WO2011058851A1

WO2011058851A1 - Dry etching apparatus and dry etching method

Info

Publication number: WO2011058851A1
Application number: PCT/JP2010/068336
Authority: WO
Inventors: 隆夫松本
Original assignee: シャープ株式会社
Priority date: 2009-11-16
Filing date: 2010-10-19
Publication date: 2011-05-19

Abstract

Disclosed is a dry etching apparatus, by which adhesion of reaction deposits on a substrate can be suppressed. The dry etching apparatus is provided with a lower electrode (10) having the substrate (50) disposed thereon, and an upper electrode (30) that faces the lower electrode (10). A high frequency voltage is applied to an etching gas to be introduced into between the lower electrode (10) and the upper electrode (30), an insulating shield (20) is provided in the peripheral region of the lower electrode (10), and a recessed section (21) is formed in the insulating shield (20).

Description

Dry etching apparatus and dry etching method

The present invention relates to a dry etching apparatus and a dry etching method, and more particularly to a dry etching apparatus using plasma.
Note that this application claims priority based on Japanese Patent Application No. 2009-260624 filed on November 16, 2009, the entire contents of which are incorporated herein by reference. .

In a manufacturing process including a thin film forming step used in a semiconductor device manufacturing technique or a liquid crystal display device manufacturing technique, a step of forming a thin film on the surface of a substrate, and a step of performing a patterning process for making the thin film a predetermined pattern Is executed many times. In the patterning step, for example, after a resist layer is formed in a predetermined pattern on the surface of the thin film by photolithography, an etching process is performed using the resist layer as a mask.

One of the etching methods is dry etching, and among them, there is dry etching using plasma. For this dry etching, for example, an apparatus having an electrode structure composed of a pair of opposed parallel plate electrodes housed in a chamber is used (for example, Patent Documents 1 and 2). The substrate is held on the surface of one of the two opposing electrodes, and a high frequency voltage is applied between the two electrodes in this state. An etching gas suitable for the material of the portion to be etched is introduced into the chamber. This etching gas is an appropriate mixture of an inert gas (eg, nitrogen gas, argon gas, etc.) and a reactive gas (eg, chlorine gas, oxygen gas, methane gas, various fluorine gases, etc.). The inside of the chamber is always kept at a constant pressure because the etching gas is introduced and exhausted by the exhaust device.

The etching gas introduced into the chamber is excited to a high energy state by being activated by a high frequency voltage applied between the electrodes. That is, by applying a high-frequency voltage between the electrodes, plasma is generated between the electrodes, and reactive ions (activated etching gas) are generated in the plasma. Reactive ions are etched by reacting with the surface of the substrate disposed on one electrode and vaporizing a thin film on the surface of the substrate.

JP 11-61452 A JP 2005-243915 A

In a dry etching apparatus using plasma, a shield ceramic (shield ring) is placed around the lower electrode in order to stably confine plasma containing an etching gas excited to a high energy state within the substrate surface. There is. FIG. 1 is a diagram showing a configuration of a plasma dry etching apparatus 1000 examined by the present inventors. FIG. 1A is a diagram illustrating a top surface configuration including the surface 111 of the lower electrode 110, and FIG. 1B is a diagram illustrating a cross-sectional configuration of the lower electrode 110 and the substrate 150.

In this dry etching apparatus 1000, a shield ceramic (shield ring) 120 is disposed in the peripheral region of the lower electrode 110. A substrate 150 is disposed on the surface (upper surface) 111 of the lower electrode 110 and part of the surface 121 of the shield ceramic 120. A thin film to be etched is formed on the surface of the substrate 150. The substrate 150 is, for example, a glass substrate for a liquid crystal panel.

When the surface of the substrate 150 is etched using the dry etching apparatus 1000, a region 122 where etching proceeds and a region 124 where deposition progresses are formed on the surface 121 of the shield ceramic 120. This is because the portion (122) close to the surface 111 of the lower electrode 110 is always etched and no deposition occurs, while the portion (124) far from the surface 111 of the lower electrode 110 reacts more than etching. This is due to the fact that deposit adhesion proceeds.

In the region 124 of the shield ceramic 120, when the deposition of the reaction deposit (dirt) becomes severe, it may peel off (see arrow 125) and adhere (reattach) on the substrate 150. When reactive deposits adhere to the substrate 150, it becomes a mask, which may lead to a defective etching process and a decrease in yield.

