JP7191558B2 - Film forming apparatus, film forming method, and cleaning method - Google Patents

Description

The present invention relates to a film forming apparatus, a film forming method, and a cleaning method, and more particularly to a technique suitable for use in film formation by CVD or ALD.

2. Description of the Related Art In the manufacture of semiconductors and the like, film forming apparatuses using techniques such as the ALD (atomic layer deposition) method and the CVD (chemical vapor deposition) method are used.

The CVD method, the plasma CVD method, and the ALD method are methods of forming films using gases such as raw material gases. In the film forming apparatus that implements these methods, when introducing the raw material gas into the film forming space, it is necessary to introduce it into the film forming space via a shower head structure or the like. Film forming apparatuses described in Patent Documents 1 to 3 are known as apparatuses that satisfy such requirements.

Japanese Unexamined Patent Application Publication No. 2005-11904 JP 2005-163183 A JP 2012-238644 A

In these film forming apparatuses, when forming a film on a substrate to be processed, the substrate to be processed is placed in a substrate processing vessel and a predetermined film is formed. There are many examples of thin films formed on substrates to be processed. In the substrate processing container, the thin film adheres to the inner wall of the substrate processing container, or to the members inside the substrate processing container such as the substrate holding table. It becomes sediments. The deposit thus attached increases in thickness as the film formation by the substrate processing apparatus is repeated, and eventually peels off. The peeled deposit floats in the substrate processing vessel and is incorporated into the thin film formed on the substrate to be processed during the film formation process as described above, causing a problem of degrading the film quality of the thin film.

Therefore, a cleaning method has been proposed as a method for removing deposits such as those described above from a substrate processing container (see, for example, Patent Documents 2 and 3). According to this, a remote plasma generator for generating fluorine radicals (F ^* ) or the like is provided outside the substrate processing vessel for cleaning, and NF ₃ is excited by microwaves or the like to generate fluorine radicals (F ^* ) or the like. and introducing the fluorine radicals into the substrate processing container to vaporize the above deposits and discharge them out of the substrate processing container.

Furthermore, in film formation by the ALD method or the CVD method, as described in Patent Document 3, before supplying the source gas to the substrate to be processed, a gas diffusion chamber having an enlarged diameter in the direction of gas flow velocity is used. In some cases, raw material gases are jetted from nozzles to mix or diffuse the raw material gases.

However, in the cleaning as described above, it is also necessary to clean the gas diffusion chamber with an enlarged diameter. There is a possibility that it reaches the upstream side where there is no gaseous part. In this case, during the film formation after cleaning, residues generated in the source gas supply pipe, etc. due to unnecessary etching may be incorporated into the thin film to be formed, and the film quality of the thin film may deteriorate as contamination in the film. Gender was also a concern.
In addition, in patent document 2, such a problem is not pointed out.

The present invention has been made in view of the above circumstances, and aims to achieve the following objects.
1. To sufficiently reduce the occurrence of damage in the film forming apparatus configuration due to cleaning.
2. To reduce particle generation caused by cleaning.
3. To set an active state such as ions in the cleaning gas to a predetermined state.
4. To suppress the occurrence of damage during cleaning of a source gas supply pipe.

A film forming apparatus of the present invention comprises a film forming chamber for storing a film forming substrate;
a raw material gas supplying means for supplying a raw material gas for forming a film on the film formation substrate;
a gas diffusion unit connected to the film forming chamber and having an enlarged diameter for diffusing the raw material gas supplied from the raw material gas supply means before being supplied to the film forming chamber;
a nozzle connected to the raw material gas supply means for ejecting the raw material gas to the gas diffusion section; a valve provided in the gas diffusion section so as to be switchable between a closed state during film formation and an open state during cleaning;
a first cleaning gas supply unit connected to the valve and capable of supplying plasmatized first cleaning gas to the gas diffusion unit and the deposition chamber;
a second cleaning gas supply unit connected to the nozzle and capable of supplying a second cleaning gas to the gas diffusion unit;
a switching means capable of switching the gas supplied to the nozzle between the raw material gas during film formation and the second cleaning gas during cleaning;
has
At the time of film formation, the raw material gas can be jetted from the nozzle to the gas diffusion part in which the valve is in a closed state,
During cleaning, the first cleaning gas can be supplied from the opened valve to the gas diffusion portion, and the switching means is switched to supply the second cleaning gas from the nozzle during cleaning to the gas diffusion portion. It is possible to squirt into the part,
The above problem is solved by providing the nozzle in the gas diffusion section so as to eject the second cleaning gas toward the valve .
In the film forming apparatus of the present invention, the direction of the second cleaning gas ejected from the nozzle is set in the gas diffusion section so as to intersect the first cleaning gas supplied from the valve. is more preferred.
In the film forming apparatus of the present invention, the nozzle may be provided in the gas diffusion section at a position facing the valve .
Also , the first cleaning gas may be a halogen-based gas, and the second cleaning gas may be an inert gas.
Further, a cleaning method for a film forming apparatus of the present invention is a cleaning method for a film forming apparatus according to any one of the above,
At the time of cleaning, the plasmatized first cleaning gas is supplied from the first cleaning gas supply unit to the gas diffusion unit through the valve in an open state, and
switching the switching means to jet the second cleaning gas supplied from the second cleaning gas supply unit from the nozzle to the gas diffusion unit during cleaning,
causing the first cleaning gas from the valve and the second cleaning gas from the nozzle to intersect at the gas diffusion part,
An active state of the first cleaning gas supplied to the film forming chamber can be set to a predetermined state.
Further, a film forming method of a film forming apparatus according to the present invention is a film forming method in any one of the above film forming apparatuses,
a film formation step of closing the valve, switching the switching means, and ejecting the raw material gas from the nozzle to the gas diffusion portion;
The valve is opened to supply the first cleaning gas converted to plasma from the first cleaning gas supply section to the gas diffusion section through the valve, and the switching means is switched to switch the second cleaning gas. The second cleaning gas supplied from the supply unit is ejected from the nozzle to the gas diffusion unit, and the first cleaning gas from the valve and the second cleaning gas from the nozzle intersect at the gas diffusion unit. a cleaning step that causes
can have

