WO2003014413A1

WO2003014413A1 - Treating device and cleaning method therefor

Info

Publication number: WO2003014413A1
Application number: PCT/JP2002/008089
Authority: WO
Inventors: Kohei Kawamura; Hidenori Miyoshi; Gishi Chung; Yasuhiro Oshima; Hiroyuki Takahashi
Original assignee: Tokyo Electron Limited
Priority date: 2001-08-07
Filing date: 2002-08-07
Publication date: 2003-02-20

Abstract

After an SiOC:H film is formed, the cleaning of the interior of a chamber (11) starts. NF3 and O2 fed from an NF3 source (S1) and an O2 source (S2) are turned into plasma inside an activator (12) on a cleaning gas line (L1), and radicals in the plasma is selectively fed into the chamber (11). Fluorine and oxygen radicals in the cleaning gas remove an Si-containing matter and a C-containing matter deposited to the interior of the chamber (11).

Description

Processing equipment and its cleaning method

The present invention relates to a processing device capable of efficient cleaning and a method of cleaning the same. Background art

Various chemical vapor deposition (CVD) devices are used in the manufacture of electronic devices such as semiconductor devices and liquid crystal display devices. Among them, the plasma CVD apparatus is capable of forming a high-quality film and is widely used.

The plasma CVD apparatus forms a film by performing CVD on a semiconductor device or the like in a decompressed chamber. Since CVD uses a gas phase reaction, film formation occurs not only on the wafer surface but also on the surface of chamber members (such as inner walls). The film formed on the chamber member causes particles and lowers the yield. Therefore, it is necessary to periodically clean the inside of the chamber to remove the film formed on the champer member.

As a method of cleaning the inside of the chamber, a dry cleaning method of cleaning the chamber 用い using a cleaning gas in a plasma state is known. Usually, a halogen-based gas such as nitrogen trifluoride (NF ₃ ) or carbon tetrafluoride (CF ₄ ) is used for dry cleaning. Specifically, halogen radicals such as fluorine radicals in a gas in a plasma state function as a cleaning species.

Halogen gas is highly reactive with silicon, and therefore has a high silicon removal rate (etching rate). However, on the other hand, the halogen-based gas carbon

The removal rate of (C), nitrogen (N), etc. is slower than that of silicon. For example, when a carbon-containing film such as a SiOC-based film is formed, even if cleaning with a halogen-based gas is performed for a time sufficient to remove silicon-based substances, stable gas is removed. Carbon present as etc. is not sufficiently removed. The remaining carbon in the chamber can be seen by the blackening of the chamber wall.

Residual substances other than silicon such as carbon as described above can be removed by extending the cleaning time. However, excessive cleaning not only increases the cleaning time, but also promotes the deterioration of the chamber members, and consequently reduces the productivity of the device. Similar cleaning problems occur not only in plasma processing apparatuses but also in other processing apparatuses.

As described above, in the conventional processing apparatus, when silicon remaining in the chamber and other substances are mixed, cleaning is not performed efficiently due to a difference in the removal rate, and is sufficiently high! /, Productivity was not obtained! /, In some cases. Disclosure of the invention

In view of the above-mentioned circumstances, an object of the present invention is to provide a processing apparatus capable of improving productivity and a tallying method thereof.

Another object of the present invention is to provide a processing apparatus capable of performing efficient cleaning and a method of talling the processing apparatus.

Further, another object of the present invention is to provide a processing apparatus capable of efficiently tallying deposits adhered to a wall surface or the like inside a chamber and a cleaning method thereof. To achieve the above object, a processing apparatus according to a first aspect of the present invention includes:

A champer (1 1) for internally performing a predetermined process on an object to be processed,

A cleaning gas introduction unit (15) provided in the chamber (11) for introducing a cleaning gas containing a halogen-containing substance and an oxygen-containing substance into the champer (11);

It is characterized by having.

