JPH0897154A - Vacuum film formation system - Google Patents

Abstract

PURPOSE: To prevent dust from flying up and chemical reaction with the components of the air from being initiated, by attaching filters direct to a jet nozzle positioned in a reaction chamber, and supplying the chamber with film formation gas through the nozzle. CONSTITUTION: A vertical low-pressure CVD system is provided with a new jet nozzle 10A instead of an ordinary jet nozzle 10. The new jet nozzle vertically extends along the inside wall of the inner tube 3, and has a filter 17 buried in each of a plurality of jet holes 9 that are positioned at equal intervals and face the reaction chamber 6. The filters 17 attached to the jet holes 9 in the jet nozzle 10A distributes the flow of fed reaction gas throughout the interior of the reaction chamber 6, and thus decelerates the rate of the gas flow. This prevents dust from flying up. Further, if the components of the air stick to the surface of the filters 17 at the time of exposure to the air after the completion of film formation, the filters 17 remove the components, which prevents products from being produced through the chemical reaction with the components of the air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum film forming apparatus such as a hot wall type vertical low pressure CVD apparatus, a plasma CVD apparatus or a cold wall type thermal CVD apparatus used for manufacturing a semiconductor device or the like. The present invention relates to an injection nozzle that is introduced into a vacuum film forming chamber and supplies a film forming gas.

[0002]

2. Description of the Related Art First, various conventional vacuum film forming apparatuses will be described with reference to FIGS. It should be noted that these explanations will be made by taking an example of forming a thin film on the surface of a semiconductor wafer. FIG. 4 is a schematic view of a vertical low-pressure CVD apparatus of the prior art, FIG. 4A is a sectional side view thereof, FIG. 4B is an enlarged sectional view of the injection nozzle shown in FIG. FIG. 1A is a schematic view of a plasma CVD device of the technology,
Is a cross-sectional side view, FIG. B is an enlarged cross-sectional view of the injection nozzle shown in FIG. A, and FIG. 6 is a schematic view of a conventional plasma CVD apparatus. B of the same drawing is an enlarged sectional view of the injection nozzle shown in A of the same figure.

FIG. 4 shows a hot-wall type vertical low-pressure CVD apparatus 1 which is a first example of a vacuum film forming apparatus. In addition to the reaction furnace 2, this vertical low-pressure CVD apparatus 1 actually transfers a plurality of semiconductor wafers S from a carrier to a quartz boat during film formation, or after the film formation, a quartz boat. From the wafer transfer chamber to the reaction furnace 2 and from the reaction furnace 2 to the wafer transfer chamber. And a mass flow controller that controls the flow rates of various reaction gases, a controller that controls the entire apparatus by a program, and a furnace body that heats the entire length of the reaction furnace 2 from the outside. Only the relevant reactor 2 is shown.

The reaction furnace 2 comprises an inner tube 3 and an outer tube 4, and the inner tube 3 and the outer tube 4 are hermetically supported by a common support flange 5. The inner side of the inner pipe 3 is a reaction chamber 6, and the support flange 5 is provided in the reaction chamber 6.
A gas supply pipe 8 is introduced through an opening 7 formed in the injection nozzle 1, and a tip of the gas supply pipe 8 extends vertically along the inner side of the inner pipe 3 to form an injection nozzle 1.
0 is connected and installed. The injection nozzle 10 is provided with a plurality of injection ports 9 facing the reaction chamber 6 at equal intervals. A filter 11 is provided at the other end of the gas supply pipe 8.
Are connected and configured to filter the reaction gas from the reaction gas source 12. Reference numeral 13 is an exhaust port formed in the support flange 5.

On the other hand, a plurality of semiconductor wafers S held in the quartz vertical boat 14 at equal intervals in the wafer transfer chamber are
The vertical boat 14 supported by the cap 15 is housed in the reaction chamber 6 above by an elevator (not shown). At the end of this storage, the support flange 5
The inside of the reaction furnace 2 is hermetically sealed with an O-ring 16 for sealing interposed between the bottom surface of the reactor and the upper surface of the cap 15.

