JP2923218B2 - Sample processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a sample processing method, and more particularly to a sample processing method suitable for processing a sample such as a semiconductor element substrate, which is required to be subjected to an anticorrosion treatment together with an etching treatment.

[0002]

2. Description of the Related Art In etching a sample such as a semiconductor element substrate, for example, a sample having an aluminum (Al) film, an Al alloy film, or a multilayer structure film using these and a barrier metal, etc. using a halogen gas plasma, Corrosion after exposure to the atmosphere after the etching process becomes a problem, and therefore, in these samples, anticorrosion treatment is required together with the etching process. The following technology has been proposed based on an idea corresponding to such a request.

For example, Japanese Patent Publication No. Sho 62-30268 discloses that a halogen compound in an active state is used in a container, and Al-silicon (Si), Al-copper (Cu), Al-S
A dry etching post-processing technique is described in which after a dry etching of an Al alloy film such as i-Cu is performed, a mixed gas plasma processing of fluorocarbon and oxygen is performed without taking out the inside of the container.

For example, Japanese Patent Publication No. 58-12343 discloses that in order to prevent erosion after etching of an Al or Al alloy film etched by using chlorinated plasma, the etched film is fluorinated. A technique for exposing to plasma is described.

[0005]

However, in the above-mentioned conventional technique, it is difficult to remove corrosive deposits generated in the etching process of the sample and adhering to the side wall of the pattern.
Further, in such a conventional technique, a substitution reaction of only a surface layer of a corrosive deposit adhered to a pattern side wall portion (for example, AlCl ₃ which is a component of a corrosive deposit and a plasma component of a post-treatment gas). For example, substitution with Al ₂ O ₃ by reaction with oxygen) occurs, and such substitution reaction on the corrosive deposit does not proceed. On the other hand, when such a sample is exposed to the atmosphere, the corrosive deposits are not dense, so that components in the atmosphere penetrate into the corrosive deposits and react with the permeated moisture and the corrosive deposit components. Generates a corrosive component (for example, hydrochloric acid), and the sample is corroded by the corrosive component. As described above, in the above-described conventional technique, the corrosiveness of the sample after the etching process is insufficient. In particular, in recent multi-layer films of Al and other materials or Al alloy films containing Cu, the so-called battery action (Al becomes an anode) causes the occurrence of corrosion, the degree of the corrosion is accelerated, and the corrosion protection Are more pronounced.

Therefore, such a sample is usually subjected to an anticorrosion treatment by a wet method after an etching treatment as described in JP-A-61-133388.
It has been implemented. In the wet-type anticorrosion treatment, corrosive deposits adhering to the pattern side wall of the sample can be removed, and the anticorrosion in the air after the etching treatment can be further improved.

[0007] In the above-mentioned conventional technique in which a sample is etched and then subjected to a wet anticorrosion treatment, if water remains after the wet anticorrosion treatment, the residual water and the residual water remain in the sample after the wet anticorrosion treatment. For example, chlorine (HCl), which is a corrosive component, is generated by a reaction with a chlorine-containing component or chlorine in the atmosphere, thereby corroding a sample that has been subjected to a wet anticorrosion treatment. For this reason, after the anticorrosion treatment by the wet method, a drying treatment is inevitably required.

Therefore, such a conventional technique has the following problems. (1) The time required to complete the anticorrosion treatment of the sample after the etching treatment increases (at least the anticorrosion treatment time in the wet method + the drying treatment time), and the throughput decreases.

(2) A configuration in which the corrosion prevention treatment of the sample after the etching treatment is carried out by using a corrosion protection treatment device of a wet type and a drying treatment device separate from the device (in this case,
If a means for transporting the sample between the devices is also required), the price of the device increases and the floor area occupied by the device increases.

[0010] (3) It is necessary to collect a waste liquid from the anticorrosion treatment by a wet method and a treatment device therefor, which complicates the structure of the device and increases its price.

It is an object of the present invention to provide a sample processing method capable of improving throughput in processing a sample which requires anticorrosion treatment together with etching treatment.

