JPH098005A - Semiconductor processing device - Google Patents

Abstract

PURPOSE: To obtain a semiconductor processing device that can prevent the adhesion of foreign materials on a wafer and can remove the foreign materials from the wafer without damaging a pattern on it. CONSTITUTION: The material of the inner walls 4a of a reaction chamber, in which the etching of a wafer 1 is performed, is silicon (Si). When the inner walls are etched, the foreign materials, that contain impurities as SUS, are not produced and the yield of semiconductor devices formed on the wafer is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor processing apparatus,
In particular, the present invention relates to a semiconductor processing apparatus that reduces foreign matter caused by a reaction product due to discharge from adhering onto a wafer.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor processing apparatus, it has been a problem that foreign matter (particles) resulting from a reaction product due to discharge adheres to a wafer. A semiconductor processing apparatus (plasma reaction processing apparatus) whose problem is shown in FIG.
This will be described in detail using a specific example. In FIG. 8, 1 is a wafer, 2 is a lower electrode, 3 is an exhaust port, 4 is an inner wall, 5 is a high frequency power source, and 6 is a gas inlet.

When the plasma reactor shown in FIG. 8 is operating to etch the wafer 1, the above-mentioned foreign substances are deposited on the inner wall 4 while the discharge is repeated to form a deposition film. Since this deposition film is not necessarily strong, it peels off and adheres to the wafer 1. Also,
The inner wall 4 itself is also etched during the processing, and foreign matter due to the material (SUS or the like) of the inner wall 4 is also generated and adheres onto the wafer 1.

As a method for removing the above deposition film, a cycle purge method (batch purge method) in which N ₂ is introduced from the gas introduction port 6 and exhausted from the exhaust port 3 is repeated,
Alternatively, a method such as a wet cleaning method for the reaction chamber is adopted.

Next, FIG. 9 is a diagram showing a conventional method for removing foreign matter on the wafer 1. In FIG. 9, 7 is a brush, 8 is a cleaning liquid injection port, 9 is a cleaning liquid, 11 is a wafer stage, 1
3 is a foreign substance. As shown in FIG. 9, the foreign matter 13 on the wafer 1 is sprayed from the cleaning solution injection port 8 to remove the cleaning solution 9 on the wafer 1 or is removed by contact with the wafer 1 such as scrubbing with a brush 7. Had been removed.

[0006]

However, the above-mentioned methods such as the cycle purge method and the wet cleaning method have a problem that the time loss is large or the effect is not improved. Further, if it is removed while being in contact with the wafer 1, there is a problem that the pattern on the wafer 1 is damaged.

The present invention has been made in order to solve such a problem, and it is a semiconductor processing apparatus capable of preventing foreign matter from adhering to a wafer and removing foreign matter without damaging a pattern on the wafer. Aim to get.

[0008]

[Means for Solving the Problems] The problem solving means according to claim 1 of the present invention comprises an inner wall of a reaction chamber made of silicon.

[0009] The means for solving the problem according to claim 2 of the present invention is:
A cathode body for discharging electrons and an inner wall of a reaction chamber serving as an anode for the cathode body are provided, and foreign matter in the reaction chamber charged with the electrons is attached to the inner wall.

The problem solving means according to claim 3 of the present invention is
Ultrasonic wave generating means for applying ultrasonic vibration to the inner wall of the reaction chamber,
Heating means for heating the inner wall of the reaction chamber while applying the ultrasonic vibration.

The problem solving means according to claim 4 of the present invention is
A shield plate that separates or connects the plasma generation chamber and the reaction chamber, an inert gas introduction unit that introduces an inert gas into the plasma generation chamber, and a plasma generation chamber that exhausts the gas in the plasma generation chamber. And an exhaust port.

The problem solving means according to claim 5 of the present invention is
A pressurizing means is provided to pressurize the reaction chamber to fix foreign substances that are gently attached to the inner wall of the reaction chamber.

[0013] The problem solving means according to claim 6 of the present invention comprises:
A wafer stage is provided so as to be oriented outward with respect to a rotation axis, and a wafer stage that rotates about the rotation axis is provided, and foreign matter adhering to the wafer is removed by a centrifugal force generated by the rotation. To do.

[0014]

In the semiconductor processing apparatus according to the first aspect of the present invention, foreign matter containing impurities such as SUS does not occur even if the inner wall is etched.

