JP2001135618A - Dry etching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dry etching device of simple constitution which can prevent electrostatic attraction of the object and besides not damaging the object. SOLUTION: A dry etching device 1 is equipped with an inert gas supply source 31. When carrying out a substrate S after etching from a reaction chamber 11, this dry etching device supplies the reaction chamber with inert gas before separating the board from a lower electrode 13 by means of a lifting mechanism 23, and shifts the electric charge to the inert gas without applying voltage to the lower electrode, and removes the statics on the board and the lower electrode. At the time of carrying the board into the reaction chamber, this device supplies the reaction chamber with inert gas before shifting the board from a carrying mechanism 22 to the lifting mechanism, and removes the statics on the board and the carrying mechanism similarly. An inert gas supply pipe 32 is connected to a reaction gas supply pipe 18 outside the reaction chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dry etching apparatus used for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, the surface is processed by dry etching. Dry etching is a process in which plasma is generated in a reaction gas and processing is performed using the generated reaction gas ions, and is suitable for removing polycrystalline silicon, an aluminum thin film, a silicon oxide film, a silicon nitride film, and the like. And has excellent accuracy in performing partial removal.

[0003] Dry etching having such features is useful for manufacturing a semiconductor circuit that requires a large area and a fine pattern. For example, in the manufacture of liquid crystal displays, the use of dry etching in the production of thin film transistor (TFT) circuits has responded to demands for larger screens, higher brightness, and higher pixel density.

FIG. 2 shows a schematic configuration of a conventional dry etching apparatus. The dry etching apparatus 5 includes a metal reaction chamber 11, an upper electrode 12 and a lower electrode 13 provided in the reaction chamber 11, and a plurality of reaction gases for supplying a reaction gas such as CF ₄ and O ₂ to the reaction chamber 11. A supply source 14 and a vacuum pump 15 for discharging gas from the reaction chamber 11 are provided.

[0005] The upper electrode 12 and the lower electrode 13 are arranged horizontally and face each other. The upper electrode 12 is an anode and is connected to a ground potential. The lower electrode 13 is a cathode and is connected to a high frequency power supply 16 via an impedance matching circuit 17. Lower electrode 1
The surface of 3 is provided with a dielectric for its protection. The substrate S to be subjected to dry etching is placed on the lower electrode 13 with the surface to be etched facing up.

[0006] The reaction gas supply source 14 and the reaction chamber 11 are connected by a reaction gas supply pipe 18. The reaction gas supply pipe 18 reaches the upper electrode 12 in the reaction chamber 11 and branches off in the upper electrode 12. The lower surface facing the lower electrode 13 has a plurality of openings. Between the reaction gas supply pipe 18 and each reaction gas supply source 14, a flow controller 19 for adjusting the flow rate of each reaction gas is provided.

A preparation chamber 21 is provided in contact with the reaction chamber 11. The reaction chamber 11 and the preparation chamber 21 are separated by a closed door 20 and can be kept airtight independently of each other.
A transfer mechanism 22 that is flat and movable in the horizontal direction is provided in the preparation chamber 21.
The substrate S is placed on the transfer mechanism 22 and is carried into the reaction chamber 11 from the preparation room 21, and is carried out from the reaction room 11 to the preparation room 21. The transport mechanism 22 is movable to a position above the lower electrode 13.

The lower electrode 13 is provided with a plurality of through holes in the vertical direction. Below the reaction chamber 11, there is provided an elevating mechanism 23 having a plurality of rod-shaped portions which are movable in the vertical direction and pass through through holes of the lower electrode 13. Lifting mechanism 23
Can abut on the substrate S at its upper end to support the substrate S from below. The upper end of the elevating mechanism 23 is the transport mechanism 2
2 can be raised to a position slightly higher than the upper surface. The transport mechanism 22 is set so as to pass between the plurality of rod-shaped portions of the elevating mechanism 23, and the two mechanisms do not collide even when the transport mechanism 22 is located above the lower electrode 13.

The processing of the substrate S by the dry etching apparatus 5 is performed as follows. First, the substrate S is placed at a predetermined position of the transport mechanism 22 in the preparation room 21, and the transport mechanism 2
The substrate S is carried into the reaction chamber 11 by moving the substrate 2. Substrate S
Stops moving when the transfer mechanism reaches a predetermined position above the lower electrode 13, and moves the substrate S to the lift mechanism 23 by raising the lift mechanism 23 in that state. Then, the transport mechanism 22 is retracted into the preparation chamber 21, the elevating mechanism 23 is lowered, the substrate S is placed on the lower electrode 13, and the door 20 between the reaction chamber 11 and the preparation chamber 21 is closed.

