JPH04196320A - Method of treatment after etching and device thereof - Google Patents

Abstract

PURPOSE:To make reactive products and the like not remain on the material to be etched by a method wherein a treatment is conducted after the pressure of an after-treatment chamber has been set at the pressure of the reactive product or lower. CONSTITUTION:After a wafer 4 has been brought in a posttreatment device 24, the device 24 is depressed to the prescribed pressure through the exhaust opening 32 which is connected to a vacuum pump (not indicated in the diagram), and the device 24 is continuously maintained in that state. The above-mentioned value of pressure is set lower than the vapor pressure of the reactive product adhered to the wafer 4. Accordingly, the reactive product on the wafer, which is heated up by a heater 35, is evaporated and exhausted to outside the chamber from and exhaust opening 32. As a result, the etching gas and the reactive product adhered to the material to be etched are removed by evaporation, and as a result, the etched material is prevented from suffering from disconnection caused by corrosion.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a semiconductor manufacturing method and a semiconductor manufacturing apparatus, and in particular, to a post-treatment method of an object to be etched after an etching process, and The present invention relates to a post-processing device for realizing this.

(Prior Art) FIG. 9 is a schematic diagram of a conventionally used etching processing apparatus. In the figure, an object to be etched 4, for example a wafer, is placed in an etching chamber 11 and a post-processing device (heat treatment chamber) 2.
Then, they are transported to the washing chamber 3 in this order. The surface of the wafer 4 that has been etched in the etching chamber 1 contains halogen alone 10 as a reactive gas for etching and nitrogen as a reaction product produced by the etching process.
Rogen compound 9 is attached (see Figure 10).

When this wafer 4 is brought into contact with the atmosphere, the moisture in the atmosphere reacts with the halogen element [0] and the reaction product 9. For example, if the halogen element 10 is chlorine, hydrochloric acid, which is a corrosive substance, is generated. . This hydrochloric acid corrodes the film to be etched 8 on the wafer 4. As a result, as shown in FIG. 11, holes 11 are formed in the film to be etched 8, resulting in disconnection. In order to prevent such disconnections, conventionally, after the etching process, as shown in FIG.
In the post-processing apparatus 2 filled with two gases, the halogen element [0] and the halogen compound 9 adhering to the wafer 4 were removed by heat treatment. Thereafter, in the washing chamber 3, ultrapure water was poured onto the rotating wafer 4 from the ultrapure water supply port to remove elemental halogen 10, halogen compound 9, etc. remaining on the wafer.

Thereafter, the wafer 4 is carried out of the washing chamber 3, thereby completing the processing and notching process. However, in the conventional post-processing apparatus 2 described above, the wafer 4
Single halogen 10 and halogen compound 9 attached on top
The vapor pressure of halogen substances such as
Because it is generally lower than atmospheric pressure), halogen alone 10
In some cases, the halogen compound 9 evaporated and remained on the wafer 4. In this case, as mentioned above, at the moment when the wafer 4 in a high temperature state is carried into the washing chamber 3 or when ultrapure water is poured onto the wafer 4 in the washing chamber 3, the amount of water remaining on the wafer 4 remains on the wafer 4. Halogens react with water. As a result, for example, hydrochloric acid is produced, and as described above, holes 11 are produced in the film to be etched 8, leading to disconnection.

(Problems to be Solved by the Invention) As explained above, conventional post-processing apparatuses have been unable to sufficiently remove single halogens and halogen compounds that have low vapor pressure and are used in etching. When these come into contact with moisture in the air, corrosive substances are produced, and as a result,
There is a problem in that wire breaks occur within the film to be etched.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a method for manufacturing an object to be etched that suppresses the generation of corrosive substances, and a post-etching device for realizing the same. The purpose is to

[Structure of the Invention (Means for Solving the Problems) The post-etching treatment method of the present invention is performed in a post-etching treatment apparatus that is provided separately from an etching chamber in which etching is performed and is equipped with a pressure reduction means and a heating means. ,
The object to be etched that has been etched in the etching chamber is carried into the post-processing apparatus, and while the pressure inside the apparatus is reduced by the pressure reducing means and maintained at a predetermined pressure, the object to be etched is heated to a predetermined temperature by the heating means. The etching post-processing apparatus of the present invention is provided separately from the etching chamber in which the etching process is performed, and in the post-processing apparatus for post-processing the object to be etched after the etching process, the post-etching apparatus comprises: The apparatus is characterized by comprising a pressure reducing means for maintaining the inside of the apparatus at a predetermined pressure and a heating means for heating the inside of the apparatus.

(Function) In the post-processing method of the present invention, the pressure inside the post-processing device is reduced to below the vapor pressure of the etching gas and the reaction product using a pressure reducing means, and while the inside of the post-processing device is maintained at a predetermined pressure, it is heated using a heating device. . As a result, the etching gas and reaction products adhering to the object to be etched are evaporated and removed, so that the object to be etched is not corroded and disconnected.

