JP2585442B2 - Continuous treatment method for the workpiece - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous processing apparatus and a post-processing method, and relates to a dry etching process and a post-processing of a laminated wiring film of an Al-based wiring film and a dissimilar metal wiring film. And a post-processing method suitable for continuously performing the following.

[Conventional technology]

Conventional processing methods include, for example, mixing a fluorine-based gas or oxygen with a fluorine-based gas as described in JP-B-58-12343, JP-B-62-30268, and JP-A-60-218847. In addition, it is disclosed that by performing a plasma treatment on an object to be processed after the etching treatment, the anticorrosion performance of the Al-based wiring film can be improved.

Further, as a processing apparatus, for example, an etching apparatus in which a post-processing chamber is integrally connected to the rear side of the etching chamber as described in JP-A-61-133388 is shown, and immediately after the etching processing using this apparatus, It is indicated that the post-treatment can improve the anticorrosion performance of the object to be treated.

[Problems to be solved by the invention]

The above-described conventional processing method is said to be effective mainly for anticorrosion treatment of an Al-based wiring film. But recent
LSI elements have been replaced with Al or Al alloy films, which have been used in the past, from the point of prevention of disconnection of wiring due to the increase in current density flowing in wiring due to the miniaturization of wiring accompanying the increase in element density. A wiring film having a laminated structure of an Al-based wiring film such as a base alloy film and a dissimilar metal film such as a TiN layer or a TiW layer is being used.

Corrosion protection after dry etching of this laminated wiring film is likely to occur due to battery action between dissimilar metals and influence between laminated films, as discussed in Semiconductor World, 1989, pp. 101-106, The conventional treatment method described above does not provide sufficient anticorrosion performance. When the laminated structure film includes a TiN or TiW layer, a post-treatment mainly using a fluorine-based gas or a resist removal treatment is performed to remove the TiN layer or the TiW layer.
There is a problem that side etching occurs in the layer and a precise wiring cannot be formed.

On the other hand, in the above-described conventional apparatus, an apparatus in which an object to be processed is heated and dried after an etching process, then washed with pure water, and then a drying process is performed.

The anticorrosion performance of the laminated wiring film in this example apparatus is unknown because it is not clearly described. However, in order to perform a series of operations including etching, post-processing, and resist removal, etching in the etching apparatus is required. In addition to the processing means, a heating drying means and a drying means after the water washing treatment and the washing are required. In addition, a separate resist removing device is required to remove the resist. For this reason, there has been a problem that the installation area of the apparatus necessary for a series of processing is large, and that transport between the processing apparatuses and a standby time are required.

An object of the present invention is a method for continuously treating an object to be processed which prevents corrosion due to an electron action between an Al-based wiring and a dissimilar metal, has a high anticorrosion performance for a laminated structure wiring film, and is small and has high production efficiency. Is to provide.

[Means for solving the problem]

An object of the present invention is to form a multilayer wiring film and a pattern of an Al-based wiring film and a dissimilar metal wiring film by using a continuous processing apparatus having an etching chamber and a post-processing chamber connected to the etching chamber under vacuum. In the method for processing an object to be processed having a resist, in the etching chamber, the stacked structure wiring film of the object to be processed is plasma-etched using a gas containing a halogen component, and the etched object to be processed is subjected to the etching. A resist removal device that is disposed in a post-processing chamber and that removes the resist from the object to be processed in the post-processing chamber, while reducing the halogen component remaining on the surface of the multilayer structure wiring film using water vapor, This is achieved by performing an anticorrosion treatment for passivating the surface of the Al-based wiring film of the laminated structure wiring film, and then taking out the object to be processed into the atmosphere.

[Action]

In general, a gas containing halogen is used for dry etching of a multilayer structure wiring film of an Al-based wiring film and a dissimilar metal wiring film, but after etching, etching is performed together with a resist which is a mask material for forming a wiring pattern. Sidewall adhered portions adhered therein remain. Components containing halogen remain in these resist and side wall deposit components, but in the present invention, the resist is first removed by radical components in the plasma using gas plasma containing oxygen as a main component, and most of the residual halogen is removed. Remove components. Next, the gas component introduced into the processing chamber is adsorbed on the surface of the object to be processed by increasing the pressure in the processing chamber to form droplets, and the halogen component remaining mainly on the components attached to the side walls of the wiring pattern is dissolved in the droplets. Dilute. After the adsorption, the dilution is sufficiently performed so that the hydrogen ion exponent of the remaining droplets on the surface to be treated is in a passivation region of aluminum having a pH of about PH4 to PH8. After that, by lowering the pressure in the processing chamber, the components attached to the surface of the processing object are evaporated,
Desorption from the surface of the workpiece.

For this reason, components containing halogen remaining in the object to be processed can be significantly reduced.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to the drawings.

FIG. 1 is a plan view of a continuous processing apparatus capable of continuously performing an etching process and a post-process under vacuum, and is used to explain a schematic procedure of a series of processes.

