JPH098001A - Dry etching equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] The in-plane uniformity of etching and the etching rate can be improved, and the controllability of the etching rate can be improved. Provided is a dry etching apparatus capable of significantly shortening A heating chamber for heating an object to be processed under vacuum, a heating means for heating the object to be processed inside the heating chamber, and an etching for etching the object to be processed heated by the heating means under vacuum. And a room.
Further, the heating chamber in the vacuum state and the etching chamber in the vacuum state are communicated with each other, and a communication means is provided for enabling the object to be transferred from the heating chamber to the etching chamber under vacuum. An isolation means is provided to enable isolation.

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 in particular, it has excellent controllability of etching rate.
The present invention relates to a dry etching apparatus capable of shortening processing time.

[0002]

2. Description of the Related Art Conventionally, dry etching apparatuses have been widely used for etching the surfaces of glass substrates for liquid crystal displays (hereinafter referred to as "LCD substrates") and silicon wafers for semiconductor manufacturing. The dry etching device includes a plasma etching device, a reactive ion etching (RIE) device, and the like, and these devices have extremely high controllability as compared with a device by a wet process. Here, the etching rate by the dry etching process may depend on the temperature of the object to be processed, and the film to be processed having such characteristics usually has an increased etching rate as the temperature of the object to be processed increases. Therefore, in the conventional dry etching apparatus, the object to be processed is heated by heating the etching table on which the object to be processed is placed, thereby increasing the etching rate.

FIG. 3 shows a chemical dry etching apparatus (hereinafter referred to as "CDE" which is one of conventional dry etching apparatuses.
Device. ) Shows the outline. In FIG. 3, reference numeral 1 indicates a vacuum container, and an etching chamber 2 is formed inside the vacuum container 1. An etching table 3 is provided inside the vacuum container 1, and an LCD substrate S, which is an object to be processed, is placed on the etching table 3. An exhaust port 5 is formed in the bottom plate 4 of the vacuum container 1, and an exhaust pipe 6 having one end connected to a vacuum pump (not shown) is attached to the exhaust port 5. The top plate 7 of the vacuum container 1 is provided with a gas introduction port 8,
A communication pipe 9 made of 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 including a waveguide 12 is provided in the middle of the quartz tube 10 so as to surround the quartz tube 10. Inside the quartz tube 10 surrounded by the plasma generator 13, a plasma generation chamber is provided. 14 is formed.

A heating means 15 is embedded in the etching table 3 provided inside the vacuum container 1, and the heat generated by the heating means 15 heats the etching table 3. .

In the CDE device having such a structure, first, the inside of the vacuum container 1 is evacuated by the vacuum pump through the exhaust pipe 6 and the exhaust port 5. Next, heat is generated from the heating means 15 to start heating the etching table 3. When the etching table 3 is heated, the LCD substrate S placed on its upper surface is also heated. Here, most of the heat transfer between the etching table 3 and the LCD substrate S is due to heat conduction through the contact portion between them and heat radiation from the surface of the etching table 3. That is, since it is heat transfer in a vacuum, heat transfer using a gas as a medium hardly contributes.

Then, while continuing to heat the LCD substrate S, an etching gas is introduced from one end of the quartz tube 10 through a sealing member 11 having a gas flow path, so that the waveguide 12 of the plasma generator 13 is guided. The plasma generation chamber 14 is irradiated with microwaves via the plasma generation chamber 14. Then, glow discharge is generated inside the plasma generation chamber 14, plasma P is generated, the etching gas is excited, and active species are generated. This activated species is supplied into the etching chamber 2 from the gas inlet 8 through the quartz tube 10 and the connecting pipe 9. The active species supplied to the inside of the etching chamber 2 reach the processing surface (surface to be etched) of the LCD substrate S mounted on the etching table 3 and etch the processing surface of the LCD substrate S. Where L
The CD substrate S is heated by the heating means 1 through the etching table 3.
Since it is heated by the heat from 5, the etching is performed at a high speed to some extent.