In the semiconductor processing apparatus according to the second aspect of the present invention, the floating foreign matter is charged with electrons by the cathode body discharging electrons in the reaction chamber. The charged foreign matter moves to the inner wall of the reaction chamber, which is the anode, and is adsorbed to the inner wall.

In the semiconductor processing apparatus according to the third aspect of the present invention, ultrasonic vibration is applied to the inner wall while heating the inner wall.
Then, the deposition film attached to the inner wall is detached.

In the semiconductor processing apparatus according to the fourth aspect of the present invention, when the plasma generation chamber and the reaction chamber are separated by the shield plate, foreign matter in the plasma generation chamber does not enter the reaction chamber. With the reaction chamber and the plasma generation chamber separated, an inert gas is introduced into the plasma generation chamber and exhausted from the plasma generation chamber exhaust port. At this time, foreign matter is also exhausted.

In the semiconductor processing apparatus according to the fifth aspect of the present invention, when the pressure in the reaction chamber is increased, the foreign substances that are gently attached to the inner wall of the reaction chamber receive the pressure and firmly adhere to the inner wall.

In the semiconductor processing apparatus according to the sixth aspect of the present invention, when the wafer stage is rotated, the foreign matter adhering to the wafer is separated by the centrifugal force.

[0020]

【Example】

{First Embodiment} A first embodiment will be described. FIG.
FIG. 3 is a schematic cross-sectional view showing a semiconductor processing apparatus (for example, plasma reaction processing apparatus) according to the first embodiment of the present invention. Reference numeral 4a in FIG. 1 corresponds to the inner wall of the reaction chamber made of silicon (Si), and other reference numerals correspond to the reference numerals in FIG.

As shown in FIG. 1, by using silicon as the material of the inner wall 4a of the reaction chamber, as described in the prior art, S caused by the material (SUS etc.) of the inner wall 4 shown in FIG.
It is possible to prevent the generation of foreign matter containing the US component.

As a method of coating the material of the inner wall 4a with silicon, a polysilicon film may be formed. The reaction formula during the film formation is SiH ₄ → Si + 2H ₂ (pyrolysis) SiCl ₄ + 2H ₂ → Si + 4HCl (reduction).

The effect of this embodiment is that the inner wall 4a of the reaction chamber is made of silicon to prevent the generation of foreign matters and improve the yield in the semiconductor device formed on the wafer 1.

In addition to the inner wall 4a of the reaction chamber, the material of the portion exposed to plasma may be silicon.
For example, if the material of the exhaust port 3 is also made of silicon, the above effect is further enhanced.

{Second Embodiment} Next, a second embodiment will be described. FIG. 2 is a schematic sectional view showing a semiconductor processing apparatus (for example, plasma reaction processing apparatus) according to the second embodiment of the present invention. In FIG. 2, 12 is a discharge cathode line, 13 is a floating foreign substance, 14 is an electron, 15 is a high voltage negative voltage, and other symbols correspond to the symbols in FIG.

As shown in FIG. 2, a discharge cathode line 12 is provided in the reaction chamber, and a high voltage 15 is connected thereto to discharge electrons 14, thereby negatively charging the floating foreign matter 13. The charged foreign matter 13 moves to the anode side (grounded inner wall 4 of the reaction chamber) and is adsorbed to the inner wall 4. This suppresses the foreign matter 13 from floating in the reaction chamber and prevents the foreign matter 13 from adhering to the wafer 1.

The effect of this embodiment is to prevent the foreign matter 13 from floating in the reaction chamber, thereby preventing the foreign matter 13 from adhering to the wafer 1, and thus yielding the semiconductor devices formed on the wafer 1. Is to be improved.

The foreign matter 13 adsorbed on the inner wall 4 of the reaction chamber
It is desirable to efficiently remove the deposits by dry or wet cleaning.

{Third Embodiment} Next, a third embodiment will be described. FIG. 3 is a schematic sectional view showing a semiconductor processing apparatus (for example, plasma etching apparatus) according to the third embodiment of the present invention. In FIG. 3, 17 is a water channel, 18 is an ultrasonic oscillator, 19 is a heater, 20 is a water inlet, 21 is a water outlet, and other reference numerals correspond to the reference numerals in FIG.

