JP3147868U - Substrate processing equipment - Google Patents

Abstract

The present invention provides a highly productive substrate processing apparatus that shortens the cleaning time of a reactor. A substrate processing apparatus includes a reactor, a susceptor for placing an object to be processed, a shower plate arranged in parallel to face the susceptor, and a remote plasma chamber provided apart from the reactor. A remote plasma chamber and a gas introduction pipe connecting the reactor, the cleaning gas is activated in the remote plasma chamber, the shower plate has a gas introduction surface and a gas injection surface, Although the film coating process is performed, the gas introduction surface is not subjected to the film coating process. [Selection] Figure 2

Description

  The present invention relates to the structure of a substrate processing apparatus, and more particularly to the structure of an apparatus for cleaning the inside of a reaction chamber.

  Conventionally, a plasma processing apparatus has been used to form or remove a thin film on an object to be processed, or to modify the surface of the object to be processed. In particular, the formation or etching process of a thin film on a semiconductor wafer such as silicon and a glass substrate has become a basic technique indispensable for manufacturing a semiconductor element such as a memory or a CPU, or a liquid crystal display (LCD).

  The plasma CVD method is a processing method in which various raw material gases are introduced into a vacuum evacuated reaction vessel and high frequency power is applied to generate plasma and deposit various thin films on a wafer. The plasma CVD processing apparatus generally includes a reactor, an upper high-frequency electrode (shower plate) that also serves as a gas dispersion plate that evenly distributes reaction gas, and a lower high-frequency electrode that also serves as a susceptor for holding a wafer. The reactor is coupled to the transfer chamber via a gate valve. Inside the transfer chamber, a transfer robot for carrying wafers into and out of the reactor is installed.

  The ion species of the source gas activated by plasma excitation in the reaction region in the reactor cause a chemical reaction in the vicinity of the surface of the semiconductor substrate, and a thin film is deposited on the semiconductor substrate. At this time, the thin film also adheres to the inner wall of the reactor and the surface of the wafer support such as the susceptor. These undesired deposits accumulate each time the thin film formation process is repeated, and eventually become contaminants that peel off the reactor inner wall and susceptor surface and float in the reactor. This contaminant causes defects in the semiconductor circuit during the manufacturing stage, resulting in a decrease in yield.

  In order to solve this problem, there is a method of periodically cleaning the inside of the reactor. For example, in order to remove contaminants attached to the inner wall of the reactor, there is a method of removing the contaminants by introducing a cleaning gas into the reactor and separating the contaminants into gaseous materials. As one method, U.S. Pat. No. 5,788,778 and U.S. Pat. No. 5,844,195, which are incorporated herein by reference, use a second plasma separated from the reactor using NF3 as a cleaning gas. A remote plasma cleaning method is disclosed in which NF3 is activated by plasma excitation using microwaves in a discharge chamber. According to this method, flow-controlled NF3 is introduced into the second plasma discharge chamber, which is dissociated by the 2.45 GHz microwave applied from the microwave oscillator to the second plasma discharge chamber through the waveguide and Activated to produce fluorine active species. In order to efficiently achieve microwave plasma discharge, a pressure regulating valve is provided between the second plasma discharge chamber and the reactor, and the pressure inside the second plasma discharge chamber is maintained at a specified pressure. The The fluorine active species thus generated is introduced into the reactor through a conduit, and decomposes and removes contaminants deposited on the reactor inner wall and the susceptor.

However, in the above-described conventional method, in the process of introducing the fluorine active species into the reactor, the fluorine active species react with components such as piping in the middle of the reactor and the shower plate inside the reactor. The amount of fluorine active species introduced is reduced compared to the initial generation. As a result, there is a problem that the cleaning time of the reactor is increased and the productivity of the apparatus is lowered.
US Pat. No. 5,788,778 US Pat. No. 5,844,195

  An object of the present application is to provide a highly productive substrate processing apparatus that shortens the cleaning time of the reactor.

In one aspect of the present invention, the substrate processing apparatus comprises:
A reactor,
A susceptor for placing an object to be processed provided in the reactor;
A shower plate inside the reactor, disposed in parallel to face the susceptor, and having a plurality of pores for injecting a gas toward the object to be processed;
A remote plasma chamber provided remotely from the reactor;
A gas introduction pipe connecting the remote plasma chamber and the reactor;
With
Within the remote plasma chamber, a cleaning gas is activated,
The shower plate has a gas introduction surface through which gas is introduced through the gas introduction pipe, and a gas injection surface for injecting the gas onto the surface of the object to be processed through the plurality of pores. Although the surface treatment is performed, the gas introduction surface is not surface-treated.

