JP2897752B2 - Sample post-treatment 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 sample post-processing method and, more particularly, to a sample post-processing method suitable for post-processing a sample etched with a sample such as a semiconductor device substrate.

[0002]

2. Description of the Related Art As a technique for post-processing a sample which has been etched with a sample such as a semiconductor element substrate, for example, a technique described in Japanese Patent Application Laid-Open No. 58-164788 is known.

In the technique described in Japanese Patent Application Laid-Open No. 58-164788, a microwave is applied to a mixed gas of oxygen gas and carbon tetrachloride gas to generate gas plasma, and excited atoms or atoms in the gas plasma are generated. The molecules are stably transferred to perform a resist removal process, which is a pattern forming microphone.

[0004]

In the above-mentioned prior art, the resist is removed from the sample after the etching process by using gas plasma. However, the point of removing the deposit on the side wall of the sample after the etching process is as follows. No consideration was given.

That is, in the above-mentioned conventional technique, for example, aluminum (A)
l) The resist after the etching process when titanium tungsten (TiW) or titanium nitride (TiN) is used as a barrier metal layer under the alloy film, particularly the Al alloy film, is removed using gas plasma. However, it is impossible to sufficiently remove the side wall deposits attached to the side wall during the etching process.

Therefore, when the sample is exposed to the air in this state, for example, the sample is corroded by the action of the residual chlorine component contained in the deposit on the side wall and the moisture in the air. Occurs.

An object of the present invention is to provide a sample post-processing method capable of improving the corrosion resistance of a sample after an etching process.

[0008]

The object of the present invention is to provide a method for post-treating a sample, comprising: loading a sample having a resist and being etched into a post-treatment chamber partitioned by a plasma generation chamber and a perforated plate; A step of generating gas plasma in a plasma generation chamber, and mainly a radical component of the gas plasma,
This is achieved by including a step of removing the resist from the sample carried into the post-processing chamber, and a step of bringing the sample closer to the perforated plate and removing the side wall deposits from the sample.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A sample having a resist and subjected to an etching process, for example, a sample having an Al alloy film etched using a chlorine-based gas plasma, is exposed to the It is transferred to the post-processing atmosphere via the atmosphere and held by the holding means. On the other hand, gas plasma, for example, gas plasma containing oxygen is generated under reduced pressure by the gas plasma generating means. The resist of the sample after the etching process is removed mainly by the radical component of the gas plasma by the resist removal processing means.

Further, the side wall deposits on the sample after the etching process are removed by the side wall deposit removal processing means by the sputtering action of the gas plasma ions.

Therefore, even if the sample is subsequently exposed to the atmosphere, for example, the side wall deposits are removed.
Corrosion of the sample can be prevented. In addition, since the resist removal processing is performed mainly by a radical reaction, when the sample is a semiconductor element substrate, damage to the element can be reduced.

An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, the plasma generation chamber 10 and the post-processing chamber 20 have their insides kept in a vacuum.
Both chambers are partitioned by a perforated plate 30 made of Al. In this case, means for converting the processing gas into plasma using a microwave is used as a method for converting the processing gas into plasma.

That is, in this case, an opening is provided in the top wall of the plasma generation chamber 10, a quartz window is attached to the opening, and a microwave oscillator 6 is provided at an end of the microwave waveguide 50.
0 is provided. The exhaust means is the exhaust port 2 of the post-processing chamber 20.
1 and comprises a pressure control valve 70, a vacuum pump (not shown), and the like. The gas supply means is the plasma generation chamber 1
0 gas inlet 11, in this case, for example,
Oxygen gas and a carbon fluoride-based gas (for example, carbon tetrachloride) are adjusted by flow control valves 80 and 81, respectively, and are composed of a gas supply pipe 82 and the like for mixing and supplying each gas.

The etched sample 90 is carried into the post-processing chamber 20 and placed on the sample table 100.

FIG. 2 is a plan cross-sectional view of a processing apparatus which can perform etching and post-processing continuously under vacuum using the post-processing apparatus of FIG. 1, and explains a schematic means of a series of processing. Used to

In the processing apparatus shown in FIG.
0, under load lock 120, 130, etching chamber 14
The chamber 0 and the post-processing chamber 20 can be evacuated, and each chamber can be independently partitioned by airtight means (not shown).

The flow of the processing using the apparatus is as follows.
After being transported into the load lock chamber 120, the air is exhausted under reduced pressure from the atmospheric pressure by an exhaust device (not shown). Thereafter, the wafer is sent into the etching chamber 140 evacuated and evacuated by the rotation arm 170 via the buffer chamber 110 evacuated and evacuated in advance.

After performing a predetermined etching process in the etching chamber 140, the sample in the post-processing chamber 20, which is also evacuated and evacuated in advance, is loaded again by the rotation arm 171 by the rotation arm 171. It is carried to the lock room 130. The inside of the load lock chamber 130 is partitioned from the inside of the buffer chamber 110 by airtight means. Thereafter, the pressure in the load lock chamber 130 is increased to atmospheric pressure by a leak gas, for example, N ₂ gas, and then released to the atmosphere. afterwards,
The sample is stored in the cassette 151 on the unloading side by the rectilinear arm 161 and a series of processing is completed.