A film forming apparatus of the present invention comprises a film forming chamber for storing a film forming substrate;
a raw material gas supplying means for supplying a raw material gas for forming a film on the film formation substrate;
a gas diffusion unit connected to the film forming chamber and having an enlarged diameter for diffusing the raw material gas supplied from the raw material gas supply means before being supplied to the film forming chamber;
a nozzle connected to the raw material gas supply means for ejecting the raw material gas to the gas diffusion portion;
a valve provided in the gas diffusion section so as to switch between a closed state during film formation and an open state during cleaning;
a first cleaning gas supply unit connected to the valve and capable of supplying plasmatized first cleaning gas to the gas diffusion unit and the deposition chamber;
a second cleaning gas supply unit connected to the nozzle and capable of supplying a second cleaning gas to the gas diffusion unit;
a switching means capable of switching the gas supplied to the nozzle between the raw material gas during film formation and the second cleaning gas during cleaning;
has
At the time of film formation, the raw material gas can be jetted from the nozzle to the gas diffusion part in which the valve is in a closed state,
During cleaning, the first cleaning gas can be supplied from the opened valve to the gas diffusion portion, and the switching means is switched to supply the second cleaning gas from the nozzle during cleaning to the gas diffusion portion. By opening the valve and supplying the plasmatized first cleaning gas to the gas diffusion portion, the switching means performs the cleaning step of ejecting the second cleaning gas from the nozzle, Deposits adhering to the film forming chamber in the film forming process (deposits resulting from the thin film adhering during the film forming process) can be removed. Further, the second cleaning gas is ejected from the nozzles to the first cleaning gas supplied to the gas diffusion section, thereby reducing the gas ions in the plasmatized first cleaning gas and generating gas radicals and gas molecules. By cleaning the inside of the film formation chamber by cleaning the inside of the film formation chamber, it is possible to realize cleaning in a state in which the occurrence of damage to metal members in the film formation chamber due to gas ions is reduced.

At the same time, by supplying the second cleaning gas to the nozzle serving as the raw material gas supply pipe in the film forming process, the first cleaning gas enters the nozzle and the upstream raw material gas supply pipe communicating with the nozzle. can be prevented.

By realizing cleaning in a state in which the occurrence of damage is reduced, it is possible to reliably reduce the generation of particles caused by members containing metal such as aluminum provided in the deposition chamber, thereby preventing the deterioration of the deposition characteristics. It becomes possible.

In addition, the inside of the deposition chamber can be cleaned without removing the shower member containing metal such as aluminum in the deposition chamber, and the shower member containing metal such as aluminum in the deposition chamber can be replaced in order to prolong the life of the shower member. It becomes possible to reduce the manufacturing cost by extending the interval.

In the film forming apparatus of the present invention, the direction of the second cleaning gas ejected from the nozzle is set in the gas diffusion section so as to intersect the first cleaning gas supplied from the valve. reduces the gas ions in the plasmatized first cleaning gas when the second cleaning gas is ejected from the nozzles in response to the first cleaning gas supplied to the gas diffusion section, thereby generating gas radicals and gas molecules. It becomes possible to clean the inside of the film forming chamber. As a result, cleaning can be achieved in a state in which the occurrence of damage to metal members in the deposition chamber due to gas ions is reduced.

Here, the intersecting of the first cleaning gas and the second cleaning gas means that the flow velocity of the first cleaning gas flowing from the valve is changed to reduce gas ions. , the crossing angle formed between the flow velocity direction of the first cleaning gas in the gas diffusion portion and the flow velocity direction of the second cleaning gas, which is the jetting direction of the nozzle, is within a predetermined range, and the crossing angle is 180°. It is also intended to include reverse or 0° parallel conditions.

Furthermore, the crossing angle formed between the flow velocity direction of the first cleaning gas in the gas diffusion portion and the flow velocity direction of the second cleaning gas, which is the ejection direction of the nozzle, can be 90° or more and 0° or less. . In particular, the intersection angle is 180°, that is, the second cleaning gas is ejected from the nozzle projecting in the vicinity of the center of the gas diffusion section toward the upstream of the supply side of the first cleaning gas in the gas diffusion section. Gas ions can be reduced.

In the film forming apparatus of the present invention, the nozzle is provided in the gas diffusion section at a position facing the valve, so that the raw material gas jetted from the nozzle is jetted toward the valve at the time of film formation. The raw material gas can be diffused, and the second cleaning gas jetted from the nozzle is jetted toward the valve in response to the first cleaning gas flowing from the valve during cleaning, whereby the first cleaning gas and the second cleaning are performed. It is possible to efficiently reduce gas ions by crossing and colliding with gas.

Further, in the present invention, the nozzle is provided in the gas diffusion section so as to eject the second cleaning gas toward the valve, so that the nozzle is directed to the valve, which is the position into which the first cleaning gas flows during cleaning. By ejecting the second cleaning gas from the nozzle, the second cleaning gas can effectively hit the first cleaning gas, and the gas ions can be efficiently reduced. At the same time, by ejecting the second cleaning gas from the nozzle in the cleaning process, it is possible to prevent the first cleaning gas from entering the inside of the nozzle and the source gas supply pipe or the like on the upstream side communicating with the nozzle.

Also, during film formation, the raw material gas ejected from the nozzle can be ejected toward the valve and diffused efficiently.

Further, by using a halogen-based gas as the first cleaning gas and an inert gas as the second cleaning gas, halogen ions are reduced during cleaning to prevent damage to the inside of the film forming chamber due to halogen radicals or halogen molecules. A small amount of cleaning can be realized, and the inert gas, which is the purge gas during film formation, can be used as the second cleaning gas as it is.

Here, the first cleaning gas can be a gas containing a fluorine compound or a gas containing a chlorine compound. Specifically, it may be selected from the group consisting of _CF4 , _C2F6 , _C3F8 , _SF6 , _{NF3 , CCl4} , _{C2Cl6 , C3Cl8 , SCl6 ,} and _NCl3 . can.
The second cleaning gas can be selected from nitrogen gas, argon gas.

