JP2909364B2 - Processing apparatus and cleaning method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus applicable to a cluster tool or a processing apparatus in which a plurality of processing vessels are integrated, and a cleaning method thereof.

[0002]

2. Description of the Related Art Generally, in order to manufacture a semiconductor integrated circuit, various processes such as film formation and etching are performed on a wafer. For example, C to form a film on the surface of each wafer
In a VD apparatus, a semiconductor wafer is mounted on a wafer mounting table (susceptor), and a processing gas for film formation is supplied to the surface of the wafer while heating the semiconductor wafer to a predetermined temperature. The product is to be deposited on a wafer.

When the film is formed on the wafer surface in this way, in addition to the wafer surface on which the film is required, unnecessary portions such as a wafer mounting table, an inner surface of a processing container, and a processing gas supply header are provided. The film adheres to even Film formation in such unnecessary portions floats as particles and causes defects in the semiconductor integrated circuit. Therefore, the vacuum processing apparatus periodically or irregularly removes the film formation. A cleaning process is performed.

As a conventional cleaning method, a method is known in which a gas containing NF ₃ is introduced as a cleaning gas into a processing vessel, and a film adhered to a mounting table, an inner surface of the processing vessel, or the like is removed with the cleaning gas. I have. In this cleaning method, plasma is used because the decomposability of NF ₃ itself is not so good. That is, an electrode plate is arranged in a position opposite to the mounting table in the processing vessel, and a high-frequency voltage is applied between the mounting table and the electrodes to generate plasma, thereby exciting and activating NF ₃ to perform cleaning. To promote it.

[0005]

The above-mentioned N
F ₃ Plasma method there of the cleaning method forming the periphery of the mounting table surface or wafer plasma is distributed can be effectively removed, beyond part of the plasma, for example, of the processing chamber interior surface and in particular The film deposited on the inner surface of the processing gas supply head and peeled off during the transfer of the wafer, and the film fragments adhered to the bottom of the container could not be effectively removed.

Therefore, in order to more effectively remove a film or the like by cleaning, a ClF-based gas is used as a cleaning gas as disclosed in JP-A-64-17857 and JP-A-2-77579. It has been proposed to use According to the cleaning method using the ClF-based gas, the film can be efficiently removed not only to the surface of the mounting table but also to every corner such as the inner surface of the processing gas supply header without using plasma. Since the ClF ₃ gas has a boiling point of about + 17 ° C., it easily liquefies at room temperature, and easily adheres to the inner wall of the container or the inner wall of the processing gas supply header. For this reason, in the film forming process performed after the cleaning operation, the ClF-based gas adhered to the wall surface is separated and the ClF-based gas is taken in during the film formation in the film forming process performed after the cleaning operation. If this occurs, there is a problem that this may cause a defect of the element.
Then, when the single supply system is closed due to gas liquefaction, the supply system must be evacuated, for example, for about half a day in order to recover the gas supply, which lowers the operation rate of the apparatus.

[0007] Such a problem is a serious obstacle particularly in a cluster apparatus in which a plurality of the same vacuum processing apparatuses or different processing apparatuses are combined to enable continuous processing of various processes without exposing a wafer to the atmosphere. . That is,
The use of a cluster device can maintain a deposition surface with high reproducibility, prevent contamination, shorten processing time, and the like.
Of the cause of failure when migrating from
% Or more has been found to be mainly caused by particles and metal contamination in the film forming apparatus.
There is a strong demand for the development of a vacuum processing apparatus and a cleaning method thereof that efficiently remove particles in the apparatus and are not affected by a cleaning gas.

The present invention focuses on the above problems,
It was created to solve this effectively. SUMMARY OF THE INVENTION It is an object of the present invention to provide a processing apparatus for cleaning particles adhered to an inner wall of the apparatus by using a ClF-based cleaning gas, and a cleaning method thereof.

In order to solve the above-mentioned problems, a first aspect of the present invention provides a processing container and a processing container provided on a ceiling portion of the processing container.
Shower head for introducing gas into the processing vessel
If, in the processing apparatus comprising a processing gas supply unit for supplying a processing gas is connected to the shower head, the
Independent shower head separate from the processing gas supply means
The cleaning gas supply means for supplying the cleaning gas containing the ClF-based gas is connected in a state where the gas introduction ports are changed.

According to a second aspect of the present invention, there is provided a vacuum processing container and a vacuum processing container provided on a ceiling of the vacuum processing container.
A vacuum for introducing gas into the vacuum processing vessel.
In a processing apparatus comprising a work head and a processing gas supply unit connected to the shower head to supply a processing gas, the shower head is provided independently of the processing gas supply unit and in a state where a gas introduction port is different. connected, and a cleaning gas supply means for supplying a cleaning gas containing ClF-based gas, at least the shower
Provided Heddo, the Shah during cleaning operations
Means for heating the work head .

According to a third aspect of the present invention, there is provided a processing apparatus comprising: a vacuum processing container provided with an object to be processed; and processing gas supply means for supplying a processing gas into the vacuum processing container. A cleaning gas supply system for supplying a cleaning gas containing a ClF-based gas is connected independently of the processing gas supply means, and the cleaning gas supply system is liquefied with the cleaning gas containing the ClF-based gas flowing therethrough. heating means to liquefy facilitating moiety liquefaction prone provided with a liquefaction prevention heating means for blocking is provided, wherein the liquefaction prevention heating means, the chestnut
Temperature gradually increases along the downstream direction of the
Thus, heating is performed so as to have a temperature gradient .