[0007]

However, since the conventional dry etching apparatus heats an object to be processed under vacuum in the etching chamber, it takes a long time to raise the temperature of the object to be processed suitable for etching. This requires a long time, which causes a problem that the time required to complete the etching treatment process becomes long. Further, in order to shorten the processing time, if the etching is started before the temperature of the object to be processed is sufficiently raised and the object to be processed is heated, the temperature of the object to be processed during the etching process is increased. However, there is also a problem that it is difficult to control the etching rate and it is difficult to determine the etching end point. Further, when the temperature of the object to be processed rises, the object to be processed is thermally deformed and warps, and the contact between the mounting surface of the etching table and the back surface of the object to be processed locally deteriorates. In addition to the insufficient heating, the heating of the entire object to be processed becomes non-uniform and the in-plane uniformity of etching also deteriorates.

Therefore, an object of the present invention is to improve the in-plane uniformity of etching and the etching rate, and to improve the controllability of the etching rate. An object of the present invention is to provide a dry etching apparatus that can reduce the time required.

[0009]

A dry etching apparatus according to the present invention comprises a heating chamber for heating an object to be processed under vacuum, and a heating means for heating the object to be processed inside the heating chamber. , An etching chamber for etching the object to be processed heated by the heating means under vacuum, the heating chamber in the vacuum state and the etching chamber in the vacuum state are communicated with each other, and the object to be processed is removed from the heating chamber. It is characterized in that it is provided with a communicating means capable of being conveyed to the etching chamber under vacuum, and an isolating means provided in the communicating means and capable of isolating the heating chamber and the etching chamber.

According to a second aspect of the present invention, there is provided a dry etching apparatus, wherein a mounting table is provided inside the heating chamber for mounting the object to be processed, first heating means for heating the mounting table, and the mounting table. A heating plate having a convex portion that is pressed against the peripheral portion of the processing surface of the object to be processed, and a second heating unit that heats the heating plate, and the heating plate and the mounting table The object to be processed is sandwiched from both sides so that the object to be processed can be heated from both sides.

A dry etching apparatus according to a third aspect of the present invention is characterized by comprising an inert gas supply means for supplying an inert gas into the heating chamber.

[0012]

In the dry etching apparatus according to the first aspect of the present invention, first, in a state where the heating chamber and the etching chamber are isolated by the isolation means, the object to be treated is removed by the heating means inside the heating chamber in a vacuum state. It is heated to a predetermined temperature suitable for etching. Next, the isolation by the isolation means is released, and the heated object to be processed is transferred from the heating chamber in the vacuum state to the etching chamber in the vacuum state via the communicating means under vacuum. As described above, since the heated object to be processed is transferred under vacuum, there is almost no heat radiation from the object to be processed, and the object to be processed is transferred to the etching chamber while maintaining a predetermined temperature. Then, when the object to be processed is etched in the etching chamber, the heating chamber and the etching chamber are separated again by the isolation means, and the object to be processed having a predetermined temperature suitable for etching is formed inside the etching chamber in a vacuum state. On the other hand, the etching process is performed at high speed. In this way, by setting the heating chamber and the etching chamber in an isolated state except when the object to be processed is being conveyed, the heating process in the heating chamber and the etching process in the etching chamber can be simultaneously performed in parallel.