Further, a cleaning method for a film forming apparatus of the present invention is a cleaning method for a film forming apparatus according to any one of the above,
At the time of cleaning, the plasmatized first cleaning gas is supplied from the first cleaning gas supply unit to the gas diffusion unit through the valve in an open state, and
switching the switching means to jet the second cleaning gas supplied from the second cleaning gas supply unit from the nozzle to the gas diffusion unit during cleaning,
crossing the first cleaning gas from the valve and the second cleaning gas from the nozzle at the gas diffusion part,
By setting the activation state of the first cleaning gas supplied to the film forming chamber to a predetermined state, the activation state of the plasmatized first cleaning gas, that is, the plasmatization of the first cleaning gas, in the cleaning step. By reducing the ratio of gas ions to gas radicals and gas molecules in the cleaning gas, the inside of the deposition chamber is cleaned mainly by gas radicals and gas molecules, thereby reducing the occurrence of damage to metal members in the deposition chamber caused by gas ions. In this state, it is possible to perform cleaning for removing deposits caused by the thin film adhered by the film forming process. As a result, the particles generated by the reaction between the metal such as aluminum contained in the members provided in the deposition chamber and the first cleaning gas are reliably reduced, thereby preventing deterioration of the deposition characteristics. becomes possible.

At the same time, in the cleaning process, the second cleaning gas is supplied to the nozzle, which serves as the raw material gas supply pipe in the film formation process, thereby preventing the first cleaning gas from entering the nozzle and the raw material gas supply pipe communicating with the nozzle. As a result, the first cleaning gas is prevented from reacting with metal such as SUS provided on the upstream side of the nozzle such as the raw material gas supply pipe, and the generation of particles in the nozzle is reliably reduced to form a film. It is possible to prevent deterioration of characteristics.

In addition, the inside of the deposition chamber can be cleaned without removing the shower member containing metal such as aluminum in the deposition chamber, and the shower member containing metal such as aluminum in the deposition chamber can be replaced in order to prolong the life of the shower member. It becomes possible to reduce the manufacturing cost by extending the interval.

Further, a film forming method of a film forming apparatus according to the present invention is a film forming method in any one of the above film forming apparatuses,
a film formation step of closing the valve, switching the switching means, and ejecting the raw material gas from the nozzle to the gas diffusion portion;
The valve is opened to supply the first cleaning gas converted to plasma from the first cleaning gas supply unit to the gas diffusion unit through the valve, and the switching means is switched to switch the second cleaning gas. The second cleaning gas supplied from the supply unit is ejected from the nozzle to the gas diffusion unit, and the first cleaning gas from the valve and the second cleaning gas from the nozzle intersect at the gas diffusion unit. a cleaning step that causes
By having A cleaning that cleans the inside of the deposition chamber with radicals and gas molecules and removes deposits caused by the thin film that has adhered during the deposition process in a state in which the occurrence of damage to metal members in the deposition chamber due to gas ions is reduced. can be realized. As a result, the particles generated by the reaction between the metal such as aluminum contained in the members provided in the film forming chamber and the first cleaning gas are reliably reduced, thereby preventing deterioration of characteristics during the film forming process. It becomes possible to perform the film-forming process in the state.

At the same time, in the cleaning process, the second cleaning gas is supplied to the nozzle, which serves as the raw material gas supply pipe in the film formation process, thereby preventing the first cleaning gas from entering the nozzle and the raw material gas supply pipe communicating with the nozzle. This prevents the metal such as aluminum provided in the source gas supply pipe from reacting with the first cleaning gas, reliably reduces the generation of particles in the nozzle, and causes the deterioration of characteristics in the film formation process. It is possible to perform the film forming process while preventing the

In addition, the inside of the deposition chamber can be cleaned without removing the shower member containing metal such as aluminum in the deposition chamber, and the shower member containing metal such as aluminum in the deposition chamber can be replaced in order to prolong the life of the shower member. It becomes possible to reduce the manufacturing cost by extending the interval.

According to the present invention, the occurrence of damage to metal members in the film formation chamber due to plasmatized cleaning gas is reduced to prevent deterioration of film formation characteristics, and a sufficient cleaning effect is exhibited, and the inside of the source gas supply pipe is cleaned. It is possible to achieve the effect of being able to prevent the occurrence of damage in the

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic cross section which shows 1st Embodiment of the film-forming apparatus which concerns on this invention. 2 is an enlarged schematic cross-sectional view showing the vicinity of a gas diffusion part in the first embodiment of the film forming apparatus according to the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a flowchart which shows 1st Embodiment of the cleaning method of the film-forming apparatus which concerns on this invention, and the film-forming method. FIG. 5 is a schematic enlarged cross-sectional view showing the vicinity of a gas diffusion part in a second embodiment of a film forming apparatus according to the present invention; FIG. 8 is a schematic enlarged cross-sectional view showing the vicinity of a gas diffusion part in a third embodiment of a film forming apparatus according to the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of a film forming apparatus, a film forming method, and a cleaning method according to the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a film forming apparatus according to this embodiment, and in the figure, reference numeral 10 denotes the film forming apparatus.

A film forming apparatus 10 according to this embodiment is an apparatus for performing a film forming process by a CVD method or an ALD method. As shown in FIG. , a raw material gas supplying means 20 for supplying a raw material gas as a film forming raw material, and a cleaning means 30 for cleaning the film forming chamber 11 .

The film forming chamber 11 is a processing container made of, for example, aluminum. A gate valve (not shown) is provided on the side wall of the film forming chamber 11 to be opened and closed when the substrate to be processed (substrate) S is carried in and out.

A substrate stage 13 on which the substrate S is placed during film formation is disposed in the film formation chamber 11 .
The position of the substrate S in the film forming chamber 11 is determined by being placed on the substrate stage 13 . Below the substrate stage 13, an elevating mechanism 13a is connected to move the substrate stage 13 vertically when the substrate S is carried in and out. The lifting mechanism 13a can also serve as a rotation driving mechanism for rotating the substrate stage 13 when the substrate S is rotated during film formation.
A substrate elevating mechanism (not shown) such as lift pins for elevating the substrate S when the substrate S is loaded or unloaded can be provided below the substrate stage 13 .

An outer peripheral ring 13 b is provided at the peripheral edge of the substrate stage 13 to cover the outer peripheral portion of the substrate S and the side periphery of the substrate stage 13 . The outer ring 13b can be made of, for example, Al ₂ O ₃ or AlN containing aluminum.