Furthermore, since the post-processing apparatus of the present invention is equipped with a pressure reducing means and a heating means for realizing the above-described method, the inside of the apparatus is reduced to a predetermined pressure and maintained at a predetermined temperature depending on the type of etching gas. Heat.

(Example) An embodiment of the present invention will be described with reference to the drawings. .

FIG. 1 is a schematic diagram of an etching apparatus equipped with a post-processing apparatus according to an embodiment of the present invention. In the figure, 20 is a loading chamber, 21 is an etching chamber, 22 is an unloading chamber, 23 is a transport chamber, 24 is a post-processing device, and 25 is a washing chamber.

26, 27 and 28 are inlet ports for introducing an inert gas such as N2 gas, and 29, 30 and 31 are exhaust ports for exhausting the gas in each chamber. 32 is
A pressure reducing means for reducing the pressure inside the post-processing device 24 is, for example, an exhaust port and a vacuum pump (not shown). 33 is a supply port for supplying ultrapure water onto the object 4 to be etched, and 34 is a drain port.

35 is a heating means for heating the object to be etched, such as a heater.

The operation of the etching apparatus equipped with the post-processing apparatus of this embodiment having the above configuration will be explained. In this example, boron trichloride (BCΩ2) was used as the reactive gas for etching.
), chlorine (C112) and carbon monoxide (Co), and helium (He) as an inert gas. Furthermore, Ag-5i-Cu was used as the film to be etched of the object to be etched 4.

First, N2 gas is introduced into the load chamber 20 from the inlet 26. When the chamber reaches atmospheric pressure, the object to be etched, for example, Ueno X4, is carried into the load chamber 20. Then, the N2 gas in the load chamber 20 is exhausted from the exhaust port 29 using a vacuum pump (not shown). Once the load chamber 20 is in a vacuum state, the wafer 4 is carried into the etching chamber 21 filled with etching gas. Then perform etching. After the etching process, the wafer 4 is carried into the unload chamber 22 which is maintained in a vacuum state.

After carrying in, N2 gas is introduced from the introduction port 27. When the pressure in the chamber reaches atmospheric pressure, the wafer 4 is carried into the transport chamber 23. At this time, the transport chamber 23 is purged with N2 gas, and the wafer 4 is not in contact with the atmosphere.

After the above steps, Ueno\4 is carried into the post-processing device 24. Thereafter, the pressure inside the post-processing device 24 is reduced to a predetermined pressure via an exhaust port 32 connected to a vacuum pump (not shown) and maintained at this pressure state. This predetermined pressure value is set lower than the vapor pressure of the reaction product adhering to way/X4. Therefore, the reaction products on the wafer 4 heated by the heater 35 are evaporated and exhausted from the exhaust port 32 to the outside. The post-processed wafer 4 is carried into the washing chamber 25 and washed with ultrapure water supplied from the supply port 33. After washing with water, the wafer 4 is spin-dried and transported outside. The ultrapure water used for washing is drained from drain 3.
From 4, it is thrown away to the outside.

The wafer is post-processed by the above-mentioned watering step.

In this manner, the pressure inside the post-processing apparatus 24 is reduced to a pressure lower than the vapor pressure of the reaction products and the like adhering to the wafer, and the heat treatment is performed in this state. As a result, most of the adhering reaction products and the like evaporate, so that corrosive substances and the like are not generated in the subsequent process (water washing treatment) and the film to be etched is not disconnected, unlike the conventional method.

Furthermore, by using the post-treatment apparatus of this embodiment, reaction products can be removed quickly, so there is no need to provide a washing chamber or perform washing with ultrapure water.

2 and 3 are cross-sectional views of post-processing devices 40 and 41 showing other embodiments of the present invention. In the embodiment shown in FIG. 2, the heater 42 serving as the heating means is a contact type hot plate, and in the embodiment shown in FIG. show. Even if the post-treatment device has a heat source configured as described above, the effect of removing reaction products remains the same.

FIG. 4 is a diagram comparing the results of measuring by ion chromatography the amount of residual chlorine on the object to be etched, that is, the wafer, obtained using the present example and the conventional post-processing apparatus. In the figure, a shows the case where no post-treatment was performed after the etching process, b shows the case where the post-processing was performed only with the conventional post-processing device, and C shows the case where the post-processing was performed with the conventional post-processing device and then washed with water. d is a case in which washing is performed in the washing room after post-processing is carried out in the post-processing device of this embodiment. Note that the heat treatment conditions for b and c were such that the pressure in the chamber was atmospheric pressure and the temperature of the wafer was 180°C. The post-processing conditions for d are that the wafer temperature is 240°C, and the pressure in the post-processing chamber is 0.3 Pa.
And so. As a result, it can be seen that when the post-processing apparatus of this example is used, the amount of residual chlorine on the object to be etched is 2 μg/wafer, which is significantly reduced compared to cases a, b, and c.

