KR20110077575A - Focus ring of plasma processing apparatus and plasma processing apparatus having the same - Google Patents

Abstract

PURPOSE: The focus ring of an apparatus for processing plasma and an apparatus for processing plasma including the same are provided to uniformly distribute the temperature of the top of a chuck by eliminating a lift pin passing through a chuck. CONSTITUTION: A chuck(20) is included in a processing chamber(10) and driven up and down. A focus ring(30) is arranged to the outer circumference of the chuck. A clamp(50) fixes a wafer or a wafer tray which is settled in the chuck. The focus ring includes a first focus ring and a second focus ring. A first focus ring is fixed in a focus ring base. A second focus ring is settled or fixed in the outer circumference of the chuck. The second focus ring descends more than the first focus ring when the chuck descends.

Description

Focus ring of plasma processing apparatus and plasma processing apparatus having the same {Focus Ring of Plasma Processing Apparatus and Plasma Processing Apparatus Having the Same}

The present invention relates to a focus ring of a plasma processing apparatus and a plasma processing apparatus having the same. More specifically, the present invention relates to a plasma processing apparatus capable of effectively loading, unloading and fixing a wafer or a tray containing a wafer in a plasma processing apparatus that performs an etching process or a deposition process for processing a wafer in a plasma state. A focus ring and a plasma processing apparatus having the same.

Plasma is used to form a thin film on a substrate or to process a desired pattern in semiconductor manufacturing. Representative examples of substrate processing using a plasma include a plasma enhanced chemical vapor deposition (PECVD) process and a plasma etching process.

Plasma increases the reactivity by making gaseous chemicals highly reactive radicals. The PECVD process using this principle is a process of forming a thin film on a substrate by reacting a gaseous process gas in a plasma atmosphere. Meanwhile, as the ions in the plasma collide with the substrate surface, the material to be etched is physically removed or chemical bonds in the material are cut to rapidly etch by radicals. In the plasma etching process using the same, a semiconductor circuit pattern is formed on the substrate by selectively removing a portion of the substrate masked with a photoresist or the like with a corrosive gas.

The plasma processing apparatus may be classified into a capacitive coupled plasma (CCP) type and an inductive coupled plasma (ICP) type according to a method of generating a plasma. In the case of a CCP type plasma processing apparatus, an upper electrode is provided at an upper portion of a reaction chamber to form a plasma, and a lower electrode is provided at a lower portion of a chuck on which a substrate or a substrate tray is placed. On the other hand, in the case of an ICP type plasma processing apparatus, an induction coil is provided around the top or the top of the reaction chamber, and a lower electrode is provided below the chuck. The CCP type and ICP type plasma processing apparatuses generate a plasma in the reaction chamber by supplying RF or DC power to the upper electrode and the lower electrode or the induction coil and the lower electrode. On the other hand, such a plasma processing apparatus is equipped with a focus ring on the outer circumference of the chuck to prevent the chuck from being damaged by the plasma and to concentrate the generated plasma on the wafer.

In addition, the plasma processing apparatus further includes a reaction chamber as described above, and a transfer chamber or a loadlock chamber for delivering a wafer tray loaded with a single wafer or a plurality of wafers to the reaction chamber. do. In the case of a cluster type plasma processing apparatus including a plurality of reaction chambers, a load lock chamber and a transfer chamber are provided and a wafer or wafer tray vacuumed in the load lock chamber is transferred to the reaction chamber via the transfer chamber. On the other hand, when a single reaction chamber is provided, the wafer or the wafer tray is directly transferred from the load lock chamber to the reaction chamber without the transfer chamber.

In the process of loading and unloading the wafer or wafer tray between the transfer chamber or the load lock chamber and the reaction chamber, the transfer arm enters into the reaction chamber. At this time, a lift pin driven vertically through the chuck supports the wafer or the wafer tray.

However, when the lift pin is provided as in the prior art, the following problems occur.

First, heat transfer around the through hole formed in the chuck to allow the lift pin to move through the chuck is not smooth, so that an even temperature distribution of the wafer or the wafer tray is not formed.

Secondly, the transfer arm moves to the top of the chuck, but there is a problem in that the shape of the transfer arm must be complicated to prevent the lift pin and the transfer arm from protruding from the top of the chuck.

Third, in the case where the lift pin is located at the center of the chuck, a problem may occur in that the wafer or the wafer tray slides downward from the lift pin if the lift pin does not accurately support the center of the wafer or the wafer tray. On the other hand, when the lift pins are provided from the center of the chuck to the outside, the width of the transfer arm should be formed narrowly to fit the gap between the lift pins, which may also cause a problem that the wafer or the wafer tray falls downward.