In the processing apparatus having the above-described configuration, for example, the cleaning gas removes a substance containing silicon adhering to the inside of the chamber (11) and at least one of carbon and nitrogen.

The processing apparatus having the above configuration may further include an activator (12) provided outside the chamber (11) and activating the cleaning gas. The activated cleaning gas may be introduced into the chamber (11).

The processing apparatus having the above configuration may further include an activator (12) for activating the tallying gas inside the chamber (11).

In the processing apparatus having the above-described configuration, the oxygen-containing substance is composed of, for example, one of oxygen (O ₂ ) and ozone (O ₃ ).

In the processing apparatus having the above-described configuration, the halogen-containing substance is made of, for example, a fluorine-based substance.

To achieve the above object, a method for cleaning a processing apparatus according to a second aspect of the present invention includes:

A method of cleaning a processing apparatus for performing a predetermined process on an object to be processed in a part of a chamber (11).

A step of introducing a talung gas containing a halogen-containing substance and an oxygen-containing substance into the chamber (11). _:

In the cleaning method for a processing apparatus having the above configuration, the cleaning gas removes a substance containing, for example, silicon adhered to the inside of the chamber (11) and at least one of carbon and nitrogen.

It is characterized by the following.

The cleaning method of the processing apparatus having the above configuration may further include a step of activating the cleaning gas outside the chamber (11) and supplying the activated cleaning gas into the chamber (11).

The cleaning method of the processing apparatus having the above configuration may further include a step of activating the cleaning gas inside the chamber (11).

In the cleaning method of the processing apparatus having the above configuration, for example, one of oxygen (O ₂ ) and ozone (〇 ₃ ) is used as the oxygen-containing substance.

In the cleaning method for a processing apparatus having the above configuration, for example, a fluorine-based substance is used as the halogen-containing substance. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a diagram illustrating a configuration of a processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a cross-sectional configuration of the chamber shown in FIG.

FIG. 3 is a diagram showing the processing steps.

FIG. 4 is a diagram showing a modification of the present embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. The processing apparatus according to the embodiment of the present invention includes a chamber, and TEO is provided in the chamber.

Using a process gas of S (TetraEthyl Ortho Silicate) and oxygen (O ₂ ), a Si OC: H film is formed on a semiconductor wafer (hereinafter, wafer) by plasma CVD. After the film formation, the inside of the chamber is cleaned with a talling gas containing nitrogen trifluoride (NF ₃ ) and oxygen (〇 ₂ ).

FIG. 1 shows a configuration of a processing apparatus 10 according to the present embodiment. As shown in FIG. 1, the processing apparatus 10 includes a chamber 11, a cleaning gas line L 1, a process gas line L 2, an exhaust line L 3, and a system controller 100.

The chamber 11 is composed of a container that can be reduced in pressure to a vacuum. As described later, plasma CVD is performed inside the chamber 11.

One end of the cleaning gas license L 1 is connected to the chamber 11, and the other end is branched and connected to the NF ₃ source S 1 and the O ₂ source S 2. NF'3 source S 1 and 0 ₂ source S 2 are respectively connected to the cleaning line L 1 through a mass flow controller Ml, M2 and valves VI, the V 2. NF ₃ and 〇 ₂ are mixed at predetermined ratios by mass flow controllers Ml, M 2, and the like, and are supplied to the channel 11.

The cleaning gas line L 1, Akuchibeta 12 is provided with, in § click Chibeta 12 NF ₃ and O ₂ are supplied are mixed. The activator 12 activates the cleaning gas inside to generate a plasma. From Akuchibeta 1 2, of the plasma of the cleaning gas containing NF ₃ and 0 _2, the radical is selectively exhausted. As a result, the channel connected to the exhaust side of the activator 12 Members 1 and 1 are supplied with a cleaning gas mainly containing fluorine radicals and oxygen radicals. Here, the cleaning gas line L1 is divided into, for example, two lines on the exhaust side of the activator 12, and the cleaning gas is introduced into the champ 11 from two places.

