JP2003100722A - Plasma processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma processing apparatus capable of preventing an abnormal discharge from occurring between a susceptor and a plasma. SOLUTION: The plasma processing apparatus comprises: a process chamber 2 in which a processing substrate G is accommodated; a susceptor 5 provided in the process chamber 2 on which the substrate G is mounted; an upper electrode 12 opposed to the susceptor 5 in the chamber 2; a process gas supply unit 19 for supplying a process gas into the chamber 2; an evacuation unit 21 for evacuating inside of the chamber 2; a high frequency power supply 26 for supplying a high frequency power to the susceptor 5 so that a plasma of the process gas is produced in a processing space 2a between the susceptor 5 and the upper electrode 12; and a shield 7 which surrounds a peripheral side wall of the substrate G so that a short-circuit path from the plasma to a side wall 5c of the substrate G on the susceptor is shielded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus for performing plasma processing such as etching on a substrate to be processed.

[0002]

2. Description of the Related Art In a manufacturing process of a semiconductor or a liquid crystal display device, a plasma etching apparatus or a plasma CVD film forming apparatus is used to perform plasma processing such as etching processing or film forming processing on a substrate to be processed such as a semiconductor wafer or a glass substrate. A plasma processing apparatus such as the above is used.

FIG. 6A is a schematic sectional view showing a plasma etching apparatus which is an example of the above plasma processing apparatus and which performs a dry etching process on a glass substrate. As shown in FIG. 6A, this plasma etching apparatus has a shower head 102 functioning as an upper electrode and a susceptor 103 functioning as a lower electrode, which are provided in a chamber 101 so as to face each other. Cage,
With the glass substrate G placed on the susceptor 103, high-frequency power is supplied from the high-frequency power source 104 to the susceptor 103, plasma is generated in the chamber 101, and a predetermined film formed on the glass substrate G is generated by the plasma. Etching.

FIG. 6B is an enlarged view of the peripheral portion of the susceptor 103 during the etching as described above. As shown in FIG. 6B, the susceptor 1
A protrusion 103a having a holding surface 103b for holding the glass substrate G is formed so as to protrude upward in the center of the upper part of 03, and the upper peripheral portion and the side surface of the susceptor 103 are covered with the insulating member 105. ing. The holding surface 103b of the projecting portion 103a has a smaller area than the glass substrate G, and when the substrate G is placed, the outer peripheral portion of the substrate G protrudes, so that during etching, The upper surface of the susceptor 103 is not exposed and is not exposed to plasma, so that the plasma of the susceptor 103 is not damaged.

However, the protruding portion 103a is provided higher than the upper surface of the insulating member 105 by about 50 to 100 μm, and therefore the side surface 103c on the upper portion of the protruding portion 103a.
Is slightly exposed, during the etching process, the side surface 103c and the plasma formed in the chamber 2 are short-circuited to cause abnormal discharge (arc discharge), and the susceptor 103 is It may be damaged.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a plasma processing apparatus capable of suppressing abnormal discharge between a susceptor holding a substrate to be processed and plasma. The purpose is to provide.

[0007]

In order to solve the above problems, according to a first aspect of the present invention, a chamber for accommodating a substrate to be processed and a susceptor provided in the chamber for holding the substrate to be processed are provided. A processing gas supply mechanism for supplying a processing gas into the chamber, an exhaust mechanism for exhausting the inside of the chamber, a plasma generating means for generating a plasma of the processing gas in the chamber, and an object to be processed held by the susceptor. A plasma processing apparatus comprising: a member surrounding a side surface of a substrate.

According to a second aspect of the present invention, a chamber for containing a substrate to be processed, a susceptor for holding the substrate to be processed, which is provided in the chamber and functions as a lower electrode, are provided in the chamber. An upper electrode provided so as to face the susceptor, a processing gas supply mechanism for supplying a processing gas into the chamber, an exhaust mechanism for exhausting the inside of the chamber, and a high frequency wave for at least one of the susceptor and the upper electrode. A high frequency power source for supplying electric power to form a plasma of a processing gas in a processing space between the susceptor and the upper electrode; and a member surrounding a side surface of the substrate to be processed on the susceptor. Provided is a plasma processing apparatus.

According to the plasma processing apparatus of the present invention, since the member surrounding the side surface of the substrate to be processed held by the susceptor is provided, it is possible to prevent the short circuit of the current from the plasma to the side surface of the susceptor, and to prevent the current path from being exposed. It becomes long and bent along a member that surrounds the side surface of the processing substrate, and it is possible to prevent abnormal discharge from occurring between the plasma and the susceptor.