In order to solve the above problems, the present invention provides a focus ring of a plasma processing apparatus for removing a lift pin and allowing a focus ring to support a wafer or a wafer tray when loading and unloading a wafer or a wafer tray, and a plasma treatment having the same. It is an object to provide a device.

The present invention, the process chamber; A chuck provided in the process chamber and driven vertically; A focus ring mounted on an outer circumference of the chuck; And a clamp for fixing a wafer or a wafer tray seated on the chuck to the chuck, wherein the focus ring includes a first focus ring fixed to a focus ring base and a second fixed or seated on an outer circumference of the chuck. The combination of the focus ring provides a plasma processing apparatus, characterized in that the second focus ring is lower than the first focus ring when the chuck is lowered.

Preferably, the focus ring base includes a first focus ring base portion to which the first focus ring is coupled, and a second focus ring base portion corresponding to the position of the second focus ring, and the second focus ring is the first focus ring. 2 It is moved up and down inside the focus ring base part.

Preferably, either the first focus ring or the second focus ring is provided with a wing at the side end, and the other side end is provided with a wing groove corresponding to the wing.

On the other hand, the clamp is a clamp plate for pressing the outer periphery of the wafer or wafer tray, a clamp body for supporting the clamp plate, a clamp lower ring coupled to or connected to the clamp body and seated on the bottom of the process chamber It includes, it is preferable that the focus ring base is seated on the step of the clamp lower ring at a predetermined position when the chuck is lowered so that it does not lower anymore.

In the operation of the plasma processing apparatus according to the present invention, the wafer or the wafer tray is loaded on the upper surface of the first focus ring or the first focus with the second focus ring lower than the first focus ring. It is unloaded from the upper surface of the ring. To this end, the plasma processing apparatus according to the present invention further includes a transfer arm which enters the process chamber and is driven up and down to load or unload the wafer or wafer tray.

In addition, the present invention, the focus ring is mounted on the outer periphery of the chuck, the focus ring base; A first focus ring fixed to the focus ring base; And a second focus ring fixed or seated on an outer circumference of the chuck, wherein the second focus ring is lowered than the first focus ring when the chuck is lowered.

In addition, according to another embodiment of the invention, the process chamber; An electrostatic chuck provided in the process chamber and driven up and down; And a focus ring mounted on an outer circumference of the chuck, wherein the focus ring comprises a combination of a first focus ring fixed to a focus ring base and a second focus ring fixed or seated on an outer circumference of the chuck. The second focus ring is lowered than the first focus ring when descending provides a plasma processing apparatus.

According to the present invention, there is an advantage that the temperature distribution of the upper part of the chuck can be even by removing the lift pin provided through the chuck. In addition, there is an advantage that the shape of the transfer arm that was limited in shape by the lift pin can be simplified.

In addition, according to the present invention, by allowing the focus ring to support the wafer or the wafer tray stably, it is possible to prevent breakage due to the fall of the wafer or the wafer tray.

In addition, according to the present invention, it is not necessary to form a moving path for the lift pin in the chuck, and components for driving the lift pin can be removed, thereby reducing the manufacturing cost of the plasma processing apparatus.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible, even if shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, preferred embodiments of the present invention will be described below, but the technical spirit of the present invention is not limited thereto and may be variously modified and modified by those skilled in the art.

1 is a configuration diagram of a plasma processing apparatus according to a first preferred embodiment of the present invention, and FIG. 2 is an exploded perspective view of a chuck, a focus ring, and a clamp in the plasma processing apparatus according to the first preferred embodiment of the present invention. 3 is an exploded perspective view of the focus ring in the plasma processing apparatus according to the first preferred embodiment of the present invention.

Referring to FIG. 1, a plasma processing apparatus according to a first preferred embodiment of the present invention includes a process chamber 10, a chuck 20, a focus ring 30, and a clamp 50 provided in the process chamber 10. Include. In FIG. 1, an induction coil 12 is provided above the process chamber 10 to generate plasma in an ICP type in the process chamber 10, but the upper electrode is formed in the process chamber in order to generate plasma in the CCP type. It is also possible to be provided in (10).

The chuck 20 is driven up and down and is mounted on a single wafer having a large diameter or a wafer tray 40 loaded with a plurality of wafers W as shown in FIG. 1. The focus ring 30 is provided on the outer circumference of the chuck 20 to prevent the chuck 20 from being damaged by the plasma and to concentrate the plasma on the wafer W.

The clamp 50 is provided to fix the wafer tray 40. As shown in FIG. 1, when the chuck 20 moves upward, the clamp plate 56 presses the outer circumference of the wafer tray 40 to the wafer tray. 40 is fixed to the top of the chuck 20.