Next, the reaction chamber 11 is moved by the vacuum pump 15.
Is evacuated, each reaction gas is supplied from the reaction gas supply source 14 into the reaction chamber 11 at a predetermined flow rate, and the high-frequency power supply 16 is operated while maintaining the inside of the reaction chamber 11 at a predetermined pressure. As a result, a high-frequency voltage is applied to the upper electrode 12 and the lower electrode 13, a discharge occurs between the two electrodes, and plasma is generated in the reaction gas in the reaction chamber 11. The ionized reactant gas molecules in the plasma are transferred to the upper electrode 12 or the lower electrode 1 depending on the polarities of the upper electrode 12 and the lower electrode 13 and their own charges.
Move toward 3. When the lower electrode 13 is positive, the reaction gas molecules which have become anions collide with the substrate S and process the surface thereof. Thereby, etching is performed.

After completion of the etching, application of the high-frequency voltage and supply of the reaction gas are stopped, the door 20 is opened, and the reaction chamber 11 and the preparation chamber 21 are evacuated. Next, the elevating mechanism 23 is raised to separate the substrate S from the lower electrode 13, the substrate S is positioned slightly above the position where the transfer was performed at the time of loading, and the transport mechanism 22 is moved below the substrate S. Then, the substrate S is transferred to the transfer mechanism 22 by lowering the elevating mechanism 23, and the transfer mechanism 22 is moved to unload the substrate S from the reaction chamber 11 to the preparation chamber 21.

As described above, the loading and unloading of the substrate S into and from the reaction chamber 11 is performed by the transport mechanism 22, and the substrate S is placed on the lower electrode 13 and separated from the lower electrode 13 by the elevating mechanism 23. Done by Processing of the substrate S until it enters the preparation room 21 in preparation for etching;
The processing of the substrate S after being carried out to the preparation room 21 differs depending on the manufacturing process of the semiconductor device. The position of the substrate S with respect to the transport mechanism 22 is, in principle, the same before loading into the reaction chamber 11 and after unloading from the reaction chamber 11, and as long as this condition is satisfied, the substrate S is transferred to the apparatus in the next step. There is no need to adjust the position.

[0013]

However, since the substrate S is etched by the reaction gas which has become an anion, the substrate S is negatively charged even after the etching is completed, which causes electrostatic attraction to cause a problem. Usually, the substrate S to be etched is a glass plate provided with a semiconductor on the upper surface, and the lower portion has extremely low conductivity. In addition, the surface of the lower electrode 13 is also made of a dielectric material and has low conductivity.
Therefore, the substrate S and the lower electrode 13 are in a state like a capacitor, and even if the lower electrode 13 is connected to the ground potential, a positive charge corresponding to the negative charge of the substrate S remains on the lower electrode 13. Therefore, after the etching is completed, the substrate S is electrostatically attracted to the lower electrode 13.

If the electrostatic attraction is strong, the substrate S is broken or the substrate S jumps and shifts its position on the elevating mechanism 23 when the substrate S is separated from the lower electrode 13 by the elevating mechanism 23. become. As the size of the substrate S increases, cracks are more likely to occur. The cracking of the substrate S does not merely mean that the substrate becomes defective and lowers the yield,
The process flow is interrupted for cleaning the reaction chamber 11, and the production efficiency is remarkably reduced. Further, the displacement of the position of the substrate S with respect to the elevating mechanism 23 inevitably results in the displacement of the substrate S with respect to the transport mechanism 22. This makes it difficult to align the device S with the substrate S in a later step, thereby lowering the manufacturing efficiency. Become.

The displacement of the substrate S with respect to the elevating mechanism 23 may occur not only after the etching is completed but also when the substrate S is carried into the reaction chamber 11. If the substrate S remains charged for some reason, such as the influence of a process before etching, or if static electricity is generated during the movement of the transport mechanism 22, electrostatic attraction of the substrate S to the transport mechanism 22 occurs. . Since the electrostatic attraction is weaker than the electrostatic attraction to the lower electrode after the etching is completed, the substrate S hardly breaks. Misalignment may occur. The displacement at this time does not significantly affect the etching itself, but remains until the end of the etching, making it difficult to align the apparatus and the substrate S in a later step.