In the dry etching apparatus according to the second aspect of the present invention, the object to be processed is placed on the placing table provided inside the heating chamber in a vacuum state. Next, the convex portion of the heating plate is pressed against the peripheral edge of the processing surface of the processing object placed on the mounting table, and the processing object is sandwiched between the heating plate and the mounting table. Then, the mounting table and the heating plate are heated by the first heating means and the second heating means, or preheated, and the object to be processed is heated from both the processing surface and the back surface. Since the object to be processed is heated from both sides in this way, it can be heated quickly and sufficiently to a predetermined temperature suitable for etching even under vacuum. Further, since the convex portion of the heating plate is pressed against the peripheral portion of the processing surface of the processing object, the heated processing object does not warp due to thermal deformation, and the mounting surface of the mounting table is The contact with the back surface of the object is sufficiently maintained, and the entire object is uniformly heated with sufficient heating efficiency. Next, the heated object to be processed is conveyed from the heating chamber in the vacuum state to the etching chamber in the vacuum state under vacuum via the communicating means. As described above, since the heated object to be processed is transferred under vacuum, there is almost no heat radiation from the object to be processed, and the object to be processed is transferred to the etching chamber while maintaining a predetermined temperature. Then, in the inside of the etching chamber in the vacuum state, the etching process is performed at high speed on the object to be processed having a predetermined temperature suitable for etching.

In the dry etching apparatus according to the third aspect of the present invention, the heating chamber in the vacuum state is isolated from the etching chamber by the isolation means, and the inert gas is introduced into the heating chamber by the inert gas supply means. And
The supply amount of the inert gas is adjusted to adjust the inside of the heating chamber to a predetermined pressure considerably lower than the atmospheric pressure, and the heating means heats the object to be processed to a predetermined temperature suitable for etching. Here, since the inert gas exists inside the heating chamber, the inert gas serves as a medium for heat transfer to the object to be processed, and thus the heating efficiency of the object to be processed is further improved. When the heating of the object to be processed is completed, the supply of the inert gas is stopped and the inside of the heating chamber is brought to the same vacuum state as that inside the etching chamber. Here, since the internal pressure of the heating chamber when the supply of the inert gas is stopped is considerably lower than the atmospheric pressure, it can be reduced to the same vacuum state as that of the etching chamber in an extremely short time. When the heating chamber and the etching chamber are in the same vacuum state, the isolation by the isolation means is released, and the heated object to be processed is transferred from the heating chamber to the etching chamber via the communication means. Then, the etching chamber is isolated from the heating chamber by the isolation means, and the object to be processed having a predetermined temperature suitable for etching is etched.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the dry etching apparatus according to the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 20 indicates a vacuum container, and the inside of the vacuum container 20 is divided into an etching chamber 22 and a heating chamber 23 by a partition wall 21. A communication port 24 is formed in the isolation wall 21, and the communication port 24 is openably closed by a gate valve 25.

An etching table 26 is provided inside the etching chamber 22, and an exhaust port 28 is formed in a bottom plate 27 of the vacuum container 20 below the etching table 26, and the exhaust port 28 has one end. An exhaust pipe 29 connected to a vacuum pump (not shown) is attached. In addition, the vacuum container 2 above the etching table 26
A gas introduction port 31 for introducing an etching gas is formed in the top plate 30 of No. 0, and a gas transportation pipe 32 for transporting the etching gas is connected to the gas introduction port 31.

A mounting table 33 is provided inside the heating chamber 23, and the first heating means 34 is provided inside the mounting table 33.
Is provided. An exhaust port 35 is provided in the bottom plate 27 of the vacuum container 20 below the mounting table 33, and one end of this exhaust port 35 is attached to an exhaust pipe 36 connected to a vacuum pump (not shown). There is. An LCD substrate S, which is an object to be processed, is mounted on the mounting table 33.
The convex portion 37 a of the heating plate 37 is pressed against the processing surface of the substrate S. A second heating means 38 is provided inside the heating plate 37. The top plate 30 of the vacuum container 20 above the heating plate 37 is provided with an inert gas inlet 39 for introducing an inert gas, and the inert gas inlet 39 is filled with the inert gas. An inert gas transportation pipe 40 for transportation is connected.

FIG. 2 is a perspective view of the heating plate 37.
As can be seen from this figure, a concave portion 37b is formed on the lower surface of the heating plate 37 so as to form a convex portion 37a on the peripheral edge, and the convex portion 37a is formed so as to correspond to the peripheral edge of the LCD substrate S. There is.