Referring to FIG. 2, the chuck 20 includes a sealing member 22 outside the upper surface and forms a cooling gas flow passage 24 therein. A gas such as helium (He) is supplied to the cooling gas flow passage 24 to cool the wafer tray 40 seated on the upper portion of the chuck 20. As the sealing member 22, an O-ring or a lip seal may be used. The sealing member 22 prevents the leakage of the cooling gas supplied to the cooling gas flow path 24 when the wafer tray 40 is seated on the chuck 20 and the plasma processing process is performed. Ensure effective cooling.

The focus ring 30 is connected to an end of the ring-shaped focus ring base 32, a pair of opposing first focus rings 34 fixed to the focus ring base 32, and the first focus ring 34. And a pair of opposing second focus rings 36 which are connected and not fixed to the focus ring base 32. The second focus ring 36 is fixed to the outer circumference of the chuck 20 and moves together with the chuck 20 when the chuck 20 moves up and down.

Referring to FIG. 3, the focus ring base 32 of the focus ring 30 includes a first focus ring base part 32a and a second focus ring base part 32b, and the second focus ring base part 32b. ) Is larger than the inner diameter of the first focus ring base portion 32a. More specifically, the inner diameter of the second focus ring base portion 32b is equal to or larger than the outer diameter of the second focus ring 36 so that the second focus ring 36 has the second focus ring base portion 32b. To move up and down on the inner side of the. Meanwhile, wing grooves 35 are formed inside both ends of the first focus ring 34, and the blades 37 protrude outward from both ends of the second focus ring 36. Accordingly, when the first focus ring 34 and the second focus ring 36 are coupled to each other, the wings 37 are coupled into the wing grooves 35 so that the plasma is connected to the first focus ring 34 and the second focus ring ( It is desirable to prevent intrusion along the mating surface of 36) and to minimize leakage of bias RF. However, in the embodiment of the present invention, the wing 37 may be provided in the first focus ring 34, and the wing groove 35 may be provided in the second focus ring 36.

Referring to FIG. 2, the clamp 50 includes a cylindrical clamp base 52, a disc shaped clamp plate 56, and a pair of opposite clamps connecting the clamp plate 56 to the clamp base 52. Body 54. The clamp plate 56 pressurizes an outer portion of the wafer tray 40 seated on the upper portion of the chuck 20 to fix the wafer tray 40 and to provide a cooling gas through the sealing member 22 provided in the chuck 20. Prevent leakage. The clamp body 54 does not have a cylindrical shape, but is opened in front and rear as shown in FIG. 2 in order to secure a moving path of a transfer arm (not shown) for loading or unloading the wafer tray 40.

On the other hand, the lower portion of the clamp base 52 is provided with a cylindrical clamp lower ring 58 as shown in FIG. The clamp 50, including the clamp lower ring 58, rests on the bottom of the process chamber 10 with the chuck 20 lowered. When the chuck 20 rises with the wafer tray 40 seated on the top of the chuck 20, the clamp plate 56 is in contact with the outside of the wafer tray 40, and in this state, the chuck 20 is further attached. When raised, the clamp lower ring 58 falls off the bottom of the process chamber 10 as in FIG. Accordingly, the function of the clamp 50 is achieved by pressing the outside of the wafer tray 40 with the total weight of the clamp 50. However, in the practice of the present invention, as long as the clamp lower ring 58 does not fall from the bottom of the process chamber 10 or the clamp lower ring 58 is fixed to the bottom of the process chamber 10, the chuck ( It is, of course, also possible to allow an appropriate load to be applied to the wafer tray 40 by adjusting the degree of elevation of 20).

1, the clamp lower ring 58 has an inner diameter smaller than that of the focus ring base 32 of the focus ring 30 so that the bottom surface of the focus ring base 32 when the chuck 20 descends. The inner bottom surface of the clamp lower ring 58 is seated. This is to allow the focus ring 30 to replace the function of the conventional lift pin, so that the wafer tray 40 is loaded or unloaded using the detachable focus ring 30 according to the present invention. This will be described in detail.

4 is a view showing a state in which the chuck is lowered in the plasma processing apparatus according to the first preferred embodiment of the present invention.

As described above, the focus ring 30 according to the present invention is configured by separating the first focus ring 34 and the second focus ring 36. The first focus ring 34 is fixed to the focus ring base 32, and the focus ring base 32 rests on the inner upper portion of the clamp lower ring 58 when the chuck 30 is lowered so that it no longer descends. Will not. On the other hand, since the second focus ring 36 is fixed to the outer circumference of the chuck 30, when the chuck 30 descends, the second focus ring 36 also descends to be in a state as shown in FIG. 4.

