JPH10107009A - Dry etching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the evenness in plasma while reducing the etching rate dispersion in a substrate by a method wherein the gap between the surface making an aperture for letting in and out of an etched substrate and the aperture is made adjustable as well as a cover shifting mechanism capable of removing a cover member from the aperture is provided. SOLUTION: The title dry etching device is provided with a cover shifting mechanism 1 capable of keeping away a cover 5 stopping up an aperture 6a letting in and out of a reticle of a shield frame 6 as well as removing the cover 5 from the aperture 6a. This cover shifting mechanism 1 is provided with a rod 2 airtightly elevating the cover 5 through the intermediary of a chamber wall and a threading mechanism making the cover 5 approach to or keep away from the aperture 6a as shown by an arrow. Besides, the slice bearing airtightly sealing the rod 2 is fitted to a plate member airtightly sliding along the chamber outside wall. Through these procedures, the error in the plasma density can be corrected thereby enabling the dispersion in etching process to be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a dry / dry etching apparatus for etching a film formed on the surface of a transparent glass substrate such as a reticle or a semiconductor substrate.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view showing the structure of a conventional dry etching apparatus. Conventionally, as shown in FIG. 5, this type of dry etching apparatus has a chamber 9 in which an etching gas is introduced and evacuated and maintained at a predetermined pressure, and a reticle 13 which is a substrate to be etched is placed in the chamber 9 A lower electrode plate 8 housed therein, an upper electrode plate 7 opposed to the lower electrode plate 8 and arranged at a predetermined interval, and a magnet attached to the outer periphery of the chamber 9 for applying a magnetic field to the chamber 9 A coil 11 and a high-frequency power supply 10 for applying a high-frequency voltage between the upper electrode plate 7 and the lower electrode plate are provided.

The reticle 1 has an inner wall surrounding the outer periphery of a rectangular reticle 13 which is a substrate to be etched.
A shield frame 6 having a frame shape similar to the outer shape of No. 3 was fixed to the lower electrode plate 8 with screws or the like. The shield frame 6 is provided in order to limit the plasma region in which the introduced etching gas is formed by the electric and magnetic fields and to make the plasma ion density reaching the reticle surface uniform.

When etching a metal film such as chromium oxide or chromium formed on the reticle 13 by this dry etching apparatus, the reticle 13 is loaded into the load lock chamber 12.
Then, the lid 5 is removed from the lower electrode plate 8 in the chamber 9 by the manipulator through the opening 6a which is exposed, and then the etching gas is introduced into the chamber 9 from the gas inlet and the reaction product is exhausted from the gas outlet. Then, high-frequency power is applied between the upper electrode plate 7 and the other lower electrode plate 8 from the high-frequency power source 10 to generate plasma in the shield frame 6, and the plasma causes the chrome film of the reticle 13 to pass through the mask. Etching was performed selectively.

[0005]

In the above-mentioned conventional dry etching apparatus having a magnetic field, the shield frame 6 in the chamber 6, which is one of the factors that determine the plasma density in the shield frame 6, is positioned with respect to the center of the magnetic field. Although it is effective that the shield frame 6 has a uniform shape, the cover 5 has a lid 5 at the opening 6a of the shield frame 6, and the lid 5 has a different distance from the other shield frame 6 and the shape of the shield frame 6 is different. It is uneven. As a result, there is a problem that the plasma density becomes non-uniform and the etching rate in the plane of the reticle 13 varies greatly, so that a highly accurate pattern cannot be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dry etching apparatus capable of improving the uniformity of plasma and reducing the variation in etching rate in the surface of a substrate to be etched.

[0007]

A feature of the present invention is that a chamber is maintained at a predetermined pressure while introducing and exhausting an etching gas, and a lower electrode plate on which a substrate to be etched is placed and housed in the chamber. An upper electrode plate facing the lower electrode plate and arranged at a predetermined interval; a magnetic field applying means attached to an outer periphery of the chamber to apply a magnetic field to the chamber; A high-frequency power source for applying a high-frequency voltage between the electrode plate and a high-frequency power supply, wherein the outer wall of the substrate to be etched mounted on the lower electrode plate is similar to the outer shape of the substrate to be etched; A frame-shaped shield frame member fixed to the lower electrode so as to surround the opening, a lid member for closing an opening of the shield frame member through which the substrate to be etched enters and exits, and the opening A lid moving mechanism capable of adjusting the distance between the opening and the opening and removing the lid member from the opening, or similar to the outer shape of the substrate to be etched placed on the lower electrode. A shield frame member having no inner wall portion and mounted on the lower electrode so as to surround an outer periphery of the substrate to be etched, and the shield frame member without changing a relative position with respect to the lower electrode. And a lifting mechanism for vertically moving the device.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.

FIGS. 1A and 1B are a sectional view and a perspective view, respectively, showing the structure of a dry etching apparatus according to an embodiment of the present invention. As shown in FIG. 1, the dry etching apparatus can move the lid 5 that closes the opening 6a through which the reticle 13 of the shield frame 6 enters and exits away from the opening, and can move the lid 5 away from the opening 6a. That is, the mechanism 1 is provided. Otherwise, it is the same as the conventional example.

This lid moving mechanism comprises a rod 2 for vertically moving the lid 5 through a chamber wall, and a screw feed for moving the lid 5 toward or away from the opening 6a as shown by an arrow through the rod 2. Mechanism. Although not shown in the drawings, a slide bearing for hermetically sealing the rod 2 is attached to a plate member that hermetically slides on the outer wall of the chamber.