The peripheral outer side of the substrate stage 13 is separated from the side portion of the film forming chamber 11 so as not to come into contact with the substrate stage 13, and the substrate stage 13 can rotate and move up and down.
A backside gas supply unit 19 is connected to the lower side of the substrate stage 13 in the film forming chamber 11 to supply the backside gas so that the raw material gas does not enter the lower side of the substrate stage 13 through the outer peripheral gap of the substrate stage 13 . there is

An exhaust mechanism 11vc such as an exhaust pump for exhausting raw material gas and the like in the film forming chamber 11 is connected to a side portion of the film forming chamber 11 through an exhaust port 11p. A pressure control valve or the like for adjusting the pressure inside the film forming chamber 11 may be installed between the exhaust port 11p and the exhaust mechanism 11vc. The exhaust mechanism 11vc is composed of various pumps such as a turbo-molecular pump and a dry pump. It is possible to control the pressure in the membrane chamber 11 to a predetermined pressure. The exhaust port 11p is arranged in the film formation chamber 11 so that the raw material gas does not enter the lower side of the substrate stage 13 through the gap around the substrate stage 13 .

A shower plate 16 having a plurality of supply holes 16 a is attached to the upper side of the substrate stage 13 in the film formation chamber 11 . The shower plate 16 has a flat plate shape facing the substrate stage 13 and is arranged substantially parallel to the mounting surface of the substrate stage 13 .
When the film forming apparatus 10 performs film formation by plasma CVD, a shower plate-side high-frequency power supply for plasmatizing the gas supplied into the film-forming chamber 11 is connected to the shower plate 16, and high-frequency power is supplied to the shower plate 16. can be supplied so that the shower plate 16 can be maintained at a predetermined potential.

A shower plate 17 having a plurality of supply holes 17 a is attached above the shower plate 16 in the film forming chamber 11 . The shower plate 17 has a flat plate shape facing the shower plate 16, and the shower plate 17 is spaced apart from the shower plate 16 and arranged in parallel.
In the shower plate 17, the plurality of supply holes 17a can be arranged and sized differently from the supply holes 16a. Shower plate 17 can be supported similarly to shower plate 16 .
In the present embodiment, the shower plates 16 and 17 are arranged in two stages, but it is also possible to adopt a structure having a single shower plate or a shower plate in more stages.

A gas distribution plate 18 having a plurality of supply holes 18a is attached above the shower plate 17 of the film forming chamber 11 . The gas distribution plate 18 has a flat plate shape with a lower surface facing the shower plate 17 , and is spaced apart from the shower plate 17 and arranged in a substantially parallel state. The upper surface of the gas distribution plate 18 can also be formed so as to descend from the center toward the edge, that is, have a shape that is inclined from the center toward the edge so as to approach the substrate stage 13 .

In the gas distribution plate 18, the plurality of feed holes 18a can be arranged and sized differently from the feed holes 17a and 16a. In the drawing, the supply holes 18a, 17a, and 16a are schematically shown.

The shower plate 16 and the shower plate 17 are made of a metal containing aluminum, for example, an aluminum-magnesium alloy surface coated with alumite. The gas distribution plate 18 is made of a metal containing aluminum, such as an aluminum-magnesium alloy.

In this embodiment, the shower plates 16 and 17 and the gas distribution plate 18 are made of the above materials, but they can be made of other materials. For example, the shower plates 16 and 17 and the gas distribution plate 18 can be made of AlN, Y ₂ O ₃ (yttria), or the like.

A supply hole 11 a to which a raw material gas supply means 20 for supplying a raw material gas for film formation is connected is provided at the top of the film formation chamber 11 , which is the center position of the substrate stage 13 .
In the gas distribution plate 18, the supply holes 18a may not be arranged in the vicinity of the center, that is, in the immediate position facing the supply holes 11a.

The supply hole 11 a of the film forming chamber 11 is connected to a raw material gas supply means 20 for supplying the film forming material gas to the film forming chamber 11 . A gas diffusion part 21 is connected to the supply hole 11 a immediately upstream and diffuses the raw material gas before it is supplied to the film forming chamber 11 .

The gas diffusion section 21 is provided with a nozzle 22 for ejecting the raw material gas supplied from the raw material gas supply means 20, and has an internal space with a larger diameter than the inner diameter of the nozzle 22. As shown in FIG. The gas diffusion part 21 needs only to retain the raw material gas in a predetermined gas state, and the cross-sectional dimension of the internal space is set large so that the gas flow velocity is reduced compared to the upstream side of the gas flow. The cross-sectional shape of the gas diffusion portion 21 can be set to a predetermined state such as substantially circular, substantially rectangular, substantially conical, etc. depending on the influence on the gas characteristics.
The nozzle 22 is connected to a raw material gas supply unit 26 capable of supplying a necessary raw material gas through a raw material gas supply pipe 25 .

The raw material gas supply unit 26 is a tank or the like capable of storing a predetermined raw material gas, and is connected to the raw material gas supply pipe 25 having a substantially uniform inner diameter. The raw material gas supply unit 26 stores one kind of raw material gas or another kind of raw material gas, and can appropriately supply the raw material gas according to the film forming conditions.
The raw material gas supply unit 26 may be provided with a mass flow control (not shown) or the like so that the raw material gas can be supplied at a predetermined flow rate.

The nozzle 22 can have an inner diameter dimension that is approximately the same diameter as the source gas supply pipe 25 on the upstream side. Furthermore, the inner diameter of the nozzle 22 can be set larger or smaller than the inner diameter of the source gas supply pipe 25 .

FIG. 2 is a schematic enlarged cross-sectional view showing the gas diffusion section of the film forming apparatus according to this embodiment.
As shown in FIG. 2, the nozzle 22 in this embodiment is provided in an open state on the side surface of the gas diffusion section 21 .
In the gas diffusion part 21 , the opening of the nozzle 22 is set to have a space wider than the inner diameter of the nozzle 22 .

The opening state of the nozzle 22 in the gas diffusion part 21 is such that the direction of the gas flow toward the supply hole 11a of the film formation chamber 11 indicated by the arrow G1 in FIG. The installation position and direction of the nozzle 22 are set so that the jetted gas flow is directed.