One end of the process gas line L 2 is connected to the chamber 1 1, and the other end branches, respectively, the TEOS source S 3, 0 and ₂ source S 4, it is connected with Ar source S 5, the. TEOS and 0 ₂ constitutes a process gas, A r is used as a carrier gas.

The TEOS sources S 3, 0 ₂ source S 4 and Ar source S 5 are connected to the tally-enough gas line L 2 via the mass flow controllers — M3, M4, M5 and valves V3, V4, V5, respectively. It is connected. TEOS, 0 ₂及Pi Ar is by the mass flow controller M3, M4, M 5 and the like, Ru are respectively supplied to the chamber 11 at a predetermined mixing ratio.

The exhaust line L 3 is connected to a turbo molecular pump (TMP) 13. A dry pump is provided downstream of the turbo-molecular pump 13 so that the pressure in the chamber 11 can be reduced to a vacuum level. An automatic pressure controller (APC) 14 is provided between the turbo molecular pump 13 and the chamber 11. The pressure inside the chamber 11 is set to a predetermined pressure by the automatic pressure control device 14. '

The system controller 100 controls the entire processing apparatus 10 including the film forming processing operation and the cleaning operation.

FIG. 2 is a sectional view of the chamber 11 of the processing apparatus 10 shown in FIG. In order to facilitate understanding, the process gas line L2 is omitted in FIG.

As shown in FIG. 2, the chamber 11 is formed in a substantially cylindrical shape, and is made of, for example, aluminum whose inner surface is oxidized (alumite). The chamber 11 is grounded.

Two cleaning gas inlets 15 are provided on the side wall of the chamber 11. The cleaning gas inlet 15 is connected to the cleaning gas line L 1, and is supplied to the chamber 11 through the cleaning gas inlet 15. Is supplied.

Further, a goo for loading / unloading a wafer is provided on a side wall of the chamber 11 via a gate valve or the like. Wafers are loaded / unloaded into / out of the champer 11 via the gate.

A susceptor 16 is provided at the center of the chamber 11. The susceptor 16 is made of, for example, an insulator such as aluminum nitride and has a substantially disk shape. The wafer W is placed on the upper surface of the susceptor 16. Not shown inside susceptor 16! / An electrostatic chuck electrode is provided, and the mounted wafer W is electrostatically attracted and fixed.

A focus ring 17 is provided on the upper surface of the susceptor 16. The four-force sling 17 allows the plasma to be effectively brought into contact with the wafer W placed on the susceptor 16. The susceptor 16 is provided with lift pins (not shown) for transferring the wafer W therethrough. A refrigerant chamber 18 is formed inside the susceptor 16. The refrigerant flows into the refrigerant chamber 18 through a refrigerant pipe. The temperature of the susceptor 16 and the temperature of the wafer W on the susceptor 16 are adjusted by the coolant.

The susceptor 16 is connected to a first RF power supply 20 via a first matching unit 19. One end of the first RF power supply 20 is grounded, and an RF voltage can be applied to the susceptor 16.

An electrode plate 21 is screwed to an electrode support 22 on the ceiling of the chamber 11. The electrode plate 21 is provided in parallel with and opposed to the susceptor 16. The electrode plate 2i is made of a conductor such as aluminum. Further, a shield ring 23 for protecting the screwed portion is provided on a peripheral portion of the electrode plate 21.

The electrode plate 21 is connected to a second RF power supply 25 via a second matching box 24. One end of the second RF power supply 25 is grounded, and an RF voltage can be applied to the electrode plate 21. Thus, the electrode plate 21 and the susceptor 16 function as the upper electrode and the lower electrode of the parallel plate type plasma CYD device, respectively.

