JP2768916B2 - Dry etching equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry etching apparatus, and more particularly to a chemical dry etching apparatus (hereinafter, referred to as a "CDE apparatus") in which a plasma generation chamber and an etching chamber are separated.

[0002]

2. Description of the Related Art In a CDE apparatus, a long-lived active species (radical) generated by exciting an etching gas with microwaves is introduced into an etching chamber in a vacuum state, so that a glass substrate for a liquid crystal display (LCD) or a semiconductor is manufactured. This is an apparatus for isotropically etching an object to be processed such as a silicon wafer for manufacturing, and has a great feature in that a plasma generation chamber and an etching chamber are separated. By separating the plasma generation chamber and the etching chamber in this manner, the object to be processed is not exposed to plasma, and direct damage to the object to be processed by plasma can be prevented.

FIG. 4 shows an outline of an example of a conventional CDE apparatus. In FIG. 4, reference numeral 1 denotes a vacuum vessel, in which an etching chamber 2 is formed. An etching table 3 is provided inside the vacuum vessel 1, and a substrate S to be processed is placed on the etching table 3. An exhaust port 5 is formed in the bottom plate 4 of the vacuum vessel 1, and an exhaust pipe 6 having one end connected to a vacuum pump (not shown) is attached to the exhaust port 5. A gas inlet 8 is formed in the top plate 7 of the vacuum vessel 1, and a communication pipe 9 made of a Teflon material is attached to the gas inlet 8. One end of a quartz tube 10 is connected to the communication pipe 9, and a sealing member 11 having a gas flow path is attached to the other end of the quartz tube 10. A plasma generator 13 having a waveguide 12 is provided in the middle of the quartz tube 10 so as to surround the quartz tube 10, and a plasma generation chamber is provided inside the quartz tube 10 surrounded by the plasma generator 13. 1
4 are formed.

In the CDE device having such a configuration, first, the inside of the vacuum vessel 1 is evacuated to a vacuum state through the exhaust pipe 6 and the exhaust port 5 by a vacuum pump. Next, an etching gas is introduced from one end of the quartz tube 10 through a sealing member 11 having a gas flow path, and microwaves are applied to a plasma generation chamber 14 through a waveguide 12 of a plasma generator 13. . Then, a glow discharge is generated inside the plasma generation chamber 14 to generate plasma P, and the etching gas is excited to generate active species. This active species is supplied from the gas inlet 8 through the quartz pipe 10 and the connecting pipe 9 to the etching chamber 2.
Supply inside. The active species supplied into the etching chamber 2 reaches the surface of the substrate S placed on the etching table 3 and etches the surface of the substrate S.

Conventionally, CDE apparatuses have been widely used for etching various kinds of workpieces.
As the area of a substrate or a silicon wafer is further increased, a CDE apparatus capable of quickly and appropriately etching such a large workpiece is demanded.

Here, when the area of the object to be processed is large, unless the number of active species as an etchant is increased correspondingly, the etching rate is reduced by the increased area and the required time for etching is prolonged. Would. Therefore, it is necessary to increase the supply amount of the active species to the object to be processed to improve the etching rate. For this purpose, the following method can be considered. Increase the flow rate of the etching gas. The power of the microwave, which is the energy source for activation, is increased. The generated active species is efficiently supplied to the object.

[0007]

However, when any of the above methods is carried out, the plasma P becomes large, so that the plasma P easily protrudes from the plasma generation chamber 14, and the noise caused by the protruding plasma causes A sensor of the CDE device may generate an erroneous signal,
There are various problems that a member formed of a low heat-resistant material such as Teflon is thermally damaged, and further, microwaves leak out of the device.

Further, the protrusion of the plasma from the plasma generation chamber 14 tends to occur in the direction of the flow of the etching gas, that is, on the side of the etching chamber 2, and various sensors and Teflon members provided on the side of the etching chamber 2 affect the plasma. Easy to receive.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a dry etching method capable of quickly and appropriately etching a large LCD substrate, a silicon wafer, or the like without causing plasma to protrude from a plasma generation chamber. It is to provide a device.

[0010]

In order to achieve the above object, the present invention provides a plasma generating apparatus having a plasma generating chamber for generating an active species by exciting an etching gas with a microwave, and an object to be processed. A vacuum vessel having an etching chamber for performing an etching process, and a gas transport pipe communicating with the plasma generation chamber and the etching chamber, wherein the plasma generated in the plasma generation chamber is the etching Magnetic field forming means provided to form a magnetic field near the outlet of the plasma generation chamber to prevent the plasma generation chamber from protruding to the chamber side; A ring-shaped magnet inserted in a part close to
A ring-shaped magnet holder accommodating the ring-shaped magnet therein, wherein the magnet holder is connected to the plasma generator so as to function as a ground for microwaves.

[0011]

In the present invention having such a configuration, even if the plasma becomes large due to the increase in the flow rate of the etching gas or the microwave power and the like, and the plasma tries to protrude from the outlet of the plasma generation chamber, the plasma is not removed. Since a magnetic field is formed near the outlet of the generation chamber by the magnetic field forming means, the charged particles constituting the plasma are captured by the lines of magnetic force forming the magnetic field, and the plasma does not protrude to the side of the etching chamber. On the other hand, since the active species generated in the plasma generation chamber have no charge, they are supplied to the etching chamber without being captured by the lines of magnetic force.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of a dry etching apparatus according to the present invention will be described with reference to the drawings. In addition,
The same members as those in the conventional example shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, reference numeral 20 denotes a magnetic field forming device provided near the outlet of the plasma generation chamber 14, and details of the magnetic field forming device 20 are shown in FIG. As shown in FIG. 2, the etching chamber 2 of the plasma generator 13
At the end on the side, a mounting flange 21 is provided, and the magnetic field forming device 20 is mounted to the end of the plasma generator 13 via the mounting flange 21.