A technique for avoiding electrostatic attraction after completion of etching has also been proposed. For example, Japanese Patent Application Laid-Open No. 5-216001
Japanese Patent Application Laid-Open Publication No. H11-163,087 discloses a device for removing gas from a substrate by supplying gas ions to a reaction chamber after completion of etching. In Japanese Patent Application Laid-Open No. 6-53191, an inert gas is supplied to a reaction chamber after completion of etching, and a high-frequency voltage is applied between both electrodes in the presence of the inert gas.
A method for removing charge on a substrate is disclosed.

However, in the apparatus for supplying gas ions to the reaction chamber, means for ionizing the gas is separately required, so that the overall configuration is inevitably complicated and large. In the method of applying a high-frequency voltage in the presence of an inert gas, a discharge occurs between the lifting mechanism and the lower electrode when the lifting mechanism supports the substrate, thereby damaging a circuit on the substrate. There is.

In these publications, the problem of electrostatic attraction before the start of etching is not considered. Even if the substrate is removed from charge after etching to prevent the displacement with respect to the elevating mechanism, if the substrate has already been displaced at the time of etching, it will hinder the efficiency of subsequent steps.

The present invention has been made in view of such a problem, and has a simple structure, which can prevent electrostatic attraction of an object, and has a dry structure that does not damage the object. An object of the present invention is to provide an etching apparatus.

[0020]

In order to achieve the above object, according to the present invention, a reaction gas is supplied into a reaction chamber having an upper electrode and a lower electrode, and a high-frequency voltage is applied between the two electrodes. In a dry etching system that generates plasma at the bottom and etches the target placed on the lower electrode with the ionized reaction gas, a non-ionized inert gas is supplied to the reaction chamber, and a voltage is applied between both electrodes. The charge of the object in the reaction chamber is removed by transferring the charge of the object to the inert gas without performing the process.

In this apparatus, the inert gas to be supplied for removing the charge of the object is not ionized in advance, and a high frequency voltage is applied to both electrodes to ionize the inert gas in the reaction chamber. I will not let you. The charge of the object is removed by being transferred to neutral inert gas molecules which impinge on it. This static elimination process is very gentle, and there is no possibility of damaging the object. Since the efficiency of removing the charge of the target object depends on the velocity and the number of molecules of the inert gas colliding with the target object, the efficiency can be freely adjusted depending on the setting of the flow rate of the inert gas and the gas pressure in the reaction chamber. it can.

The treatment for removing the charge of the object by supplying the non-ionized inert gas to the reaction chamber may be performed after the object is etched. Electrostatic attraction of the object to the lower electrode after the etching is completed can be released, and the object can be prevented from being damaged or displaced when being carried out of the reaction chamber.

Here, the dry etching apparatus is vertically movable and supports the object from below, and separates the object from the lower electrode and lifts the object to a predetermined position above the lower electrode; It is movable and supports the object from below,
A transfer mechanism for receiving the object from the elevating mechanism at the predetermined position and transporting the object to the outside of the reaction chamber. A non-ionized inert gas is supplied to the chamber. When the etched object is separated from the lower electrode, the electrostatic attraction of both is already released, so that the object can be easily separated from the lower electrode by the elevating mechanism, causing damage or displacement of the object. There is no fear.

Further, it is preferable to keep the inert gas in the reaction chamber until the elevating mechanism finishes separating the object from the lower electrode at the earliest. The object can be separated from the lower electrode in a state where the electrostatic attraction is surely released. In this case, the lifting mechanism comes into contact with the object in an inert gas for charge removal, but since no voltage is applied between the two electrodes, no discharge occurs between the lifting mechanism and the lower electrode, and the discharge is performed. There is no danger of damage to the object due to this.

The process of supplying the non-ionized inert gas to the reaction chamber to remove the charge of the object may be performed before etching the object. By removing the charge on the target object before the target object is carried into the reaction chamber and placed on the lower electrode, even if electrostatic adsorption has occurred between the carrying / placement member and the target object, The electrostatic attraction can be released, and the object can always be placed at a fixed position on the lower electrode.

Here, the dry etching apparatus is capable of moving in the horizontal direction, supporting the object from below, and carrying the object from outside the reaction chamber to a predetermined position above the lower electrode;
A vertically movable mechanism for supporting the object from below, receiving the object at a predetermined position from the transfer mechanism, and placing the object on the lower electrode, and before the lift mechanism receives the object from the transfer mechanism. Then, a non-ionized inert gas is supplied to the reaction chamber. Even if the object and the transport mechanism are electrostatically attracted, the electrostatic attraction is released when the elevating mechanism receives the object from the transport mechanism. There is no displacement with respect to the electrodes.