According to a fourth aspect of the present invention, there is provided a vacuum processing container, a processing gas supply means for supplying a processing gas into the vacuum processing container, and an independent processing gas supply means. When cleaning a processing apparatus connected to the vacuum processing container and including a cleaning gas supply unit for supplying a cleaning gas containing a ClF-based gas, a cleaning gas is supplied through the cleaning gas supply unit to perform a cleaning operation. At the same time, an inert gas is supplied from the processing gas supply means.

[0013]

According to the first aspect of the present invention, when the cleaning operation is performed, the ClF-based cleaning gas is supplied via the cleaning gas supply unit formed separately from the processing gas supply unit. The film is supplied and the film and the like in the processing gas supply means and the processing container are removed. And
After the cleaning operation, the processing gas is supplied into the processing container via the processing gas supply means. In this case, since the cleaning gas supply means is formed independently of the processing gas supply means and has no common part, When the processing gas flows, the ClF-based gas adhering to the tube wall or the like is not mixed therein.

Since the second invention is configured as described above, when performing a cleaning operation, a cleaning gas supply means supplies a ClF-based cleaning gas into the vacuum processing vessel. In this case, since the processing gas supply unit is heated to a predetermined temperature by the heating unit, it is possible to prevent the cleaning gas from adhering to the inner wall. It is possible to prevent ClF-based gas, which causes a defect, from being mixed into the gas. In this case, if the inner wall of the processing container is also heated at the time of cleaning, it is possible to prevent the ClF-based gas from adhering thereto, and the effect can be further improved.

In the third aspect of the present invention, when the cleaning operation is performed, the cleaning gas supply means is heated by the liquefaction prevention heating means provided in the cleaning gas supply means. Thus, liquefaction of the ClF-based cleaning gas passing through the supply means can be prevented, and smooth gas supply can be performed. In this case, the supply means is provided with a temperature gradient so that the temperature gradually increases from the cleaning gas supply source toward the vacuum processing vessel, and a liquefaction facilitating portion where a gas liquefaction phenomenon easily occurs, such as a joint portion, is heated by the heating means. By individually heating, liquefaction of the cleaning gas can be almost completely prevented.

In the fourth aspect of the present invention, the cleaning gas is supplied from the separately provided cleaning gas supply means during the cleaning operation. At the same time, for example, the processing gas supply means supplies the cleaning gas from the processing gas supply means. N
₂ Flow an inert gas such as (nitrogen) through, for example, a processing gas shower head. As a result, the cleaning gas does not adhere to the inner wall on the supply end side of the processing gas supply means during the cleaning gas operation, and a ClF-based material that causes a defect during the film formation during the film formation process performed after the cleaning operation is completed. It is possible to prevent gas from being taken in.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a processing apparatus and a cleaning method according to the present invention will be described below in detail with reference to the accompanying drawings.
1 is a schematic plan view showing a cluster device in which a plurality of processing devices according to the present invention are assembled, FIG. 2 is a schematic perspective view showing the cluster device shown in FIG. 1, and FIG. 3 is an example of a processing device according to the present invention. FIG. 4 is a configuration diagram showing a header heating unit used in the apparatus shown in FIG. 3, FIG. 5 is a configuration diagram showing a cleaning gas supply system connected to FIG. 3, and FIG. 6 is a transfer unit such as a transfer arm. FIG.

In this embodiment, three first to third processing apparatuses, for example, vacuum processing apparatuses 2A, 2B, and 2C are connected to a common transfer chamber 4 and connected to the transfer chamber 4 in common. Another transfer chamber 8 is provided via the first and second preliminary vacuum chambers 6A and 6B provided, and the first and second cassette chambers 10A and 10B are connected to the transfer chamber 8 in a continuous manner. A description will be given of an example of a so-called cluster device structure.

Each of the above vacuum processing apparatuses 2A, 2B, 2C
The first vacuum processing apparatus 2A is a set of apparatuses required for continuously processing the surface of a semiconductor wafer as an object to be processed.
The second vacuum processing apparatus 2B is, for example, 400 to 5 mm on a wafer on which a fine pattern is formed.
A titanium film is formed by sputtering at a temperature of 00 ° C., and the third vacuum processing apparatus 2C is for etching back the tungsten layer. These various processing apparatuses are not limited to this quantity and type.

First, the entire cluster device will be described. The first cassette chamber 10A and the second cassette chamber 10A are provided on both sides of the first transfer chamber 8 via gate valves G1 and G2, respectively.
Are connected to each other. These cassette chambers 10A and 10B constitute a wafer loading / unloading port of the cluster apparatus, and each have a cassette stage 12 (see FIG. 2) which can be moved up and down.

The first transfer chamber 8 and both cassette chambers 10A,
10B are each constructed in an airtight structure,
Gate doors G3 and G4 are provided at 0A and 10B so as to open and close with the outside working room atmosphere, respectively, and a carry-in / out robot 15 having a U-shaped holding member is provided (see FIG. 2). This loading / unloading robot 15
As shown in FIG. 2, the wafer cassette 14 set outside and forward is loaded into both cassette chambers 10A and 10B and set horizontally, and the wafer cassette 14 is placed in the cassette chambers 10A and 10B. After being carried in, it is pushed up by the cassette stage 12 and rises to a predetermined position.