  According to the present application, the time required for cleaning the reactor can be shortened, and a highly productive substrate processing apparatus can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First embodiment of the invention]
FIG. 1 schematically shows a semiconductor processing apparatus according to a first embodiment of the present invention. The semiconductor processing apparatus 1 according to the first embodiment includes a reactor 2, a susceptor 4 installed inside the reactor 2 for supporting a semiconductor substrate 3, and located inside the reactor 2, facing the susceptor 4. A shower plate 5 disposed in parallel therewith and a remote plasma chamber 6 disposed away from the reactor are configured.

  The susceptor 4 embeds, for example, a resistance heater (not shown), and heats and holds the semiconductor substrate 3 at a desired temperature. Further, the susceptor 4 is coupled to the lifting mechanism 7 and can move up and down in the vertical direction. Further, when the semiconductor processing apparatus is a plasma CVD apparatus, the susceptor 4 is electrically grounded 8 and defines one electrode for plasma discharge.

  A transfer chamber (not shown) is coupled to the reactor 2 via a gate valve 9. In addition, an exhaust port 10 is provided at the bottom of the reactor 2, and the exhaust port 10 is coupled to a vacuum exhaust pump (not shown) via a conductance adjustment valve 11 so that the inside of the reactor 2 has a desired pressure. Controlled.

  The shower plate 5 has a plurality of pores (see FIG. 2) for injecting gas uniformly to the semiconductor substrate 3. A gas inlet 19 is provided in the upper part of the shower plate, and the gas inlet 19 is connected to the remote plasma chamber 6 through the gas inlet tube 12. A pipe 13 is coupled to the gas introduction pipe 12, and the pipe 13 is coupled to a source gas supply device (not shown). In the case where the semiconductor processing apparatus 1 is a plasma CVD apparatus, the shower plate 5 is electrically connected to a high frequency oscillator 14 (for example, 13.56 MHz) via an output cable 15, and the other electrode for plasma discharge. Is defined. In addition, a matching circuit 16 may be provided between the high-frequency oscillator 14 and the shower plate 5.

  The remote plasma chamber 6 is connected to a microwave oscillator (not shown) that generates a microwave of 2.45 GHz, for example. A pipe 17 is coupled to the remote plasma chamber 6, and a cleaning gas such as NF 3 is supplied through the pipe 17. A valve 18 is provided in the gas introduction pipe 12.

  The shower plate 5 of the substrate processing apparatus according to the first embodiment of the present invention is shown in FIG. FIG. 2A is a sectional view of the shower plate 5, and FIG. 2B is a partial enlarged sectional view of the shower plate 5. The same components as those in FIG. 1 are denoted by the same reference numerals.

  The shower plate 5 of the substrate processing apparatus according to the first embodiment of the present invention has an upper gas introduction surface 21, a lower gas injection surface 22, and a divisor that penetrates between the gas introduction surface 21 and the gas injection surface 22. One hundred to several thousand pores 23 are provided. The shower plate 5 is made of, for example, aluminum or an aluminum alloy by polishing or grinding, but may be made of other metals, ceramics, or the like.

  As shown in FIG. 2B, in the first embodiment of the present invention, for example, an anodic oxide film treatment 24 is applied to the gas injection surface 22 of the shower plate 5. Similarly, the side surfaces of the pores 23 are also subjected to anodic oxide film treatment 25. On the other hand, the gas introduction surface 21 is not subjected to an anodic oxide film treatment. In the first embodiment of the present invention, by configuring the shower plate 5 in this way, loss of active species can be prevented, and a highly productive substrate processing apparatus can be provided. Hereinafter, this point will be described in detail.

  Originally, the anodic oxide film is applied to the shower plate in order to protect the aluminum or aluminum alloy constituting the shower plate from corrosion and sputtering accompanying the plasma reaction. However, there is also an aspect of depriving the activity of the cleaning active species.

  The inventors of the present application have obtained knowledge on this point. That is, by performing the anodic oxide film treatment only on the gas injection surface side of the shower plate 5, corrosion and sputtering associated with the plasma reaction are prevented, and at the same time, the gas introduction surface side is not subjected to the anodic oxide film treatment. They found that deactivation could be minimized.