The transfer arm 60 transfers the wafer tray 40 to the upper portion of the chuck 20 and then lowers it so that the wafer tray 40 is seated on the upper portion of the first focus ring 34. That is, in the present invention, instead of using the lift pin to seat the wafer tray 40 on the chuck 20, the focus ring 30 replaces the function of the lift pin.

FIG. 5 is a view schematically illustrating a process of seating a wafer tray on a chuck in a plasma processing apparatus according to a first embodiment of the present invention.

Referring to FIG. 5A, when the chuck 20 descends, the focus ring 30 descends like the chuck 20, and the first focus ring 34 has the focus ring base 32 clamped under the ring. It is seated at the top of 58 to stop the descent and the second focus ring 36 descends with the chuck 20. In this state, the transfer arm 60 transfers the wafer tray 40 to the upper portion of the chuck 20.

Next, referring to FIG. 5B, the transfer arm 60 moves to the upper portion of the chuck 20 and then descends. Then, as shown in FIG. 5C, the wafer tray 40 is seated on the first focus ring 34, and the transfer arm 60 retreats. In the present invention, as the second focus ring 36 is lowered than the first focus ring 34, the transfer arm 60 rests the wafer tray 40 on the upper portion of the first focus ring 34. It can retract between one focus ring 34.

Referring to FIG. 5D, in the state where the wafer tray 40 is seated on the first focus ring 34, the chuck 20 is raised so that the second focus ring 36 is also the bottom surface of the wafer tray 40. You will encounter the outer circumference. In this state, when the chuck 20 is further raised, as shown in FIG. 1, the chuck 20 is raised as the first focus ring 34 is in contact with the outer circumference of the chuck 20, thereby clamping the outer circumference of the wafer tray 40. The plate 56 is in contact.

On the other hand, when the wafer tray 40 is unloaded, the transfer arm 60 enters and rises between the ends of the first focus ring 34 in the state where the chuck 20 is lowered to the lowest position so that the wafer tray 40 can be lifted. Hold back and retreat.

The focus ring 30 is a pair of opposing first focus rings 34 fixed to the focus ring base 32 and a pair of opposing second focus rings which are lifted and lowered together. It has been described as including (36). However, in the practice of the present invention, it is also possible to include the second focus ring 36 only at the portion where the transfer arm 60 enters.

6 is an exploded perspective view of a focus ring according to another exemplary embodiment of the present invention.

As shown in FIG. 6, the focus ring 30 includes one first focus ring 34 fixed to the focus ring base 32 and one second focus provided only in one direction of the transport arm 60 in the direction of entry. Ring 36. In this case, however, the shape of the transfer arm 60 may be configured such that the wafer tray 40 transferred by the transfer arm 60 does not collide with the first focus ring 34 when the upper portion of the chuck 20 is positioned. There is a need.

Next, a plasma processing apparatus according to a second preferred embodiment of the present invention will be described.

7 is a configuration diagram of a plasma processing apparatus according to a second preferred embodiment of the present invention, and FIG. 8 is an exploded perspective view of the chuck and the focus ring in the plasma processing apparatus according to the second preferred embodiment of the present invention.

The plasma processing apparatus according to the second preferred embodiment of the present invention is characterized by having an electrostatic chuck 200 instead of the chuck 20 and removing the clamp 50 as compared to the first embodiment.

As the electrostatic chuck 200 is provided, the wafer tray 40 can be fixed or closely adhered to the electrostatic chuck 200 without the clamp 50 being provided on the electrostatic chuck 200. In the plasma processing apparatus according to the second preferred embodiment of the present invention, the configuration of the focus ring 30 is the same as that of the first embodiment.

Meanwhile, a component for supporting the focus ring base 32 of the focus ring 30 is required when the electrostatic chuck 200 descends, and a cylindrical focus ring support 210 is formed on the inner bottom of the process chamber 10. It is fixed. Accordingly, when the electrostatic chuck 200 descends, the focus ring base 32 on which the first focus ring 34 is fixed is supported by the upper portion of the focus ring support 210 to stop the down, and the outer circumferential edge of the electrostatic chuck 200 is fixed. The second focus ring 36 fixed to is lowered together with the electrostatic chuck 200.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by the embodiments and the accompanying drawings. . The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a block diagram of a plasma processing apparatus according to a first embodiment of the present invention,

2 is an exploded perspective view of the chuck, the focus ring and the clamp in the plasma processing apparatus according to the first preferred embodiment of the present invention;

3 is an exploded perspective view of a focus ring in the plasma processing apparatus according to the first embodiment of the present invention;

4 is a view showing a state in which the chuck is lowered in the plasma processing apparatus according to the first preferred embodiment of the present invention;

5 is a view schematically illustrating a process of seating a wafer tray on a chuck in a plasma processing apparatus according to a first embodiment of the present invention;

6 is an exploded perspective view of a focus ring according to another exemplary embodiment of the present invention;

7 is a configuration diagram of a plasma processing apparatus according to a second preferred embodiment of the present invention;

8 is an exploded perspective view of the chuck and the focus ring in the plasma processing apparatus according to the second preferred embodiment of the present invention.