The magnetic field forming apparatus 20 comprises a first and second ring-shaped magnet holders 2 made of aluminum material.
The first magnet holder 22 is fixed to the mounting flange 21 by bolts 24. Recesses for receiving magnets are formed inside the magnet holders 22 and 23, respectively.
Ring-shaped magnets 25 are fitted into these recesses, respectively. Regarding the polarity of these ring-shaped magnets 25, the surface on the side of the etching chamber 2 is an N pole, and the surface on the side of the plasma generation chamber 14 is an S pole. The first and second magnet holders 22 and 23 are integrated by bolts 27 so as to sandwich a ring-shaped spacer 26 made of a steel material from both sides. The magnetic field forming device 20 has a ring shape as a whole, and the quartz tube 10 passes through the center of the ring.

The magnetic field forming means 20 is fixed to a mounting flange 21 provided on the plasma generator 13 by bolts 24, and the magnet holder 22 and the mounting flange 21 are in surface contact with a high surface pressure. The magnetic field forming means 20 and the plasma generator 13 are electrically connected to each other to have the same potential, and a ground for microwaves is formed. Here, since the plasma generator 13 is electrically connected to the main body of the dry etching apparatus, the magnetic field forming means 20 has the same potential as the main body of the dry etching apparatus.

In this embodiment having such a configuration, the plasma becomes large due to an increase in the flow rate of the etching gas, an increase in the microwave power, and the like, and the plasma generation chamber 14
Even when the plasma is about to protrude from the outlet of the plasma generating device, since the magnetic field is formed by the magnetic field forming means 20 near the outlet of the plasma generation chamber 14, the charged particles constituting the plasma are captured by the magnetic field lines forming the magnetic field. And
The plasma does not protrude toward the etching chamber 2.
On the other hand, the active species generated in the plasma generation chamber 14 are not charged, and are supplied to the etching chamber 2 without being captured by the lines of magnetic force.

As described above, according to this embodiment, in order to improve the etching rate, the flow rate of the etching gas is increased,
Even when a method such as an increase in microwave power is performed, since the plasma does not protrude from the plasma generation chamber 14, the sensor may generate an erroneous signal due to the noise due to the plasma, or the connecting pipe 9 formed of Teflon may be thermally damaged. Therefore, a large substrate can be etched quickly and appropriately without being subjected to heat. The same effect can be obtained even if the polarity of the ring-shaped magnet 25 is reversed.

Next, a second embodiment of the dry etching apparatus according to the present embodiment will be described with reference to FIG. In this embodiment, a pair of magnets 30a and 30b constitute a magnetic field forming means. Above the quartz tube 10 near the outlet of the plasma generator 14, one magnet 30a is provided with the N pole facing down.
The other magnet 30b is provided below with a south pole facing up.

According to this embodiment, a pair of magnets 3
Since a magnetic field is formed near the outlet of the plasma generation chamber 14 by the plasma generation chambers 0a and 30b, even when a method such as an increase in the flow rate of the etching gas or an increase in the microwave power is performed to improve the etching rate, the plasma is generated by the plasma. Since the sensor does not protrude from the generation chamber 14, the sensor may generate an erroneous signal due to noise due to plasma,
The connecting pipe 9 made of Teflon is not damaged by heat, and the large-sized substrate can be etched quickly and appropriately. The same effect can be obtained even if the polarities of the magnets 30a and 30b are reversed.

Although the first and second embodiments of the dry etching apparatus according to the present invention have been described above, the present invention is not limited to the above-described embodiments, but forms a magnetic field near the exit of the plasma generation chamber 14. It is intended to include everything having the configuration described below.

[0021]

As described above, according to the present invention, a magnetic field is formed near the outlet of the plasma generation chamber by the magnet, and the magnet holder containing the magnet therein functions as a ground for microwaves. Therefore, even when the etchant is increased by increasing the etching gas flow rate or increasing the microwave power in order to improve the etching rate, the plasma does not protrude from the plasma generation chamber, and the sensor is not affected by the plasma noise. This makes it possible to quickly and appropriately etch a large object to be processed without causing an erroneous signal or a member formed of a low heat-resistant material such as Teflon to be thermally damaged.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing a first embodiment of a dry etching apparatus according to the present invention.

FIG. 2 is a longitudinal sectional view showing a main part of the embodiment.

FIG. 3 is a longitudinal sectional view showing a main part of a second embodiment of the dry etching apparatus according to the present invention.

FIG. 4 is a longitudinal sectional view schematically showing a conventional dry etching apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Etching chamber 9 Connecting pipe 10 Quartz tube 12 Waveguide 13 Plasma generator 14 Plasma generation chamber 20 Magnetic field forming device 21 Mounting flange 22 First magnet holder 23 Second magnet holder 25 Ring magnet 26 Spacer 30a, 30b Magnet S Substrate P Plasma

Claims (1)

(57) [Claims] 1. A plasma generator having a plasma generation chamber for generating an active species by exciting an etching gas with a microwave, a vacuum vessel having an etching chamber for etching an object to be processed, and the plasma In a dry etching apparatus comprising: a gas generation pipe communicating with the etching chamber; and a gas transport pipe communicating with the etching chamber. In order to prevent plasma generated in the plasma generation chamber from protruding toward the etching chamber, Magnetic field forming means provided so as to form a magnetic field in the vicinity of the outlet, wherein the magnetic field forming means is a ring-shaped magnet inserted into a portion of the gas transport pipe near the plasma generation chamber; A ring-shaped magnet holder accommodating the magnets therein, wherein the magnet holder serves as a ground for microwaves. Dry etching apparatus characterized by being connected to the plasma generating apparatus to function.