JP2777085B2 - 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 dry etching apparatus which is excellent in controllability of an etching rate.
The present invention relates to a dry etching apparatus capable of reducing processing time.

[0002]

2. Description of the Related Art Conventionally, a dry etching apparatus has been widely used for etching a surface of a glass substrate for a liquid crystal display (hereinafter, referred to as an "LCD substrate") or a silicon wafer for semiconductor production. The dry etching apparatus includes a plasma etching apparatus, a reactive ion etching (RIE) apparatus, and the like, and these apparatuses have much higher controllability than an apparatus using a wet process. Here, the etching rate in the dry etching process depends on the temperature of the object to be processed, and the film to be processed having such characteristics usually increases the etching rate as the temperature of the object to be processed increases. Therefore, in a conventional dry etching apparatus, an object to be processed is heated by heating an etching table on which the object to be processed is mounted, thereby increasing an etching rate.

FIG. 3 shows a chemical dry etching apparatus (hereinafter referred to as “CDE”) which is one of the conventional dry etching apparatuses.
Device ". ) Is shown below. In FIG. 3, reference numeral 1 denotes a vacuum vessel, in which an etching chamber 2 is formed. Further, an etching table 3 is provided inside the vacuum vessel 1, and an LCD substrate S as 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 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 a top plate 7 of the vacuum vessel 1.
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. 14 are formed.

A heating means 15 is embedded in the etching table 3 provided in the vacuum vessel 1, and the etching table 3 is heated by heat generated from the heating means 15. .

In the CDE apparatus having such a configuration, first, the inside of the vacuum vessel 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 mounted on the upper surface is also heated. Here, most of the heat transfer between the etching table 3 and the LCD substrate S is caused by heat conduction through a contact portion between the two and heat radiation from the surface of the etching table 3. That is, since the heat transfer is performed in a vacuum, the 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, and the waveguide 12 of the plasma generator 13 is turned on. The microwave is irradiated to the plasma generation chamber 14 through the same. 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 to the inside of the etching chamber 2 through the quartz tube 10 and the connecting pipe 9. The active species supplied into the etching chamber 2 reaches the processing surface (etched surface) of the LCD substrate S placed on the etching table 3 and etches the processing surface of the LCD substrate S. Where L
The CD substrate S is heated by the heating means 1 via the etching table 3.
Since the substrate is heated by the heat from Step 5, the etching is performed at a relatively high speed.

[0007]

However, since the conventional dry etching apparatus heats an object to be processed under vacuum in an etching chamber, it takes a long time for the object to be heated to a temperature suitable for etching. It takes time, and therefore, there is a problem that the time required until the etching process is completed becomes long. Further, in order to shorten the processing time, when the etching is started before the temperature of the object to be processed is sufficiently increased and the etching is performed while heating the object to be processed, the temperature of the object during the etching process is increased. And it is difficult to control the etching rate, which makes it difficult to determine the etching end point. Further, when the temperature of the processing object rises, the processing object is thermally deformed and warped, and the contact between the mounting surface of the etching table and the back surface of the processing object is locally deteriorated. In addition to the insufficient heating, there is a problem that the heating is not uniform throughout the object to be processed and the in-plane uniformity of the etching is deteriorated.

Accordingly, it is an object of the present invention to improve the in-plane uniformity of the etching and to increase the etching rate, to improve the controllability of the etching rate, and to improve the etching process. An object of the present invention is to provide a dry etching apparatus capable of shortening a required time.

[0009]

According to a first aspect of the present invention, there is provided a dry etching apparatus comprising: 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 heated heated by the heating means under vacuum, the heating chamber in a vacuum state and the etching chamber in a vacuum state communicate with each other, and the object to be processed is removed from the heating chamber. Communication means capable of being transported to the etching chamber under vacuum; isolation means provided in the communication means for separating the heating chamber and the etching chamber; and the object to be processed provided inside the heating chamber. A mounting table having a mounting surface for mounting the same, and a heating plate having a convex portion pressed against a peripheral portion of the processing surface of the object to be processed mounted on the mounting table,
Wherein the heating means has a first heating means for heating the mounting table, and a second heating means for heating the heating plate, wherein the object to be processed is heated by the heating plate and the mounting table. Sandwiching from both sides, pressing the convex portion of the heating plate against the peripheral edge of the processing surface of the processing object, while sufficiently maintaining the contact between the mounting surface and the back surface of the processing object, The object to be processed can be heated from both sides.

The dry etching apparatus according to the second aspect of the present invention further includes an inert gas supply means for supplying an inert gas as a heat transfer medium for heating the object to be processed into the heating chamber. It is characterized by.

