JP2006156122A - Plasma treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent treatment omission by securing a gas flow rate in a place where an electrode interval becomes narrow in a plasma treatment apparatus. <P>SOLUTION: An inlet formation part 22 having a process gas inlet 23 is provided in on an upstream side of a discharge space 30 between electrodes 31, 32. An open width variable member 40 is provided in a prescribed part of the inlet formation part 22 to be capable of advancing/retreating in a width direction of the inlet 23. An end face on an advance side of the open width variable member 40 faces the inlet 23 to be an inner surface of the inlet 22 of the prescribed part. Inclined stripes 41, 42 inclined to a prescribed position as going to the discharge space 30 are formed in the end face on the advance side of the open width variable member 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus that applies a process gas to a substrate through a discharge space to perform plasma surface treatment of the substrate.

This type of plasma processing apparatus is provided with a pair of parallel plate electrodes, for example. An electric field is applied between these electrodes to form a discharge space, and a process gas is introduced into the space to form plasma. The plasma-processed process gas is applied to the substrate, and surface treatments such as cleaning, surface modification, film formation, and etching are performed.
JP-A-9-92493 Japanese Patent Laid-Open No. 11-251304 JP 2002-353000 A JP 2004-111385 A

  In a parallel plate type electrode, warping is likely to occur due to Coulomb force, thermal expansion coefficient difference between the electrode and the solid dielectric, and thermal stress due to temperature difference inside the electrode. If it does so, an electrode space | interval will partially narrow, it will become difficult to flow process gas in the part, and the uniformity of a process will be impaired.

The present invention has been made to solve the above problems,
In a plasma processing apparatus that applies process gas to a substrate through a discharge space,
A pair of electrodes extending in one direction alongside each other and forming the discharge space therebetween;
An inlet forming part having a process gas inlet connected to the upstream end of the discharge space,
The introduction port forming part is provided with a drifting means for biasing the flow of the process gas to the discharge space toward a predetermined position in the one direction (electrode extending direction) or a predetermined portion including the predetermined position.
As a result, even when the electrode interval in the predetermined portion is narrowed, the gas flow rate can be secured to prevent the processing from being lost, and the uniformity of the processing can be secured.
Here, the predetermined portion is preferably a portion (for example, the central portion in one direction) where the electrode interval tends to be narrow, and the predetermined position tends to have the smallest electrode interval among the predetermined portions. It is preferable that it is a high place, for example, the exact center position in the one direction.

The present invention also provides:
In a plasma processing apparatus that applies process gas to a substrate through a discharge space,
A pair of electrodes extending in one direction alongside each other and forming the discharge space therebetween;
An inlet forming part having a process gas inlet connected to the upstream end of the discharge space,
As the drifting means, a predetermined portion in the one direction of the introduction port forming portion can be moved forward and backward in the width direction of the introduction port (the same direction as the arrangement direction of the electrodes and a direction perpendicular to the one direction). An opening width variable member is provided, and an end face on the advance side of the opening width variable member faces the introduction port and defines an inner surface of the introduction port of the predetermined portion.
Thereby, even if the electrode interval in the predetermined portion is narrowed, the opening at the predetermined portion of the introduction port is retracted from the inner surface of the introduction port of the portion other than the variable opening width member by retracting the forward end surface of the variable opening width member. The degree can be made larger than the portion other than the predetermined portion, the gas flow rate at the predetermined portion can be ensured to prevent the processing from being lost, and the processing uniformity can be ensured. Also, even if the coulomb force between the electrodes or the heat generation amount of the electrode changes due to the difference in the input power amount of the process, etc., the amount of retraction of the variable opening width member should be adjusted even when the amount of electrode warpage is not constant. As a result, the gas flow rate at the predetermined portion can be reliably ensured, and the uniformity of the processing can be reliably ensured.

The length along the one direction of the opening width variable member or the predetermined portion is preferably sufficiently smaller than the length of the introduction port. It is desirable that the opening width variable member is disposed only in the predetermined portion of the introduction port forming portion and does not extend to a portion other than the predetermined portion.
It is desirable that a concave portion for accommodating the opening width variable member is formed in the predetermined portion of the introduction port forming portion.
A push member that pushes the variable opening width member in the forward direction and a reverse direction is pulled on the opposite side of the introduction port forming portion from the variable opening width member (the back portion of the variable opening width member, that is, the backward side portion). It is desirable that a pulling member is provided.
As a result, the opening width variable member can be reliably moved forward and backward, and after being positioned at an appropriate forward and backward position, the opening width variable member is brought to the position by the pressing force of the pressing member and the pulling force of the pulling member. Can be fixed firmly.