The plasma processing apparatus according to the first aspect of the present invention may be configured to have a high frequency power source for applying high frequency power to the susceptor. Further, the plasma generating means may have a coil or an antenna for generating inductively coupled plasma in the chamber.

In the plasma processing apparatus according to the first and second aspects of the present invention, the susceptor has a protrusion having a holding surface for holding a substrate to be processed in a central portion thereof, and the protrusion is provided. It may be configured to further include an insulating member that covers the periphery of the. A member surrounding the side surface of the substrate to be processed may be provided in contact with the insulating member. Further, a member surrounding the side surface of the substrate to be processed may be provided integrally with the insulating member. Furthermore, it is preferable that the member surrounding the side surface of the substrate to be processed has an overhanging portion that projects to the inner peripheral side so as to cover the peripheral portion of the substrate to be processed held by the holding surface of the protrusion. . Thereby, the current path from the plasma to the side surface of the susceptor can be made longer and bent more. Furthermore, in the case where the susceptor holds the substrate to be processed in a mounted state, from the viewpoint of preventing adhesion of reaction products and the like, the projecting portion is provided at a position distant from the surface to be processed of the substrate to be processed. It is preferable that it is formed so as to project toward the inner peripheral side and become thinner from the outer peripheral side toward the inner peripheral side.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view schematically showing a plasma etching apparatus for an LCD glass substrate according to an embodiment of the present invention. The plasma etching apparatus 1 is configured as a capacitively coupled parallel plate plasma etching apparatus.

This plasma etching apparatus 1 has a chamber 2 formed in the shape of a rectangular tube made of, for example, aluminum whose surface is anodized (anodized). A prismatic insulating plate 3 made of an insulating material is provided at the bottom of the chamber 2, and a susceptor 5 functioning as a lower electrode is further provided on the insulating plate 3. An LCD glass substrate G (hereinafter, simply referred to as a substrate G) that is a substrate to be processed is provided at the center of the upper portion of the susceptor 5.
The columnar projecting portion 5a on which is mounted is formed so as to project upward, and the upper surface of this projecting portion 5a serves as a holding surface 5b for holding the substrate G. Further, the peripheral portion and the side surface of the protruding portion 5a on the upper surface of the susceptor 5 are covered with an insulating member 6 made of ceramics or the like, and substantially only the holding surface 5b of the upper surface of the susceptor 5 is exposed. The holding surface 5b of the projecting portion 5a has a smaller area than the substrate G, and when the substrate G is placed, the outer peripheral portion of the substrate G protrudes, and the substrate G is placed on the holding surface 5b. In the state in which is held, there is no exposed portion on the upper surface of the susceptor 5, and the upper side surface 5c of the protrusion 5a is slightly exposed.

A power supply line 24 for supplying high frequency power is connected to the susceptor 5, and a matching unit 25 and a high frequency power supply 26 are connected to the power supply line 24. A high frequency power of 13.56 MHz, for example, is supplied from the high frequency power supply 26 to the susceptor 5.

A shower head 12 functioning as an upper electrode is provided above the susceptor 5 so as to face the susceptor 5 in parallel. The shower head 12 is supported on the upper part of the chamber 2, has an internal space 13 inside, and has a large number of discharge holes 14 for discharging a processing gas formed on the surface facing the susceptor 5. The shower head 12 is grounded and constitutes a pair of parallel plate electrodes together with the susceptor 5.

A gas introduction port 15 is provided on the upper surface of the shower head 12, and a processing gas supply pipe 16 is connected to the gas introduction port 15. The processing gas supply pipe 16 has a valve 17 and A processing gas supply source 19 is connected via the mass flow controller 18. The processing gas supply source 19 supplies a processing gas for etching. As a processing gas, a halogen-based gas, O ₂
Gases commonly used in this field, such as gas and Ar gas, can be used.

An exhaust pipe 2 is provided at the bottom of the side wall of the chamber 2.
0 is connected, and an exhaust device 21 is connected to the exhaust pipe 20.
Are connected. The exhaust device 21 is equipped with a vacuum pump such as a turbo molecular pump, which allows the chamber 2
The inside is configured to be able to be evacuated to a predetermined reduced pressure atmosphere. Further, a substrate loading / unloading port 22 and a gate valve 23 for opening / closing the substrate loading / unloading port 22 are provided on the side wall of the chamber 2, and the load lock chamber adjacent to the substrate G in a state where the gate valve 23 is opened. It is designed to be transported to and from (not shown).