[0012]

SUMMARY OF THE INVENTION The above objects are achieved by forming an Al film,
l alloy film or multilayer structure of these films and barrier metal
In a sample processing method for processing a sample having a film, the method comprises the steps of:
converting a gas containing l ₃ and Cl ₂ into plasma;
Utilizing plasma of gas containing BCl ₃ and Cl ₂
A step of etching the sample, and removing 90% or more of chlorine.
Converting the contained anticorrosive gas into a plasma,
Chloride adhering to the sample at the time of
An anti-corrosion plasma treatment step of reacting with and removing plasma
A resist formed on the sample after the anticorrosion plasma processing step
Having a step of removing the etching end point detecting means.
The etching gas is determined by an etching end point determination signal.
Of the anticorrosion gas to plasma
This is achieved by a sample processing method characterized in that:

[0013]

The sample is held in the processing chamber by the sample holding means. The etching gas is turned into plasma by the plasma generating means. The sample held by the sample holding means is
Etching is performed using the plasma. On the other hand, the anticorrosion gas is turned into plasma by means of plasma. The etched state held by the sample holding means is processed using the plasma.

By performing the anticorrosion treatment, a reaction product or an etching gas component generated in the etching process of the sample and adhered to the sample and having a corrosive property in the air (hereinafter, abbreviated as an adhering substance) is prevented. The processing of the sample using the plasma of the edible gas is sufficiently and easily removed from the sample without generating new deposits.

Accordingly, the wet type anticorrosion treatment is not required, and the time required for completing the anticorrosion treatment of the sample is greatly reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, two openings 12 and 13 having a predetermined interval and a diameter are provided in the buffer chamber 10, in this case, a top wall 11.
Is formed. A means (not shown) for depressurizing and exhausting the inside of the buffer chamber 10 is provided in the buffer chamber 10.
A discharge tube 20 is provided airtightly on the top wall 11 of the buffer chamber 10 corresponding to the opening 12. The shape of the discharge tube 20 is
In this case, it is substantially hemispherical. The waveguide 30 is connected to the discharge tube 20.
And the discharge tube 20 is disposed inside the inside.
The axis of the waveguide 30 is aligned with that of the discharge tube 20. The waveguide 30 and the magnetron 40 are
They are linked by one. The magnetic field generating means, for example, the solenoid coil 50 is provided outside the waveguide 30 and in the discharge tube 2.
It is mounted around the waveguide 30 substantially corresponding to 0. The solenoid coil 50 is electrically connected to a power supply (not shown) via a power supply adjusting means (not shown).

The sample table shaft 60 has an upper part protruding into the buffer chamber 20 and the discharge tube 20, and a lower part protruding outside the buffer chamber 10, so as to be airtightly attached to the bottom wall 14 of the buffer chamber 10. It is inserted. The sample stage 61 is provided substantially horizontally on the upper end of the sample stage shaft 60. The planar shape and the size of the sample table 61 are smaller than the opening 12 and larger than the sample 70. The sample stage 61 has a sample setting surface on its surface, that is, a surface corresponding to the top of the discharge tube 20. The axes of the sample stage shaft 60 and the sample stage 61 are:
It is made to substantially match that of the discharge tube 20. For example, the metal bellows 80 is placed in the
0 is provided around. The lower end of the bellows 80 is provided on the inner surface of the bottom wall 14 of the buffer chamber 10. A flange 81 is provided at the upper end of the bellows 80. A seal ring (not shown) is provided on the surface of the flange 81 corresponding to the inner surface of the top wall 11 of the buffer chamber 10.

Further, means (not shown) for driving the bellows 80 to expand and contract is provided. The bellows 80 is extended by the expansion / contraction drive means, whereby the flange 81
However, in a state where the space 90 is pressed against the inner surface of the top wall 11 of the buffer chamber 10 via the seal ring, a space 90 that is airtightly shut off from the inside of the buffer chamber 10 is formed. Exhaust nozzle 10
0 is formed on the bottom wall 14 of the buffer chamber 10 in communication with the space 90. An exhaust pipe (not shown) connected to a reduced-pressure exhaust device (not shown) is connected to the exhaust nozzle 100. An on-off valve, an exhaust resistance variable valve, and the like (not shown) are provided in the exhaust pipe. A gas introduction passage 110 is formed on the top wall 11 of the buffer chamber 10 in communication with the space 90.
Gas conduit 112 connected to etching gas source 111
Are connected to the gas introduction path 110. An on-off valve, a gas flow control device, and the like (not shown) are provided in the gas conduit 112.