Therefore, when the deposition of reaction deposits becomes severe on the shield ceramic 120, it is necessary to replace the shield ceramic 120. However, the shield ceramic 120 is expensive and the dry etching apparatus 1000 cannot be used when the shield ceramic 120 is replaced. This reduces the throughput of the etching process.

The present invention has been made in view of such a point, and a main object thereof is to provide a dry etching apparatus capable of suppressing reaction deposits from adhering to a substrate.

A dry etching apparatus according to the present invention includes a lower electrode on which a substrate is disposed and an upper electrode facing the lower electrode, and an etching gas introduced between the lower electrode and the upper electrode has a high frequency voltage. Is applied, and an insulating shield is provided in a peripheral region of the lower electrode, and a concave portion is formed in the insulating shield.
In a preferred embodiment, the upper surface of the lower electrode and the upper surface of the insulating shield are located on a substrate plane.
In a preferred embodiment, the recess is composed of a wall surface located on the center side of the lower electrode and a bottom surface in contact with the wall surface, and the bottom surface of the recess is in contact with the outer peripheral surface of the insulating shield.
In a preferred embodiment, the height difference between the top surface of the insulating shield and the bottom surface of the recess is 10 mm or more.
In a preferred embodiment, the concave portion has a first wall surface located on the center side of the lower electrode, a bottom surface in contact with the first wall surface, and in contact with the bottom surface, on a side opposite to the center side of the lower electrode. It is comprised from the 2nd wall surface located.
Another dry etching apparatus according to the present invention includes a lower electrode on which a substrate is disposed, and an upper electrode facing the lower electrode, and an etching gas introduced between the lower electrode and the upper electrode is used as an etching gas. A high frequency voltage is applied, an insulating shield is provided in the peripheral region of the lower electrode, and an inclined surface is formed in the peripheral region of the insulating shield.
In a preferred embodiment, the insulating shield is made of a ceramic material.
The dry etching method according to the present invention excites the etching gas by introducing an etching gas between the lower electrode and the upper electrode facing each other and applying a high frequency voltage between the lower electrode and the upper electrode. And a dry etching method for etching a surface of a substrate disposed on the lower electrode, wherein an insulating shield is provided in a peripheral region of the lower electrode, and the concave portion is provided in the insulating shield. Is formed.
In another dry etching method according to the present invention, an etching gas is introduced between a lower electrode and an upper electrode facing each other, and a high frequency voltage is applied between the lower electrode and the upper electrode, thereby the etching gas. And etching the surface of the substrate disposed on the lower electrode, and an insulating shield is provided in the peripheral region of the lower electrode, and the peripheral region of the insulating shield Is formed with an inclined surface.
In a preferred embodiment, the substrate is a glass substrate for a liquid crystal panel.

According to the present invention, in the dry etching apparatus in which a high-frequency voltage is applied to the etching gas introduced between the lower electrode and the upper electrode, the insulating shield is provided in the peripheral region of the lower electrode, A recess is formed. Therefore, since the reaction deposit deposited on the insulating shield is confined in the recess, it is possible to suppress the reaction deposit from adhering to the substrate. In addition, since the replacement time of the insulating shield can be extended, it is possible to reduce the apparatus cost and the throughput of the etching process.

(A) is a top view which shows the structure of the lower electrode surface 111 and the ceramic shield 120 of the dry etching apparatus 1000, (b) is a cross section which shows the structure of the lower electrode 110 and the ceramic shield 120 of the dry etching apparatus 1000 FIG. (A) is a top view which shows the structure of the surface 11 and insulating shield 20 of the lower electrode of the dry etching apparatus 100 which concerns on embodiment of this invention, (b) is the lower electrode 10 of the dry etching apparatus 100, and 2 is a cross-sectional view showing a configuration of an insulating shield 20. FIG. It is a figure which shows typically an example of a structure of the dry etching apparatus 100 which concerns on embodiment of this invention. It is sectional drawing which shows the modification of the insulating shield 20 which concerns on embodiment of this invention. It is sectional drawing which shows the modification of the insulating shield 20 which concerns on embodiment of this invention. It is sectional drawing which shows the modification of the insulating shield 20 which concerns on embodiment of this invention. It is sectional drawing which shows the modification of the insulating shield 20 which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, components having substantially the same function are denoted by the same reference numerals for the sake of brevity. In addition, this invention is not limited to the following embodiment.