In the first transfer chamber 8, a first transfer means 16 as a transfer arm composed of, for example, an articulated arm,
A rotary stage 18 for aligning the center of a semiconductor wafer W as an object to be processed and an orientation flat (orientation flat) is provided, and the rotary stage 18 includes a light emitting unit and a light receiving unit (not shown). Is configured.

The first transfer means 16 comprises a cassette 14 in both cassette chambers 10A and 10B and a preliminary vacuum chamber 6
A, for transferring a wafer between 6A and 6B,
Suction holes 16A for vacuum-sucking the wafer W are formed on both sides of the distal end of the arm serving as the wafer holding unit. The suction hole 16A is connected to a vacuum device via a passage (not shown).

Behind the first transfer chamber 8, the first pre-vacuum chamber 6 is connected via gate valves G5 and G6, respectively.
A and a second auxiliary vacuum chamber 6B are connected, and the first and second auxiliary vacuum chambers 6A and 6B have the same structure. These preliminary vacuum chambers 6A and 6B have
The apparatus is provided with a wafer mounting device, a heating unit for heating the wafer held thereon, and a cooling unit for cooling the wafer. The wafer is heated or cooled as required. The second transfer chamber 4 is connected to the rear side of the first and second preliminary vacuum chambers 6A and 6B via gate valves G7 and G8.

The first and second transfer chambers 4 have first and second transfer chambers.
Preliminary vacuum chambers 6A, 6B and three vacuum processing devices 2A-2
A second transfer unit 20 as a transfer arm including, for example, an articulated arm for transferring the wafer W to and from C is disposed. The three vacuum processing apparatuses 2A to 2C are connected to the second transfer chamber 4 on the left, right, and rear sides through gate valves G9 to G11, respectively.

Next, the first vacuum processing apparatus 2A will be described as an example of the vacuum processing apparatus. As described above, this first
The vacuum processing apparatus 2A is for forming a tungsten film as a metal film by CVD, for example. As shown in FIG. 3, the vacuum processing container 22 is formed into a substantially cylindrical shape, for example, by aluminum and vacuum-processed inside. A chamber 24 is formed,
The second transfer chamber 4 is connected to one side wall of the processing container 22 via a gate valve G9.

In the processing container 22, a wafer mounting table 26 made of, for example, aluminum or the like for mounting the wafer W thereon is supported by a support tube 28 standing upright from the bottom of the container. An electrostatic chuck 3 connected to a DC voltage source (not shown) is provided on the upper surface of the wafer mounting table 26.
0 is provided thereon, and the wafer W is attracted and held thereon by electrostatic force.

The bottom of the container below the wafer mounting table 26 is opened, and a quartz window 32 is hermetically attached to the opening, and a halogen lamp 34 for heating is arranged below this. During the film forming process, the light from the halogen lamp 34 is transmitted to the quartz window 32.
Then, the back surface of the mounting table 26 is radiated, and the light energy is used to indirectly heat the wafer W to a predetermined processing temperature. A vacuum pump 36 is provided at the bottom of the processing vessel 22.
The exhaust passage 38 connected to the processing container 22 is connected, and the inside of the processing container 22 is evacuated as necessary.

On the other hand, in the ceiling of the processing container 22, for example, a circular mounting hole 42 for mounting the shower head 40 is provided.
A shower head 40 formed of, for example, aluminum into a cylindrical shape is inserted into the mounting hole 42, and a flange portion 42 formed around the periphery thereof is connected to a peripheral edge of a ceiling portion via an O-ring 44. It is air-tightly attached and fixed.

A processing gas supply system 54 as processing gas supply means for supplying a processing gas and a ClF such as ClF, ClF ₃ , and ClF ₅ are provided above the shower head 40.
Cleaning gas supply systems 56 as cleaning gas supply means for supplying the system gas as the cleaning gas are separately and independently connected. The shower head 40 is configured as a part of a cleaning gas supply unit. In the shower head 40, in the illustrated example, the partition plate 4 is disposed horizontally, and
6, a diffusing plate 48 and a rectifying plate 50 are sequentially provided and divided into three rooms 52A, 52B, and 52C.

One communication hole 46 is provided at the center of the partition plate 46.
A is formed, and a large number of diffusion holes 48A are formed in the diffusion plate 48 so as to be dispersed over the entire surface thereof.
Are formed with a large number of flow regulating holes 50A dispersed over the entire surface thereof. In this case, the diameter of the diffusion hole 48A is 0.1 mm.
The diameter of the rectifying hole 50A is set to be in the range of about 2 to 1.5 mm and the rectifying hole 50A is
A is set to a range of about 0.5 to 2.0 mm larger than A and is dispersed at a large density. In addition, the communication hole 46A
Is set in a range of about 0.5 to 3.0 mm. Accordingly, by changing the hole diameter and the distribution of the holes, a differential pressure is given to each of the upper and lower chambers, so that a plurality of locally introduced processing gases are uniformly mixed and uniformly supplied onto the wafer surface. It has become. Therefore, the wafer W
Is approximately 200 mm, the diameter of the current plate 50 is slightly larger than this, for example, 220 to 230 m.
m. Incidentally, the number of the diffusion plate 48 or the rectification plate 50 may be further increased and provided in multiple stages.

The inner and outer surfaces of the shower head 40, the partition plate 46, the diffusion plate 48, the rectifying plate 50, and the inner surfaces of the processing container 22 are subjected to a surface polishing treatment for preventing ClF-based gas from adsorbing during cleaning. ing.