In this case, the gas conduit 114 connected to the anticorrosive gas source 113 is connected to the gas conduit 11 on the downstream side such as an on-off valve or a gas flow control device provided in the gas conduit 112.
2 are joined together. The gas conduit 114 is provided with an on-off valve, a gas flow control device, and the like (not shown).
In addition, the gas conduit 114 may be directly connected to the gas introduction path 110. Power supply for bias application, for example,
A high frequency power supply 120 is provided. The sample stage 61 is
It is electrically connected to the high frequency power supply 120 via the sample stage shaft 60. The buffer chamber 10 and the high-frequency power supply 12
0 are each grounded. The temperature of the sample 70 can be controlled to a predetermined temperature via the sample table 61.

In FIG. 1, a discharge tube 21 is provided airtightly on the top wall 11 of the buffer chamber 10 corresponding to the opening 13. In this case, the shape of the discharge tube 21 is a substantially cylindrical shape having a substantially flat closed end on one side and an open end on the other side. Waveguide 3
2 is provided outside the discharge tube 21 and including the discharge tube 21 inside. The axis of the waveguide 32 is aligned with the discharge tube 21.
It is almost matched with that of. The sample stage shaft 62 is provided upright on the inner surface of the bottom wall 14 of the buffer chamber 10. Sample table 6
3 is provided substantially horizontally on the upper end of the sample stage shaft 63.
The planar shape and size of the sample stage 63 are smaller than the opening 13 and larger than the sample 70. Sample table 6
Reference numeral 3 has a sample mounting surface on its surface, that is, a surface facing the inner surface of the closed end of the discharge tube 21. The axes of the sample stage shaft 62 and the sample stage 63 are substantially aligned with those of the discharge tube 21. For example, a metal bellows 82 is provided around the sample stage axis 62 in the buffer chamber 10. The lower end of the bellows 82 is provided on the inner surface of the bottom wall 14 of the buffer chamber 10. A flange 83 is provided at an upper end of the bellows 82. A seal ring (not shown) is provided on the surface of the flange 83 corresponding to the inner surface of the top wall 11 of the buffer chamber 10.

A means (not shown) for driving the bellows 82 to expand and contract is provided. The bellows 82 is extended by the telescopic drive means, whereby the flange 8
With the space 3 pressed against the inner surface of the top wall 11 of the buffer chamber 10 via a seal ring, a space 91 is formed that is airtightly shut off from the inside of the buffer chamber 10. Exhaust nozzle 101
Are formed on the bottom wall 14 of the buffer chamber 10 in communication with the space 91. An exhaust pipe (not shown) connected to a reduced-pressure exhaust device (not shown) is connected to the exhaust nozzle 101. An on-off valve, an exhaust resistance variable valve, and the like (not shown) are provided in the exhaust pipe. A gas introduction passage 115 is formed on the top wall 11 of the buffer chamber 10 in communication with the space 91.
Gas conduit 11 connected to a gas source 116 for post-treatment gas
7 is connected to the gas introduction path 115. An on-off valve, a gas flow control device, and the like (not shown) are provided in the gas conduit 117. In FIG. 1, reference numeral 130 denotes a reflection end.

In FIG. 1, the sample 70 is stored in the buffer chamber 10.
Means for transferring the sample 70 to the sample setting surface of the sample table 61, means for transferring the sample 70 from the sample table 61 to the sample table 63 through the buffer chamber 10, and means for transferring the sample 70 to the sample table 6
Means (not shown) for carrying out of the receiving buffer chamber 3 out of the receiving buffer chamber 10 are provided.

In FIG. 1, the bellows 80 and 82 are respectively contracted by the operation of the respective expansion and contraction driving means. In this state, the evacuation means is operated. Thus, the inside of the buffer chamber 10 and the inside of the discharge tubes 20 and 21 are evacuated to a predetermined pressure. Thereafter, in this case, one sample 70 is loaded into the buffer chamber 10, and the loaded sample 70 is set on the sample setting surface of the sample stage 61 in an upward position on the surface to be processed. Thereafter, a space 90 is formed. A predetermined etching gas is supplied from the etching gas source 111,
It is introduced into the space 90 at a predetermined flow rate. In this case, the introduction of the anticorrosion gas from the anticorrosion gas source 113 into the space 90 is stopped. A part of the etching gas in the space 90 is exhausted through the exhaust nozzle 100, thereby
The pressure of 0 is adjusted to a predetermined etching processing pressure.
On the other hand, a microwave electric field is generated by the operation of the magnetron 49, and a magnetic field is generated by the operation of the solenoid coil 50.