In FIG. 1 and FIG. 2, the microwave having a frequency of 2.45 GHz generated by the microwave oscillator 60 travels in the microwave waveguide 50 and is guided into the plasma generation chamber 10 through the window 40 made of quartz. . A microwave is applied to the mixed gas for processing introduced into the plasma generation chamber 10 to generate plasma in the plasma generation chamber 10. Plasma generation chamber 1
A perforated plate 30 made of Al is provided between 0 and the post-processing chamber 20 to prevent the microwave from traveling to the post-processing chamber,
A radical component is mainly led to the post-processing chamber 20.

In the post-processing according to the present embodiment, the ashing process for removing the resist is performed by using the radicals led to the post-processing chamber 20 as a main component. 70 is controlled to further reduce the pressure in the ashing process step, and the ions generated in the plasma generation chamber 10 are reduced in the post-processing chamber 20 to increase and lead the mean free path of the ions. Is removed by the ion sputtering effect.

According to this embodiment, a chlorine compound, for example,
The amount of residual chlorine remaining after the Al etching process using chlorine-based gas plasma can be much more reduced than before, and Ti or Al alloy film and TiW,
The anticorrosion performance of the Al alloy film having a barrier metal layer such as TiN after the etching process can be improved.

Next, another embodiment of the present invention will be described with reference to FIG. 3, the same reference numerals are used for the same devices and the like as those in FIG. 1, and the description is omitted. The apparatus shown in FIG. 3 is the same as the apparatus shown in FIG.
80 and a vertical airtight member 181 that can move up and down.

In this embodiment, an ashing process is carried out with a radical as a main component in order to remove the resist in the same manner as in the first embodiment.
Airtight member 181 capable of moving the sample stage 100 on which
And the vertical drive unit 180 is used to approach the perforated plate 30. By bringing the sample 90 closer to the perforated plate 30, the sample 90 comes closer to the plasma generation region, the effect of the ionic action flowing from the perforated plate 30 increases, and the deposits on the side walls can be more effectively removed.

On the other hand, arbitrarily controlling the height of the sample table makes it possible to control the ion damage to the sample. Further, by combining this embodiment with the above-described embodiment in which the pressure in the post-processing chamber is reduced, it is possible to more effectively remove the deposit on the side wall.

Next, still another embodiment of the present invention will be described with reference to FIG. 4, the same reference numerals are used for the same devices as those in FIG. 1, and the description is omitted. The apparatus shown in FIG. 4 applies a high-frequency output to the apparatus shown in FIG. 1 by a power supply for bias application, for example, a high-frequency power supply 190 to the sample table 100, and electrically connects the sample table 100 and the post-processing chamber 20 to each other. The configuration is such that an insulating member 200 is provided for the purpose of ensuring insulation.

In this embodiment, as in the embodiment described with reference to FIG. 1, the ashing process for removing the resist is carried out by using a radical as a main component. A high-frequency power is applied to the sample 100 to generate a high-frequency bias voltage on the surface of the sample.

Further, in this embodiment, by arbitrarily controlling the high-frequency applied power, it is possible to adjust the removal rate of the deposit on the side wall and the degree of substrate damage due to ion bombardment.

FIG. 5 is a diagram showing a processing procedure of the post-processing shown in FIGS. 1, 3 and 4.

The post-processing method according to the present invention is characterized in that a resist film of a wiring pattern is first subjected to an ashing process with a radical component as a main component, and the remaining side wall deposits are removed by an ion sputtering effect. .

According to this processing procedure, the resist component can be removed with a gas mainly composed of oxygen with low damage and at a high speed, and the surface of the remaining side wall deposits is oxidized or fluorinated when the resist is removed. Can also be removed by the ion sputtering action, and the optimum processing conditions for each processing can be individually set, so that the residual chlorine component can be effectively removed.

As described above, according to the present invention, the post-treatment of the Al or Al alloy film can obtain low damage and high anticorrosion performance.

In the post-processing in each of the above embodiments, an example was described in which a perforated plate was provided between the plasma generation chamber and the post-processing chamber. The processing may be performed excluding. In this case, since the sample is directly exposed to the plasma, the ion sputtering effect is enhanced, and the residual chlorine component can be more effectively removed.

[0034]

According to the present invention, the resist and the side wall deposits can be effectively removed from the sample after the etching process at high speed and with low damage, so that the corrosion resistance of the sample after the etching process can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a post-processing apparatus showing an embodiment of the present invention.

FIG. 2 is a plan cross-sectional view of an apparatus that continuously performs an etching process and a post-process using the device of FIG.

FIG. 3 is a longitudinal sectional view of a post-processing apparatus showing another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a post-processing apparatus showing still another embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a processing procedure of post-processing in the present invention.

[Explanation of symbols]

Reference Signs List 10: plasma generation chamber, 20: post-processing chamber, 30: perforated plate, 40: quartz window, 50: microwave waveguide, 60
... microwave oscillator, 70 ... pressure control valve, 80, 81 ...
Flow control valve, 100: sample stage.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoichi Ito 502 Kandate-cho, Tsuchiura-shi, Ibaraki Hitachi, Ltd.Mechanical Research Laboratory Co., Ltd. (56) References JP-A-2-191325 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) H01L 21/3065

Claims (1)

(57) [Claims] 1. A step of loading a sample having a resist and subjected to an etching process into a post-processing chamber partitioned by a plasma generation chamber and a perforated plate; a step of generating gas plasma in the plasma generation chamber; Mainly comprising a radical component of plasma, a step of removing the resist from the sample carried into the post-processing chamber, and a step of bringing the sample closer to the perforated plate and removing side wall deposits from the sample. Characteristic sample post-treatment method.