In the present embodiment, since the processing gas supply system 54 forms a tungsten film, the first and second processing gas introduction ports connected to the shower head 40 for introducing two kinds of processing gases. The ports have first and second port opening / closing valves 58A and 60A, respectively. At this time, by setting the distance from the on-off valves 58A, 60A to the gas shower head 40 as short as possible, the adverse effect of the residual gas adhering to the inner wall of the pipe can be eliminated. The first and second processing gas introduction passages 62 and 64 connected to the first and second processing gas introduction ports 58 and 60 respectively include first and second mass flow controllers 66A as flow control valves on the way. , 66B and the first and second processing gas sources 70A, 70B via the first and second on-off valves 68A, 68B, respectively. In this embodiment, WF ₆ is used as the first processing gas, and one of H ₂ , SiH ₄ and SiH ₂ Cl ₂ is used as the second processing gas. In the illustrated example, SiH ₄ is shown.

The first and second processing gas introduction passages 62, 64 are respectively provided with branch passages 72A, 72B on the way.
Are formed, and the third and fourth mass flow controllers 66C, 66C are respectively provided in the branch paths 72A, 72B.
D and third and fourth on-off valves 68C and 68D are interposed and commonly connected to the first nitrogen source 74A as an inert gas source, respectively, so that an inert gas flows during cleaning as described later. Has become.

On the other hand, the cleaning gas supply system 56
It has a cleaning gas introduction port 76 connected to the shower head 40, and a cleaning gas port opening / closing valve 76A is interposed in this port 76. A cleaning gas introduction passage 78 connected to the cleaning gas introduction port 76 is provided with a fifth mass flow controller 66E and a fifth opening / closing valve 68E as flow control valves on the way.
Is connected to a cleaning gas source 80 via a ClF-based gas such as ClF ₃ as a cleaning gas.
The gas can be supplied after being vaporized. A branch path 72C is formed in the cleaning gas introduction path 78 in the middle, and a second nitrogen source 74B is connected to the branch path 72C via a sixth mass flow controller 66F and a sixth on-off valve 68F. The cleaning gas is diluted as necessary to control the concentration.
And each of the above mass flow controllers, on-off valves, etc.
For example, it is controlled by a control unit 82 including a microprocessor or the like based on a program stored in advance.

As described above, the ClF-based gas used as the cleaning gas, for example, ClF ₃ has a boiling point of +
It is about 17 ° C. and liquefies at room temperature (+ 10 ° C.). Therefore, in some cases, this gas may be reliquefied due to adiabatic expansion or the like in the supply line. Therefore,
In order to prevent liquefaction of the cleaning gas, a heating means 84 for preventing liquefaction and an individual heating means 86 are provided in the cleaning gas introduction passage 78 as shown in FIG.

First, the liquefaction-preventing heating means 84 is provided over the entire length of the cleaning gas introduction passage 78, and is divided into a plurality of, in the illustrated example, three zones in the length direction thereof. The first along the introduction passage 78
, A second heating tape 84B, and a third heating tape 84C. The heating tape is formed, for example, by sandwiching a linear resistance heating wire with a Teflon tape, and can be easily wound around a desired portion.

Then, the heating tape 8 of each zone
Each of the temperatures T1, T2, and T3 of 4A to 84C is the processing container 22.
A temperature gradient is provided so as to gradually increase toward the side. For example, T1 is set to 20 ° C., T2 is set to 30 ° C., and T3 is set to 40 ° C., so that liquefaction of the cleaning gas is prevented. ing.

Even if the liquefaction-preventing heating means 84 is provided, the ClF ₃ gas is very easily liquefied as described above, so that the flow path area is changed, for example, the fifth mass flow controller 66E or the fifth mass flow controller 66E. Opening / closing valve 68E or joint portion 88A, 88B, 88 of a pipe where a slight gap is generated
Since liquefaction is likely to occur in the liquefaction facilitating portions such as C, individual heating means 86 are provided individually in these portions. Each individual heating means 86 is formed in the same manner, for example, joints 88A to 88C, fifth mass flow controller 66
E, each liquefaction facilitating portion such as the fifth on-off valve 68E is entirely covered with a metal box 92 having a built-in ceramic heater 90, for example, to form a kind of constant temperature chamber. By setting the inside of each metallic box 92 to a relatively high temperature, for example, about 50 ° C. in accordance with a command from the control unit 82, liquefaction of the cleaning gas in each unit is completely prevented. The number of zones is not limited to three, but can be reduced or increased as needed.

On the other hand, the inner wall surface of the processing vessel 22 and the inner and outer wall surfaces of the processing gas shower head 40 are surface-polished to prevent the ClF ₃ gas from adhering. is not. Therefore, in this embodiment, the processing gas shower head 40 is provided with a head heating means 94 as shown in FIGS. 1 and 4 in order to almost completely prevent the adhesion of the ClF ₃ gas. The head heating means 94 is formed by a medium passage 96 and a ceramic heater 98 formed over the entire side wall of the head. Hot water at a maximum temperature of 100 ° C. is passed through the medium passage 96 to heat the medium to a higher temperature. In this case, when the ceramic heater 98 is energized, for example, 100 ° C. to 200 ° C.
It is designed to heat to a temperature range of about ° C.