The etching gas in the inner portion of the discharge tube 20 in the space 90 is turned into plasma by the synergistic action of the microwave electric field and the magnetic field. The processing surface of the sample 70 set on the sample setting surface of the sample stage 61 is etched using the plasma. During this etching process, a high frequency bias is applied to the sample 70,
The temperature of the sample 70 is controlled to a predetermined temperature via the sample stage 61. At the end of such an etching process, the introduction of the etching gas is stopped, and
The operations of the magnetron 40, the solenoid coil 50, and the high-frequency power supply 120 are stopped.

Thereafter, the space 90 is evacuated to a predetermined pressure again. Further, the on-off valve provided in the gas conduit 114 is opened. That is, a predetermined anticorrosion gas is introduced at a predetermined flow rate from the anticorrosion gas source 113 into the space 90 evacuated to a predetermined pressure in place of the etching gas. Part of the anticorrosion gas in the space 90 is supplied to the exhaust nozzle 100
, Whereby the pressure of the space 90 is adjusted to a predetermined anticorrosion treatment pressure. On the other hand, a microwave electric field is generated by the operation of the magnetron 40, and a magnetic field is generated by the operation of the solenoid coil 50.
The anticorrosion gas in the inner portion of the discharge tube 20 in the space 90 is turned into plasma by the synergistic action of the microwave electric field and the magnetic field. The etched sample 70 set on the sample setting surface of the sample stage 61 is subjected to anticorrosion processing using the plasma. That is, the deposits generated by the plasma etching of the sample 70 are removed from the sample 70. During such anticorrosion treatment, a high-frequency bias is applied to the etched sample 70, and the temperature of the etched sample 70 is controlled to a predetermined temperature via the sample stage 61. When such anticorrosion treatment is completed, the introduction of the anticorrosion gas is stopped, and at the same time, the magnetron 4
0, the operations of the solenoid coil 50 and the high frequency power supply 120 are stopped. Thereafter, the bellows 80 is contracted.

Thereafter, in this state, the anticorrosion-treated sample 7
Numeral 0 is conveyed from the sample stage 61 to the sample stage 63 via the inside of the buffer chamber 10 and installed on the sample installation surface of the sample stage 63 in a posture in which the surface to be processed faces upward. After that, a space 91 is formed. A predetermined post-processing gas, for example, a resist ashing gas or a passivation gas is introduced from the post-processing gas source 116 into the space 91 at a predetermined flow rate. A part of the post-processing gas in the space 91 is exhausted through the exhaust nozzle 101, whereby the pressure in the space 91 is adjusted to a predetermined post-processing pressure. On the other hand, a microwave electric field is generated by the operation of the magnetron 41. Discharge tube 21 in space 91
The post-processing gas in the inner portion is turned into plasma by the action of the microwave electric field. The sample 70 set on the sample setting surface of the sample stage 63 is subjected to post-processing such as resist ashing and passivation using the plasma. At the end of such post-processing, the introduction of the post-processing gas is stopped, and at the same time, the operation of the magnetron 41 is stopped. Further, the bellows 82 is contracted. In this state, the processed sample 70 is received from the sample table 63 and carried out of the buffer chamber 10.

The processing operations as described above are sequentially performed.
The samples are processed continuously one by one.

As the sample 70, for example, the one shown in FIG. 2 is used. In FIG. 2, the sample 70 has a stacked structure in which a TiN film 72 is provided as a barrier metal of a Si oxide film 71 as a base oxide film, an Al—Cu—Si alloy film 73 is further provided thereon, and a cap metal 74 is provided thereon. The resist 75 is provided on the cap metal 74.