FIG. 2 is a graph showing the etching rate of the reticle surface with respect to the distance between the lid and the opening of the shield frame. Here, in order to investigate the change in the etching rate due to the movement of the lid 5 described above, the following equation (1) was used.
Prepare zero 80 mm square reticle,
Was changed, and etching was attempted without using a mask. As a result, as shown in FIG. 2, the variation in etching was the smallest at a distance of 2.6 mm. However, 0
mm is small, but in this case, the lid 5
And in a state pressed against the opening 6a of the shield frame 6,
In the actual operation of the lid moving mechanism 1, even when the lid 5 is closed, the lid 5
The gap between the opening 6a and the opening 6a is about 0.3 mm, which is difficult to realize. As described above, it has been found that uniformity of the plasma density in the shield frame 6 can be obtained by optimizing the distance between the surface formed by the opening 6a of the shield frame 6 and the lid 5 according to the size of the reticle 13. .

FIGS. 3A and 3B are diagrams showing three-dimensionally the etching rates of the conventional apparatus and the apparatus according to the present invention. Using the same sample from the experiment described above,
A state in which the opening 6a is closed by the lid 5 as in the conventional device,
When etching was performed in a state where the distance between the opening and the opening was 2.6 mm, as shown in FIG.
The etching rate is large near the opening 6a and small elsewhere, and the variation is large. On the other hand, as shown in FIG. 3B, the etching rate by the apparatus of the present invention is relatively small, although there is a slight difference between the peripheral portion and the central portion.

FIG. 4 is a perspective view showing a modification of the shield frame mechanism shown in FIG. This dry etching apparatus is shown in FIG.
As shown in FIG. 1, when the reticle 13 moves into and out of the chamber 9 from the load lock chamber 12 in FIG. 1, the shield frame 6 is placed upward so that the reticle 13 and the manipulator holding the reticle 13 do not interfere with the shield frame 6. The lifting mechanism 3 having the rod 4 that penetrates the chamber low wall 9a in an airtight manner is provided. When the dry etching is started, the lifting mechanism 3 is operated to lower the shield frame 6 by the rod 4 and to contact the lower electrode plate 8.

The lifting mechanism 3 uses a pneumatic or hydraulic cylinder, and the shield frame 6 is brought into close contact with the lower electrode plate 8 with a certain pressing force. It is also desirable to provide a guide post or the like for guiding the vertical movement in order to obtain reproducibility of the position. Since the shield frame 6 has no opening, the inner shape of the shield frame 6 becomes uniform, and the uniformity of the plasma density in the shield frame 6 can be further improved.

In the embodiment described above, the rectangular reticle is described as the substrate to be etched, but the present invention can also be applied to a circular semiconductor substrate. However, in this case, the inner shape of the shield frame is to be a circular shape similar to the outer shape of the semiconductor substrate.

[0016]

As described above, according to the present invention, a shield frame having an inner wall similar in shape to the outer shape of a substrate to be etched is provided so as to surround the outer shape of the substrate to be etched. In the case of having an opening through which the opening and exit can be performed, by moving the lid member that closes the opening closer to or away from the opening during etching, it is possible to correct the variation in plasma density due to the opening and reduce the variation in etching. was gotten.

If there is no opening in the shield frame, the shield frame is lifted when the substrate to be etched enters and exits, and a mechanism for positioning and fixing the shield frame to the lower electrode plate with good reproducibility when etching is provided. The effect of is obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a dry etching apparatus according to an embodiment of the present invention, and a perspective view showing a part extracted therefrom.

FIG. 2 is a graph showing an etching rate of a reticle surface with respect to a distance between a lid and an opening of a shield frame.

FIG. 3 is a diagram showing three-dimensionally the etching rates of a conventional apparatus and an apparatus according to the present invention.

FIG. 4 is a perspective view showing a modification of the shield frame mechanism of FIG. 1;

FIG. 5 is a cross-sectional view illustrating a configuration of a conventional dry etching apparatus.

[Description of Signs] 1 lid moving mechanism 2, 4 rod 3 elevating mechanism 5 lid 6 shield frame 6a opening 7 upper electrode plate 8 lower electrode plate 9 chamber 9a chamber low wall 10 high frequency power supply 11 magnetic coil 12 load lock chamber 13 reticle

Claims (2)

[Claims] 1. A chamber maintained at a predetermined pressure while introducing and evacuating an etching gas, a lower electrode plate on which a substrate to be etched is placed and housed in the chamber, An upper electrode plate disposed at an interval of; a magnetic field applying means attached to the outer periphery of the chamber to apply a magnetic field to the chamber; and applying a high-frequency voltage between the upper electrode plate and the lower electrode plate. A high-frequency power supply, and having an inner wall portion similar to the outer shape of the substrate to be etched placed on the lower electrode plate and fixed to the lower electrode so as to surround the outer periphery of the substrate to be etched. A frame-shaped shield frame member, a cover member for closing the opening of the shield frame member through which the substrate to be etched enters and exits, and adjusting a distance between the surface formed by the opening and the opening. And a lid moving mechanism capable of removing the lid member from the opening. 2. A chamber in which an etching gas is introduced and exhausted and maintained at a predetermined pressure, a substrate to be etched is placed in a fixed position, and a lower electrode plate is housed in the chamber. An upper electrode plate opposed to and disposed at a predetermined interval; a magnetic field applying means attached to an outer periphery of the chamber to apply a magnetic field to the chamber; and a high frequency between the upper electrode plate and the lower electrode plate. In a dry etching apparatus having a high frequency power supply for applying a voltage,
A shield frame member without an opening, which has an inner wall portion similar to the outer shape of the substrate to be etched mounted on the lower electrode and is mounted on the lower electrode so as to surround the outer periphery of the substrate to be etched, An elevating mechanism for moving the shield frame member up and down without changing the relative position with respect to the lower electrode.