In the apparatus shown in FIG. 1, the buffer chamber 3 and the load lock chamber
The vacuum chambers 4, 9, the etching chamber 6, and the post-processing chamber 8 can be evacuated, and each chamber can be independently partitioned by an airtight device. The processing flow using this apparatus is as follows.
After being transported to the load lock chamber 4, the air is evacuated and reduced from the atmosphere by an exhaust device not shown. After that, the swing arm 5 passes through the buffer chamber 3 which has been evacuated and evacuated in advance.
Is sent to the etching chamber 6 evacuated and evacuated.
After performing a predetermined etching process in this etching chamber, the wafer is also evacuated and evacuated in advance by the revolving arm 7 before being transferred to the processing chamber 8. The workpiece processed in the post-processing chamber 8 is transported to the load lock chamber 9 by the turning arm 7 again. After the load lock chamber 9 is separated from the buffer chamber 3 by an airtight device, the load lock chamber 9 is pressurized to the atmospheric pressure by N ₂ gas, and then the object to be processed is stored in the unload side cassette 11 by the rectilinear arm 10. Then, a series of processing ends.

FIG. 2 shows an embodiment of the present invention, and is a longitudinal sectional view of the post-processing chamber 8 shown in FIG. FIG. 3 shows a saturated vapor pressure curve, which is used to explain the adsorption / desorption process.

In FIG. 2, the plasma generation chamber 40 and the processing chamber 60 are kept in a vacuum and are separated by a perforated plate 50 made of aluminum. In this case, the means for converting the introduced gas into plasma is performed by using a microwave, an opening is provided in the plasma generation chamber 40, a quartz window 30 is attached to the opening, and an end of the microwave waveguide 20 is provided. Is provided with a microwave oscillator 15.

The exhaust means is connected to an exhaust port 70 of the processing chamber 60, and includes a pressure control valve 80 and a vacuum pump (not shown).

The gas supply means for plasma generation is connected to a gas supply port 42 of the plasma generation chamber 40. In this case, oxygen gas and carbon fluoride-based gas (for example, carbon tetrafluoride) are supplied to flow control valves 46 and 48, respectively.
And a gas supply device 44 that mixes and supplies each gas.

On the other hand, the gas supply means for adsorption / desorption treatment is connected to a gas supply port 62 of the processing chamber 60, and in this case, is constituted by a gas supply device 64 for adjusting pure water by a flow control valve 66 and supplying evaporative gas.

An object 90 to be processed is carried into the processing chamber 60, and is set on the sample stage 100.

1 and 2, the microwave having a frequency of 2.45 GHz generated by the microwave oscillator 15 travels in the microwave waveguide 20 and passes through the quartz window 30 through the plasma generation chamber. Guided within 40. Plasma generation chamber 40
The microwave is applied to the mixed gas for plasma processing introduced into the plasma generation chamber, and plasma is generated in the plasma generation chamber 40. Aluminum perforated plate between plasma generation chamber 40 and processing chamber 60
50 is provided to prevent the microwave from traveling to the processing chamber 60, and mainly a radical component is guided to the processing chamber 60.

In the post-processing according to the present embodiment, an ashing process for removing the resist is first performed with the radicals led to the processing chamber 60 as a main component, and a pair of operations is performed after the ashing process is completed. First, a gas (in this case, a pure water component gas) is supplied into the treatment chamber 60 by a gas supply means for the adsorption / desorption treatment.
The pressure control valve 80 for controlling the pressure in the processing chamber 60 is closed,
The pressure in the processing chamber increases. Next, when the pressure reaches a predetermined processing chamber pressure, that is, a pressure region higher than the saturated vapor pressure curve shown in FIG. 3 (more than the pressure at which the introduced gas is condensed), the supply of the adsorption / desorption processing gas is stopped and the pressure control valve is stopped. Fully open 80.

By performing the above operation, the adsorption / desorption gas introduced is absorbed on the surface of the object after the ashing process, and the deposition and dissolution of the deposit on the pattern side wall due to the formation of liquid droplets due to the increase in the gas pressure are performed. (The pressure in the processing chamber 60 is reduced and the region moves to the region shown in FIG. 3). As a result, evaporation and desorption of the side-wall adhering components on the surface of the object to be processed proceed, and the adhered substance adheres to the object to be processed. Halogen components can be greatly reduced. In addition, the adsorption gas is converted into droplets, and the hydrogen ion exponent of the remaining droplets on the surface of the processing object is adjusted to PH4 to PH8, so that the surface of the processing object is stabilized, and the aluminum wiring on the surface of the processing object is stabilized. The membrane is passivated.

According to this embodiment, the amount of halogen remaining after the etching process and the ashing process of the Al-based wiring film or the laminated structure wiring film is significantly reduced, and a high anticorrosion performance is obtained for the Al-based wiring film or the laminated structure wiring film. In addition, the washing means becomes unnecessary. Further, since the resist removing means is provided internally, the size of an apparatus for performing a series of processes from the etching process to the post-processing and the resist removal can be reduced. Moreover, since the processing can be performed continuously and consistently, the transport time and the standby time of the object to be processed between the processing apparatuses can be reduced, and the production efficiency can be improved.