Here, the barrier metal is a Si oxide film 71
And Al-Cu-Si alloy film 73 is used to prevent the deposition of Si in the contact portion electrically connected, and is also used to prevent the disconnection of the wiring due to electromigration or stress migration. Is done. As the barrier metal, in addition to the TiN film 72, for example, MoSi ₂ , TiW, TiW / Ti, Ti
An N / Ti, WSi ₂ , W-based high melting point metal film or an alloy film thereof is used. The cap metal 74 is used to prevent disconnection of wiring due to electromigration or stress migration, like the barrier metal, and is also used to prevent halation at the time of resist film exposure. Is done. As the cap metal, for example, TiN, MoSi ₂ ,
A film made of TiW, Poly-Si, WSi ₂ or the like is used.

In this case, as the etching gas, a halogen gas, for example, a gas containing chlorine, for example, BC
A mixed gas of l ₃ + Cl ₂ is used. In FIG. 1, the BCl ₃ + Cl ₂ mixed gas in the inner part of the discharge tube 20 in the space 90 is:
Plasma is generated by the synergistic action of the microwave electric field and the magnetic field. The sample 70 shown in FIG. 2 is etched using the plasma. The etching conditions in this case are as follows.

Flow rate of etching gas introduction: BC
l _3: 40cc / min. Cl ₂ : 60 cc / min. Etching pressure ・ ・ ・ 10mTorr Microwave power ・ ・ ・ 700W Magnetic field strength ・ ・ ・ 875Gauss High frequency bias power ・ ・ ・ 70W Temperature of sample 70 ・ ・ ・ 40 ℃ Longitudinal section of sample 70 etched under such conditions The figure is shown in FIG. As shown in FIG. 3, deposits (chlorides such as reaction products and etching gas components) 140 adhere to the side walls and the surface of the resist 75. Such an etched sample 70 is converted to a gas for corrosion protection by chlorine gas (Cl ₂ ).
Was used to perform a plasma anticorrosion treatment. That is, in FIG.
Cl _{2 in} the inner portion of the 0 discharge tube 20 is turned into plasma by the synergistic action of the microwave electric field and the magnetic field. The etched sample 70 shown in FIG. 3 is subjected to anticorrosion treatment using the plasma. The anticorrosion treatment conditions in this case are as follows:
It is as follows.

Introducing flow rate of anticorrosion gas: Cl ₂ : 90 cc / mi
n. Anticorrosion treatment pressure: 10 mTorr Microwave power: 700 W Magnetic field strength: 875 Gauss High frequency bias power: 40 W Discharge (corrosion prevention treatment) time: 20 sec. Temperature of the sample 70: 40 ° C. In other words, the chlorine-containing deposit 140 of the etched sample 70 is etched by reacting chlorine ions and chlorine radicals in the Cl ₂ gas plasma with the deposit 140. 70. By such anticorrosion treatment, generation of new deposits on the etched sample 70 is not observed. If the discharge (corrosion prevention) time is set to a short time of 20 seconds or less, the removal of the deposit 140 from the etched sample 70 becomes insufficient, so that the discharge (corrosion prevention) time is at least 20 seconds. Degree is needed. However, if the discharge (anticorrosion treatment) time is too long, the wiring film itself is etched, which causes a disadvantage that the wiring becomes thinner than a predetermined pattern. Such an anticorrosion-treated sample 70 is stored in the buffer chamber 10 after completion of the post-processing.
It is carried out. In this case, in the post-process, the resist ashing process and the passivation process are performed simultaneously. That is, an oxygen gas or a gas containing oxygen is used as the post-processing gas, and the resist 75 is removed from the anticorrosion-treated sample 70 by using the post-processing gas plasma. Is formed.
After that, such a sample 70 was left in the air, but no corrosion of the sample 70 was observed even after the lapse of 48 hours. Such an effect is further improved by the effect of the passivation film formed on the pattern surface by performing the passivation process in addition to the anticorrosion process.

As the anticorrosion gas, an inert gas such as helium (He) or argon (Ar) may be used.
The same effect as described above was obtained even when a mixed gas of chlorine gas and inert gas was used. In other words, for example, when an inert gas is used as the anticorrosive gas, only a sputter action occurs and no new deposits are generated without being involved in a chemical reaction. The same effect can be obtained. As an example, A
When anticorrosion treatment was performed using the r gas under the following anticorrosion treatment conditions, the same effect as in the case where chlorine gas was used as the anticorrosion gas as described above was obtained.