A process gas inlet pipe 26 is provided above the chamber 11 containing the electrode support 22. Have been killed. The process gas introduction pipe 26 is connected to the process gas line L2, and the process gas is introduced into the champ 11 through the process gas introduction pipe 26. At the top of the chamber 11, a hollow diffusion part 22a for diffusing the process gas is provided. The electrode plate 21 is provided with a plurality of holes 21 a penetrating the electrode plate 21. The process gas diffused by the diffusion part 22 a is supplied to the wafer W through the hole 2 la of the electrode plate 21.

An annular exhaust port 27 surrounding the susceptor 16 is provided at the bottom of the chamber 11. The exhaust port 27 is connected to the exhaust line L3, and the inside of the chamber 11 is exhausted through the exhaust port 27. The system controller 100 controls the APC 14 connected to the exhaust line L3 to keep the inside of the chamber at a predetermined pressure.

Further, at the time of cleaning, the system controller 100 detects the end point of cleaning from the opening / closing degree of the control valve of the APC 14 based on the pressure fluctuation in the chamber 11. That is, the degree of opening and closing of the APC 14 becomes constant as the removal of residues such as SiOC: H existing in the chamber 11 progresses. When the opening / closing degree of the APC 14 becomes constant, the system controller 100 determines that the cleaning has reached the end point, and ends the cleaning operation.

Next, the cleaning operation of the processing apparatus 10 will be described with reference to FIGS. 1 and 2, and a process chart shown in FIG. In addition, the process shown below is an example, and is not limited to this.

First, the wafer W is loaded into the chamber 11 and placed on the susceptor 16. The wafer W is fixed by an electrostatic chuck. Thereafter, the system controller 100 opens the valve V5 to start supplying Ar, and applies RF power to the upper electrode (electrode plate 21). Subsequently, by opening the valves V3, V 4, and supplies the TEO S, 0 ₂ into the chamber 11. Subsequently, power is applied to the lower electrode (susceptor 16). As a result, plasma of the process gas is generated, and a SiOC: H film is formed on the surface of the wafer W.

After a predetermined thickness of the SiOC: H film is formed on the wafer W or after a predetermined time, the system controller 100 turns off the application of the RF power to the lower electrode, and switches the valves V3 and V4. closed to stop the supply of TEOS, 0 _2. Then, the electrostatic chuck Is canceled. The system controller 100 stops the supply of Ar by closing the valve V5, and turns off the application of the RF power to the upper electrode. Subsequently, the wafer W is carried out of the chamber 11, and the film forming process ends.

After performing the above-described film forming process on a predetermined number of wafers W, the system controller 100 starts cleaning the chamber 11. Here, the cleaning is performed every period during which a film having a thickness of about 2 m is formed in the champer 11. First, for example, under 2 X 10- ³ P a pressure below, the Damiwe wafer W for cleaning is carried into the chamber 1 1 to the placing on the susceptor 16. The dummy wafer W on the susceptor 16 is fixed by an electrostatic chuck. The wafer W is heated to, for example, about 400 ° C.

Then, the chamber 1 1, for example, 50 after the P a pressure of about, at the same time to start the supply of NF ₃ and 0 ₂ by opening the valve V 1, V 2. Here, NF ₃ and O ₂ are supplied, for example, at a flow rate of 20 ° sccm / 50 sccm (about 4 ′: 1). In cleaning, the pressure is in the range of 5 to 50 ° Pa, the ratio of NF ₃ (F-containing substance) / 〇 ₂ (O-containing substance) is in the range of 1/1 to 101, and the total flow rate is 10 The thickness may be in the range of 0 sccm to 2000 sccm, and can be appropriately changed depending on the type of film and the amount of film formation.

After the supply of the NF ₃ and O ₂ gas, the activator 12 is turned on. Activator 1

The NF ₃ and O ₂ fed into 2 are turned into plasma, and radicals in the plasma are selectively supplied into the chamber 11.

At this time, Si in the Si OC: H film deposited in the champer 11 reacts with fluorine radicals in the cleaning gas to generate a gas such as silane tetrafluoride (Si F ₄ ). The generated gas is exhausted from the chamber 11.