In this way, the semiconductor wafer S is sealed,
While heating the reaction chamber 6 in a vacuum with the furnace body, the reaction gas from the reaction gas source 12 is passed through the filter 11,
A desired thin film can be formed on the surface of the semiconductor wafer S by supplying the gas from the gas supply pipe 8 to the injection nozzle 10 and uniformly injecting the gas from the plurality of injection ports 9 into the reaction furnace 2. The reaction gas after the reaction rises in the inner pipe 3, hits the dome-shaped upper end of the outer pipe 4, and descends along the outer pipe 4,
The gas is exhausted from the exhaust port 13 to the outside.

Next, FIG. 5 shows a plasma CVD apparatus 20 which is a second example of a vacuum film forming apparatus. This plasma CVD
In the apparatus 20, a disk-shaped upper electrode 22 and a susceptor 23 are installed in a chamber 21 so as to face the upper electrode 22. In the structure of the upper electrode 22, as shown in FIG. 5B, an injection nozzle 25 is connected to a gas supply pipe 24, and a plurality of injection ports 26 uniformly branched from the injection nozzle 25.
Are arranged so as to face the lower surface of the upper electrode 22. A filter 27 is connected to the other end of the gas supply pipe 24, and is configured to filter the reaction gas from the reaction gas source 28.

When a thin film is formed on the surface of the semiconductor wafer S by the plasma CVD apparatus 20, each semiconductor wafer S is placed on the susceptor 23 and the chamber 21 is evacuated. A high voltage is applied from the upper electrode 22, a filter 27 is supplied from the reaction gas source 28, a gas supply pipe 24 supplies an injection nozzle 25, and the plurality of injection ports 26 uniformly inject into the chamber 21. Then, a desired thin film can be formed on the surface of the semiconductor wafer S.

Next, FIG. 6 shows a cold wall type thermal CVD apparatus 30 which is a third example of the vacuum film forming apparatus. In this thermal CVD apparatus 30, a susceptor 32 is installed in a chamber 31, and a rod-shaped injection nozzle 33 is installed vertically along the inner wall of the chamber 31 next to the susceptor 32. As shown in FIG. 6B, this injection nozzle 33 is connected to the tip of a gas supply pipe 34, and its structure is such that a plurality of injection ports 36 uniformly branched from a common pipe 35 are inside the chamber 31. It is arranged facing the surface. A filter 37 is connected to the other end of the gas supply pipe 34, and is configured to filter the reaction gas from the reaction gas source 38.

When a thin film is formed on the surface of the semiconductor wafer S by the thermal CVD apparatus 30, each semiconductor wafer S is placed on the heated susceptor 32 and the inside of the chamber 21 is depressurized. Alternatively, when heated under a normal pressure state, passed through the filter 37 from the reaction gas source 38, supplied to the injection nozzle 33 from the gas supply pipe 34, and uniformly injected into the chamber 31 from the plurality of injection ports 36, A desired thin film can be formed on the surface of the semiconductor wafer S.

[0011]

These conventional vertical low-pressure CVD apparatus 1, plasma CVD apparatus 20, thermal CVD
In a vacuum film forming apparatus such as the apparatus 30, the flow velocity of the reaction gas injected from the injection port (9, 26, 36) of the injection nozzle (10, 25, 33) is high, and the reaction gas flow causes the reaction chamber or the chamber to flow. Since dust in the vacuum film forming chamber such as (6, 21, 31) is soared, it is one of the causes for generating particles on the surface of the semiconductor wafer S.

After the film formation is completed, when the vacuum film formation chamber is opened to the atmosphere, atmospheric components such as oxygen, nitrogen, and water vapor flow back from the ejection port of the ejection nozzle, and these components flow through the respective filters (11, 27,). Adsorbs on a large surface area of 37). All of the above-mentioned atmospheric components are disposed in the middle of the gas supply pipes (8, 24, 34) and have a large resistance, so that it is sufficient to evacuate the reaction furnace 2 for the next work. Can not be removed. Therefore, when a reaction gas is flown during the next film formation, the reaction gas reacts with the atmospheric components adsorbed on the filter to produce a product. This flows into the vacuum film forming chamber together with the reaction gas, which is also one of the causes for generating particles on the surface of the semiconductor wafer S.