Introducing flow rate of anticorrosion gas: Ar: 50 cc / min. Corrosion prevention pressure 6 mTorr Microwave power 700 W Magnetic field strength 875 Gauss High frequency bias power 50 W Discharge (corrosion protection) time 60 sec. The temperature of the sample 70: 40 ° C. In this case, if the discharge (corrosion protection treatment) time is 60 seconds or less, the removal of the deposit 140 from the etched sample 70 is insufficient, so that the discharge (corrosion protection treatment) is performed. ) The time required is at least about 60 seconds. However, in this case, even when the discharge (corrosion prevention treatment) time is 60 seconds or more, the above-mentioned inconvenience when the chlorine gas is used as the anticorrosion gas is small.

Further, the same effect was obtained by using a mixed gas containing at least 90% chlorine gas (the remaining gas was a gas other than the inert gas) as the anticorrosive gas. Here, as a gas other than the inert gas and added to the chlorine gas, a gas having no deposition property, for example, SF ₆ , Br ₂ or the like is used. For example, as a sample, a TiW film is formed as a barrier metal on a Si oxide film as a base oxide film, and an Al-Cu alloy film is formed thereon. The sample having been subjected to the etching treatment under the same conditions as the etching treatment conditions of the sample 70 was subjected to the anticorrosion treatment using a mixed gas of Cl ₂ + SF ₅ as the anticorrosion gas. was gotten. In this case, the introduction flow rate of the anticorrosion gas was Cl ₂ : 90 cc / min. , S
F ₆ : 5 cc / min. The other conditions of the anticorrosion treatment are the same as the conditions when chlorine gas was used as the anticorrosion gas.

In each of the above embodiments, for example,
Samples containing Al, especially Al films and Al alloy films (for example,
It is particularly suitable when using a sample of a multilayer structure film using 0.5 to 5% Cu-containing Al alloy film) or a barrier metal or the like.

In order to passivate the anticorrosion-treated sample 70, ozone may be used in addition to the above embodiment. In this case, the means for converting the post-treatment gas into a plasma in the above embodiment is unnecessary, and instead, a means for generating ozone and a means for introducing the ozone aggregated by the means into the space 91 are provided. is necessary. Also,
If the ozone can be irradiated with ultraviolet (UV) light, the passivation film formed on the pattern surface becomes denser and stronger, which is more preferable in terms of anticorrosion.

In the above embodiment, the following effects can be obtained.

(1) Since the wet anticorrosion treatment is not required, the time required to complete the anticorrosion treatment of the sample can be greatly reduced, and the throughput can be improved.

(2) In the wet anticorrosion treatment technology,
It is necessary to install the anticorrosion treatment device and the drying treatment device in the wet method, but in this embodiment, since the drying treatment device is unnecessary, the cost of the device can be reduced, and the floor area occupied by the device can be reduced. it can.

(3) Since a waste liquid recovery and processing apparatus is unnecessary, the apparatus configuration is simplified and the price can be reduced.

(4) Since the etching process and the anticorrosion process can be performed in the same processing chamber, it is not necessary to transport the sample from the etching process unit to the anticorrosion process unit. Therefore, the time required for the anticorrosion treatment of the sample can be further reduced, and the throughput can be further improved.

(5) Since the etching process and the anticorrosion process are performed in the same processing chamber, the cost of the apparatus can be reduced and the floor area occupied by the apparatus can be reduced.

(6) The sample can be over-etched using the plasma of the anticorrosion gas. in this case,
Switching between the etching gas and the anticorrosion gas is performed by time control or an etching end point determination signal from an etching end point detecting means (not shown).

(7) The sample can be subjected to the anticorrosion treatment using the plasma of the anticorrosion gas during the etching process of the sample using the plasma of the etching gas containing the anticorrosion gas. In this case, during the period of the sample etching process, alternate introduction of the etching gas and the anticorrosion gas is performed.

It is to be noted that, instead of the above embodiment, the above processing can be performed by using an apparatus in which the etching processing space and the anticorrosion processing space are separate spaces (that is, two processing rooms).