The medium passage 96 is branched into a hot water side and a cold water side on the introduction side, and the switching valves 100 and 102 are operated according to a command from the control unit 82 to switch the hot water and the cold water as required. The shower head 4 is configured so that the shower head 4 can be alternatively supplied.
0 is cooled to prevent a film from being formed thereon. A ceramic heater 104 and a medium passage 106 having the same structure as described above are also provided on the wall of the processing container 22.
The F ₃ gas is prevented from adhering.

In this embodiment, since a ClF-based gas is used as the cleaning gas, a portion exposed to this gas, for example, the processing vessel 22 or the processing vessel 22
The wafer mounting table 26 and the electrostatic chuck 30 in the
It must be composed of system gas corrosion resistant material and used at corrosion resistance temperature.

As such materials, polyimide and silicon rubber cannot be used, and SiC, ceramic-based materials, Teflon, alumina ceramic, quartz glass (200 ° C. or less), carbon (300 ° C. or less) and the like can be used. Can be used. When the electrostatic chuck is formed of the above material, for example, quartz glass, the conductive film is formed so as to be sandwiched between the quartz glasses. Further, as other materials, materials shown in Table 1 can be used.

[0044]

[Table 1]

Further, as shown in FIG. 1, the other vacuum processing apparatuses 2B and 2C have substantially the same configuration as the first vacuum processing apparatus 2A, that is, a processing gas supply system 108 and a cleaning gas supply system 110 are separately provided. The gas shower head is provided with head heating means, and the processing vessel is provided with similar heating means. Reference numeral 112 denotes a vacuum exhaust system.

When the cleaning operation is performed, not only the vacuum processing apparatuses 2A to 2C but also the entire cluster apparatus, that is, the first and second transfer chambers 8, 4 and the first and second preliminary vacuum chambers 6A , 6B and the first and second cassette chambers 10A, 10B are performed similarly or individually, so that each chamber has the same cleaning structure as the cleaning gas supply system 52 connected to the first vacuum processing apparatus 2A. A gas supply system 114 and a vacuum exhaust system 116 are connected to each other. Although not shown, a gas supply pipe for supplying an inert gas into the chamber is connected to each chamber.

The heaters (not shown) are also provided on the walls defining the respective chambers, and particularly on the arm-shaped first and second transfer means 16 and 20 in the first and second transfer chambers 8 and 4. To prevent ClF-based gas from adhering during cleaning. The members in each of these chambers are also made of the above-described material having corrosion resistance to the ClF-based gas. For example, the transfer arm and the like are made of Teflon in which a ceramic heater is embedded.

Next, the operation of the present embodiment configured as described above will be described. First, the cassette 14 accommodating, for example, 25 wafers W is loaded by the loading / unloading robot 15 into the first position.
Is placed on the cassette stage 12 in the cassette room 10A, and then the gate door G3 is closed to make the room an inert gas atmosphere.

Next, the gate valve G1 is opened, the wafer W in the cassette 14 is vacuum-adsorbed to the arm of the first transfer means 16, and the wafer W in the first transfer chamber 8, which is previously in an inert gas atmosphere, is placed in the first transfer chamber 8. The wafer is loaded into the wafer. Here the rotating stage 18
Thereby, the orientation flat and the center position of the wafer W are aligned.

The wafer W after the alignment is placed in a first preliminary vacuum chamber 6A which is previously set in an inert gas atmosphere at atmospheric pressure.
Then, the gate valve 5 is closed, for example, the inside of the vacuum chamber 6A is evacuated to 10 ⁻³ to 10 ⁻⁶ Torr, and the wafer W is preheated to about 500 ° C. for 30 to 60 seconds. . The unprocessed wafer W subsequently carried in is similarly carried into the second preliminary vacuum chamber 6B and preheated.

The wafer W after the preliminary heating is transferred to the gate valve G
7 is opened and is taken out while being held and taken out by the arm of the second transfer means 20 of the second transfer chamber 4 which has been previously reduced to a degree of vacuum of about 10 ^-7 to 10 ^-8 Toor. For this purpose, the wafer is loaded into a predetermined vacuum processing apparatus which has been previously set in a reduced pressure atmosphere.

The processed wafer W having undergone a series of processes is held by the second transfer means 20 and taken out of the vacuum processing apparatus, and is placed in the vacant first preliminary vacuum chamber 6A. Will be accommodated. After the processed wafer W is cooled to a predetermined temperature in the vacuum chamber 6A, the wafer cassette 14 in the second cassette chamber 10B for accommodating the processed wafer by the operation reverse to that described above. Housed in

The preheated wafer W is
The film forming process and the etching process are sequentially performed according to a desired sequence programmed in advance. For example, first, for example, a titanium film is formed in the second vacuum processing apparatus 2B, and then, for example, a tungsten film is formed in the first vacuum processing apparatus 2A. Etchback of the tungsten film is performed at 2C to complete the entire process.

Here, the operation of forming a tungsten film in the first vacuum processing apparatus 2A will be described with reference to FIG. First, the wafer mounting table 26 is heated at a predetermined processing temperature by heating the wafer mounting table 26 by the light energy from the halogen lamp 34, and at the same time, the vacuum pump 36 Is introduced into the processing chamber 24 while controlling the flow rates of the first processing gas from the first processing gas source 70A and the second processing gas from the second processing gas source 70B. Is maintained at a predetermined processing pressure, and a film forming process is performed.