The semiconductor processing apparatus shown in FIG. 3 is provided with an ultrasonic oscillator 18 for applying ultrasonic vibration to the water channel 17, a heater 19 for heating the inner wall 4, and the water channel 17 outside the inner wall of the reaction chamber. Be prepared to contact. The waterway 17 is filled with water.

Next, the operation will be described. After etching,
In order to effectively remove the deposition film attached to the inner wall 4 of the reaction chamber, ultrasonic vibration is applied to the inner wall 4 of the reaction chamber by the ultrasonic oscillator 18 via the water passage 17. This allows
Detach the deposition film. Further, in order to promote the separation of the deposition from the inner wall 4, the inner wall is heated to 50 to 100 ° C. At this time, since the separated deposition is discharged from the exhaust port 3, vacuuming is performed.

The effect of this embodiment is that the deposition film attached to the inner wall 4 of the reaction chamber can be easily removed.

{Fourth Embodiment} Next, a fourth embodiment will be described. FIG. 10 shows a specific example of a conventional semiconductor processing apparatus. In FIG. 10, 1 is a wafer, 2 is a lower electrode, and 13
Is a foreign substance, 22 is a coil, 23 is a microwave introduction tube, 29
Is a reaction chamber exhaust port for exhausting gas in the plasma generation chamber and the reaction chamber. Further, a gas inlet (not shown) for introducing the etching process gas is provided in the plasma generation chamber and the reaction chamber.

In the semiconductor processing apparatus shown in FIG. 10, the plasma is generated by the etching process gases that are turned into plasma during plasma generation in the plasma generation chamber having the coil 22 and the microwave introduction tube 23 or by the reaction between the etching process gas and the inner wall. The charged foreign matter 13 is generated in the generation chamber. While the plasma is being generated, an electric field is generated between the plasma generation chamber and the lower electrode 2 having the wafer 1, so that the charged foreign matter 13 does not enter the reaction chamber below the plasma generation chamber. However, when the processing of the wafer 1 is completed, the generation of plasma is completed, the electric field disappears, and the foreign matter 13 in the plasma generation chamber enters the reaction chamber and adheres onto the wafer 1.

FIG. 4 is a schematic sectional view showing a semiconductor processing apparatus (for example, plasma reaction processing apparatus) according to the fourth embodiment of the present invention. In FIG. 4, 25 is a shield plate, 26 is an inert gas inlet for introducing an inert gas such as N ₂ into the plasma generation chamber, 27 is a plasma generation chamber exhaust port for exhausting gas in the plasma generation chamber, 28 Is a shield plate storage unit, and other reference numerals correspond to the reference numerals in FIG. Further, a gas inlet (not shown) for introducing the etching process gas is provided in the plasma generation chamber and the reaction chamber.

As shown in FIG. 4, a shield plate 25 for separating and connecting the plasma generating chamber and the reaction chamber to each other.
Is provided. The shield plate 25 can completely separate the plasma generation chamber and the reaction chamber, and the reaction chamber exhaust port 29
Therefore, the gas in the reaction chamber can be discharged to bring the reaction chamber into a vacuum state, and in that state, the inside of the plasma generation chamber can be purged to the atmosphere. Further, when the plasma generation chamber and the reaction chamber are connected to each other, the shield plate storage unit 2 is provided to store the shield plate 25.
8 is provided.

Next, the operation will be described. The shielding plate 25 is stored in the shielding plate storage unit 28 during the processing of the wafer 1. After the processing of the wafer 1 is completed, the shield plate 25 separates the plasma generation chamber and the reaction chamber. After that, the generation of plasma ends.

It is desirable that the material of the shielding plate 25 is a substance such as Teflon which has poor reactivity and is not easily deteriorated even when exposed to plasma.

If the shielding plate 25 is charged to the same polarity as the foreign matter 13, the foreign matter 13 can be prevented from adhering to the shielding plate 25.

Further, in order to more effectively remove the foreign matter 13 in the plasma generation chamber, an inert gas inlet port 26 and a plasma generation chamber exhaust port 27 are provided in the plasma generation chamber, as shown in FIG. An inert gas such as N ₂ is introduced from the inert gas introduction port 26 by an inert gas introduction means (not shown).

The shielding plate 25 separates the reaction chamber from the plasma generation chamber, discharges gas from the reaction chamber exhaust port 29 to bring the reaction chamber into a vacuum state, and while maintaining this state, N gas is passed through the inert gas inlet port. An inert gas such as ₂ is introduced and exhausted from the plasma generation chamber exhaust port 27. At the same time, the foreign matter 13
Is also exhausted. In order to efficiently perform this action, it is desirable to use the cycle purge method in which the introduction and exhaust are repeated.