It is desirable that the pressing member and the pulling member are disposed apart from each other in the one direction on the opening width variable member.
As a result, the entire variable opening width member can be tilted with respect to the one direction.
The opening width variable member may be divided into a plurality of parts in the one direction. In this case, it is preferable that each opening width variable member can be moved forward and backward independently. Thereby, the opening width of the inlet can be adjusted for each opening width variable member.
The pressing member and the pulling member may be arranged in each opening width variable member so as to be separated in the one direction. Accordingly, for example, each opening width variable member can be inclined so as to be retracted from the introduction port toward the boundary between the two opening width variable members.
The push member is formed of, for example, a male screw member, and is screwed into a female screw hole formed in the introduction port forming portion of the back portion of the opening width variable member, and on the back surface (reverse side end surface) of the opening width variable member. It is hit.
The pulling member is composed of, for example, a male screw member, and the head is hooked on the introduction port forming part of the back part of the variable opening width member, and the leg part penetrates the through hole formed in the introduction port forming part. Then, it is screwed into a female screw hole formed in the back portion (end portion on the receding side) of the opening width variable member.

It is desirable that an inclined strip which is inclined toward a predetermined position toward the discharge space is formed on the end surface on the forward side of the opening width variable member.
As a result, a larger amount of process gas can flow into a predetermined position in a predetermined portion, and processing omission at the predetermined position can be reliably prevented.
The inclined line includes an inclined protruding line (convex inclined line) or an inclined groove (concave inclined line).
By adjusting the advancing / retreating position of the opening width variable member so that at least the groove bottom (inner bottom surface) of the inclined groove is retracted from the inner surface of the introduction port other than the opening width variable member, the width of the introduction port is at least inclined groove. However, the process gas can be surely easily flowed.

The present invention also provides:
In a plasma processing apparatus that applies process gas to a substrate through a discharge space,
A pair of electrodes extending in one direction alongside each other and forming the discharge space therebetween;
An inlet forming part having a process gas inlet connected to the upstream end of the discharge space,
As the drifting means, on the inner surface near the predetermined position in the one direction of the introduction port, an inclined strip that is inclined toward the predetermined position toward the discharge space is formed.
As a result, a large amount of process gas can flow into the predetermined position, and the processing omission at the predetermined position can be reliably prevented.
Here, the portion near the predetermined position substantially corresponds to the predetermined portion.

The inclined strips are respectively provided at a first position near the predetermined position and a second position closer to the predetermined position than the first position, and the inclined strip at the second position is the first position. It is desirable that the slope is larger than the slope.
As a result, at the first position relatively far from the predetermined position, it is possible to reduce the process gas bias, reliably prevent the processing from being lost around the center position, and ensure the uniformity of the overall processing.

The plasma treatment of the present invention is preferably performed under a pressure close to atmospheric pressure (substantially normal pressure). Here, the near atmospheric pressure refers to the range of ^{1.013 × 10 4 ~50.663 × 10 4} Pa, considering the convenience of easier and device configuration of the pressure adjustment, 1.333 × 10 ⁴ ~ 10.664 × 10 ⁴ Pa is preferable, and 9.331 × 10 ^{4 to} 10.9797 × 10 ⁴ Pa is more preferable.

  According to the present invention, it is possible to secure a gas flow rate at a portion where the electrode interval is narrowed to prevent the processing from being lost, and to ensure the uniformity of the processing.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the atmospheric pressure plasma processing apparatus includes a processing head 1. A substrate W is disposed below the processing head 1 to perform plasma surface treatment such as cleaning, film formation, and etching.
The processing head 1 is configured by stacking a gas introduction unit 10 and a discharge processing unit 20 vertically. As shown in FIGS. 2 and 3, these upper and lower units 10, 20, and thus the processing head 1, extend long from side to side.

As shown in FIG. 2, the gas supply path 2 a from the process gas supply source 2 is bifurcated and connected to both ends of the gas introduction unit 10.
As shown in FIGS. 1 and 2, a pair of passages 12 extending in the longitudinal direction of the unit 10 and chambers 13 and 14 disposed above and below the passages 12 and 12 are formed inside the gas introduction unit 10. Has been. One end of one passage 12 is connected to one gas supply passage 2a, and the other end of the other passage 12 is connected to another gas supply passage 2a. In each passage 12, a large number of small holes 12a connected to the upper chamber 13 are arranged in the longitudinal direction. The upper and lower chambers 13, 14 are connected via communication slits 15 on both sides of the passage 12. An introduction groove 16 extending in the longitudinal direction is formed on the bottom plate of the gas introduction unit 10 (the bottom surface of the lower chamber 14).

