JP3117187B2 - Plasma cleaning method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma cleaning method and, more particularly, to a plasma cleaning method, and more particularly to a film containing Al and TiW, TiN.
The present invention relates to a plasma cleaning method suitable for cleaning the inside of a processing chamber in etching of a laminated structure film such as described above.

[0002]

2. Description of the Related Art Conventionally, as a cleaning method, for example, in the autumn of 1992, the 53rd Annual Meeting of the Japan Society of Applied Physics, Proceedings 465P, "in Si si in HBr RIE"
As described in “tu chamber cleaning”, a plasma processing method using a mixed gas such as O ₂ or SF ₆ + O ₂ for removing a reaction product deposited in the chamber at the time of etching a Si-based film is shown. It shows that the reaction products attached to the chamber wall can be removed.

[0003]

Deposits due to reaction products generated during the etching process cause fogging of the emission monitor window for detecting the end point, and cause non-uniform etching performance and particle generation due to a decrease in the accuracy of detecting the end point. It has become. For this reason, the deposits due to the reaction products are monitored,
The plasma emission intensity and the number of generated particles are measured, and a cleaning process is appropriately performed according to a predetermined management standard. The above-described conventional cleaning method includes the steps of:
No consideration is given to cleaning in etching a laminated film such as an iW or TiN film and cleaning in plasma processing for each wafer, and components of a reaction product during cleaning of an etching processing chamber in etching of a laminated film containing Al. C component, Cl component, T
It is important to effectively remove the i component, the Si component, and the Al component.
There was a problem that the components were excessively oxidized and very difficult to remove.

An object of the present invention is to provide a film containing Al and TiW,
C component and Cl component remaining in the etching chamber due to etching of the laminated structure film with a barrier metal such as TiN.
It is an object of the present invention to provide a plasma cleaning method capable of effectively removing bimetal components such as Al , Al, and Ti.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a semiconductor device, comprising the steps of: removing a reaction product adhered into an etching chamber by etching a laminated structure film of an Al-containing film and a barrier metal using an organic film on which a wiring pattern is formed; upon removal, and曝the etching chamber in _{H 2} O gas plasma, _{H 2} O gas
Excessive oxidation of the reaction product by hydrogen components in the gas
To produce products such as CO and HCl without etching
Carbon component from management chamber, removing the chlorine component, after of the step, the etching treatment chamber曝the gas plasma containing chlorine components, oxidation was inhibited from etching chamber
A step of removing Al, barrier metal components, and the like; and, after the step , exposing the etching chamber to oxygen gas plasma.
Then, the step of removing the organic substance from the etching treatment chamber is continuously performed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 2 shows a microwave etching apparatus as an example of an apparatus for implementing the present invention. A sample table 8 on which a sample 15 is placed is provided in the etching chamber 6, and a quartz window 7 is attached to the upper part of the etching chamber 6 so as to face the sample table 8. A processing gas introduction pipe 12 for supplying a processing gas into the etching chamber 6 and an exhaust port 14 connected to a vacuum pump (not shown) for evacuating the interior of the etching chamber 6 to a predetermined pressure are provided. Here, an etching chamber is formed by the etching chamber 6 and the quartz 7 or the like. The coil 11 and the high frequency power supply 13 are not used during the plasma cleaning process. When the etching process is performed using this apparatus, the coil 11 is placed in a quartz window at 400 to 400 mm.
It is used to generate a magnetic field of 1500 Gauss, and the high frequency power supply 13 is used to control ion energy in plasma incident on the sample stage 8.