  In order to improve the cleaning speed of the shower plate, it is effective to keep the temperature of the shower plate at a high temperature. The shower plate 5 is heated by the radiant heat from the susceptor 4, and the anodic oxide film applied to the gas injection surface absorbs infrared rays and has an action of keeping the shower plate 5 at a high temperature. In addition, a heater for a shower plate or a temperature control device may be provided on the upper surface of the reactor.

  Next, a method for producing a shower plate according to the first embodiment of the present invention will be described.

  First, a shower plate is produced from aluminum or an aluminum alloy by machining using a known polishing or grinding technique.

  Next, after dimensional inspection of the produced shower plate, degreasing cleaning is performed to remove impurities.

  Subsequently, masking for preventing the formation of the anodized film is performed on the gas introduction surface of the shower plate.

  Next, the entire shower plate is anodized through a pretreatment process for removing the natural oxide film or impurities on the surface of the shower plate. Thereafter, a cleaning process is performed as a post-treatment to remove the chemical solution.

  Finally, the masking of the gas introduction surface is removed and the anodic oxide film is inspected. In addition, after removing the mask, the gas introduction surface may be flattened by performing at least one of chemical and mechanical polishing. Further, a fluorination passivation treatment may be performed on the gas introduction surface.

  Next, the operation of the substrate processing apparatus according to the first embodiment of the present invention will be described in detail.

  First, after the processed semiconductor substrate 3 is unloaded through the gate valve 9, the gate valve is closed and the inside of the reactor 2 is evacuated, and then a valve (not shown) provided in the pipe 13 is closed.

  Next, the valve 18 is opened, and a cleaning gas such as NF 3 is supplied to the remote plasma chamber 6 through the pipe 17.

  Subsequently, a microwave of 2.45 GHz is applied to the remote plasma chamber 6, the cleaning gas is dissociated, activated to generate fluorine active species, and introduced into the shower plate 5 through the gas introduction pipe 12.

  Finally, fluorine active species are introduced into the reactor 2 from the pores 23 of the shower plate 5, and the deposits adhering to the inner wall of the reactor 2 or the surface of the susceptor 4 are decomposed into gaseous materials and exhausted from the exhaust port 10. .

  Comparative Example 1 in which the entire surface of the shower plate was subjected to anodic oxide film processing, Comparative Example 2 in which the entire surface of the shower plate was not subjected to anodic oxide film processing, and anodic oxide film processing only on one side according to the first embodiment of the present invention The applied example will be described because an experiment for measuring the reactor cleaning speed and an experiment for examining the relationship between the number of processed wafers and the number of particles on the wafer were performed.

  Table 1 compares the reactor cleaning rate (nm / min) for Comparative Example 1, Comparative Example 2, and Example. FIG. 3 shows the shower plate of Comparative Example 1. 3A is a cross-sectional view of a conventional shower plate of Comparative Example 1, and FIG. 3B is a partially enlarged cross-sectional view thereof. The same components as those in FIG. 2 are denoted by the same reference numerals. As shown in FIG. 3B, in the conventional shower plate, an anodic oxide film 31 is provided on the gas introduction surface 21 and an anodic oxide film 24 is provided on the gas injection surface 22.

表１の結果より、比較例１と比較例２を対比すると、全面に陽極酸化膜処理を施した比較例１の方が、陽極酸化膜処理を施さない比較例２に比べリアクタのクリーニング速度が遅いことがわかる。これは、シャワープレートの全面に付着された陽極酸化膜表面の微細な構造により、遠隔プラズマチャンバで生成されたクリーニング活性種の活性が奪われるためであると推測される。

From the results of Table 1, when comparing Comparative Example 1 and Comparative Example 2, the cleaning speed of the reactor in Comparative Example 1 in which the entire surface was subjected to the anodic oxide film treatment was higher than in Comparative Example 2 in which the anodic oxide film treatment was not performed. I understand that it is slow. This is presumably because the activity of the cleaning active species generated in the remote plasma chamber is deprived by the fine structure of the surface of the anodized film attached to the entire surface of the shower plate.

  Further, when Comparative Example 1 is compared with the Example, it can be seen that the cleaning rate is greatly improved in the Example in which the anodic oxide film treatment is performed only on one side. From this result, it was proved that the shower plate according to the first embodiment of the present invention can sufficiently suppress the deactivation of the cleaning active species.