  The process gas supply source 2 stores a process gas corresponding to the processing purpose. The process gas is bifurcated by the gas supply pipe 2a and flows in the pair of passages 12 and 12 in opposite directions. However, it leaks sequentially into the upper chamber 13 through the small holes 12a, 12a, and further flows into the lower chamber 14 through the slit 15. The process gas is made uniform in the longitudinal direction in the flow process in the gas introduction unit 10. The homogenized process gas is introduced into the discharge processing unit 20 from the introduction groove 16.

As shown in FIG. 1, the discharge processing unit 20 includes a metal casing 21 and a pair of electrodes 31 and 32 housed in the casing 21. The electrodes 31 and 32 and the casing 21 are insulated by a holder 24 made of an insulating resin.
As shown in FIGS. 1 and 2, the electrodes 31 and 32 have a rectangular cross section and extend long to the left and right. The pair of electrodes 31 and 32 are disposed opposite to each other in the front-rear direction, and a gap 30 is formed between the electrodes 31 and 32. One electrode 31 is connected to a power source (not shown), and the other electrode 32 is grounded. As a result, the gap 30 between the electrodes 31 and 32 becomes a normal pressure discharge space. A solid dielectric layer (not shown) is provided on the discharge space forming surface of at least one of the electrodes 31 and 32.

As shown in FIGS. 1 to 3, the upper plate 22 of the housing 21 extends to the left and right. A process gas inlet 23 is formed at the center of the upper plate 22 in the width direction (front-rear direction). The introduction port 23 extends in the longitudinal direction of the upper plate 22 in a narrow slit shape (for example, 1 to 2 mm). The upper end opening of the introduction port 23 is continuous with the introduction groove 16 of the gas introduction unit 10, and the lower end opening is continued with the inter-electrode space 30 through a slit-like introduction port 25 formed in the insulating holder 24.
The housing upper plate 22 having the introduction ports 23 and 25 and the insulating holder 24 constitute the “introduction port forming portion” in the claims.

A metal plate 27 is provided on the bottom of the discharge processing unit 20 (below the electrodes 31 and 32) via an insulating member 26 such as resin or ceramic, and the metal plate 27 is electrically grounded. Thus, electric field shielding between the electrodes 31 and 32 and the base material W is performed. The insulating member 26 and the metal plate 27 are formed with a blow-off port 28 connected to a gap between the electrodes, that is, a lower end portion of the discharge space 30. The outlet 28 has a slit shape extending in the longitudinal direction of the discharge processing unit 20.
Although illustration is omitted, a push bolt and a pull bolt are provided on the side wall of the casing 21 to maintain the linearity by pushing or pulling the electrodes 31 and 32 and to keep the thickness of the discharge space 30 constant. It has been.

The main configuration of the present invention will be described.
As shown in FIGS. 3 and 4, in the central portion (predetermined portion) in the longitudinal direction of the casing upper plate 22 of the discharge processing unit 20, recesses 22 a are formed on the inner surfaces of both edges in the width direction of the inlet 23. Has been. An opening width variable member 40 is fitted in each recess 22a. Two (a plurality) opening width variable members 40 are arranged in each recess 22a. That is, the opening width variable member 40 of each recess 22a is divided into two (plural) on the left and right at the exact center position (predetermined position) in the longitudinal direction of the housing upper plate 22. Each variable opening width member 40 has a plate shape elongated to the left and right having the same thickness as the upper plate 22 of the housing. The inner end surfaces of these opening width variable members 40 face the introduction port 23 and define the inner surface of the central portion of the introduction port 23.

  As shown in FIGS. 5 and 6, a plurality of thin inclined ridges 41 are formed on the inner end face of each opening width variable member 40 with a space left and right, and the inclined protrusions 41 are adjacent to each other. A shallow inclined groove 42 that is sufficiently wider than the strip 41 is formed. For example, the width of the inclined ridge 41 is about 1 mm, the protrusion amount of the inclined ridge 41 or the depth of the inclined groove 42 is about 2 mm, and the width of the inclined groove 42 is about 7 to 9 mm in a narrow area. It is about 10 mm in a wide area. The inclined ridges 41 and the inclined grooves 42 are collectively referred to as “inclined ridges”.