Specifically, the direction of the gas flow toward the supply hole 11a of the film forming chamber 11 indicated by the arrow G1 in FIG. The installation position and direction of the nozzle 22 can be set. The gas flow G2 ejected from the nozzle 22 is preferably directed toward the center of the cross-sectional direction of the gas flow G1 toward the supply hole 11a of the film forming chamber 11. FIG.

The gas diffusion unit 21 is provided with a valve 23 capable of switching between a closed state during film formation and an open state during cleaning.
A first cleaning gas supply unit 31 serving as a cleaning unit 30 and a plasma generation unit 32 are connected to the gas diffusion unit 21 via a valve 23 .
At the end of the valve 23, the first cleaning gas is directed toward the supply hole 11a of the film formation chamber 11 so that the gas flow G3 is directed in the same direction as the gas flow G1 toward the supply hole 11a of the film formation chamber 11. A cleaning means 30 is connected to the end 23f of the valve 23 corresponding to .
The first cleaning gas supply unit 31 is a tank or the like capable of storing a predetermined cleaning gas.

As shown in FIG. 2, the valve 23 has a case 23a whose axis is in the direction of the gas flow G1 toward the supply hole 11a of the film formation chamber 11, and the direction of the gas flow G1 toward the supply hole 11a of the film formation chamber 11. A valve body 23b that cuts off the gas flow G1 so as to be orthogonal, a driving part 23c that drives the valve body 23b to open and close, and an O-ring or the like that seals between the case 23a and the valve body 23b when the valve body 23b is closed. and a sealing member 23d.

In the case 23a, the downstream side of the valve body 23b of the case 23a also serves as the inner wall of the gas diffusion part 21 together with the valve body 23b.
The case 23a and the valve body 23b have plasma resistance and are made of, for example, alumina, aluminum, quartz, AlN _, Y2O3 ₍ yttria), or the like.

In the valve 23, the valve body 23b is driven by the driving portion 23c, and it is sufficient to cut off the gas flows G1 and G3 from the cleaning means 30 to the supply hole 11a of the film formation chamber 11. The type of the valve 23, such as butterfly type or swing type, is sufficient. It is not particularly limited.
The sealing member 23d is made of, for example, fluorocarbon resin, and has plasma resistance.

A source gas supply pipe 25 connected to the nozzle 22 is connected via a switching valve (switching means) 33 to a second cleaning gas supply section 34 capable of supplying a second cleaning gas.
The second cleaning gas supply unit 34 is a tank or the like capable of storing a predetermined cleaning gas.
The switching valve 33 may have any structure as long as it can switch between the source gas from the source gas supply unit 26 and the second cleaning gas from the second cleaning gas supply unit 34 .

In this embodiment, the first cleaning gas can be a gas containing a fluorine compound or a gas containing a chlorine compound. Specifically, it may be selected from the group consisting of _CF4 , _C2F6 , _C3F8 , _SF6 , _{NF3 , CCl4} , _{C2Cl6 , C3Cl8 , SCl6 ,} and _NCl3 . can.
Also, the second cleaning gas can be selected from nitrogen gas and argon gas.

Next, a film forming method and a cleaning method in the film forming apparatus 10 of this embodiment will be described.

FIG. 3 is a flow chart showing a film forming method and a cleaning method in the film forming apparatus of this embodiment.
In film formation and cleaning in the film formation apparatus 10 of the present embodiment, as shown in FIG. It has a step S05, a plasma generation step S06, and a cleaning end step S07.

Next, in the film forming apparatus 10 of the present embodiment, first, as a valve closing step S01 shown in FIG. . Then, the substrate to be processed S carried into the film forming chamber 11 is placed on the substrate stage 13, and after setting the atmospheric conditions and temperature conditions in the film forming chamber 11 within a predetermined range, the switching valve 33 is switched. , a predetermined raw material gas can be supplied from the raw material gas supply unit 26 to the nozzle 22 .

Next, as a film-forming gas supply step S02 shown in FIG. 3, a predetermined source gas is supplied from the source gas supply unit 26 to the nozzle 22 through the source gas supply pipe 25 . As a result, the raw material gas ejected from the nozzle 22 as the gas flow G2 into the gas diffusion section 21 is diffused in the gas diffusion section 21 and flows into the film forming chamber 11 as the gas flow G1 through the supply hole 11a.

At this time, when film formation is performed by plasma CVD, high-frequency power is supplied to the shower plate 16 so that the shower plate 16 can maintain a predetermined potential. Alternatively, when film formation is performed by ALD, other raw material gases or the like can be supplied to the film forming chamber 11 from raw material gas supply means other than the raw material gas supply unit 26 .

At the same time, the exhaust mechanism 11vc such as an exhaust pump evacuates the raw material gas and the like in the deposition chamber 11 through the exhaust port 11p.
Further, the rear surface gas is supplied to the lower side of the substrate stage 13 from the rear surface gas supply unit 19 so that the raw material gas does not enter the lower side of the substrate stage 13 through the outer peripheral gap of the substrate stage 13 .

The raw material gas that has flowed into the film forming chamber 11 is brought into a predetermined gas state through the gas distribution plate 18 and the shower plates 16 and 17, reaches the substrate S placed on the substrate stage 13, and is deposited on the substrate S. Predetermined film formation is performed.

In the film forming gas supply step S02, in addition to film formation on the substrate S, deposits (deposits resulting from thin films adhered during the film forming process) are formed on the gas distribution plate 18, the shower plates 16 and 17, and the outer ring 13b. It tends to stick.

When the film formation in the film formation chamber 11 is completed, as a film formation end step S03 shown in FIG. 3, the supply of the raw material gas from the raw material gas supply unit 26 is stopped, and the inside of the film formation chamber 11 is evacuated by the exhaust mechanism 11vc. The processed substrate S to be processed is moved from the substrate stage 13 and unloaded from the film forming chamber 11 .

At the same time, the evacuation of the deposition chamber 11 through the evacuation port 11p by the evacuation mechanism 11vc is terminated.
In addition, the supply of the rear surface gas from the rear surface gas supply unit 19 to the lower side of the substrate stage 13 is terminated.

When film formation is subsequently performed on another substrate S, the valve 23 is closed in the valve closing step S01 shown in FIG. 3 to prepare for film formation.

When the film forming process is finished and the film forming apparatus 10 is cleaned, the cleaning is started as the valve opening step S04 shown in FIG.