[0011]

[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 separated by the separating means, the object to be processed is heated by the heating means inside the heating chamber in a vacuum state. Heat to a predetermined temperature suitable for etching. Specifically, first, an object to be processed is mounted on a mounting table provided inside a heating chamber in a vacuum state. Next, the convex portion of the heating plate is pressed against the periphery 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 pre-heated,
The object to be processed is heated from both the processing surface and the back surface. As described above, since the object to be processed is heated from both sides, it can be quickly and sufficiently heated 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 and 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 isolation by the isolation means is released, and the heated workpiece is transferred from the heating chamber in a vacuum state to the etching chamber in a vacuum state through the communication means under vacuum. As described above, since the heated object is transferred under vacuum, there is almost no heat radiation from the object, and the object is transferred to the etching chamber while maintaining the predetermined temperature. When the object to be processed is etched in the etching chamber, the heating chamber and the etching chamber are again separated by the isolation means, and the object at a predetermined temperature suitable for etching is separated inside the etching chamber in a vacuum state. On the other hand, an etching process is performed at a high speed. In this manner, by setting the heating chamber and the etching chamber apart from each other except when the object is transported, the heating processing in the heating chamber and the etching processing in the etching chamber can be performed simultaneously in parallel.

In the dry etching apparatus according to the second aspect of the present invention, the heating chamber in a vacuum state is isolated from the etching chamber by the isolation means, and an inert gas is introduced into the heating chamber by the inert gas supply means. And
The inside of the heating chamber is adjusted to a predetermined pressure considerably lower than the atmospheric pressure by adjusting the supply amount of the inert gas, and the object to be processed is heated to a predetermined temperature suitable for etching by the heating means. Here, since an inert gas is present inside the heating chamber, the inert gas serves as a medium for heat transfer to the object to be processed, and therefore, 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 into the same vacuum state as the inside of the etching chamber. Here, since the internal pressure of the heating chamber at the time 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 the etching chamber in a very 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 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 at a predetermined temperature suitable for etching is subjected to an etching process.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a dry etching apparatus according to the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 20 denotes a vacuum vessel, and the inside of the vacuum vessel 20 is divided into an etching chamber 22 and a heating chamber 23 by an isolation 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. An exhaust port 28 is formed in the bottom plate 27 of the vacuum vessel 20 below the etching table 26, and one end of the exhaust port 28 is formed in the exhaust port 28. An exhaust pipe 29 connected to a vacuum pump (not shown) is attached. The vacuum vessel 2 above the etching table 26
A gas inlet 31 for introducing an etching gas is formed in the top plate 30 of the No. 0, and a gas transport pipe 32 for transporting the etching gas is connected to the gas inlet 31.

A mounting table 33 is provided inside the heating chamber 23, and a first heating means 34 is provided inside the mounting table 33.
Is provided. An exhaust port 35 is formed in the bottom plate 27 of the vacuum vessel 20 below the mounting table 33, and one end of the exhaust port 35 is attached to an exhaust pipe 36 connected to a vacuum pump (not shown). I have. An LCD substrate S, which is an object to be processed, is mounted on the mounting table 33.
The convex portion 37a of the heating plate 37 is pressed against the processing surface of the substrate S. Inside the heating plate 37, a second heating means 38 is provided. The top plate 30 of the vacuum vessel 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 provided with an inert gas. An inert gas transport pipe 40 for transport 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 periphery, and the convex portion 37a is formed so as to correspond to the peripheral edge of the LCD substrate S. I have.

The first heating means 34 and the second heating means 34 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
The inert gas is introduced into the inside of the heating chamber 23 through 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 the rear surface by heat conduction and heat radiation from the mounting surface via the contact portion between the rear surface of the LCD substrate S and the mounting surface of the mounting table 33, and the front surface of the heating plate 37. The LCD substrate S is heated from the processing surface side by the heat radiation from the LCD panel S, and furthermore, the LCD substrate S is heated using an inert gas existing inside the heating chamber 23 as a heat transfer medium. As described above, since the LCD substrate S is heated from both sides and the inert gas is heated as a heat transfer medium, the LCD substrate S can be quickly and sufficiently heated under vacuum to a predetermined temperature suitable for etching. it can. Further, since the periphery of the LCD substrate S is pressed by the convex portion 37a of the heating plate 37, warpage due to thermal deformation of the LCD substrate S can be prevented, and the rear surface of the LCD substrate S and the mounting surface of the mounting table 33 can be prevented. And the heat conduction efficiency is not reduced, and the entire LCD substrate S is uniformly heated.

In the heating chamber 23, the LCD
When the substrate S is heated to a temperature suitable for etching, the heating plate 37 is pulled up to release the pressing on the LCD substrate S, the supply of the inert gas is stopped, and the pressure inside the heating chamber 23 is reduced to a predetermined value. Further reduce to vacuum. Here, since 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, the pressure can be reduced to a predetermined degree of vacuum in a very short time.