The first heating means 34 and the second heating means provided inside the mounting table 33 and the heating plate 37, respectively.
The heating means 38 may be, for example, an electric heater, or may be configured to circulate a high temperature fluid.

Next, the operation of this embodiment will be described.
First, the inside of the heating chamber 23 is evacuated by a vacuum pump through the exhaust port 35 and the exhaust pipe 36 to be in a vacuum state. Then, the inert gas transport pipe 40 and the inert gas inlet 39
An inert gas is introduced into the heating chamber 23 via the, and the supply amount of the inert gas is adjusted to adjust the inside of the heating chamber 23 to a predetermined pressure considerably lower than the atmospheric pressure. Next, the mounting table 33 and the heating plate 37 are heated by the first heating means 34 and the second heating means 38. Then, the LCD substrate S is heated from its back surface by heat conduction and heat radiation from the mounting surface of the back surface of the LCD substrate S and the mounting surface of the mounting table 33, and the surface of the heating plate 37. The LCD substrate S is heated by the heat radiation from the processing surface side, and further, the LCD substrate S is heated by using the inert gas existing inside the heating chamber 23 as a heat transfer medium. Since the LCD substrate S is heated from both sides and the inert gas is used as a heat transfer medium in this way, the LCD substrate S can be quickly and sufficiently heated to a predetermined temperature suitable for etching even under vacuum. it can. Further, since the peripheral edge of the LCD substrate S is pressed by the convex portion 37a of the heating plate 37, it is possible to prevent warpage due to thermal deformation of the LCD substrate S, and the back surface of the LCD substrate S and the mounting surface of the mounting table 33. A sufficient contact state with is not lowered and the heat conduction efficiency is not lowered, and the entire LCD substrate S is heated uniformly.

Thus, the LCD in the heating chamber 23
When the substrate S is heated to a temperature suitable for etching, the heating plate 37 is pulled up to release the pressure on the LCD substrate S, the supply of the inert gas is stopped, and the pressure inside the heating chamber 23 is adjusted to a predetermined value. Further reduce to vacuum. Here, the internal pressure of the heating chamber 23 at the time when the supply of the inert gas is stopped is considerably lower than the atmospheric pressure, so that the pressure can be reduced to a predetermined degree of vacuum in an extremely short time.

Next, the inside of the etching chamber 22 is exhausted to the exhaust port 2.
A vacuum state is established by a vacuum pump through the exhaust pipe 8 and the exhaust pipe 29. Here, the evacuation of the etching chamber 22 can be performed in parallel with the heat treatment of the LCD substrate S, or another LCD substrate can be evacuated in parallel with the heat treatment of the etching chamber 22.
It is also possible to carry out the etching treatment in 1., and from the viewpoint of shortening the time required for the etching treatment step, the method in which the heating treatment and the etching treatment are carried out simultaneously in parallel is optimal. When the inside of the etching chamber 22 is evacuated, the gate valve 25 is opened, the LCD substrate S is carried into the etching chamber 22 through the communication port 24, and the etching table 2 is opened.
Place on top of 6. The LCD substrate S is carried in by, for example, a robot (not shown) provided inside the vacuum container 20. Next, the gate valve 25 is closed, and the etching gas is introduced into the etching chamber 22 through the gas transport pipe 32 and the gas inlet 31 to perform the etching process. Here, the heating chamber 23 and the etching chamber 2
Since both 2 are in a vacuum state, the temperature of the LCD substrate S heated in the heating chamber 23 is unlikely to decrease, and the etching process can be started at the optimum temperature for etching. If the etching process takes a long time, the etching table 26 may be provided with a heating means to keep the temperature of the LCD substrate S being etched.