FIG. 2 schematically shows the configuration of the dry etching apparatus 100 of the present embodiment. The dry etching apparatus 100 of this embodiment is a dry etching apparatus using plasma. Specifically, in the dry etching apparatus 100, plasma is generated between the electrodes by applying a high frequency voltage between the electrodes, and the reactive ions generated in the plasma are reacted with the surface of the substrate 50 to perform etching. Do.

2A is a top view showing the lower electrode 10 and its peripheral structure of the dry etching apparatus 100 according to the embodiment of the present invention, and FIG. 2B is a cross section showing the lower electrode 10 and its peripheral structure. FIG. 2A and 2B do not show the configuration of the upper electrode or the like.

The dry etching apparatus 100 according to this embodiment includes a lower electrode 10 on which a substrate 50 is disposed and an upper electrode (not shown) facing the lower electrode. During the operation of the dry etching apparatus 100, an etching gas is introduced between the lower electrode 10 and the upper electrode, and a high frequency voltage is applied between the lower electrode 10 and the upper electrode to form plasma.

An insulating shield (shield ring) 20 is provided in the peripheral region of the lower electrode 10. The insulating shield of this embodiment is made of a ceramic material. A groove 15 is formed in the peripheral region of the lower electrode 10 of the present embodiment, and the insulating shield 20 is disposed in the groove 15. As shown in FIG. 2A, the lower electrode 10 has a square-shaped groove 15 when viewed from above, and an insulating shield 20 is disposed along the groove 15. A substrate 50 to be etched is disposed on the upper surface 11 of the central region of the lower electrode 10.

A recess 21 is formed in the insulating shield 20 of the present embodiment. In the example illustrated in FIG. 2, the recess 21 includes a wall surface 21 c located on the center side of the lower electrode 10 and a bottom surface 21 b in contact with the wall surface 21 c. The height difference (H) between the upper surface 20a of the insulating shield 20 and the bottom surface 21b of the recess 21 is, for example, 10 mm or more. Further, the bottom surface 21 b of the recess 21 in this example is in contact with the outer peripheral surface 20 b of the insulating shield 20. That is, the recess 21 shown in FIG. 2 has an L-shaped cross section. The outer peripheral surface 20b of the insulating shield 20 is a surface continuous with the upper surface 20a of the insulating shield 20.

Furthermore, in the configuration of this embodiment, the upper surface 11 of the lower electrode 10 and the upper surface 20a of the insulating shield 20 are located on the same plane (or substantially the same plane). In the present embodiment, the substrate 50 is disposed on the upper surface 11 of the lower electrode 10 and a part of the upper surface 20 a of the insulating shield 20. Thereby, compared with the case where the direction of the upper surface 11 of the lower electrode 10 is made low, it can suppress that the peripheral area | region of the board | substrate 50 raises. Depending on the size of the substrate 50, it is possible to dispose the substrate 50 within the upper surface 11 of the lower electrode 10 without disposing the substrate 50 on the upper surface 20 a of the insulating shield 20. Further, a thin film to be etched is formed on the surface of the substrate 50, and the substrate 50 of this embodiment is a glass substrate (for example, an array substrate) for a liquid crystal panel.

As shown in FIG. 2A, when the dry etching apparatus 100 is operated to perform etching of the surface of the substrate 50, a region (center side) 22 where etching proceeds and deposition are formed on the surface of the insulating shield 20. And a region (outer edge side) 24 in which the travel proceeds. This is because the portion (22) close to the upper surface 11 of the lower electrode 10 is always etched and no deposition occurs, while the portion (24) far from the upper surface 11 of the lower electrode 10 reacts more than etching. This is due to the fact that deposit adhesion proceeds.

In the configuration of the present embodiment, the recess 21 is formed in the region (outer edge side) 24 where deposition proceeds. Therefore, even if the deposition of reaction deposits (dirt) due to etching becomes severe, it is deposited exclusively on the bottom surface 21 b of the recess 21. Therefore, even if the reaction deposit deposited on the bottom surface 21b of the recess 21 peels off and tries to adhere (reattach) to the surface of the substrate 50, it is blocked by the wall surface 21c of the recess 21 (arrow 25a), and as a result. Adhering to the surface of the substrate 50 can be suppressed. Further, if the reaction deposit on the bottom surface 21b of the recess 21 is peeled off and moves to the outside (arrow 25b), it is not exhausted thereafter, and therefore does not adhere to the surface of the substrate 50.