Further, it is preferable to keep the inert gas in the reaction chamber until the elevating mechanism finishes placing the object on the lower electrode at the earliest. Even if the object is not charged, if the lower electrode is charged for some reason, induced polarization occurs in the object approaching the lower electrode, and an electrostatic force acts on the object and the lower electrode. The displacement of the object with respect to the electrodes may occur. By keeping the inert gas in the reaction chamber until the object is placed on the lower electrode, the possibility of such a displacement can be eliminated.

The above-mentioned dry etching apparatus is provided with a reaction gas supply path for supplying a reaction gas to the reaction chamber, and an inert gas supply path for supplying an inert gas to the reaction chamber. The path is preferably connected outside the reaction chamber and shares a portion from the connection position to the opening in the reaction chamber. The overall configuration of the device becomes extremely simple. Further, a function of removing the charge of the substrate can be added to the existing apparatus without making any change to the reaction chamber.

Here, the reactant gas supply path and the inert gas supply path may have a plurality of openings on the surface of the upper electrode facing the lower electrode. With this configuration, the gas can be supplied uniformly to the entire surface of the target object, and uneven etching does not occur. In addition, the charge on the target object can be quickly and uniformly removed.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the dry etching apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a dry etching apparatus 1 according to one embodiment of the present invention. The dry etching apparatus 1 includes several components having the same functions as those of the conventional dry etching apparatus 5 shown in FIG. These components are denoted by the same reference numerals as those in FIG. 2, and redundant description will be omitted.

The dry etching apparatus 1 includes an inert gas supply source 31 for supplying an inert gas such as Ar and He, and an inert gas supply pipe 3 for guiding the inert gas to the reaction chamber 11 therefrom.
2 is provided. The inert gas supply pipe 32 is connected to the reaction chamber 1
1, the reaction gas supply pipe 18 and the inert gas supply pipe 32 share a portion from the connection position of the two to the opening on the lower surface of the upper electrode 12 in the reaction chamber 11. are doing. The inert gas supply pipe 32 from the inert gas supply source 31 to the connection position with the reaction gas supply pipe 18 is provided with a flow controller 33 for adjusting the flow rate of the inert gas.

The lower electrode 13 is made of aluminum and has an area of several hundred mm in length and width, for example, about 600 × 700 mm. The size of the upper electrode 12 is almost the same as that of the lower electrode 13. The surface of the lower electrode 13 is made alumite by oxidation treatment for protection, and is a dielectric.

As the vacuum pump 15, a turbo molecular pump and a dry pump are used. Thereby, the reaction chamber 1
1 can be made a high vacuum of about 1 × 10 ⁻³ Pa, and gas can be discharged from the reaction chamber 11 at a stable flow rate.

The processing of the substrate S by the dry etching apparatus 1 of the present embodiment is performed as follows. First, the substrate S is placed at a predetermined position of the transfer mechanism 22 in the preparation room 21, and the transfer mechanism 22 is slowly moved to load the substrate S into the reaction chamber 11. At this time, the lifting mechanism 23 has its upper end set at a position lower than the upper surface of the transport mechanism 22. When the substrate S reaches a predetermined position above the lower electrode 13, the movement of the transport mechanism 22 is stopped, and the vacuum pump 15 is operated to evacuate the reaction chamber 11 and the preparation chamber 21.

Then, an inert gas is supplied from the inert gas supply source 31 to the reaction chamber 11 at a predetermined flow rate. Upper electrode 1
The inert gas flowing from the plurality of openings provided on the lower surface of the substrate 2 is uniformly sprayed on the entire upper surface of the substrate S. The inside of the reaction chamber 11 is maintained at a predetermined pressure while the supply of the inert gas is continued, and after a predetermined time of about several seconds has elapsed, the elevating mechanism 23 is slowly raised. The upper end of the elevating mechanism 23 is in contact with the lower surface of the substrate S at a position at the same height as the upper surface of the transport mechanism 22. At a position slightly higher than this position, the lifting mechanism 23 is stopped. This allows
The substrate S is transferred from the transport mechanism 22 to the elevating mechanism 23.