—Si OC: Carbon (C) in H has low reactivity with fluorine radicals, and may not be easily removed depending on the concentration of fluorine radicals and the bonding state of C. However, reactivity with oxygen radicals in Riyungugasu is high carbon monoxide (CO), it is converted to carbon dioxide (C0 ₂₎ or the like. The gas generated in this way is exhausted from the chamber 11, so that the carbon (C) of the S i OC: H film is also decomposed and removed at the same speed as that of S i OC. Efficient removal is performed. As described above, the cleaning proceeds, and the system controller 100 monitors the progress of the cleaning from the state of the control valve of the APC 14. When the system controller 100 determines that the cleaning has reached the end point, the system controller 100 turns off the activator 12. Further, the valves VI and V2 are closed to stop the supply of the cleaning gas into the chamber 11. Thereafter, the valve V5 is opened, and the chamber is purged with Ar. Subsequently, after releasing the electrostatic chuck, the supply of Ar is stopped. After that, the dummy wafer W is unloaded from the chamber 11 with the pressure inside the chamber 11 at normal pressure, and the cleaning is completed.

As described above, S i OC: as a cleaning gas for removing H film, according to this embodiment using oxygen (0 ₂₎ in addition to the fluorine-based gas, only silicon (S i) And carbon (C) can be removed at the same rate. As a result, the cleaning of the chamber 11 can be efficiently performed without deterioration of the chamber member and the like, without performing cleaning for a long time to remove C. The present inventors conducted an experiment to compare a case where NF ₃ alone was used for cleaning after forming a 3 m OC film of S i OC: H with a case where cleaning was performed using a mixture of NF ₃ O ₂ . As a result, it was confirmed that while NF ₃ alone required 30 minutes or more to sufficiently clean the chamber, tally Jung was completed in 15 minutes with NF ₃ / O ₂ mixture.

Further, the inside surface of the chamber 11 made of an anode is covered with an oxide film (alumite), and the effect of compensating for the damage of the oxide film due to plasma or the like is obtained by oxygen. As described above, by using oxygen as the cleaning gas, it is possible to not only prevent deterioration of the chamber member due to excessive cleaning, but also to actively delay the deterioration of the chamber member. In this way, by cleaning the inside of the chamber 11 with a cleaning gas containing oxygen, it is possible to reduce the cleaning time and the downtime for replacing the champer members, thereby substantially improving the productivity. Becomes

In addition, the cleaning using the cleaning gas containing oxygen can efficiently remove the carbon-containing substance adhering not only in the chamber 11 but also in the piping constituting the exhaust line L3. The present invention is not limited to the above embodiment, and various modifications and applications are possible. Hereinafter, modifications of the above-described embodiment applicable to the present invention will be described.

In the above-described embodiment, the processing apparatus 10 is configured to form the S i OC: H film. 1 The present invention is not limited to this. (: H) film, SiCN film and the like.

The present invention is also applicable to the removal of a SiN film. This is because oxygen radicals are highly reactive with nitrogen (N) and easily react to produce gases such as NO ₂ and N ₂ 〇. As a result, the removal rate of N is also increased, and more efficient tally jung is possible.

In the above embodiment, NF ₃ and O ₂ are used as the cleaning gas. However, the gas used for cleaning is not limited to this. For example, instead of _{_{_{NF 3, F 2, SF 6}}} , CF 4, C 4 F 8, C 5 F 8, a fluorine-based gas such as C ₂ F _6, or,, C 1 _2, BC 1 chlorine such as ₄ Gas can be used. Further, 0 ₂ instead, it is possible to use _{_{_{0 3, NO 2, N 2}}} 0, H 2 0, CO, C0 2 , such as an oxygen-based gas.