Next, the configuration of the dry etching apparatus 100 of this embodiment will be described in detail with reference to FIG. FIG. 3 is a diagram schematically illustrating an example of the configuration of the dry etching apparatus 100.

The dry etching apparatus 100 shown in FIG. 3 is a parallel plate type plasma etching apparatus, and the upper electrode 30 and the lower electrode 10 are disposed in the chamber 40 so as to face each other. In this example, the upper electrode 30 is connected to the ground 43, while the lower electrode 10 is connected to the high frequency power supply 44. An exhaust port 42 is formed in a part (here, the bottom portion) of the chamber 40, and exhaust is performed through the exhaust port 42 (arrow 45). An etching gas inlet (not shown) is also arranged in the chamber 40.

An insulating shield (for example, a ceramic shield) 20 is disposed in the peripheral region of the lower electrode 10. In the illustrated configuration, the insulating shield 32 is also disposed in the peripheral region of the upper electrode 30. When the dry etching apparatus 100 is operated, a plasma 60 is generated between the upper electrode 30 and the lower electrode 10, and the plasma does not spread more than necessary by the insulating

shields

32 and 20. Has been.

According to the dry etching apparatus 100 of the present embodiment, the insulating shield 20 is provided in the peripheral region of the lower electrode 10 in a structure in which a high frequency voltage is applied to the etching gas introduced between the lower electrode 10 and the upper electrode 30. A recess 21 is formed in the insulating shield 20. Therefore, even if the reaction deposit is deposited on the insulating shield 20, it is confined in the recess 21, so that the reaction deposit can be prevented from adhering to the surface of the substrate 50. As a result, it is possible to prevent the occurrence of defects in the etching process and suppress a decrease in yield. In addition, since the replacement time of the insulating shield 20 used in the dry etching apparatus 100 can be extended, the apparatus cost can be reduced and the interval between replacements can be increased. This also leads to suppression of a decrease in throughput caused by stopping the process.

In addition, according to the thin film (layer to be etched) formed on the substrate 50, a suitable etching gas (etchant) to be used is appropriately selected. Further, the substrate 50 of the present embodiment is a glass substrate for a liquid crystal panel, but the substrate 50 may be a mother glass before cutting out to the dimensions of the liquid crystal panel, or the size of the liquid crystal panel after cutting out. Glass may also be used. Further, the substrate 50 may be an array substrate on which a thin film transistor (TFT) is manufactured (or a product in the middle of manufacturing), or a CF substrate on which a color filter (CF) is formed (or a device in the middle of manufacturing thereof). It may be. The substrate 50 may be a glass substrate, a resin substrate, or another thin plate such as a wafer. In addition, the substrate 50 is not limited to the liquid crystal panel 50, and may be a thin substrate for manufacturing a PDP, an organic EL panel, other flat panel displays, or electronic devices.

Further, the configuration of the dry etching apparatus 100 of the present embodiment is not limited to the above-described configuration, and can be changed to other forms. Next, a modified example of the dry etching apparatus 100 of the present embodiment will be described with reference to FIGS. 4 to 7 show cross-sectional configurations of the lower electrode 10 and the insulating shield 20 in the dry etching apparatus 100, respectively.

An insulating shield 20 having a recess 21 is formed on the lower electrode 10 of the dry etching apparatus 100 shown in FIG. The recess 21 includes a wall surface 21c located on the center side of the lower electrode 10, a bottom surface 21b, and a wall surface 21d located on the opposite side (outside) from the center side. The wall surface 21d is in contact with the second upper surface 20c of the insulating shield 20, and the second upper surface 20c is in contact with the outer peripheral surface 20b.

In the case of the concave portion 21 in this example, a reaction deposit (dirt) due to etching is deposited in a region surrounded by the wall surface 21c, the bottom surface 21b, and the wall surface 21d. Therefore, even when the reaction deposit is peeled off, the reaction deposit can be trapped by the concave portion 21, and as a result, adhesion (reattachment) to the surface of the substrate 50 can be suppressed.