Furthermore, in a vacuum film forming apparatus using a plurality of types of reaction gases, a main reaction gas type injection nozzle and a sub reaction gas type injection nozzle face the inside of the reaction furnace, and such a vacuum is used. When a film is formed by a film forming apparatus, generally,
First, a side reaction gas is flown into the vacuum film forming chamber to create a side reaction gas atmosphere. In this case, since the injection nozzle of the conventional injection nozzle has an opening, the side reaction gas flows back to the injection nozzle of the main reaction gas system from the injection nozzle, and when the main reaction gas flows, the gas supply pipe A chemical reaction occurs inside to produce a product. This is one of the causes for causing particles to flow into the vacuum film forming chamber together with the reaction gas. An object of the vacuum film forming apparatus of the present invention is to solve such a problem.

[0014]

Therefore, in the vacuum film forming apparatus of the present invention, the injection nozzle is introduced into the vacuum film forming chamber such as the reaction chamber or the chamber without disposing the filter in the middle of the gas supply pipe. The problem is solved by supplying the film forming gas into the vacuum film forming chamber with the filter directly attached to the.

[0015]

Therefore, according to the vacuum film forming apparatus of the present invention, the flow of the supplied reaction gas can be spread throughout the vacuum film forming chamber by the filter attached to the injection port of the injection nozzle. The flow velocity can be slowed. Therefore, it is possible to prevent dust from rising. Further, by mounting a filter on the injection port of the injection nozzle arranged in the vacuum film forming chamber, it is possible to sufficiently remove the atmospheric components adsorbed on the filter, so that it is found in the prior art when a reaction gas is flown. No products are generated by chemical reaction with atmospheric components.

[0016]

EXAMPLES Next, the vacuum film forming apparatus of the present invention will be described with reference to FIGS. 1 is a cross-sectional side view showing an injection nozzle of a vertical low-pressure CVD apparatus according to a first embodiment of the present invention, and FIG. 2 is a view corresponding to FIG. 5B. FIG. 3 is a sectional side view showing an injection nozzle of a plasma CVD apparatus according to a second embodiment of the present invention,
3 is a view corresponding to FIG. 6B and is a cross-sectional side view showing the injection nozzle of the thermal CVD apparatus according to the third embodiment of the present invention. The same components as those of the conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

First, the injection nozzle of the vertical low pressure CVD apparatus according to the first embodiment of the present invention will be described with reference to FIG.
In the vertical low-pressure CVD apparatus of the present invention, the filter 11 in the conventional vertical low-pressure CVD apparatus 1 shown in FIG. 4A is removed, and instead, the inner tube 3 is extended in the vertical direction along the inside, An injection nozzle 10 in which a filter 17 was embedded was arranged at each of a plurality of injection ports 9 opened toward the reaction chamber 6 at equal intervals.

Next, also in the plasma CVD apparatus according to the second embodiment of the present invention, the filter 27 in the conventional plasma CVD apparatus 20 shown in FIG. 5A is removed, and instead, as shown in FIG. , Upper electrode 22
A filter 29 was covered so as to cover at least each of the injection ports 26 of the injection nozzle 25 provided in the above.

Also in the subsequent thermal CVD apparatus according to the third embodiment of the present invention, the filter 37 in the prior art plasma CVD apparatus 30 shown in FIG. 6A is removed, and instead shown in FIG. So that each injection port 3
The filter 39 was covered so as to cover all the rod-shaped injection nozzles 33 including No. Of course, the structure may be such that only the injection port 36 is covered with a filter.

When a usual polycrystalline silicon film, a silicon nitride film, or a silicon oxide film is formed on the surface of the semiconductor wafer S, the injection nozzle for supplying the reaction gas is a cross section of the injection port. When the shape is circular, semicircular or rectangular, the reaction gas can be supplied uniformly. Further, regarding an injection nozzle having a large number of injection ports used in a process reaction system using a horizontal CVD apparatus, it is preferable to have a structure in which a filter is attached to the reaction gas outlet.