In the above-described embodiment, the cleaning gas plasma is generated by the activator 12 provided outside the chamber 11 and introduced into the champer 11. However, as shown in FIG. 4, Cree - an NF ₃ and 〇 ₂ is Ngugasu supplied to Chang bar 1 1, applying an RF electrode on at least one sides of the upper electrode or the lower electrode in the chamber 1 1 Then, the plasma may be generated in the chamber 11. Further, the cleaning gas activated by the activator 12 may be further activated as plasma in the chamber 11.

In the above embodiment, the cleaning gas is converted into a plasma by the activator 12, and the radicals in the plasma are selectively supplied into the chamber 11. However, the activator 12 is not limited to plasma, but may be any mechanism that activates the cleaning gas to generate radicals.

In the above embodiment, the cleaning gas is introduced into the chamber 11 through the two cleaning gas introduction ports 15 provided on the side wall of the chamber 11. However, three or more cleaning gas inlets 15 may be provided. Like the process gas, the gas may be introduced into the chamber 11 from the process gas introduction pipe '26. However, in this case, it is of course difficult to remove the deposits on the ceiling portion of the chamber 11.

Further, the present invention is not limited to the parallel plate type, but can be applied to other plasma processing apparatuses such as an ECR type, an CCP type, a helicon type, a microwave type and the like. Further, the present invention is not limited to a plasma processing apparatus, and can be applied to other apparatuses such as an etching apparatus, a sputtering apparatus, and a heat treatment apparatus.

In the above embodiment, the processing apparatus 10 performs processing on a semiconductor wafer. However, the present invention is not limited to this, and may be applied to an apparatus that performs processing such as a liquid crystal display device. Industrial applicability

INDUSTRIAL APPLICABILITY The present invention can be suitably applied to a processing apparatus that performs a plasma processing such as a film forming process and an etching process on an object to be processed such as a semiconductor wafer and a liquid crystal display device.

The present invention is based on Japanese Patent Application No. 2001-239720 filed on Aug. 7, 2001, and includes the specification, claims, and drawings and abstract. The disclosure in the above application is incorporated herein by reference in its entirety.

Claims

The scope of the claims

1 .. A chamber (11) for internally performing a predetermined process on a workpiece,

A cleaning gas introduction unit (15) provided in the chamber (11) for introducing a cleaning gas containing a halogen-containing substance and an oxygen-containing substance into the chamber (11);

A processing device comprising:

2. The processing apparatus according to claim 1, wherein the cleaning gas removes a substance attached to the inside of the champ (11) and containing at least one of carbon and nitrogen.

3. An activator (12) provided outside the chamber (11) for activating the cleaning gas,

3. The processing apparatus according to claim 1, wherein the activated cleaning gas is introduced into the chamber (11).

4. The method according to claim 1, further comprising an activator (12) for activating the cleaning gas inside the chamber (11).

5. The oxygen-containing material, oxygen (0 _2), ozone (0 ₃₎ constituted from either, that the processing device according to any one of claims 1 to 4, characterized in.

6. The processing apparatus according to any one of claims 1 to 5, wherein the halogen-containing substance is made of a fluorine-based substance.

7. A cleaning method for a processing apparatus for performing a predetermined process on a processing object inside a chamber (11),

A method for cleaning a processing apparatus, comprising a step of introducing a cleaning gas containing a halogen-containing substance and an oxygen-containing substance into the chamber (11).

8. The cleaning apparatus according to claim 7, wherein the cleaning gas removes a substance containing at least one of carbon and nitrogen attached to the inside of the chamber (11). Method.

9. The method according to claim 7, further comprising activating the cleaning gas outside the champer (11) and supplying the activated cleaning gas into the chamber (11). Clearing method for processing equipment.

10. The method according to claim 7 or 8, further comprising a step of activating the cleaning gas inside the champer (11).

11. The cleaning apparatus according to claim 7, wherein one of oxygen (O ₂ ) and ozone (O ₃ ) is used as the oxygen-containing substance. Method.

12. The method for cleaning a processing apparatus according to claim 7, wherein a fluorine-based substance is used as the halogen-containing substance.