In the valve opening step S04 shown in FIG. 3, the valve body 23b is driven by the drive unit 23c to open the valve 23, the switching valve 33 is switched, and the connection to the source gas supply unit 26 is cut off to perform the second cleaning. A connection state to the gas supply unit 34 is established.

Next, as a cleaning gas supply step S05 shown in FIG. 3, the first cleaning gas is supplied from the first cleaning gas supply unit 31 to the gas diffusion unit 21, and the second cleaning gas is supplied from the second cleaning gas supply unit . is ejected from the nozzle 22 into the gas diffusion portion 21 .
At the same time, an exhaust mechanism 11vc such as an exhaust pump evacuates cleaning gas and the like from the deposition chamber 11 through the exhaust port 11p.
In addition, the rear surface gas is supplied to the lower side of the substrate stage 13 from the rear surface gas supply unit 19 so that the cleaning gas does not enter the lower side of the substrate stage 13 through the peripheral gap of the substrate stage 13 .

Next, as a plasma generation step S06 shown in FIG. 3, which is a cleaning step, the first cleaning gas supplied from the first cleaning gas supply section 31 to the gas diffusion section 21 is turned into plasma by the plasma generation means 32 .

As a result, deposits (deposits resulting from thin films that adhere during the film forming process) adhering to the film forming chamber 11 in the film forming gas supply step S02 or the like, which is a film forming step, are removed.

Here, in the plasma generation step S06, as shown in FIG. 22, the second cleaning gas is ejected as a gas flow G2, and the second cleaning gas in the gas flow G2 crosses and collides with the first cleaning gas in the gas flow G3.

As a result, before the plasmatized first cleaning gas becomes the gas flow G1 and reaches the film forming chamber 11, the gas ions in the cleaning gas are reduced, and the gas that can be cleaned by the gas radicals and gas molecules is removed. As a state, the cleaning gas flows into the film forming chamber 11 .

The cleaning gas, whose gas ions are reduced and which can be cleaned by gas radicals and gas molecules, efficiently removes deposits adhering to the gas distribution plate 18, the shower plates 16 and 17, and the outer ring 13b in the film forming chamber 11 in particular. And it can be removed with low damage.

In this embodiment, the second cleaning gas of the gas flow G2 collides with the first cleaning gas of the gas flow G3 in the gas diffusion section 21 at an angle of approximately 90°. , by setting the opening state of the nozzle 22, it is possible to form a predetermined angle.

As a result, the state of reduction of gas ions in the cleaning gas and the cleaning ability by gas radicals and gas molecules are set to desired states, and the gas distribution plate 18, shower plates 16 and 17, outer ring 13b, etc., containing metals, are set to desired states. It is possible to deal with each cleaning state in the member, that is, the degree of damage occurrence, and set it to the necessary damage range for members with low damage resistance, and for members with high damage resistance, It can be in a good cleaning state.

In addition to the gas distribution plate 18, the shower plates 16 and 17, and the outer ring 13b, it is also possible to remove deposits adhering to the inside of the film forming chamber 11 efficiently with low damage.
As a result, it is possible to perform cleaning while reducing damage to the metal member caused by gas ions.

Further, in the plasma generation step S06 shown in FIG. 3, which is the cleaning step, the second cleaning gas is also supplied to the nozzle 22 serving as the source gas supply pipe 25 in the film formation gas supply step S02 , etc., which is the film formation step. there is This prevents the first cleaning gas from entering the nozzle 22 and the source gas supply pipe 25 communicating therewith. Therefore, it is possible to prevent the metal members in the nozzle 22 and the source gas supply pipe 25 from being damaged by the gas radicals and gas molecules of the cleaning gas.

When the cleaning in the film forming chamber 11 is finished, as a cleaning ending step S07 shown in FIG. to terminate the supply of
Then, the valve 23 is closed, the switching valve 33 is switched, the connection to the second cleaning gas supply section 34 is cut off, and the source gas supply section 26 is made connectable.
At the same time, the evacuation of the deposition chamber 11 through the evacuation port 11p by the evacuation mechanism 11vc is terminated.
In addition, the supply of the rear surface gas from the rear surface gas supply unit 19 to the lower side of the substrate stage 13 is terminated.

When film formation is to be performed on the substrate S after the cleaning is completed, the valve 23 is closed in the valve closing step S01 shown in FIG. 3 to prepare for film formation.

As a result, it is possible to form a film on the substrate S by the film formation process while cleaning the inside of the film formation chamber 11 by the cleaning process.

According to the film forming apparatus 10, the film forming method, and the cleaning method of the present embodiment, deposits adhering to the film forming chamber 11 in the film forming process are removed to reduce particle generation in film forming in subsequent processes. be able to. Furthermore, the gas ions in the cleaning gas are reduced in the gas diffusion part 21 by the first cleaning gas and the second cleaning gas ejected from the nozzle 22 and colliding during cleaning, and gas radicals and gas molecules are mainly generated by the metal member. It is possible to realize cleaning while reducing the occurrence of damage to the substrate.
At the same time, it is possible to prevent the cleaning gas from entering the inside of the nozzle 22 .

Furthermore, the inside of the film forming chamber 11 is cleaned without removing the gas distribution plate 18 containing a metal such as aluminum, the shower plates 16 and 17, the outer ring 13b, etc. in the film forming chamber 11, and good results can be obtained following the cleaning. It becomes possible to form a film in a film space state. In addition, the life of the gas distribution plate 18 containing metal such as aluminum, the shower plates 16 and 17, the outer ring 13b, etc. in the film forming chamber 11 can be extended, and the replacement interval can be extended to reduce the manufacturing cost. becomes.

A second embodiment of a film forming apparatus, a film forming method, and a cleaning method according to the present invention will be described below with reference to the drawings.
FIG. 4 is a schematic cross-sectional view showing the gas diffusion section of the film forming apparatus according to this embodiment. This embodiment differs from the above-described first embodiment in terms of the nozzles. Configurations corresponding to those of the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

The nozzle 42 in the present embodiment protrudes into the gas diffusion section 21 and has a distal end portion 42 a that opens upstream in the gas flow direction at a position corresponding to the valve body 23 b of the valve 23 .