  As shown in FIG. 6, the inclined ridge 41 and thus the inclined groove 42 of each opening width varying member 40 are inclined toward the center as going downward. Moreover, the inclined ridge 41 closer to the center is inclined more than the inclined ridge 41 that is relatively far away. The inner end face shape composed of the inclined strips 41 and 42 of the left and right opening width variable members 40 is symmetric.

  As shown in FIG. 4, the housing upper plate 22 on the back of the opening width variable member 40 (on the side opposite to the introduction port 23 across the opening width variable member 40) has a pushing member 51 and a pulling member made of male screws. 52 is provided. The pressing member 51 is screwed into the upper plate 22 and is abutted against the central portion of the back surface of the opening width variable member 40. The opening width variable member 40 can be pushed by the pushing member 51 and advanced toward the introduction port 23.

  Two pulling members 52 are provided for each opening width variable member 40. These pulling members 52 are arranged slightly apart on the left and right sides of the pressing member 51. Each pulling member 52 passes through the upper plate 22 and is screwed into the opening width variable member 40. The opening width variable member 40 can be pulled and retracted by the pulling member 52.

  By these push-pull members 51 and 52, the position of the opening width variable member 40 can be adjusted in the front-rear direction (width direction of the introduction port 23). As shown by the solid line in FIG. 7, when the opening width variable member 40 is retracted, the entire inner end face of the opening width variable member 40, that is, the groove bottom (inner bottom surface) of the inclined groove 42 as well as the inclined ridge 41 is also a housing. It is located at a position retracted from the inner surface of the inlet 23 of the upper plate 22. As shown by the phantom line in FIG. 7, when the opening width variable member 40 is advanced, the inclined ridge 41 protrudes from the inner surface of the introduction port 23 of the housing upper plate 22.

A method for plasma processing the substrate W by the atmospheric pressure plasma processing apparatus having the above configuration will be described.
A substrate W is disposed below the processing head 1. Then, the process gas from the process gas source 2 is made uniform in the left-right longitudinal direction by the gas introduction unit 10 and introduced into the inter-electrode space 30 through the introduction ports 23 and 25. Further, voltage supply from the power source 3 to the hot electrode 31 is performed. As a result, an atmospheric pressure glow discharge is formed in the interelectrode space 30, and the process gas is turned into plasma. The plasma-processed process gas is blown out from the blow-out port 28 and hits the substrate W. Thereby, surface treatments, such as washing | cleaning of the base material W, can be performed.

The electrodes 31 and 32 tend to be distorted so that, for example, the central portions thereof are close to each other due to Coulomb force or thermal stress. If it does so, the discharge space 30 between the electrodes 31 and 32 will become narrow in the center part of a longitudinal direction. The amount of distortion varies depending on process conditions such as input power and is not constant.
Therefore, the position of the opening width variable member 40 in the front-rear direction is adjusted in anticipation of this distortion amount. That is, for example, as shown in FIG. 4, the projecting end surface of the inclined ridge 41 is adjusted to be flush with the inner surface of the inlet 23 of the upper plate 22, that is, the inlet 23 other than the opening width variable member 40. Keep it. Therefore, at the inclined groove 42, the opening width of the introduction port 23 is wider than the portion other than the opening width variable member 40. As a result, the gas flow resistance of the central portion where the opening width variable member 40 is arranged can be made smaller than the other portions, and more process gas can flow into the central portion. Thereby, even if the center part of the discharge space 20 becomes narrow due to distortion of the electrodes 31 and 32, the gas flow rate can be prevented from decreasing. As a result, it is possible to prevent the processing from being lost at the center portion and to ensure the uniformity of the processing.

  Further, as shown by the solid line in FIG. 7, when the electrodes 31 and 32 are expected to be further distorted, the opening width variable member 40 is retracted from FIG. 4, and the protruding end surface of the inclined ridge 41 has the variable opening width. Adjustment is made so that the position is retracted from the inner surface of the introduction port 23 at a portion other than the member 40. As a result, the central portion of the inlet 23 can be further widened, and the flow resistance of the process gas at the central portion can be further reduced. Thereby, even when the amount of distortion of the electrodes 31 and 32 is large and the central portion of the discharge space 20 becomes narrower, it is possible to reliably prevent the processing from being lost at the central portion, and to ensure the uniformity of the processing. .