  FIG. 4 is a graph showing the relationship between the number of wafers processed and the number of particles on the wafer for Comparative Example 1, Comparative Example 2 and Examples described above. According to the shower plate according to the first embodiment of the present invention, even when the number of wafers processed increases, the number of particles does not increase, and it has been proved that the effect of suppressing contaminants can be sufficiently obtained. .

  According to the first embodiment of the present invention, it is possible to suppress the deactivation of cleaning active species, improve the reactor cleaning speed, and provide stable process performance. As a result, it is possible to improve productivity by reducing the amount of gas required for cleaning and shortening the cleaning time.

[Second Embodiment of the Invention]
Next, a substrate processing apparatus according to a second embodiment of the present invention will be described. The substrate processing apparatus according to the second embodiment is different from the first embodiment in that an anodic oxide film is not provided on the side surfaces of the pores 23 of the shower plate.

  Since other configurations and operations are the same as those in the first embodiment, the description thereof is omitted.

  According to the second embodiment of the present invention, the deactivation of cleaning active species can be further suppressed, and the reactor cleaning speed can be improved and stable process performance can be provided. As a result, it is possible to improve productivity by reducing the amount of gas required for cleaning and further shortening the cleaning time.

[Others]
Although specific embodiments of the present invention have been described above, the structure of the apparatus disclosed herein is merely an example, and various configurations can be made without departing from the spirit of the present invention described in the claims of the utility model registration. Those skilled in the art know that modifications and changes are possible.

  For example, although embodiments of the present invention have been described with reference to plasma CVD apparatus, thermal CVD apparatus, atomic layer deposition apparatus (ALD), plasma enhanced atomic layer deposition apparatus (PE-ALD), physical vapor deposition The same applies to the apparatus (PVD). Needless to say, the present invention can be applied not only to the anodic oxide film but also to a coating film having a similar function.

1 is a schematic view of a substrate processing apparatus according to the present invention. FIG. 2A is a sectional view of the shower plate of the substrate processing apparatus according to the first embodiment of the present invention, and FIG. 2B is a partially enlarged sectional view of the shower plate. FIG. 3A is a sectional view of a shower plate of a conventional substrate processing apparatus, and FIG. 3B is a partially enlarged sectional view of the shower plate. The relationship between the number of particles on the wafer and the number of wafers processed when the anodized film is treated on the entire surface of the shower plate, when the anodized film is treated on one side, or when the anodized film is not treated on the entire surface It is a graph which shows.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Semiconductor manufacturing apparatus, 2 ... Reactor, 3 ... Semiconductor substrate, 4 ... Susceptor, 5 ... Shower plate, 6 ... Remote plasma chamber, 7 ... Lifting device, 8 ... Grounding, 9 ... Gate valve, 10 ... Exhaust port, 11 ... Conductance adjustment valve, 12 ... Gas introduction pipe, 13 ... Pipe, 14 ... High frequency oscillator, 15 ... ..Output cable, 16... Matching circuit, 17 .piping, 18 .valve, 19... Gas introduction port, 21. ..Pore, 24 ... anodized film, 25 ... anodized film.

Claims (5)

A reactor,
A susceptor for placing an object to be processed provided in the reactor;
A shower plate inside the reactor, disposed in parallel to face the susceptor, and having a plurality of pores for injecting a gas toward the object to be processed;
A remote plasma chamber provided remotely from the reactor;
A gas introduction pipe connecting the remote plasma chamber and the reactor;
With
Within the remote plasma chamber, a cleaning gas is activated,
The shower plate has a gas introduction surface through which gas is introduced through the gas introduction pipe, and a gas injection surface for injecting the gas onto the surface of the object to be processed through the plurality of pores. Although the film coating process is performed, the gas introduction surface is not subjected to a film coating process.
Substrate processing equipment. The substrate processing apparatus according to claim 1, wherein an inner surface of the plurality of pores is also subjected to a film coating process. The substrate processing apparatus according to claim 1, wherein the film coating process is an anodic oxide film process. The substrate processing apparatus according to claim 1, wherein the film coating process is a coating process. 5. The substrate processing apparatus according to claim 1, wherein at least one of chemical and mechanical polishing is performed on the gas introduction surface. 6.

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