary shield is preferably made of a sintered metal. By using a sintered metal, unnecessary deposition on the auxiliary shield can be prevented.

[0014]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Each drawing is a schematic diagram for facilitating understanding of the invention, and the dimensions and shapes shown in each drawing do not always correspond to actual ones.

FIG. 1 shows an embodiment of a sputtering apparatus to which the present invention is applied. The sputtering apparatus includes a vacuum chamber 14 in which a sputtering process is performed on a substrate 12 such as a semiconductor wafer. A pedestal 1 for holding the substrate 12 is provided in the vacuum chamber 14.
6 are provided. A disk-shaped target 18 made of a material deposited on the surface of the substrate 12 is disposed above the vacuum chamber 14, and the lower surface thereof is opposed to and parallel to the upper surface of the pedestal 16. A cathode and an anode of a DC power supply (not shown) are connected to the target 18 and the pedestal 16, respectively. Further, a vacuum pump (not shown) for evacuating the inside is connected to the vacuum chamber 14.

In order to introduce a process gas for plasma generation, usually argon gas, into the inside, a gas supply pipe 10 made of, for example, a porous ceramic connected to a gas supply source (not shown) is provided inside the vacuum chamber 14. , That is, along the outer peripheral surface of the packing plate 20 in the upper portion of the vacuum chamber 14, is disposed substantially in a substantially circular shape. The vacuum chamber 1 is sandwiched between the gas supply pipes 10.
4, a shield 13 for blocking a substantially annular gas flow is provided on the wall side.
A substantially annular and air-permeable auxiliary shield 22 is disposed on the packing plate 20 side. The auxiliary shield 22 is preferably made of, for example, a sintered metal and has a mesh structure.

In such a configuration, an argon gas is introduced from a gas supply source through a gas supply pipe 10 into a vacuum chamber 14 reduced to a predetermined pressure by a vacuum pump, and a gas is supplied between a target 18 and a pedestal 16. When a voltage is applied, plasma is generated in a space above the substrate 12 inside the shield 13. The argon ions in the plasma collide with the lower surface of the target 18 and repel target atoms, and the target atoms are deposited on the substrate 12 to form a thin film.

At this time, since the gas supply pipe 10 is made of a porous ceramic, a part of the argon gas flowing in the gas supply pipe 10 leaks from the pipe surface, so that the argon gas is substantially uniform from the entire pipe surface. Released outside the tube. A part of the argon gas released in this way is
, And flows into the shield 13 through the space between the auxiliary shield 22. Also, a part of the auxiliary shield 22 is mesh-shaped.
Through the packing plate 22 and the target 18
And flows into the substrate 12 from above. Therefore, the argon gas concentration in the space above the substrate 12 can be averaged. In the prior art,
When the argon gas is introduced by the nozzle, the gas is ejected from the nozzle portion at a relatively high speed, so that the pressure distribution in the chamber is also biased, but according to the present embodiment,
Since the argon gas is discharged from the entire surface of the gas supply pipe 10, the gas ejection speed is reduced, and since the gas is ejected from the entire surroundings, the pressure distribution is substantially uniform. Therefore, emission of target atoms from the target 8 is also uniformed, and as a result, a uniform film can be formed on the entire wafer surface.

Further, since the auxiliary shield 22 exists between the target 18 and the gas supply pipe 10, the target 18
Since the sputtered particles released from the gas do not reach the gas supply pipe 10 and do not block the porous small holes, the flow of the process gas is always kept uniform.

In the above description, the sputtering apparatus has been described as an example. However, the present invention is not limited to this, and various PVD apparatuses such as a vapor deposition apparatus and the like, and a raw material gas is supplied as a process gas. The present invention can be similarly applied to a process gas supply of a CVD apparatus for depositing a film by a chemical reaction.

Here, the case where the supply pipe is formed of porous ceramics has been described. However, the supply pipe is not limited to this, and the same effect can be obtained even if a pipe having a large number of holes formed in the surface is used. Can be The annular supply pipe is preferably arranged in a substantially circular annular shape, but the arrangement shape is not limited to this depending on the shape of the device. However, the arrangement surrounding the substrate is preferable in order to uniformly supply the gas onto the substrate.

[0022]

As described above, according to the present invention,
Since the process gas can be uniformly supplied onto the substrate in the vacuum chamber, the deposition of the film is made uniform, and a uniform film can be formed on the entire surface of the wafer.

[Brief description of the drawings]

FIG. 1 is a sectional view of a film forming apparatus of the present invention.

FIG. 2 is a cross-sectional view of a conventional film forming apparatus.

[Explanation of symbols]

10 ... gas supply pipe, 11 ... nozzle, 12 ... substrate, 13 ...
Shield, 14 ... vacuum chamber, 16 ... pedestal,
18 ... Target, 20 ... Packing plate, 22 ...
Auxiliary shield.

Claims (6)

[Claims] 1. A film forming apparatus for depositing a film on a substrate, comprising: a vacuum chamber; support means for supporting the substrate in the vacuum chamber; and an annular arrangement in the vacuum chamber; A gas supply pipe for supplying a process gas to a space above the substrate through a number of provided ventilation holes. 2. The film forming apparatus according to claim 1, wherein the supply pipe is arranged coaxially with the substrate supported by the support means and in a substantially circular shape. 3. The film forming apparatus according to claim 1, wherein said supply pipe is made of a porous ceramic. 4. The film forming apparatus according to claim 1, further comprising a substantially annular and air-permeable auxiliary shield inside the supply pipe in the vacuum chamber. 5. The film forming apparatus according to claim 4, wherein the auxiliary shield has a mesh structure. 6. The film forming apparatus according to claim 4, wherein said auxiliary shield is made of a sintered metal.