In this embodiment, for example, WF ₆ is used as the first processing gas, and SiH ₄ is used as the second processing gas, and is diluted to a predetermined concentration by the nitrogen gas from the first nitrogen source 74 or Undiluted WF ₆ and SiH ₄ are respectively introduced into the uppermost mixing chamber of the shower head 40. The two kinds of processing gases introduced into the mixing chamber are introduced into the lower diffusion chamber through the communication hole 46A of the partition plate 46 while being mixed here. This mixed gas is supplied to the diffusion plate 48.
Is introduced into the lower rectification chamber through the diffusion hole 48A of
Thereafter, the processing gas is supplied uniformly over the entire surface of the wafer through the rectifying holes 50A of the rectifying plate 50. In this case, since the processing gas introduced into the shower head is mixed while being gradually expanded in the plurality of chambers, the two types of processing gas can be uniformly mixed, and moreover, the lowermost rectifying plate 50 Since the diameter is set slightly larger than the diameter of the wafer W, the mixed processing gas can be supplied uniformly over the entire surface of the wafer.

If the temperature of the shower head 40 or the temperature of the inner wall of the processing vessel 22 increases during the film forming process, the reaction product forms a film on the wall surface other than the wafer surface. In order to prevent this, during the process, a coolant composed of cold water of about 15 ° C. is flowed through the medium passage 96 provided in the shower head 40 and the medium passage 104 provided in the wall of the processing container 22, respectively. The walls of the processing vessel are cooled so that no film is formed on them. Such a cooling operation is similarly performed during the process in the other processing apparatuses 2B and 2C, and the adhesion of the film to unnecessary portions is prevented.

As described above, a series of processing of the wafer W is performed as follows.
If a predetermined number of wafers, for example, one lot (25 wafers) have been processed, a small amount of film will adhere to each processing apparatus, and the processing will be performed even when the processed wafers W are transferred on the wafer W transfer route. The film tends to peel off and become particles and float or settle at the bottom. Therefore, a cleaning operation is performed in order to form a film on an unnecessary portion that causes such a defect and to remove a film piece. This cleaning operation may be performed on the entire cluster apparatus at once, or may be performed individually on a specific vacuum processing apparatus or a specific room of a transport route.

The cleaning operation will be described with reference to FIG. 3. The first and second on-off valves 68A and 68B of the processing gas supply system 54 are closed and the first
The supply of the processing gas and the second processing gas is stopped. First, a ClF-based gas, for example, ClF-based gas,
₃ gas is generated, and the flow rate of the gas is controlled by the fifth mass flow controller 66E.
8 and is supplied from the cleaning gas introduction port 76 into the shower head 40. The cleaning gas flows down the shower head 40 and flows through the processing container 22, reacting with the film or the film piece adhering to the header wall surface, the inner wall of the processing container, the wafer mounting table 26, etc. to remove the film. Air is exhausted from the exhaust passage 38. In this case, the flow rate of the ClF ₃ gas is set to, for example, 5 liters / minute or less, and the cleaning gas is diluted by supplying the nitrogen gas from the second nitrogen source 74B while controlling the flow rate as needed. Further, the pressure in the processing vessel is maintained, for example, in the range of 0.1 to 100 Torr.

Here, if the ClF ₃ gas adheres to the head, the inner wall surface of the processing container, or the like, the ClF ₃ gas separated from the wall surface during the subsequent film formation after the cleaning process is taken in during the film formation, and defects are generated. Cause.

Then, each part is heated to prevent the ClF ₃ gas from adhering to the wall surface. That is, the medium passage 96 of the head heating means 94 provided in the shower head 40
Then, a heating medium made of, for example, hot water of about 80 ° C. is caused to flow through a medium passage 104 provided in a wall of the processing container 24 to heat the shower head 40 and the processing container 22. In this case, when heating is further performed, the ceramic heater 98 provided on the head and the ceramic heater 106 provided on the wall of the processing container are energized to set a high cleaning temperature. The wafer mounting table 26 and its vicinity can be heated to a predetermined temperature by driving a halogen lamp 34 used to heat the wafer. The cleaning temperature at this time is set, for example, within the range of + 17 ° C. to + 700 ° C., which is the boiling point temperature of ClF ₃ gas.
When the wafer mounting table 26 is heated during cleaning, the mounting table itself and the electrostatic chuck 30 are made of a material having high corrosion resistance to ClF ₃ gas as shown in Table 1 and the like. Since the temperature is set within a range in which corrosiveness is exhibited, there is no problem of corrosion.

Since the shower head and the wall surface of the processing container are heated during the cleaning operation, the cleaning gas does not adhere to the wall surface.
Accordingly, in the film forming process restarted after the completion of the cleaning, ClF ₃ gas which causes a defect is not taken in during the film forming, and the yield can be greatly improved.

At the same time as flowing the cleaning gas, nitrogen gas is supplied from the first nitrogen source 74 provided in the processing gas supply system 54 to the first and second processing gas introduction passages 62 and 64 as an inert gas. Is supplied into the shower head 40 via the In this case, the supply pressure of the nitrogen gas is set slightly higher than the supply pressure of the cleaning gas, and the cleaning gas is supplied to the first and second processing gas introduction ports 58,
Avoid backflow to 60. As described above, by flowing the inert gas into the processing gas supply system 54 during the cleaning process, the cleaning gas flows back to the inner surfaces of the first and second processing gas introduction ports 58 and 60 or more and the processing gas introduction passage. Adhesion to the inner surfaces of 62 and 64 can be prevented. Therefore, the ClF ₃ gas is not taken in during the film formation at the time of the film formation process restarted after the completion of the cleaning, and the yield can be further improved in combination with the above-described reason.