Next, the transfer mechanism 22 is moved and retracted to the preparation room 21, and the door 2 between the reaction room 11 and the preparation room 21 is moved.
0 is closed, and the elevating mechanism 23 is slowly lowered. The lower surface of the substrate S contacts the upper surface of the lower electrode 13 at a position where the upper end of the lifting mechanism 23 is at the same height as the upper surface of the lower electrode 13. At a position further lower than this position, the lifting mechanism 23 is stopped. As a result, the substrate S is placed on the lower electrode 13, and the elevating mechanism 23 is separated from the substrate S. After placing the substrate S on the lower electrode 13, the supply of the inert gas to the reaction chamber 11 is stopped, and the reaction chamber 11 is evacuated.

No voltage is applied from the high frequency power supply 16 to the lower electrode 13 from the start of the supply of the inert gas to the reaction chamber 11 until the reaction chamber 11 is evacuated. Therefore, the molecules of the inert gas supplied to the reaction chamber 11 remain neutral and are not ionized by an external action. The neutral inert gas molecules are transferred to the substrate S and the transport mechanism 2
2. If it collides with the elevating mechanism 23 and these are charged,
Receiving the charge and ionizing it, the substrate S, the transport mechanism 2
2. Remove all charges from the lifting mechanism 23. Since the inert gas is supplied while keeping the pressure in the reaction chamber 11 constant, the ionized inert gas molecules are discharged from the reaction chamber 11.

After evacuating the reaction chamber 11, each reaction gas is supplied from the reaction gas supply source 14 to the reaction chamber 11 at a predetermined flow rate. Then, while maintaining the supply of the reaction gas, the inside of the reaction chamber 11 is maintained at a predetermined pressure, a predetermined high-frequency voltage is applied from the high-frequency power supply 16 to the lower electrode 13, and a discharge is generated between the upper electrode 12 and the lower electrode 13. Wake up. Plasma is generated in the reaction gas by the discharge, and the generated negative ions of the reaction gas molecules collide with the substrate S when the lower electrode 13 is positive, and peel off the easily processed portion of the upper surface of the substrate S.
Thereby, etching is performed. The stripped material is discharged from the reaction chamber 11 together with the reaction gas.

Since the reaction gas flows into the reaction chamber 11 through a plurality of openings provided on the lower surface of the upper electrode 12, plasma is uniformly generated between the upper electrode 12 and the lower electrode 13. Therefore, the ionized reaction gas molecules uniformly collide with the entire upper surface of the substrate S, and etching unevenness does not occur.

After a lapse of a predetermined time, the application of the high-frequency voltage is stopped. Also, the supply of the reaction gas is stopped, and the reaction chamber 11 is evacuated. Next, an inert gas is supplied from the inert gas supply source 31 to the reaction chamber 11 at a predetermined flow rate, and the supply of the inert gas is continued while maintaining the inside of the reaction chamber 11 at a predetermined pressure. After a lapse of a predetermined time of about several seconds to several tens of seconds, the elevating mechanism 23 is slowly raised. The lifting of the lifting mechanism 23 continues even after the upper end thereof is at the same height as the upper surface of the lower electrode 13. As a result, the substrate S is separated from the lower electrode 13 and transferred to the elevating mechanism 23.

At a position where the upper end of the elevating mechanism 23 is slightly higher than the upper surface of the transport mechanism 22, the elevating mechanism 23 is stopped and the door 20 is opened. Then, the transport mechanism 22 is moved into the reaction chamber 11 and accurately stopped at a position where the transport mechanism 22 is stopped above the lower electrode 13 when the substrate S is loaded. Next, the supply of the inert gas to the reaction chamber 11 is stopped, and the elevating mechanism 23 is slowly lowered. The lowering of the elevating mechanism 23 continues even after its upper end is at the same height as the upper surface of the transport mechanism 22. Thus, the substrate S is moved from the lifting mechanism 23 to the transport mechanism 22.

Thereafter, the transport mechanism 22 is moved to move the substrate S
Is carried out to the preparation room 21, and the elevating mechanism 23 is stopped. Thus, all the processes of loading the substrate S into the reaction chamber 11, etching in the reaction chamber, and unloading the substrate S from the reaction chamber are completed.

After the completion of the etching, while the inert gas is being supplied to the reaction chamber 11, no voltage is applied to the lower electrode 13 from the high frequency power supply 16. Therefore, the molecules of the inert gas supplied to the reaction chamber 11 are not ionized by an external action. The substrate S etched by the negative ions of the reaction gas is negatively charged, and is electrostatically attracted to the lower electrode 13. The neutral inert gas molecules supplied to the reaction chamber 11 collide with the substrate S and the lower electrode 13, receive charges therefrom, ionize them, and remove the charges on the substrate S and the lower electrode 13. Since the inert gas is supplied while maintaining the pressure in the reaction chamber 11 constant, the ionized inert gas molecules are discharged from the reaction chamber 11.