Next, the inside of the etching chamber 22 is
8 and a vacuum pump through the exhaust pipe 29 to make a vacuum state. Here, the exhaust of the etching chamber 22 can be performed simultaneously and in parallel with the heat treatment of the LCD substrate S, or another LCD substrate can be removed in parallel with the heat treatment of the etching chamber 22.
It is also possible to perform the etching process at the same time, and from the viewpoint of shortening the time required for the etching process, it is optimal to perform the heating process and the etching process simultaneously in parallel. When the inside of the etching chamber 22 is evacuated, the gate valve 25 is opened, and 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 loading of the LCD substrate S is performed, for example, by a robot (not shown) provided inside the vacuum vessel 20. Next, the gate valve 25 is closed, and an etching process is performed by introducing an etching gas into the etching chamber 22 through the gas transport pipe 32 and the gas inlet 31. Here, the heating chamber 23 and the etching chamber 2
2 are both 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 time is long, a heating means may be provided in the etching table 26 to keep the temperature of the LCD substrate S being etched.

As described above, according to the present embodiment, before the etching process is started, the LC
Since the D substrate S is heated to a predetermined temperature, the etching process can be started at an optimum temperature for the etching, which not only increases the etching rate but also significantly improves the controllability of the etching. I do.
Further, an LCD is formed by the heating plate 37 and the mounting table 33.
Since the substrate S is heated from both sides, an inert gas is introduced into the heating chamber 23, and the convex portion 37a of the heating plate 37 prevents the LCD substrate S from warping. It is possible to quickly heat to the temperature, to shorten the time required for the etching process, and to uniformly heat the entire LCD substrate S to improve the in-plane uniformity of the etching. Furthermore, since the etching process can be performed in the etching chamber 22 at the same time as the heating process in the heating chamber 23, the time required for the etching process can be further reduced as a whole.

[0024]

According to the dry etching apparatus according to the first aspect of the present invention, the object to be processed is heated to a predetermined temperature suitable for etching by the heating means in the heating chamber before the etching process is started. Since the object to be processed is transferred to the etching chamber under vacuum through the communicating means to perform the etching process, the etching process can be started at an optimum temperature for etching,
For this reason, not only the etching rate is increased, but also the controllability of the etching is remarkably improved. In addition, the heating chamber and the etching chamber are separated from each other except during the transfer of the object to be processed, so that the heating in the heating chamber is performed. Since the process and the etching process in the etching chamber can be performed simultaneously and in parallel, the time required for the etching process can be greatly reduced as a whole.

Further, according to the dry etching apparatus of the present invention, the object to be processed is heated from both sides by the heating plate and the mounting table, and the warpage of the object to be processed is prevented by the convex portion of the heating plate. As a result, 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 reduced as a whole, and the entire object to be processed can be uniformly heated. Can be greatly improved in-plane uniformity.

According to the dry etching apparatus of the second 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 processed can be quickly and sufficiently provided inside the heating chamber. , And the time required for the etching process can be further reduced as a whole.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one 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 longitudinal sectional view showing an example of a conventional dry etching apparatus.

[Explanation of symbols]

 Reference Signs List 20 vacuum vessel 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 portion 38 second heating means 39 inert gas inlet 40 inert gas transport pipe

Claims (2)

(57) [Claims] 1. A heating chamber for heating an object under vacuum, a heating means for heating the object inside the heating chamber, and a heating means for heating the object heated by the heating means under vacuum. An etching chamber for performing an etching process, a communication unit that communicates the heating chamber in a vacuum state with the etching chamber in a vacuum state, and enables the object to be processed to be conveyed from the heating chamber to the etching chamber under vacuum; An isolation unit provided in a communication unit and capable of isolating the heating chamber and the etching chamber; a mounting table provided in the heating chamber and having a mounting surface on which the object to be processed is mounted; A heating plate having a convex portion pressed against a peripheral portion of a processing surface of the processing object placed on the substrate, wherein the heating unit is configured to: a first heating unit configured to heat the mounting table; and the heating plate. Add Second heating means, and the object to be processed is sandwiched between the heating plate and the mounting table from both sides, and the convex portion of the heating plate is pressed against the peripheral edge of the processing surface of the object to be processed. A dry etching apparatus wherein the object to be processed can be heated from both sides while maintaining sufficient contact between the mounting surface and the back surface of the object to be processed. 2. An apparatus according to claim 1, further comprising an inert gas supply means for supplying an inert gas as a heat transfer medium for heating the object to be processed into the heating chamber.
The dry etching apparatus as described.