At the same time as supplying the cleaning gas from the cleaning gas supply system 52, the liquefaction prevention heating means 84 and the plurality of individual heating means 86 provided in the cleaning gas introduction passage 78 of the cleaning gas supply system 52 as shown in FIG. Is driven to prevent liquefaction of the ClF ₃ gas during supply. That is, the heating tapes 84A, 84A of the liquefaction prevention heating means 84 divided into three zones
B, 84C, and the temperatures T1, T2, T3 of each zone.
Are set to 20 ° C., 30 ° C., and 40 ° C., respectively, and a temperature gradient is provided so that the temperature gradually increases along the downstream direction of the cleaning gas.
Prevents liquefaction of F ₃ gas.

In this case, the heating by the heating tape is insufficient at a portion where the flow path area changes in the middle of the passage or a portion where a slight gap is formed due to the joint, and the liquefaction of the ClF ₃ gas may occur. Therefore, in this embodiment, these liquefaction facilitating parts, for example, the fifth
Mass flow controller 66E, fifth on-off valve 68E
Metal box 9 that covers this facilitation part on the joints and
Since the individual heating means 86 including the ceramic heater 2 and the ceramic heater 90 is provided and is heated to, for example, about 50 ° C., the liquefaction of the ClF ₃ gas in the cleaning gas supply system 52 can be almost completely prevented, and the operation of the apparatus can be performed. The rate can be greatly improved.

The cleaning operation as described above is performed by the processing gas supply system 10 having the same structure as described above for each processing apparatus.
8. Cleaning gas supply system 110 and evacuation system 11
2, the processing can be performed independently for each of the processing devices 2B and 2C, and the same operation and effect can be achieved.

Further, the first and second transfer chambers 8 and 4, which are wafer transfer paths, the first and second preliminary vacuum chambers 6A and 6B, and the first and second cassette chambers 10A and 10B are respectively provided. Since the cleaning gas supply system 114 and the evacuation system 116 having the same configuration as those described above are individually provided, the cleaning operation can be performed individually and independently as needed, and the same operation and effect can be achieved. be able to. In this case, a partition wall for partitioning each room and the first and second transfer means 1
Since heating means is also provided on the arms 6 and 20,
By heating these during cleaning, ClF ₃
It is possible to prevent the gas from adhering, and it is possible to eliminate the possibility that the ClF ₃ gas will adhere to the wafer surface during the subsequent wafer transfer.

By cleaning the wafer transfer path in this way, when the processed wafer W is transferred by the transfer means, the film pieces which are separated from the wafer and fall or float are eliminated to eliminate particles. Can be
The product yield can be further improved.

As shown in FIG. 6, the entirety of the first and second transfer means 16 and 18 having a rotating portion, for example, arms and gears, are converted to ClF ₃ gas shown in Table 1 above. It is composed of a material having corrosion resistance. Since the cleaning gas supply system may be provided separately and independently in the conventional vacuum processing apparatus for film formation, it can be easily adopted with a minimum design change.

In the above embodiment, the cleaning process is performed independently in each vacuum processing apparatus and each chamber. However, the present invention is not limited to this. The cluster device may be opened to clean a plurality of devices and chambers in common, or the entire cluster device may be communicated and the entire cluster device may be cleaned at once. As described above, by applying the present invention to a cluster device, a large improvement in throughput and yield can be achieved, and it is possible to cope with high miniaturization and high integration of 256 MDRAM and the like.

[0070] Further, in the above embodiment has been described for cleaning metal tungsten film, film to be cleaned is not limited thereto, MoSi _2, WSi
_{2, TiN, TiW, Mo,} SiO 2, Poly-Si
And the like, and a gas corresponding to the film formation is used as the processing gas. For example, in the case of a tungsten film, in addition to the combination of WF ₆ + SiH ₄ ,
A combination of F ₆ + H ₂ , WF ₆ + Si ₂ H _{6 and} the like are used, and in the case of WSix film formation, a combination of WF ₆ + SiH _4, a combination of WF ₆ + Si ₂ H _{6, and} a combination of WF ₆
A combination of + SiH ₂ Cl _{2 and} the like can be used.

Further, the inert gas used is N ₂
Not limited to gas, but other inert gases such as He, Ar
Etc. can also be used. Further, the present invention is applicable not only to a CVD apparatus but also to a sputtering apparatus, an LCD apparatus, a diffusion apparatus, and the like. In the above embodiment, the vacuum processing apparatus has been described as an example, but the present invention can be applied to a normal pressure processing apparatus.

[0072]