In the dry etching apparatus 1 operating as described above, when the substrate S after the etching is separated from the lower electrode 13, the charge of the substrate S and the lower electrode 13 is already removed, and the electrostatic attraction of both is released. Therefore, the lifting mechanism 23 can separate the substrate S from the lower electrode 13 very easily. Therefore, at the time of separation from the lower electrode 13, the substrate S is not broken, and the position of the substrate S with respect to the elevating mechanism 23 does not shift due to jumping.

Further, since the inert gas is supplied to the reaction chamber 11 until after the substrate S is transferred to the elevating mechanism 23, the substrate S is removed from the lower electrode 13 in a state where the electrostatic attraction is completely released. It can be transferred to a lifting mechanism. For this reason,
The effect of preventing damage and displacement of the substrate S can be reliably obtained.

In the dry etching apparatus 1, an inert gas is supplied to the reaction chamber 11 after the substrate S is carried into the reaction chamber 11 and before the substrate S is transferred from the transport mechanism 22 to the elevating mechanism 23. Even if the substrate S and the transport mechanism 22 are electrostatically attracted, the substrate S can be moved to the elevating mechanism 23 with the electrostatic attraction released. Therefore, the position of the substrate S with respect to the elevating mechanism 23 does not shift.

Further, the supply of the inert gas to the reaction chamber 11 is continued until the mounting of the substrate S on the lower electrode 13 is completed. Is removed from the substrate S, so that no electrostatic force acts on the substrate S and the lower electrode 13. Therefore, the position of the substrate S does not shift when the substrate S is placed on the lower electrode 13.

Therefore, in the dry etching apparatus 1, the substrate S is always kept at a predetermined position in the reaction chamber 11, and the position of the substrate S in the preparation chamber 21 is maintained even after the etching is completed. It will be the same as before the start. As a result, it is not necessary to newly perform the alignment by the apparatus that performs the processing of the next step on the substrate S, and the overall processing efficiency is improved. Further, since the substrate S is not damaged in the reaction chamber 11, the yield is high, and it is not necessary to suspend the processing in the reaction chamber 11 for cleaning or the like.

Moreover, since the charge on the substrate S is removed by a gentle process of supplying an inert gas that has not been ionized to the reaction chamber 11, the circuit being manufactured on the substrate S may be damaged by the charge removal process. Nor.

Here, when the substrate S is carried into the reaction chamber 11, the reaction chamber 11 is once evacuated and then the inert gas is supplied, but this is not always necessary. In the normal case, since the substrates S are successively processed by the dry etching apparatus 1, the inert gas supplied after the completion of the etching remains in the reaction chamber 11, and this gas is used for removing the charges of the substrate S at the time of loading. Can be used.

Although the dry etching apparatus 1 according to the present embodiment is provided with only one preparation room 21,
Two preparation chambers may be provided so that the substrate S is loaded into the reaction chamber 11 from one of the preparation chambers and unloaded from the reaction chamber 11 to the other preparation chamber. In this case, two transport mechanisms are provided for loading and unloading.
One.

A specific example of the processing of the substrate S by the dry etching apparatus 1 will be described taking the manufacture of a TFT circuit for a large liquid crystal display as an example. A semiconductor layer having a 400-nm-thick SiN _x film on the surface has a size of 550 × 6 on the upper surface.
A substrate S made of glass of 00 mm was carried into the reaction chamber 11 from the preparation chamber 21 by the transfer mechanism 22, and Ar gas was supplied to the reaction chamber 11 as an inert gas at a flow rate of 0.4 L / min. After maintaining the pressure of the reaction chamber 11 at 66.5 Pa for 3 seconds, the substrate S was transferred to the elevating mechanism 23 and placed on the lower electrode 13.

Next, the supply of Ar gas was stopped, and the reaction chamber 11 was evacuated to a high vacuum of about 1 × 10 ^-2 Pa. Then, CF ₄ gas and O ₂ gas were used as reaction gases at a flow rate of 0.36 L each.
/ Min and 0.24 L / min.
1 was maintained at 40.0 Pa. In this state, power 1
A high frequency voltage of 800 W and a frequency of 1 MHz is applied to the lower electrode 13.
For 2 minutes to etch the SiN _x film.