Next, another embodiment will be described with reference to FIG. The apparatus used in this embodiment is the same as the apparatus shown in FIG.
The temperature control means (consisting of the constant temperature water tank 110 and the cooling water passage 105) for controlling the temperature of the cooling water is provided.

In this embodiment, as in the previous embodiment, an ashing process is performed with a radical as a main component in order to remove the resist, and thereafter, the object to be processed is subjected to the adsorption / desorption process as in the previous embodiment. At this time, the temperature of the sample stage 100 on which the object is set is controlled to a temperature lower than room temperature by the temperature adjusting means. For this reason, in the adsorption / desorption process for the object to be treated, when the introduced gas is adsorbed, the sample table and the object to be treated are at a lower temperature than the surrounding substances, so that the introduced gas is intensively adsorbed. This improves the efficiency of dissolving and diluting the object to be deposited on the pattern side wall,
The amount of halogen remaining after desorption can be further reduced.

According to the present embodiment, the anticorrosion performance can be further improved as compared with the above-described embodiment.

Next, still another embodiment will be described. In this embodiment, an ashing process for removing a resist is performed after the etching process, that is, an ashing process for removing a resist after the etching process. After the adsorption / desorption operation, a desorption accelerating process (in this embodiment, an oxygen plasma treatment is applied to the object after the adsorption / desorption operation and the object is heated) is added. Thus, a series of processing is performed.

According to this embodiment, the effect of moisture remaining after the adsorption / desorption operation can be reduced, so that a higher anticorrosion performance than the previous embodiment can be obtained.

Next, still another embodiment will be described with reference to FIG. This embodiment uses an apparatus having a configuration in which a workpiece heating means for heating a workpiece is attached to the load lock chamber 9 shown in FIG. 1, and a longitudinal sectional view is shown in FIG.

As in the previous embodiment, the ashing process, the adsorption / desorption process, and the desorption promotion process are performed after the etching process, and the desorption promotion process is a means for taking out an object to be processed from a vacuum to the atmosphere, as shown in FIG. 9 is an airtight device 1 in which an object to be processed 90 installed on a sample 120 is combined with a quartz glass 130.
The heating is performed by the object heating means 140 (lamp heater in this embodiment) attached to 25.

According to this embodiment, in addition to the effects of the above-described embodiment, the desorption acceleration processing time by heating in the post-processing chamber (the above-described oxygen plasma heating processing) can be shortened, and the unit time for performing the continuous integrated processing can be reduced. The effect that the processing amount of the folding object per contact can be increased is obtained.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to the present invention, a resist remaining after the etching treatment of a laminated structure wiring film of an Al-based wiring film and a dissimilar metal wiring film and a halogen component in a sidewall deposit are effectively removed, and the surface of the Al-based wiring film is not damaged. Since it is activated, high corrosion protection performance is obtained for a wiring structure having a laminated structure of an Al-based wiring film and a dissimilar metal wiring film, and the constituent devices can be reduced in size and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view of an apparatus for continuously performing an etching process and a post-process. FIG. 2 is a longitudinal sectional view of a post-processing means showing one embodiment of the present invention, FIG. 3 is a view showing a saturated vapor pressure curve,
FIG. 4 is a vertical sectional view of a post-processing means showing another embodiment, and FIG.
The figure is a longitudinal sectional view of an atmosphere extracting means showing another embodiment. 15 …… Microwave oscillator, 40 …… Plasma generation chamber, 44…
... gas supply device, 60 ... processing chamber, 64 ... gas supply device,
80 ... pressure control valve, 90 ... workpiece, 100 ... sample stand, 1
10 ... constant temperature water bath, 140 ... heating means

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-41728 (JP, A) JP-A-59-161036 (JP, A) JP-A-63-70428 (JP, A) JP-A-61-1986 250185 (JP, A)

Claims (2)

(57) [Claims] 1. A continuous processing apparatus comprising an etching chamber and a post-processing chamber connected to the etching chamber under vacuum,
In a method for processing an object having a multilayer structure wiring film of an Al-based wiring film and a dissimilar metal wiring film and a resist for forming a pattern, a halogen component is formed in the etching chamber in the multilayer structure wiring film of the object to be processed. Plasma etching is performed using a gas containing: the etched object to be processed is disposed in the post-processing chamber; and in the post-processing chamber, a resist removing device that removes the resist from the object to be processed; Performing an anticorrosion treatment to reduce the halogen component remaining on the surface of the multilayer structure wiring film and passivate the Al-based wiring film surface of the multilayer structure wiring film, and thereafter, place the object to be treated in the air. A method for continuously processing an object to be processed, wherein the object is taken out. 2. The method according to claim 1, wherein the object to be processed is
A continuous processing method for an object to be processed, comprising a wiring film having a laminated structure of an Al-based wiring film and a TiN layer or a laminated structure of the Al-based wiring film and a TiW layer.