The tip portion 42a of the nozzle 42 is positioned within the gas diffusion portion 21 so as to coincide with the center of the gas flows G3 and G1 in the cross-sectional direction.
A tip portion 42a of the nozzle 42 is opened so as to face the directions of the gas flows G3 and G1.

Here, since the diameter dimension of the nozzle 42 is smaller than the inner diameter in the cross-sectional direction of the gas flows G3 and G1 of the gas diffusion portion 21, the gas flow G1 of the raw material gas and the gas flow G3 of the cleaning gas are located near the tip portion 42a. will flow.

In this embodiment, the opening state of the nozzle 42 in the gas diffusion section 21 is opposite to the direction of the gas flow toward the supply hole 11a of the film formation chamber 11 indicated by the arrow G1 in FIG. The installation position and direction of the tip portion 42a are set so that the gas flow ejected from the nozzle 42 is directed in the direction.

Specifically, the angle formed by the gas flow jetted from the nozzle 42 indicated by the arrow G2 in FIG. The installation position and direction of the tip portion 42a can be set so as to be 180°.
The gas flow G2 ejected from the nozzle 42 is ejected at the center of the cross-sectional direction of the gas flow G1 toward the supply hole 11a of the film forming chamber 11, and is ejected toward the center of the valve body 23b of the valve 23.

In the film formation method and cleaning method of the present embodiment, in the film formation gas supply step S02 shown in FIG. 2, the gas is ejected into the gas diffusion portion 21 from the tip portion 42a as a gas flow G2. As a result, the raw material gas is ejected from the tip portion 42a toward the center of the valve body 23b of the valve 23, diffused in the gas diffusion portion 21, and flows into the film formation chamber 11 through the supply hole 11a as a gas flow G1. .

As a result, the diffusion of the raw material gas in the gas diffusion section 21 can be further promoted, the uniformity of the gas can be improved, and the film formation characteristics can be improved.

In the film formation method and cleaning method of the present embodiment, in the plasma generation step S06 shown in FIG. In contrast to the state in which the gas flow G3 is flowing, the second cleaning gas is ejected from the nozzle 42 as the gas flow G2, and the second cleaning gas in the gas flow G2 is in front of the first cleaning gas in the gas flow G3. It collides in a direction that flows backward from the center.

As a result, the collision rate between the first cleaning gas and the second cleaning gas is increased, and before the plasmatized first cleaning gas reaches the film forming chamber 11 as the gas flow G1, Gas ions are further reduced, gas radicals and gas molecules are further increased, and damage is further reduced by these, and the cleaning gas is supplied to the film forming chamber 11 in a gas state capable of cleaning.

In the film formation method and cleaning method of the present embodiment, film formation characteristics during film formation can be improved, and gas ions in the cleaning gas can be further reduced to further reduce damage during cleaning. can be made possible.

A third embodiment of a film forming apparatus, a film forming method, and a cleaning method according to the present invention will be described below with reference to the drawings.
FIG. 5 is a schematic cross-sectional view showing the gas diffusion section of the film forming apparatus according to this embodiment. This embodiment differs from the above-described first and second embodiments in terms of the nozzles. The same reference numerals are given to the structures corresponding to those of the above-described first and second embodiments, and the description thereof is omitted.

The nozzle 52 in this embodiment protrudes into the gas diffusion portion 21 and has its tip portion 52a opened at a position corresponding to the gas flow direction toward the supply hole 11a. In other words, the nozzle 52 in this embodiment is arranged such that the tip portion 42a of the nozzle 42 in the second embodiment is turned 180° and opens downstream in the direction of gas flow.

The tip portion 52a of the nozzle 52 is positioned in the gas diffusion portion 21 so as to coincide with the centers of the gas flows G3 and G1 in the cross-sectional direction.
A tip portion 52a of the nozzle 52 is opened so as to face the directions of the gas flows G3 and G1.
Note that the nozzle 52 of the present embodiment is located closer to the valve body 23b of the valve 23, that is, further upstream than the nozzle 42 of the second embodiment.

Here, similarly to the nozzle 42, the diameter of the nozzle 52 is smaller than the inner diameters of the gas flows G3 and G1 in the gas diffusion section 21 in the cross-sectional direction. , flow around the tip 52a.

In this embodiment, the opening state of the nozzle 52 in the gas diffusion section 21 is in the order indicated by the arrow G2 in FIG. The installation position and direction of the tip portion 52a are set so that the gas flow ejected from the nozzle 52 is directed in the direction.

Specifically, the direction of the gas flow toward the supply hole 11a of the film forming chamber 11 indicated by the arrow G1 in FIG. The installation position and direction of the tip portion 52a can be set so as to be 0°.

The gas flow G2 ejected from the nozzle 52 is ejected at the center of the cross-sectional direction of the gas flow G1 toward the supply hole 11a of the film forming chamber 11, and is ejected toward the center of the valve body 23b of the valve .

Further, the flow velocity of the gas flow G2 ejected from the nozzle 52 is set higher than the flow velocity of the gas flow G1 toward the supply hole 11a of the film forming chamber 11, and is 1.5 to 20 times, more preferably 2 times. It is supposed to have a flow velocity of about 10 times.

In the film formation method and cleaning method of the present embodiment, in the film formation gas supply step S02 shown in FIG. 2, the gas is ejected into the gas diffusion portion 21 from the tip portion 52a as a gas flow G2. As a result, the raw material gas is ejected from the tip portion 52a toward the center of the valve body 23b of the valve 23, diffused in the gas diffusion portion 21, and flows into the film formation chamber 11 through the supply hole 11a as a gas flow G1. .

In the film forming method and cleaning method of the present embodiment, in the plasma generation step S06 shown in FIG. In contrast to the gas flow G3, the second cleaning gas is ejected from the nozzle 52 as the gas flow G2. Collision from the center in an overtaking direction from the rear.

As a result, the first cleaning gas and the second cleaning gas are suitably collided and diffused, and before the plasmatized first cleaning gas reaches the film forming chamber 11 as the gas flow G1, gas ions are reduced, gas radicals and gas molecules are increased, damage is reduced by these, and the cleaning gas is supplied to the film forming chamber 11 in a gas state capable of cleaning.

In the film formation method and the cleaning method of the present embodiment, the film formation characteristics during film formation can be improved, and gas ions in the cleaning gas can be reduced to enable cleaning with reduced damage. can be done.