As described above, according to the present invention, the following excellent functions and effects can be obtained. According to the first aspect, since the cleaning gas supply means is provided independently of the processing gas supply means and connected to the shower head, the cleaning gas does not adhere to the pipe of the processing gas supply means. Therefore, it is possible to prevent the cleaning gas from being included in the film formation during the subsequent film formation processing, and to improve the yield. According to the second aspect of the present invention, the shower head is provided with a heating unit, and by heating the shower head during cleaning, the cleaning gas is prevented from adhering to the shower head, and the cleaning gas is heated by the heating unit. The cleaning effect can be enhanced. According to the third aspect of the present invention, the cleaning gas supply means is provided with a heating means for preventing liquefaction and a separate heating means to prevent the cleaning gas flowing therethrough from being liquefied. It is possible to prevent the decrease and to greatly improve the operation rate of the apparatus. In particular, processing vessel walls and showerheads
Heating means for preventing the adhesion of the cleaning gas
So that the gas is released during cleaning.
It can be prevented from adhering to the wall, and as a result
This cleaning gas is
No longer ingested heat, greatly improving yield
Can be done. Furthermore, in the passage of the cleaning gas
The cleaning gas flow is provided by the provided liquefaction prevention heating means.
Temperature gradient so that the temperature gradually increases along the downstream direction of the
The cleanliness in the middle of the aisle
Liquefaction of the gas can be reliably prevented. According to the fourth aspect, the cleaning gas is supplied simultaneously with the inert gas from the processing gas supply means, so that the cleaning gas flows back into the processing gas supply means and adheres to the piping. Therefore, it is possible to prevent the cleaning gas from being taken in during the film formation at the time of the film formation after the cleaning operation, and to improve the yield.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a cluster device in which a plurality of processing devices according to the present invention are assembled.

FIG. 2 is a schematic perspective view showing the cluster device shown in FIG.

FIG. 3 is a sectional view showing an example of a processing apparatus according to the present invention.

FIG. 4 is a configuration diagram showing a header heating means used in the apparatus shown in FIG.

FIG. 5 is a configuration diagram showing a cleaning gas supply system connected to FIG. 3;

FIG. 6 is a side view showing a transfer unit such as a transfer arm.

[Explanation of symbols]

 2A to 2C Vacuum processing apparatus (processing apparatus) 22 Vacuum processing container 24 Vacuum processing chamber 26 Wafer mounting table 40 Shower head 54 Processing gas supply system (means) 56 Cleaning gas supply system (means) 62, 64 Processing gas introduction passage 66A- 66F Mass flow controller 70A, 70B Processing gas source 74A, 74B Nitrogen source 84 Liquefaction prevention heating means 86 Individual heating means (heating means) 90 Ceramic heater 92 Metal box 94 Header heating means 96 Medium passage 98 Ceramic heater W Semiconductor wafer

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-185977 (JP, A) JP-A-5-29285 (JP, A) JP-A-5-13345 (JP, A) JP-A-2-185 190472 (JP, A) JP-A-1-152274 (JP, A) JP-A-4-96321 (JP, A) JP-A-3-215687 (JP, A) (58) Fields investigated (Int. ⁶ , DB name) H01L 21/3065 H01L 21/205

Claims (10)

(57) [Claims] 1. A processing container and a ceiling mounted on the processing container.
Shower for introducing gas into the processing vessel
In a processing apparatus comprising a head and processing gas supply means connected to the shower head to supply processing gas, a state in which the shower head has a different gas introduction port independently of the processing gas supply means. And C
A processing apparatus, wherein a cleaning gas supply unit for supplying a cleaning gas containing an IF gas is connected. 2. A vacuum processing container and a top of the vacuum processing container .
Introducing gas into the vacuum processing vessel provided in the well
For the shower head and connected to this shower head
A processing gas supply means for supplying a processing gas to the shower head , wherein the shower head is provided with a different gas introduction port independently of the processing gas supply means .
Cleaning gas supply means for supplying a cleaning gas containing a ClF-based gas, which is connected in a state, and means for heating the shower head at the time of a cleaning operation provided at least in the shower head. Processing equipment. 3. The cleaning gas supply means includes an inert gas supply source for introducing an inert gas into the supplied cleaning gas to control the concentration of the cleaning gas. 3. The processing device according to 1 or 2. 4. A vacuum processing container in which a processing object is provided,
In a processing apparatus comprising processing gas supply means for supplying a processing gas into the vacuum processing container, a cleaning gas supply system for supplying a cleaning gas containing a ClF-based gas is connected independently of the processing gas supply means. the cleaning gas supply system is provided with heating means liquefied facilitating moiety liquefaction prone provided with a liquefaction prevention heating means for preventing liquefaction of the cleaning gas containing ClF-based gas flowing therethrough, the Liquefaction prevention heating means
Gradually along the downstream direction of the cleaning gas flow
Heat so that the temperature rises and has a temperature gradient.
Processing apparatus according to claim and. 5. The cleaning gas supply system according to claim 1, further comprising an inert gas supply source for introducing an inert gas into the supplied cleaning gas to control the concentration of the cleaning gas. 5. The processing apparatus according to 4. Wherein said inert gas includes a processing unit according to claim 3 or 5, characterized in that a nitrogen gas. 7. The processing apparatus according to claim 1, wherein a heating unit for preventing a cleaning gas from adhering to the wall of the processing container is provided. . 8. The processing gas and the inert gas are supplied from a shower head provided on a ceiling portion of the processing container, and the shower head has a heating unit for preventing a cleaning gas from adhering thereto. The processing apparatus according to claim 1, wherein the processing apparatus is provided. 9. The processing apparatus according to claim 7, wherein said heating means comprises a medium passage through which a heating medium flows and / or a ceramic heater. 10. A vacuum processing container, processing gas supply means for supplying a processing gas into the vacuum processing container, and a ClF-based gas connected to the vacuum processing container independently of the processing gas supply means. When cleaning a processing apparatus including a cleaning gas supply unit that supplies a cleaning gas including the cleaning gas, a cleaning operation is performed by supplying a cleaning gas through the cleaning gas supply unit, and at the same time, an inert gas is supplied from the processing gas supply unit. And a cleaning method for the processing apparatus.