The effect of this embodiment is that by separating the reaction chamber and the plasma generation chamber by the shield plate 25 before the plasma generation is completed, the foreign matter 13 is prevented from adhering to the wafer 1 or the inner wall of the reaction chamber. And to improve the yield in the semiconductor device formed on the wafer 1.

{Fifth Embodiment} Next, a fifth embodiment will be described. FIG. 5 is a schematic sectional view showing a semiconductor processing apparatus (for example, an ECR etching apparatus) according to the fifth embodiment of the present invention. Reference numeral 30 in FIG. 5 is a high-pressure pump that pressurizes the pressure of the reaction chamber (in the present embodiment, the reaction chamber also includes the plasma generation chamber), and other reference numerals correspond to the reference numerals in FIG. Further, a reaction chamber exhaust port (not shown) for exhausting gas in the plasma generation chamber and the reaction chamber, and a gas introduction port (not shown) for introducing etching process gas into the plasma generation chamber and the reaction chamber are provided.

Next, the operation will be described. After the etching process on the wafer is completed and the wafer is unloaded, a gas of the same type as the gas in the reaction chamber used during the etching process is introduced into the reaction chamber by the high-pressure pump 30, and the pressure in the reaction chamber becomes several hundred atmospheric pressure. Continue to introduce until. As a result, immediately after the etching process, the foreign matter that was gently attached to the inner wall of the reaction chamber is subjected to the pressure of the gas and is firmly attached to the inner wall.

The effects of this embodiment are as follows:
By firmly adhering the foreign matter to the inner wall of the reaction chamber, the foreign matter is prevented from flying into the reaction chamber, and when the etching process is performed on the wafer thereafter, the foreign matter is prevented from adhering to the wafer and formed on the wafer. That is, the yield of the semiconductor device is improved.

{Sixth Embodiment} Next, a sixth embodiment will be described. FIG. 6 is a schematic sectional view showing a semiconductor processing apparatus (for example, plasma reaction processing apparatus) according to the sixth embodiment of the present invention. 6, 1a and 1b are wafers, 13 is a foreign substance, 31 is a lower electrode, 32a and 32b are stages, and other reference numerals correspond to the reference numerals in FIG. Also,
FIG. 7 is a diagram showing the operation of the semiconductor processing apparatus shown in FIG. Each code in FIG. 7 corresponds to each code in FIG.

As shown in FIG. 7, the lower electrode 31 is of a rotary type. Further, the lower electrode 31 is a stage 32a,
32b, and as shown in FIG.
The a and 32b can be placed in a state of facing the outer side of the rotation shaft and downward of the reaction chamber, and can be fixed so that the state can be maintained during rotation. The wafers 1a and 1b are fixed on the stages 32a and 32b by a clamp or an electrostatic chuck, respectively. Also, the lower electrode 3
1. A wafer stage is composed of the stages 32a and 32b.

Next, the operation will be described. First, the wafer 1a,
Before performing processing such as etching or film formation on 1b, foreign matter 13 may be attached to wafers 1a and 1b as shown in FIG. Therefore, as shown in FIG. 7, the stages 32a and 32b are tilted and the lower electrode 31 is rotated.
Then, the foreign matter 13 is detached downward from the wafers 1a and 1b by the centrifugal force. Since the separated foreign matter 13 is discharged from the exhaust port 3, the foreign matter 13 does not separate upward in the reaction chamber and does not fly up into the reaction chamber.

The above operation may be carried out even after the processing such as etching and film formation.

The effect of this embodiment is different from the case of removing with the brush 7 shown in FIG. 9, because the foreign matter 13 on the wafer is removed by the centrifugal force in a non-contact state, so that the pattern on the wafer 1 is not damaged. That is, the foreign matter 13 can be effectively removed.

[0051]

According to the first aspect of the present invention, by forming the material of the inner wall of the reaction chamber from silicon, the generation of foreign substances containing impurities is prevented, and the yield in the semiconductor device formed on the wafer is improved. Has the effect.

According to the second aspect of the present invention, by suppressing the floating of the foreign matter in the reaction chamber, it is possible to prevent the generation of the foreign matter and to improve the yield in the semiconductor device formed on the wafer.