In the above embodiment, the opening of the nozzle 22 and the tip portions 42a, 52a of the nozzles 42, 52 are opened at 0°, 90°, and 180° with respect to the gas flow. It is also possible to arrange the first cleaning gas and the second cleaning gas to intersect at an angle.

Examples of the present invention will be described below.

A specific example of the present invention will be described.
Here, as shown in FIG. 4, the film forming apparatus 10 was manufactured with the tip portion 42a of the nozzle 42 opening on the upstream side, and ALD film forming and cleaning were performed.

Materials of parts, film formation and cleaning specifications of the film forming apparatus 10 are shown below.
Gas distribution plate; A5052
Shower plate; A5052 + surface alumite outer ring; AlN

<Deposition>
valve; closed source gas; total 1000 scmm
Raw material (TiCl ₄ ) + Ar3SLM; supplied to nozzle
Modified gas (NH ₃ )+Ar3SLM; backside gas supplied to nozzle (N ₂ : 1000 sccm)
Substrate temperature; 437°C
Deposition chamber pressure; 210 Pa

Under the above conditions, 20,000 cycles of film formation were performed.

After that, cleaning was performed in order to confirm the effect of the present invention.

<Cleaning>
Valve; open First cleaning gas: NF3; 1000 _scmm
Discharge for plasma generation; RF (high frequency), 6.5 kW
Second cleaning gas: Ar; 1000 scmm
Backside gas (N ₂ : 1000 sccm)
Substrate temperature; 400°C
Deposition chamber pressure; 150 Pa

After performing cleaning for 340 seconds, particle evaluation was performed.
As a result, the total number of particles on the substrate did not change, and no significant particles were generated.

In addition, damage to metal parts in the deposition chamber was visually confirmed.
Adhered films were confirmed on all of the gas distribution plate, the shower plate, and the outer ring before cleaning.

It was confirmed that the adhered film was removed from the gas distribution plate by cleaning for 100 seconds of the cumulative discharge time. On the shower plate and the outer ring, an adhered film remained after cleaning with an accumulated discharge time of 100 seconds, but was removed after cleaning with an accumulated discharge time of 340 seconds.

The gas distribution plate was not over-etched even after cleaning for an accumulated discharge time of 340 seconds, and no surface roughness or damage was observed.

From these results, it can be seen that arrival of F ions, which cause damage, can be suppressed in spite of being directly under the discharge.

DESCRIPTION OF SYMBOLS 10... Film-forming apparatus 11... Film-forming chamber 11a... Supply hole 11p... Exhaust port 11vc... Exhaust mechanism 13... Substrate stage 13a... Lifting mechanism 13b... Outer ring 16, 17... Shower plate 16a, 17a, 18a... Supply hole 18... Gas distribution plate 19 Rear gas supply unit 20 Source gas supply means 21 Gas diffusion units 22, 42, 52 Nozzles 42a, 52a Tip end 23 Valve 23a Case 23b Valve body 23c Drive unit 23d Seal Member 25 Raw material gas supply pipe 26 Raw material gas supply unit 30 Cleaning means 31 First cleaning gas supply unit 32 Plasma generating means 33 Switching valve (switching means)
34 Second cleaning gas supply unit S Substrate to be processed (substrate)

Claims (6)

a film formation chamber for housing the film formation substrate;
a raw material gas supplying means for supplying a raw material gas for forming a film on the film formation substrate;
a gas diffusion unit connected to the film forming chamber and having an enlarged diameter for diffusing the raw material gas supplied from the raw material gas supply means before being supplied to the film forming chamber;
a nozzle connected to the raw material gas supply means for ejecting the raw material gas to the gas diffusion portion;
a valve provided in the gas diffusion section so as to switch between a closed state during film formation and an open state during cleaning;
a first cleaning gas supply unit connected to the valve and capable of supplying plasmatized first cleaning gas to the gas diffusion unit and the deposition chamber;
a second cleaning gas supply unit connected to the nozzle and capable of supplying a second cleaning gas to the gas diffusion unit;
a switching means capable of switching the gas supplied to the nozzle between the raw material gas during film formation and the second cleaning gas during cleaning;
has
At the time of film formation, the raw material gas can be jetted from the nozzle to the gas diffusion part in which the valve is in a closed state,
During cleaning, the first cleaning gas can be supplied from the opened valve to the gas diffusion portion, and the switching means is switched to supply the second cleaning gas from the nozzle during cleaning to the gas diffusion portion. It is possible to squirt into the part,
A film forming apparatus, wherein the nozzle is provided in the gas diffusion section so as to eject the second cleaning gas toward the valve. 2. The gas diffusion section of claim 1 , wherein the second cleaning gas ejected from the nozzle is oriented so as to intersect the first cleaning gas supplied from the valve. deposition equipment. 3. The film forming apparatus according to claim 1, wherein the nozzle is provided in the gas diffusion section so as to face the valve. 4. The film forming apparatus according to claim 1 , wherein the first cleaning gas is a halogen-based gas, and the second cleaning gas is an inert gas. A cleaning method for a film forming apparatus according to any one of claims 1 to 4 ,
At the time of cleaning, the plasmatized first cleaning gas is supplied from the first cleaning gas supply unit to the gas diffusion unit through the valve in an open state, and
switching the switching means to jet the second cleaning gas supplied from the second cleaning gas supply unit from the nozzle to the gas diffusion unit during cleaning,
crossing the first cleaning gas from the valve and the second cleaning gas from the nozzle at the gas diffusion part,
A cleaning method for a film forming apparatus, wherein the active state of the first cleaning gas supplied to the film forming chamber is set to a predetermined state. A film forming method in the film forming apparatus according to any one of claims 1 to 4 ,
a film formation step of closing the valve, switching the switching means, and ejecting the raw material gas from the nozzle to the gas diffusion portion;
The valve is opened to supply the first cleaning gas converted to plasma from the first cleaning gas supply unit to the gas diffusion unit through the valve, and the switching means is switched to switch the second cleaning gas. The second cleaning gas supplied from the supply unit is ejected from the nozzle to the gas diffusion unit, and the first cleaning gas from the valve and the second cleaning gas from the nozzle intersect at the gas diffusion unit. a cleaning step that causes
A film forming method for a film forming apparatus, comprising:

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