In the SiH ₄ process reaction system, the oxygen gas and water adsorbed on the filter in the gas supply pipe chemically react with SiH _{4 in} the SiH ₄ process reaction system by constructing the jet nozzle as described above. Although particles of SiO ₂ were generated, the generation of these particles could be reduced in the present invention. In addition, SiH ₂ Cl ₂ -NH
_{In the three-} process reaction system, SiH ₂ C
NH ₃ flows backward in the gas supply pipe for flowing l ₂ ,
_{When 2} Cl ₂ was flown, NH ₄ Cl was generated and became particles, but in the present invention, since the filter is attached to the injection port of the injection nozzle, the resistance becomes very large, and therefore NH ₃ flows almost backward. No longer, NH ₄ Cl
It was possible to reduce particles without generating

[0022]

Therefore, according to the vacuum film forming apparatus of the present invention using these injection nozzles, the flow of the reaction gas supplied to the entire vacuum film forming chamber is controlled by the filter attached to the injection port of the injection nozzle. The flow rate of the reaction gas can be slowed down. Therefore, it is possible to prevent dust from rising. Particularly, in the plasma CVD apparatus using the injection nozzle shown in FIG. 2, the reaction gas can be more uniformly supplied to the entire surface of the semiconductor wafer, and the uniformity of the thin film thickness can be improved.

Further, when the atmospheric components are adsorbed on the surface of the filter when the atmosphere is released after the film formation is completed, the atmospheric components adsorbed on the filter are sufficiently removed by attaching the filter to the injection port. Therefore, when a reaction gas is flowed, a product due to a chemical reaction with atmospheric components found in the prior art does not occur.

Furthermore, since a filter is attached to the injection port,
Even if the atmosphere in the reaction chamber tries to flow backward, the resistance is large, so that the backflow can be prevented. Therefore, it is possible to suppress the generation of reaction products in the gas supply pipe, and it is possible to suppress the generation of particles.

[Brief description of drawings]

FIG. 1 is a vertical low pressure CVD which is a first embodiment of the present invention.
It is a cross-sectional side view which shows the injection nozzle of an apparatus.

FIG. 2 is a plasma CVD which is a second embodiment of the present invention.
It is a cross-sectional side view which shows the injection nozzle of an apparatus.

FIG. 3 is a sectional side view showing an injection nozzle of a thermal CVD apparatus that is a third embodiment of the present invention.

4 is a schematic view of a vertical low-pressure CVD apparatus of the prior art, FIG. 4A is a sectional side view thereof, and FIG. 4B is an enlarged sectional view of the injection nozzle shown in FIG.

5A and 5B are schematic views of a conventional plasma CVD apparatus, wherein FIG. 5A is a sectional side view thereof, and FIG. 5B is an enlarged sectional view of the injection nozzle shown in FIG.

6A and 6B are schematic views of a conventional plasma CVD apparatus, in which FIG. 6A is a sectional side view thereof, and FIG. 6B is an enlarged sectional view of the injection nozzle shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical low-pressure CVD apparatus 2 Reaction furnace 3 Inner tube 4 Outer tube 5 Support flange 6 Reaction chamber 7 Opening 8 Gas supply pipe 9 Injection port 10A Injection nozzle 12 Reaction gas source 13 Exhaust port 14 Vertical boat 15 Cap 16 O-ring 17 Filter 20 Plasma CVD apparatus 21 Chamber 22 Upper electrode 23 Susceptor 24 Gas supply pipe 25 Injection nozzle 26 Injection port 27 Filter 28 Reactive gas source 29 Filter 30 Thermal CVD device 31 Chamber 32 Susceptor 33 Injection nozzle 34 Gas supply pipe 35 Pipe 36 Injection port 37 Filter 38 Reactive Gas Source 39 Filter

Claims (1)

[Claims] 1. A vacuum characterized in that a film forming gas is supplied to the vacuum film forming chamber with a filter directly attached to a film forming gas injection nozzle introduced into the vacuum film forming chamber. Deposition apparatus.