In the example shown in FIG. 4, when a reaction deposit is deposited on the second upper surface 20 c of the insulating shield 20, the reaction deposit is further prevented from adhering (reattaching) to the surface of the substrate 50. Therefore, the second upper surface 20c is set lower than the first upper surface 20a. However, if the reaction deposit deposited on the second upper surface 20c is trapped in the recess 21 and does not adhere to the surface of the substrate 50, the second upper surface 20c and the first upper surface 20a may be set to the same height. Is possible.

Moreover, in the above-described configuration, the insulating shield 20 having the recess 21 is shown. However, as shown in FIG. 5, the inclined surface 23 can be formed on the insulating shield 20. In the example shown in FIG. 5, an inclined surface 23 is provided on the outer edge portion of the insulating shield 20.

According to this configuration, even if the reaction deposit is peeled off after the reaction deposit is deposited on the inclined surface 23, the reaction deposit only moves outward (arrow 25c). It can prevent adhering to the surface. Here, the angle θ formed by the inclined surface 23 and the upper surface 20a (or horizontal line) may be set to a desired angle in consideration of various conditions.

As mentioned above, although this invention has been demonstrated by suitable embodiment, such description is not a limitation matter and, of course, various modifications are possible. For example, as shown in FIG. 6, the inclined surface 23 of the insulating shield 20 is not limited to a straight line but may be a curved line. In addition, as shown in FIG. 7, it is possible to form both the concave portion 21 and the inclined surface 23 in the insulating shield 20.

According to the present invention, it is possible to provide a dry etching apparatus and a dry etching method capable of suppressing reaction deposits from adhering to a substrate.

DESCRIPTION OF SYMBOLS 10 Lower electrode 15 Groove 20 Insulating shield 21 Recess 23 Inclined surface 30 Upper electrode 32 Insulating shield 40 Chamber 42 Exhaust port 43 Ground 44 High frequency power supply 50 Substrate 60 Plasma 100 Dry etching apparatus 1000 Dry etching apparatus

Claims

A lower electrode on which the substrate is disposed;
An upper electrode facing the lower electrode,
A high frequency voltage is applied to the etching gas introduced between the lower electrode and the upper electrode,
An insulating shield is provided in the peripheral region of the lower electrode,
A dry etching apparatus in which a recess is formed in the insulating shield.
The dry etching apparatus according to claim 1, wherein an upper surface of the lower electrode and an upper surface of the insulating shield are located on the same plane.
The recess is
A wall surface located on the center side of the lower electrode;
A bottom surface in contact with the wall surface,
The dry etching apparatus according to claim 1, wherein a bottom surface of the recess is in contact with an outer peripheral surface of the insulating shield.
The dry etching apparatus according to claim 3, wherein a height difference between the upper surface of the insulating shield and the bottom surface of the recess is 10 mm or more.
The recess is
A first wall surface located on the center side of the lower electrode;
A bottom surface in contact with the first wall surface;
The dry etching apparatus according to claim 1, further comprising: a second wall surface that is in contact with the bottom surface and is located on a side opposite to a center side of the lower electrode.
A lower electrode on which the substrate is disposed;
An upper electrode facing the lower electrode,
A high frequency voltage is applied to the etching gas introduced between the lower electrode and the upper electrode,
An insulating shield is provided in the peripheral region of the lower electrode,
A dry etching apparatus in which an inclined surface is formed in a peripheral region of the insulating shield.
The dry etching apparatus according to any one of claims 1 to 6, wherein the insulating shield is made of a ceramic material.
An etching gas is introduced between the lower electrode and the upper electrode facing each other, and the etching gas is excited by applying a high frequency voltage between the lower electrode and the upper electrode, and is disposed on the lower electrode. A dry etching method for etching the surface of a substrate,
An insulating shield is provided in the peripheral region of the lower electrode,
A dry etching method in which a concave portion is formed in the insulating shield.
An etching gas is introduced between the lower electrode and the upper electrode facing each other, and the etching gas is excited by applying a high frequency voltage between the lower electrode and the upper electrode, and is disposed on the lower electrode. A dry etching method for etching the surface of a substrate,
An insulating shield is provided in the peripheral region of the lower electrode,
A dry etching method, wherein an inclined surface is formed in a peripheral region of the insulating shield.
The dry etching method according to claim 8 or 9, wherein the substrate is a glass substrate for a liquid crystal panel.