After the completion of the etching, the reaction chamber 11 is substantially 1 × 1
A high vacuum of 0 ^-2 Pa and a flow rate of Ar gas of 0.4 L / m
The reaction chamber 11 was maintained at 66.5 Pa for 10 seconds. Thereafter, the substrate S is moved by the lifting mechanism 23 to the lower electrode 1.
3, the supply of Ar gas was stopped, and the substrate S was transferred to the transfer mechanism 22 and carried out to the preparation room 21.

When the above processing was performed on a large number of substrates S, there was no damage to the substrates S.
The position of the substrate S on the transfer mechanism 22 did not change before and after the etching. Further, all the TFT circuits manufactured from these substrates S operated well.

For comparison, the supply of the inert gas to the reaction chamber 11 before and after the etching was omitted, and the same substrate S was etched under the same conditions as above.
Could be damaged. Even when the substrate S is not damaged, the position of the substrate S on the transport mechanism 22 is several meters before and after the etching.
m in many cases.

After the etching, an Ar gas is supplied to the reaction chamber 11, the pressure is maintained at 40.0 Pa, and the
When a high-frequency voltage of 00 W was applied for 10 seconds, the substrate S
No breakage or displacement occurred. However, if the substrate S is separated from the lower electrode 13 by the raising / lowering mechanism 23 during application of the high-frequency voltage, the obtained TFT circuit may include a defective product that does not operate properly.

Here, an example of the processing by the dry etching apparatus 1 is shown with specific numerical values.
The amount of the inert gas supplied to 1 is the size of the reaction chamber 11,
In addition, it may be determined according to the degree of charging of the substrate S and therefore the plasma generation conditions at the time of etching. In etching under normal conditions, the pressure of the inert gas in the reaction chamber 11 is 10 to 150 Pa, the flow rate of the inert gas supplied to the reaction chamber 11 is 0 to 0.5 L / min, If the supply time of the gas is set to several to several tens of seconds, the charge on the substrate S can be sufficiently removed and the electrostatic attraction can be released. When the pressure is relatively high, it is not necessary to keep supplying the inert gas to the reaction chamber 11.

The dry etching apparatus 1 can be obtained by adding an inert gas supply source 31, an inert gas supply pipe 32, and a flow controller 33 to a conventional apparatus. By connecting the inert gas supply pipe 32 to the reaction gas supply pipe 18 outside the reaction chamber 11, the conventional apparatus can be easily improved without causing any change to the reaction chamber 11,
The device of the present invention having a charge removing function can be provided.

[0060]

According to the dry etching apparatus of the present invention, damage and displacement of an object due to electrostatic attraction can be prevented, and the efficiency of the entire semiconductor device manufacturing process can be improved. In addition, since the charge removal of the object is performed by a gentle process, the circuit being manufactured on the object is not damaged. Further, the inert gas for removing the charge can be supplied as it is, and there is no need to provide a means for performing a process such as ionization, so that the overall configuration of the apparatus is simple.

A process for supplying non-ionized inert gas to the reaction chamber to remove the charge of the target object is performed after the target object is etched, so that the electrostatic charge applied to the lower electrode of the target object after the etching is completed. Suction can be released. This prevents the target object from being damaged or displaced when being taken out of the reaction chamber, and improves the yield,
Processing efficiency is also improved.

In the configuration in which the object is separated from the lower electrode by the elevating mechanism and transferred to the carrying mechanism for carrying out, the reaction gas is discharged from the reaction chamber before the elevating mechanism separates the object from the lower electrode, and the reaction is performed. By supplying a non-ionized inert gas to the chamber, the etched object can be separated from the lower electrode in a state where electrostatic adsorption is released. Therefore, there is no breakage or misalignment at the time of separation.

In addition, by keeping the inert gas in the reaction chamber until the lifting / lowering mechanism finishes separating the object from the lower electrode at the earliest, the above-mentioned effects can be surely obtained.

Further, by carrying out a process of supplying non-ionized inert gas to the reaction chamber and removing the charge of the target object before etching the target object, the loading / unloading member and the target object can be separated. Even if electrostatic attraction occurs, the electrostatic attraction can be released, and the object can always be placed at a fixed position on the lower electrode.