On the insulating member 6, there is provided a frame-shaped member 7 made of ceramics or the like, which surrounds the side surface of the substrate G placed on the protruding portion 5a of the susceptor 5. The member 7 surrounding the periphery of is in contact with the insulating member 6 during the etching process. When plasma is formed between the susceptor 5 functioning as the lower electrode and the shower head 12 functioning as the upper electrode, if the member 7 is not present, the plasma and the side surface upper part 5c of the protruding portion 5a slightly exposed are formed. Although a short circuit path is formed between the two, the member 7 is provided so as to interrupt the short circuit path. The insulating member 6 and the member 7 that surrounds the periphery of the substrate G may be integrally configured.

Next, the processing operation of the plasma etching apparatus 1 having the above-mentioned structure will be described. First, the substrate G, which is an object to be processed, is loaded into the chamber 2 from the load lock chamber (not shown) through the substrate loading / unloading port 22 after the gate valve 23 is opened, and is formed in the central portion of the upper portion of the susceptor 5. The protrusion 5a is held by the holding surface 5b.
In this case, the substrate G is delivered through a lifter pin (not shown) that is inserted through the susceptor 5 and can project from the susceptor 5. Then, the gate valve 23 is closed, and the exhaust device 21 is used to move the chamber 2
The inside is evacuated to a predetermined degree of vacuum.

Thereafter, the valve 17 is opened and the processing gas is supplied from the processing gas supply source 19 to the mass flow controller 1.
The processing gas supply pipe 1 while its flow rate is adjusted by 8
6, is introduced into the internal space 13 of the shower head 12 through the gas introduction port 15, and further passes through the discharge hole 14 to the substrate G.
And the pressure in the chamber 2 is maintained at a predetermined value.

In this state, the high frequency power supply 26 is changed to the matching device 25.
High-frequency power is applied to the susceptor 5 via the susceptor 5, whereby a high-frequency electric field is generated in the processing space 2a between the susceptor 5 and the showerhead 12, and the processing gas is dissociated into plasma, whereby the substrate G is etched. Is applied.

When performing the etching process in this way,
If there is no member 7 that surrounds the periphery of the substrate G, as shown in FIG. 2, a short circuit path d is formed between the plasma and the upper side surface 5c of the protrusion 5a of the susceptor 5 to cause abnormal discharge (arc discharge). Is likely to occur. On the other hand, when the member 7 is provided, the periphery of the substrate G on the protruding portion 5a of the susceptor 5 is surrounded by the member 7 as shown in the enlarged view of FIG. Since it is provided so as to shield the short circuit path from the plasma formed in 2a to the side surface upper portion 5c of the protruding portion 5a, as shown in FIG. 3, it is provided between the plasma and the side surface upper portion 5c of the protruding portion 5a. A long curved current path d1 is formed around the member 7. The arc discharge that constitutes the abnormal discharge becomes less likely to occur as the current path becomes longer and bends, and thus the member 7 forms the long bent current path d1 from the plasma to the upper side surface 5b of the protrusion 5a. As a result, it is possible to reliably prevent abnormal discharge from occurring between them.

After performing the etching process in this manner, the application of high frequency power from the high frequency power source 26 is stopped,
The gate valve 23 is opened, and the substrate G is moved to the substrate loading / unloading port 2
The etching process of the substrate G is completed by being carried out from the chamber 2 to the load lock chamber (not shown) through the chamber 2.

Next, another embodiment of the member 7 surrounding the substrate G will be described. As described above, in order to suppress abnormal discharge, the side surface upper part 5 of the protrusion 5a is removed from the plasma.
It is preferable that the short-circuit path to c is shielded and the current path therebetween is longer and bent. Therefore, for example, as shown in FIG. 4, the holding surface 5b of the protrusion 5a is
It is preferable to provide a member 7'having an overhanging portion 7a overhanging on the inner peripheral side so as to cover the peripheral portion of the substrate G held by. As described above, by providing the overhanging portion 7a, it is possible to form the short-circuit path d2 that is longer and more bent, so that it is possible to more reliably prevent the occurrence of abnormal discharge.

Further, as shown in FIG. 5, by forming a member 7 "having an overhanging portion 7a 'which is tapered so that the thickness decreases from the outer circumference toward the inner circumference, reaction to the overhanging portion occurs. It is more preferable from the viewpoint of particle contamination on the substrate G, since the products and the like are less likely to adhere.

In the configuration of FIGS. 4 and 5, the substrate G
Since the members 7'and 7 "that surround the periphery of the substrate hinder the loading and unloading of the substrate G, they are provided so as to project around the insulating member 6, and an actuator (not shown) is provided via a support column 8 connected to the lower part of them. Thus, the members 7'and 7 "can be moved upward and downward when the substrate G is carried in and out.