Figure 5 shows the amount of residual chlorine on the wafer and the open yield (
(open yield). According to the figure, it can be seen that as the amount of residual chlorine on the wafer increases, the open yield ratio decreases.

FIG. 6 is a diagram showing the relationship between the heating temperature in the post-processing apparatus and the amount of chlorine remaining on the wafer. In the figure, the X mark indicates the case where the post-processing was performed using the conventional post-processing device (FIG. 4c), and the O mark indicates the case where the post-processing device of this embodiment was used. According to the figure, it can be seen that when the heating temperature is set high, the amount of residual chlorine on the wafer decreases.

FIG. 7 is a diagram showing the relationship between the pressure inside the apparatus and the amount of residual chlorine on the wafer when the post-processing apparatus of this embodiment is used. The figure shows that the lower the pressure inside the apparatus, the lower the amount of residual chlorine on the wafer.

Figure 8 shows Co, BC, O3, and C as etching gases.
This figure shows the relationship between the internal pressure of the apparatus and the processing temperature in the post-processing apparatus of this example when N2 and H2 are used, and the shaded area is the optimum condition for the post-processing.

For example, the pressure inside the post-processing device is atmospheric pressure (~]05 Pa)
In the case of
(-1Torr) is 383K (110℃) or more, and IPa (~10-2Torr) is 273K (110℃) or more.
K (0°C) or higher.

In addition, in the above-mentioned example, Co, HCl3. C (72,
Although the case where a gas such as He is used has been explained, other etching gases such as CO2 or CI2 may be used instead of CO.
Instead of CCF2. CHCl3, CH2C(12,C
Chlorine gas such as H3CIO, CH4, 5iC12, He
It has been found that similar effects can be obtained when a gas such as O2°N2 is used alone or in combination in place of zero. In this case, Al1 which is the film to be etched (wiring)
-8i-Cu or A, pure Ag, Ag-5i was used in place of l11-Si-Cu.

Furthermore, the same effect was obtained even when etching was performed using the above-mentioned etching gas in a plasma state.

Furthermore, similar effects were obtained even when a gas other than the above-mentioned chlorine-based gas, such as a bromine-based gas or a fluorine-based gas, was used as the etching gas.

Furthermore, although this embodiment shows an etching processing apparatus equipped with a loading chamber, an etching chamber, an unloading chamber, a transport chamber, a post-processing device, and a washing chamber, the present invention is not limited thereto. For example, the structure may include only an etching chamber and a post-processing device.

[Effects of the Invention] As explained above, in the etching post-treatment method and post-treatment apparatus of the present invention, the post-treatment is carried out by setting the pressure in the post-treatment chamber to a pressure lower than the vapor pressure of the reaction product. No reaction products remain on the object to be etched. Therefore, a good etching process can be performed without generating corrosive substances or the like and causing wire breakage in the object to be etched in the subsequent process.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an etching apparatus equipped with a post-processing apparatus of the present invention, Fig. 2 is a block diagram showing an embodiment of the post-processing apparatus of the present invention, and Fig. 3 is a block diagram of an etching apparatus equipped with a post-processing apparatus of the present invention. Figure 4 is a diagram showing the amount of residual chlorine on the wafer after post-processing, Figure 5 is a diagram showing the relationship between the amount of residual chlorine on the wafer and open yield, and Figure 6 is a diagram showing the configuration of another embodiment. A diagram showing the relationship between the heating temperature and the amount of residual chlorine on the wafer. Figure 7 is a diagram showing the relationship between the pressure inside the post-processing equipment and the amount of residual chlorine on the wafer. Figure 8 is a diagram showing the relationship between the pressure inside the post-processing equipment and the amount of residual chlorine on the wafer. FIG. 9 is a block diagram of a conventional etching processing apparatus, FIG. 10 is a sectional view of a film to be etched, and FIG. 11 is a sectional view of a broken film to be etched. 4... Object to be etched 24... Post-processing device 32... Exhaust port (pressure reducing means) 35... Heater (heating means)

Claims (3)

[Claims] (1) In an etching post-processing device that is provided separately from an etching chamber in which etching processing is performed and is equipped with decompression means and heating means, the object to be etched that has been etched in the etching chamber is carried into the post-processing device. . A post-etching treatment method, comprising heating the object to be etched at a predetermined temperature using the heating means while reducing the pressure in the apparatus using the pressure reducing means and maintaining the pressure at a predetermined pressure. (2) A post-processing device that is provided separately from the etching chamber that performs the etching process and performs post-processing of the etched object after the etching process, the post-processing device comprising: a depressurizing means for maintaining the inside of the device at a predetermined pressure; 1. A post-etching treatment apparatus comprising: heating means for heating the inside of the etching post-treatment apparatus. (3) Boron trichloride, chlorine, carbon monoxide, and helium as the etching gas, and A as the film to be etched.
2. The post-etching treatment method according to claim 1, wherein when l-Si-Cu is used, the predetermined temperature is 240[deg.] C. and the predetermined pressure is 0.3 Pa.