In the configuration in which the elevating mechanism receives the object from the transfer mechanism for loading and places the object on the lower electrode, the inert gas that has not been ionized is supplied to the reaction chamber before the elevating mechanism receives the object from the transfer mechanism. Is supplied, even if the object and the transport mechanism are electrostatically attracted, the lifting mechanism can receive the object from the transport mechanism in a state where the electrostatic attraction is released. Therefore, the position of the object with respect to the elevating mechanism and the lower electrode is always kept constant.

In addition, by keeping the inert gas in the reaction chamber until the lifting mechanism finishes placing the object on the lower electrode, the electrostatic action between the object and the lower electrode can be reliably prevented. As a result, there is no displacement of the object with respect to the lower electrode.

In a configuration in which the reaction gas supply path and the inert gas supply path are connected outside the reaction chamber, and both paths share a portion from the connection position to the opening in the reaction chamber,
The overall configuration of the device becomes extremely simple. Moreover, the function of removing the charge on the substrate can be added to the existing apparatus without adding any change to the reaction chamber only by adding the inert gas supply path and the inert gas supply source.

In a configuration in which the reaction gas supply path and the inert gas supply path have a plurality of openings on the surface of the upper electrode on the side facing the lower electrode, uneven etching does not occur and charging of the object is not uneven. And it can be removed promptly.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a dry etching apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a conventional dry etching apparatus.

DESCRIPTION OF SYMBOLS 1 Dry etching apparatus 11 Reaction chamber 12 Upper electrode 13 Lower electrode 14 Reaction gas supply source 15 Vacuum pump 16 High frequency power supply 17 Impedance matching circuit 18 Reaction gas supply pipe 19 Flow rate controller 20 Door 21 Preparation room 22 Transport mechanism 23 Elevating mechanism 31 Inert gas supply source 32 Inert gas supply pipe 33 Flow rate controller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05H 1/46 H01L 21/302 C

Claims (9)

[Claims] An object placed on a lower electrode by supplying a reaction gas into a reaction chamber having an upper electrode and a lower electrode, generating a plasma in the reaction gas by applying a high-frequency voltage between the two electrodes, In a dry etching apparatus that etches with an ionized reaction gas, a non-ionized inert gas is supplied to the reaction chamber, and the charge of the object is transferred to the inert gas without applying a voltage between both electrodes. A dry etching apparatus for removing charge of an object in a reaction chamber. 2. The dry etching apparatus according to claim 1, wherein the process of supplying the non-ionized inert gas to the reaction chamber to remove the charge of the object is performed after the object is etched. . 3. An elevating mechanism for moving the object vertically and supporting the object from below, separating the object from the lower electrode and elevating the object to a predetermined position above the lower electrode, and moving the object horizontally and moving the object downward. And a transport mechanism for receiving the object from the elevating mechanism at the predetermined position and transporting the object out of the reaction chamber.The elevating mechanism discharges the reaction gas from the reaction chamber before the object is separated from the lower electrode. 3. The dry etching apparatus according to claim 2, wherein a non-ionized inert gas is supplied to the reaction chamber. 4. The dry etching apparatus according to claim 3, wherein an inert gas is kept in the reaction chamber until the elevating mechanism finishes separating the object from the lower electrode at the earliest. 5. The dry etching according to claim 1, wherein the process of supplying the non-ionized inert gas to the reaction chamber to remove the charge of the object is performed before etching the object. apparatus. 6. A transfer mechanism for moving the object horizontally and supporting the object from below and carrying the object from outside the reaction chamber to a predetermined position above the lower electrode, and supporting the object from below and movable vertically. An elevating mechanism for receiving an object from the transfer mechanism at the predetermined position and placing the object on the lower electrode, and supplying an unionized inert gas to the reaction chamber before the elevating mechanism receives the object from the transfer mechanism. The dry etching apparatus according to claim 5, wherein the etching is performed. 7. The dry etching apparatus according to claim 6, wherein an inert gas is kept in the reaction chamber until the lifting mechanism finishes placing the object on the lower electrode at the earliest. 8. A reaction gas supply path for supplying a reaction gas to the reaction chamber, and an inert gas supply path for supplying an inert gas to the reaction chamber, wherein the reaction gas supply path and the inert gas supply path are provided in the reaction chamber. 2. The dry etching apparatus according to claim 1, wherein the dry etching apparatus is connected outside and shares a portion from the connection position to the opening in the reaction chamber. 9. The dry etching according to claim 8, wherein the reactant gas supply path and the inert gas supply path have a plurality of openings in the surface of the upper electrode facing the lower electrode. apparatus.