According to claim 3 of the present invention, it is possible to easily remove the deposition film attached to the inner wall of the reaction chamber.

According to the fourth aspect of the present invention, by separating the reaction chamber and the plasma generation chamber by the shield plate, it is possible to prevent the foreign substances from adhering to the wafer or the inner wall of the reaction chamber and to easily remove the foreign substances in the plasma generation chamber. It is possible to effectively evacuate the wafer and improve the yield in the semiconductor device formed on the wafer.

According to claim 5 of the present invention, the foreign matter is prevented from flowing into the reaction chamber by firmly adhering the foreign matter to the inner wall of the reaction chamber by the pressurizing means, and thereafter, when performing the etching process on the wafer. In addition, it is possible to prevent foreign matter from adhering to the wafer and improve the yield in the semiconductor device formed on the wafer.

According to the sixth aspect of the present invention, since the foreign matter on the wafer is removed by the centrifugal force in a non-contact state, the foreign matter can be effectively removed without damaging the pattern on the wafer.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a semiconductor processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a semiconductor processing apparatus according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional view showing a semiconductor processing apparatus according to a third embodiment of the present invention.

FIG. 4 is a schematic sectional view showing a semiconductor processing apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a schematic sectional view showing a semiconductor processing apparatus according to a fifth embodiment of the present invention.

FIG. 6 is a schematic sectional view showing a semiconductor processing apparatus according to a sixth embodiment of the present invention.

FIG. 7 is a diagram showing an operation of a semiconductor processing apparatus according to a sixth embodiment of the present invention.

FIG. 8 is a schematic sectional view showing a specific example of a conventional semiconductor processing apparatus.

FIG. 9 is a diagram showing a conventional method for removing foreign matter on a wafer.

FIG. 10 is a schematic sectional view showing a specific example of a conventional semiconductor processing apparatus.

[Explanation of symbols]

1, 1a, 1b wafer, 2 lower electrode, 3 exhaust port,
4, 4a inner wall, 5 high frequency power source, 6 gas inlet, 12
Discharge cathode ray, 13 foreign matter, 14 electron, 15 negative voltage, 16 upper electrode, 17 water channel, 18 ultrasonic oscillator, 19 heater, 20 water inlet, 21 water outlet,
22 coil, 23 microwave introduction pipe, 25 shield plate, 26 inert gas introduction system, 27 plasma generation chamber exhaust port, 28 shield plate storage part, 29 reaction chamber exhaust port, 30
High-pressure pump, 31 lower electrode, 32a, 32b stage.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenichiro Shiozawa 4-1-1 Mizuhara, Itami City, Hyogo Prefecture Mitsubishi Electric Corporation ULS AI Development Research Center (72) Inventor Akemi Teratani Mizuhara, Itami City, Hyogo Prefecture 4-chome Mitsubishi Electric Co., Ltd. ULS Development Research Center (72) Inventor Kenji Kawai 4-1-1 Mizuhara, Itami City, Hyogo Prefecture Mitsubishi Electric Co., Ltd. ULS Development Research Center

Claims (6)

[Claims] 1. A semiconductor processing apparatus comprising an inner wall of a reaction chamber made of silicon. 2. A cathode body that discharges electrons, and an inner wall of a reaction chamber that serves as an anode with respect to the cathode body, wherein foreign matter in the reaction chamber charged with the electrons is attached to the inner wall. Semiconductor processing equipment. 3. A semiconductor processing apparatus comprising: an ultrasonic wave generating means for applying ultrasonic vibration to the inner wall of the reaction chamber; and a heating means for heating the inner wall of the reaction chamber while applying the ultrasonic vibration. 4. A shield plate for separating or connecting the plasma generating chamber and the reaction chamber, an inert gas introducing means for introducing an inert gas into the plasma generating chamber, and a gas in the plasma generating chamber. A semiconductor processing apparatus comprising: a plasma generation chamber exhaust port for exhausting gas. 5. A semiconductor processing apparatus equipped with a pressurizing means for pressurizing the inside of the reaction chamber to fix foreign substances gently adhering to the inner wall of the reaction chamber. 6. A wafer stage, which is installed with a wafer facing outward with respect to a rotation axis, and rotates around said rotation axis, and removes foreign matter adhering to the wafer by centrifugal force generated by said rotation. A semiconductor processing apparatus characterized in that.