As described above, according to this embodiment, the LC is previously set in the heating chamber 23 before the etching process is started.
Since the D substrate S is heated to the predetermined temperature, the etching process can be started at the optimum temperature for etching, which not only increases the etching rate but also significantly improves the controllability of the etching. To do.
In addition, the heating plate 37 and the mounting table 33 are used for the LCD.
Since the substrate S is heated from both sides, an inert gas is introduced into the heating chamber 23, and the convex portions 37a of the heating plate 37 prevent the LCD substrate S from warping. The temperature can be rapidly heated to the temperature, the time required for the etching process can be shortened, and the entire surface of the LCD substrate S can be uniformly heated to improve the in-plane uniformity of etching. Furthermore, since the etching process can be performed in the etching chamber 22 concurrently with the heating process in the heating chamber 23, the time required for the etching process can be further shortened as a whole.

[0024]

According to the dry etching apparatus of the first aspect of the present invention, before starting the etching process, the object to be processed is heated to a predetermined temperature suitable for etching in the heating chamber and heated. Since the object to be processed is conveyed to the etching chamber under vacuum via the communicating means to perform the etching process, the etching process can be started at the optimum temperature for etching,
Therefore, not only the etching rate is increased, but the controllability of etching is significantly improved, and the heating chamber and the etching chamber are separated from each other except when the object to be processed is conveyed, so that the heating in the heating chamber is not performed. Since the processing and the etching processing in the etching chamber can be performed in parallel at the same time, the time required for the etching processing step can be significantly reduced as a whole.

According to the dry etching apparatus of the second aspect of the present invention, the object to be processed is heated from both sides by the heating plate and the mounting table, and the convex portion of the heating plate prevents the object to be warped. Therefore, the object to be processed can be quickly and sufficiently heated to a predetermined temperature, the time required for the etching process can be further shortened as a whole, and the entire object to be processed can be uniformly heated. The in-plane uniformity can be significantly improved.

According to the dry etching apparatus of the third aspect of the present invention, since the inert gas supply means for supplying the inert gas to the inside of the heating chamber is provided, the object to be treated can be swiftly and sufficiently supplied inside the heating chamber. The heating time can be further increased, and the time required for the etching process can be further shortened as a whole.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a dry etching apparatus according to the present invention.

FIG. 2 is a perspective view showing a heating plate of the embodiment.

FIG. 3 is a vertical sectional view showing an example of a conventional dry etching apparatus.

[Explanation of symbols]

 20 vacuum container 21 isolation wall 22 etching chamber 23 heating chamber 24 communication port 25 gate valve 26 etching table 28, 35 exhaust port 29, 36 exhaust pipe 31 gas inlet port 32 gas transport pipe 33 mounting table 34 first heating means 37 heating plate 37a Convex part 38 Second heating means 39 Inert gas inlet 40 Inert gas transport pipe

Claims (3)

[Claims] 1. A heating chamber for heating an object to be processed under vacuum, a heating means for heating the object to be processed inside the heating chamber, and the object to be processed heated by the heating means under vacuum. An etching chamber for performing an etching process, a heating unit in a vacuum state, and an etching chamber in a vacuum state are communicated with each other, and a communication unit capable of transporting the object to be processed from the heating chamber to the etching chamber under vacuum, and A dry etching apparatus, characterized in that it is provided with a communication means and is provided with an isolation means capable of isolating the heating chamber and the etching chamber. 2. A mounting table provided inside the heating chamber for mounting the object to be processed, first heating means for heating the table, and the object to be processed mounted on the table. A heating plate having a convex portion that is pressed against the peripheral edge of the processing surface and a second heating unit that heats the heating plate are provided, and the object to be processed is sandwiched from both sides by the heating plate and the mounting table. The dry etching apparatus according to claim 1, wherein the object to be processed can be heated from both sides. 3. An inert gas supply means for supplying an inert gas to the inside of the heating chamber.
Alternatively, the dry etching apparatus according to item 2.