[0007] With the apparatus having the above structure, a laminated structure film of an Al-containing film and a barrier metal (for example, TiW or TiN) using an organic film on which a wiring pattern is formed is formed by BC.
is etched by mixed gas plasma of l ₃ and Cl ₂ (This is shown in step 1 of FIG. 1.) thereby adhering reaction products in etching chamber. The attached reaction product is removed as follows. First,
H ₂ O gas is introduced into the etching chamber 6 at a flow rate of 100 cc / min through the processing gas introduction pipe 12, and the pressure in the etching chamber 6 is maintained at 100 Pa.
As a result, a microwave of 1000 W is generated, and the waveguide 9
Into the etching chamber 6 through the quartz window 7
1 minute (this is shown in step 2 of FIG. 1). Next, a gas containing chlorine, in this case, Cl ₂ gas is introduced at a flow rate of 150 cc / min in place of the H ₂ O gas, and the pressure in the etching chamber 6 is maintained at 100 Pa.
A microwave of 1000 W is generated by the magnetron 10 and subjected to plasma processing in the etching chamber 6 for 3 minutes (this is shown in Step 3 in FIG. 1). Thereafter, O ₂ gas is further introduced into the etching chamber 6 at a flow rate of 200 cc / min, and plasma processing is performed for 3 minutes at a microwave output of 1000 W in the same manner as described above while maintaining the pressure in the etching chamber 6 at 200 Pa ( This is shown in step 4 of FIG. 1). After plasma cleaning in the etching chamber, plasma of the same gas as in the etching processing is generated for the next etching, and the etching chamber is replaced with an etching atmosphere (this is shown in step 5 in FIG. 1). ). Here, Cl is used as the gas containing chlorine.
BCl instead of ₂ gas ₃ gas or Cl ₂ gas and B
A mixed gas of Cl ₃ gas can be used.

As described above, according to the present embodiment, the continuous plasma treatment using the H ₂ O gas, the gas containing chlorine, and the O ₂ gas allows the C component, the Al component, the Ti component, and the Si component remaining in the etching chamber. Components can be effectively removed.

In particular, by performing H ₂ O plasma treatment first to remove the reaction products remaining in the etching chamber, the reaction components remaining in the etching chamber are excessively oxidized by the hydrogen component in the H ₂ O gas. C without doing
The products such as O and HCl can remove carbon components and chlorine components from the etching chamber. Next, by performing a plasma treatment mainly using a chlorine component, the Al, Ti, Si components and the like whose oxidation has been suppressed can be effectively removed. Further, organic substances attached to the etching chamber can be removed by a plasma treatment mainly using O ₂ . As a result, in particular, the Al, Ti, and Si components can be effectively removed without excessive oxidation as compared with the conventional method.

[0010]

According to the present invention, a wiring pattern is formed.
Film and TiW, such as TiN containing Al using an organic film
C component, which is a reaction product remaining in the etching chamber due to etching of the laminated structure film with the barrier metal ,
Cl component, Al component, a barrier metal components such as Ti, especially
Excessively oxidizes Al and Ti and other barrier metal components
There is an effect that it can be effectively removed without performing.

[Brief description of the drawings]

FIG. 1 is a view showing a processing flow of an embodiment of a plasma cleaning processing method of the present invention.

FIG. 2 is a sectional view showing an example of an apparatus for performing the plasma cleaning method of the present invention.

[Explanation of symbols]

6 etching chamber, 7 quartz window, 8 sample stage, 9 waveguide, 10 magnetron.

Continuation of the front page (56) References JP-A-6-104227 (JP, A) JP-A-6-53193 (JP, A) JP-A-5-62936 (JP, A) JP-A-61-250185 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/3065 H01L 21/304 645

Claims (3)

(57) [Claims] An etching process for removing a reaction product attached in an etching chamber by etching a laminated structure film of an Al-containing film and a barrier metal using an organic film having a wiring pattern formed thereon. and曝the room in H _{2 O} gas plasma, before the hydrogen component of the in H 2 _O gas
CO, HCl, etc. without excessive oxidation of the reaction product
Of carbon and chlorine from the etching chamber
Removing the minute, after of the step, the etching treatment chamber曝the gas plasma containing chlorine components, etching
Al component and barrier metal formation with suppressed oxidation from the processing chamber
Removing the minute or the like, after of the step, exposing the etching chamber to an oxygen gas plasma, or etching chambers
And a step of removing organic substances from the plasma cleaning treatment method. 2. The method according to claim 1, wherein the barrier metal is TiW or TiN during the etching process .
Plasma cleaning process how. 3. The gas containing a chlorine component according to claim 1 is Cl.
A plasma cleaning method using _two gases, BCl ₃ gas, or a mixed gas thereof.