In each of the above embodiments, the sample is etched by plasma generated by the magnetic field microwave discharge, and then subjected to anticorrosion treatment by using the plasma generated by the magnetic field microwave discharge. There is no particular limitation on whether to use plasma generated by such discharge. For example, a sample after plasma etching is subjected to DC discharge or AC discharge (high-frequency discharge)
The anticorrosion treatment may be performed by using plasma generated by a magnetic field high-frequency discharge such as a magnetron discharge or a magnetron discharge. Also,
The anticorrosion treatment may be performed using plasma generated by a non-magnetic field microwave discharge. In this case, it is desirable to apply a bias to the sample subjected to the anticorrosion treatment.

Further, the formation of the anticorrosion gas into plasma may be performed by using other energy, for example, light energy (light excitation), without depending on the discharge.

In each of the above embodiments, the etching gas and the anticorrosion gas are turned into plasma in the processing chamber. In addition, the etching gas and the anticorrosion gas are turned into plasma outside the processing chamber. The plasma may be transported (transferred) into the processing chamber. In this case, for example, the sample after the plasma etching treatment is subjected to anticorrosion treatment using plasma of an anticorrosion gas generated outside the processing chamber and transported (transferred) into the processing chamber. For example, the sample is etched by plasma of an etching gas generated outside the processing chamber and transported (transferred) into the processing chamber, and the etched sample is generated outside the processing chamber and transported (transferred) into the processing chamber. The anticorrosion treatment is performed by using the plasma of the anticorrosion gas.

In the present invention, Al, S
Metal films of i, Cu, W, Ti, Mo, etc., alloy films thereof, alloy films of these metals and Si, or these films, refractory metals of W, Mo, etc., and silicide films of these, or TiN, TiW A sample of a laminated structure film with a film can be employed.

[0051]

According to the present invention, BCl ₃ and Cl ₂ are contained.
Reaction attached to a sample etched using gas
Products can be effectively removed by the anticorrosion process,
After the etching step, use the etching end point detection means.
Then, etching is performed in the same processing chamber as the etching processing chamber.
Subsequently, the transfer time to another processing chamber is necessary to perform the anticorrosion process.
Since it is not required, it has the effect of improving processing time (throughput) .

[Brief description of the drawings]

FIG. 1 is an apparatus configuration diagram of a plasma etching apparatus according to one embodiment of the present invention.

FIG. 2 is a vertical sectional view of a main part of an example of a sample processed using the plasma etching apparatus of FIG. 1;

FIG. 3 is a longitudinal sectional view of a main part of the sample shown in FIG. 2 after an etching process.

[Explanation of symbols]

10: buffer chamber, 20, 21: discharge tube, 30-33 ...
Waveguides, 40, 41: magnetron, 50: solenoid coil, 61, 63: sample stage, 70: sample, 100, 1
01 ... exhaust nozzle, 110, 115 ... gas introduction path, 11
1. Etching gas source, 112, 114, 117: gas conduit, 113: anticorrosion gas source, 116: post-processing gas source.

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI H01L 21/88 D (72) Inventor Hironobu Kawahara 794, Higashi-Toyoi, Kazamatsu-shi, Yamaguchi Prefecture Hitachi, Ltd. Kasado Plant (72) Inventor Yoshiaki Sato 794, Higashi-Toyoi, Oaza, Kudamatsu City, Yamaguchi Prefecture Inside the Kasado Factory, Hitachi, Ltd. (56) References JP-A-56-55050 (JP, A) JP-A-63-241933 (JP, A) JP-A-57-117241 (JP, A) JP-A-63-274147 (JP, A)

Claims (1)

(57) [Claims] 1. A sample processing method for processing a sample having an Al film, an Al alloy film or a multilayer structure film of these films and a barrier metal, comprising the steps of: converting a gas containing BCl ₃ and Cl ₂ into plasma; Etching the sample using plasma of a gas containing BCl ₃ and Cl ₂ , converting the anticorrosive gas containing 90% or more of chlorine into plasma, An anticorrosion plasma treatment step of removing chlorides adhered to the plasma by reacting with the plasma of the anticorrosion gas, and a step of removing a resist formed on the sample after the anticorrosion plasma treatment step. A sample processing method, wherein the etching gas is switched from plasma to plasma using the anticorrosion gas in response to an etching end point determination signal.