The present invention is not limited to the above embodiment, but can be variously modified. For example, in the above embodiment, the parallel plate type plasma etching apparatus of the type in which the susceptor holding the substrate to be processed is used as the lower electrode and the high frequency power for plasma formation is applied to the susceptor has been described, but the present invention is not limited to this. It may be of a type in which a high frequency power for plasma formation is applied to the susceptor as a lower electrode and a high frequency power for ion attraction is applied to the susceptor as a lower electrode. A type that applies high-frequency power can also be adopted. Further, it may be of a type in which the susceptor is grounded without applying high frequency power to the susceptor. Further, the device is not limited to such a parallel plate type, and may be a device of a type that uses an antenna or a coil as plasma means and applies high frequency power to the antenna or coil to generate inductively coupled plasma. Further, the present invention can be applied not only to the etching apparatus but also to various plasma processing apparatuses such as an ashing apparatus and a CVD film forming apparatus.
The substrate to be processed is not limited to the LCD glass substrate G, but may be a semiconductor wafer.

[0028]

As described above, according to the present invention,
Since a member surrounding the side surface of the substrate to be processed held by the susceptor is provided, it is possible to prevent current short circuit from the plasma to the susceptor, and the current path is long and bent along the member surrounding the side surface of the substrate to be processed. Therefore, it is possible to prevent abnormal discharge from occurring between the plasma and the susceptor.

[Brief description of drawings]

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

FIG. 2 is a view for explaining a short circuit path between plasma and a side surface of a susceptor formed when a member surrounding a side surface of a substrate to be processed is not provided.

3 is an enlarged cross-sectional view showing a susceptor peripheral portion and its vicinity of the plasma etching apparatus shown in FIG.

FIG. 4 is an enlarged cross-sectional view showing another example of the peripheral portion of the susceptor and the vicinity thereof.

FIG. 5 is an enlarged cross-sectional view showing another example of the peripheral portion of the susceptor and its vicinity.

FIG. 6 is a sectional view schematically showing a conventional plasma etching apparatus.

[Explanation of symbols]

1; Plasma etching device 2; chamber 2a; processing space 3; insulating plate 5; Susceptor 5a; protrusion 5b; holding surface 5c; upper side 6; Insulation member 7,7 ', 7 "; members surrounding the periphery of the substrate 7a, 7a '; overhang 12; Shower head 19; Processing gas supply source 21; Exhaust device 26; High frequency power supply G: Glass substrate

Claims (9)

[Claims] 1. A chamber for accommodating a substrate to be processed, a susceptor provided in the chamber for holding the substrate to be processed, a processing gas supply mechanism for supplying a processing gas into the chamber, and an interior of the chamber. A plasma processing apparatus comprising: an exhaust mechanism for exhausting; a plasma generating unit that generates plasma of a processing gas in the chamber; and a member that surrounds a side surface of a substrate to be processed held by the susceptor. . 2. The plasma processing apparatus according to claim 1, further comprising a high frequency power source for applying high frequency power to the susceptor. 3. The plasma processing apparatus according to claim 1, wherein the plasma generating unit has a coil or an antenna that generates inductively coupled plasma in the chamber. 4. A chamber for accommodating a substrate to be processed, a susceptor provided in the chamber for holding the substrate to be processed, which functions as a lower electrode, and a chamber provided to face the susceptor in the chamber. An upper electrode, a processing gas supply mechanism that supplies a processing gas into the chamber, an exhaust mechanism that exhausts the inside of the chamber, a high frequency power is supplied to at least one of the susceptor and the upper electrode, and the susceptor and the A plasma processing apparatus comprising: a high frequency power source for generating a plasma of a processing gas in a processing space between the upper electrode and a member surrounding a side surface of the substrate to be processed on the susceptor. 5. The susceptor has a protrusion having a holding surface for holding a substrate to be processed in a central portion thereof, and further comprises an insulating member covering the periphery of the protrusion. The plasma processing apparatus according to any one of claims 1 to 4. 6. The plasma processing apparatus according to claim 5, wherein a member surrounding a side surface of the substrate to be processed is provided in contact with the insulating member. 7. The plasma processing apparatus according to claim 6, wherein a member surrounding a side surface of the substrate to be processed is integrally provided with the insulating member. 8. The member surrounding the side surface of the substrate to be processed has an overhanging portion that projects to the inner peripheral side so as to cover the peripheral portion of the substrate to be processed held by the holding surface of the projecting portion. The plasma processing apparatus according to claim 5, wherein the plasma processing apparatus is a plasma processing apparatus. 9. The susceptor holds the substrate to be processed in a mounted state, and the projecting portion projects to the inner peripheral side at a position away from the surface to be processed of the target substrate, and the inner periphery from the outer periphery thereof. The plasma processing apparatus according to claim 7, wherein the plasma processing apparatus is formed so that the thickness thereof decreases toward.