<Description of reference numerals for the main parts of the drawings>

10 process chamber 20 chuck

30: focus ring 40: wafer tray

50: clamp 200: electrostatic chuck

Claims (17)

A process chamber; A chuck provided in the process chamber and driven vertically; A focus ring mounted on an outer circumference of the chuck; And A clamp for securing a wafer or wafer tray seated on the chuck to the chuck, The focus ring may include a combination of a first focus ring fixed to a focus ring base and a second focus ring fixed or seated on an outer circumference of the chuck, so that the second focus ring is the first focus when the chuck descends. Plasma processing apparatus, characterized in that descending more than the ring. The method of claim 1, The focus ring base includes a first focus ring base portion to which the first focus ring is coupled, and a second focus ring base portion corresponding to a position of the second focus ring, and the second focus ring base includes the second focus ring base. A plasma processing apparatus, which is moved up and down inside the section. The method of claim 1, Any one of the first focus ring or the second focus ring is provided with a wing at the side end, and the other side end is provided with a wing groove corresponding to the wing. The method of claim 1, The clamp includes a clamp plate for pressing the outer circumference of the wafer or wafer tray, a clamp body for supporting the clamp plate, and a clamp lower ring coupled to or connected to the clamp body and seated on a bottom surface of the process chamber. And the focus ring base is seated on the step of the clamp lower ring at a predetermined position when the chuck is lowered and no longer descends. The method of claim 1, Characterized in that the wafer or wafer tray is loaded onto the top surface of the first focus ring or unloaded from the top surface of the first focus ring while the second focus ring is lowered than the first focus ring. Plasma processing apparatus. The method of claim 5, And a transfer arm which enters the process chamber and is driven up and down to load or unload the wafer or wafer tray. The method of claim 1, And the first focus ring consists of a pair of opposing pairs, and a pair of opposing second focus rings is positioned between the ends of the pair of first focus rings. The method of claim 1, The first focus ring is a plasma processing apparatus, characterized in that the first focus ring is partially fixed to the focus ring base, the second focus ring is located in the open portion. In the focus ring attached to the outer circumference of the chuck, Focus ring base; A first focus ring fixed to the focus ring base; And Including a second focus ring fixed or seated on the outer circumference of the chuck, And the second focus ring is lower than the first focus ring when the chuck is lowered. The method of claim 9, The focus ring base includes a first focus ring base portion to which the first focus ring is coupled, and a second focus ring base portion corresponding to the position of the second focus ring, and the second focus ring is the second focus ring. A plasma processing apparatus, which is moved up and down inside the base part. The method of claim 9, And the first focus ring consists of a pair of opposing pairs, and a pair of opposing second focus rings is positioned between the ends of the pair of first focus rings. The method of claim 9, The first focus ring is a plasma processing apparatus, characterized in that the first focus ring is partially fixed to the focus ring base, the second focus ring is located in the open portion. A process chamber; An electrostatic chuck provided in the process chamber and driven up and down; A focus ring mounted on an outer circumference of the chuck, The focus ring may include a combination of a first focus ring fixed to a focus ring base and a second focus ring fixed or seated on an outer circumference of the chuck, so that the second focus ring is the first focus when the chuck descends. Plasma processing apparatus characterized in that the lowering than the ring. The method of claim 13, The focus ring base includes a first focus ring base portion to which the first focus ring is coupled, and a second focus ring base portion corresponding to a position of the second focus ring, and the second focus ring base includes the second focus ring base. A plasma processing apparatus, which is moved up and down inside the section. The method of claim 13, At least one of the first focus ring and the second focus ring is provided with a wing at a side end portion, and the other side side end is provided with a wing groove corresponding to the wing. The method of claim 13, Characterized in that the wafer or wafer tray is loaded onto the top surface of the first focus ring or unloaded from the top surface of the first focus ring while the second focus ring is lowered than the first focus ring. Plasma processing apparatus. The method of claim 16, And a transfer arm which enters the process chamber and is driven up and down to load or unload the wafer or wafer tray.

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