On the other hand, as shown by the phantom line in FIG. 7, when the distortion amount of the electrodes 31 and 32 is expected to be small, the opening width variable member 40 is advanced from FIG. 4, and the inclined ridge 41 is other than the opening width variable member 40. It is also possible to protrude from the inner surface of the introduction port 23 of this part.
Of course, the advance / retreat position of the opening width variable member 40 may be adjusted in the middle of the processing in accordance with the actual distortion of the electrodes 31 and 32.

  Further, as shown by the arrow line in FIG. 6, the process gas in the central portion of the introduction port 23 is drifted by the inclined strips 41 and 42 so as to gather toward the center position. As a result, a larger amount of process gas can flow into the central position, and processing omission at the central position can be reliably prevented. In addition, the closer to the center position of the process gas, the greater the inclination in the direction of the center position, and the smaller the distance from the center position, the more reliably the processing can be prevented from being lost around the center position. Can be ensured.

Further, as shown in FIG. 8, by adjusting the screwing amounts of the push-pull members 51 and 52, the left and right opening width variable members 40 are inclined by a minute angle so as to recede toward the center position. Is also possible. Thereby, the process gas flow rate at the central position can be further increased, and the processing omission at the central position can be more reliably prevented.
In FIG. 8, the inclination of the opening width variable member 40 is exaggerated, and actually, the inclination is minute according to the clearance between the recess 22 a of the housing upper plate 22 and the opening width variable member 40.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, the opening width variable member 40 may be provided only on one of the edges on both sides in the width direction of the inlet 23.
Only one variable opening width member 40 may be provided at each edge of the introduction port 23, or may be divided into three or more.
The predetermined portion is not necessarily limited to the central portion in the introduction port longitudinal direction. When the end portions between the electrodes tend to be narrower than the center portion, both end portions are set as “predetermined portions” instead of the center portion, and the opening width variable member 40 and the inclined strips 41 and 42 are provided there.
As the drifting means, a current plate that spans between the inner surfaces of both sides in the width direction of the inlet port 23 and partitions the inlet port 23 may be provided obliquely.

  The present invention is applicable to, for example, a surface treatment apparatus used in a surface treatment process such as cleaning or film formation in manufacturing a semiconductor substrate.

It is a side sectional view of the above-mentioned processing head which shows the processing head of the atmospheric pressure plasma processing apparatus concerning one embodiment of the present invention, and follows the II line of Drawing 2. It is front sectional drawing of the said processing head. It is a top view of the housing | casing upper board (introduction port formation part) of the said processing head. It is a top view which expands and shows the center part of the said housing | casing upper board. It is a perspective view of the opening width variable member provided in the center part of the said housing | casing upper board. It is a front view of two opening width variable members provided in the inner surface of the one side of the width direction of the inlet of the said housing | casing upper plate, and the flow direction of a process gas is shown by the arrow line. FIG. 5 is a plan view showing a state where the opening width variable member is further retracted by a solid line and a state where the opening width variable member is advanced by a virtual line. It is a top view which shows the state which inclined the opening width variable member so that it might reverse | retreat toward a center position, exaggerating the inclination angle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing head 20 Discharge processing unit 22 Case upper board (introduction port formation part)
23 Inlet 30 Discharge space 31, 32 Electrode 40 Opening width variable member (Diffusion means to predetermined part)
41 Inclined ridges (convex ridges, drifting means to a predetermined position)
42 Inclined groove (concave inclined strip, means for drifting to a predetermined position)
51 Pushing member 52 Pulling member

Claims (7)

In a plasma processing apparatus that applies process gas to a substrate through a discharge space,
A pair of electrodes extending in one direction alongside each other and forming the discharge space therebetween;
An inlet forming part having a process gas inlet connected to the upstream end of the discharge space,
The plasma processing apparatus, wherein the introduction port forming portion is provided with a drifting means for biasing a flow of the process gas to the discharge space to a predetermined position in the one direction or a predetermined portion including the predetermined position. In a plasma processing apparatus that applies process gas to a substrate through a discharge space,
A pair of electrodes extending in one direction alongside each other and forming the discharge space therebetween;
An inlet forming part having a process gas inlet connected to the upstream end of the discharge space,
An opening width variable member that can be advanced and retracted in the width direction of the introduction port is provided at a predetermined portion in the one direction of the introduction port forming portion, and an end surface on the advance side of the opening width variable member is the introduction port. The plasma processing apparatus is characterized in that an inner surface of the introduction port of the predetermined portion is defined.   A pressing member that pushes the opening width variable member in the forward direction and a pulling member that pulls in the backward direction are provided on the side opposite to the introduction port across the opening width variable member of the introduction port forming portion. The plasma processing apparatus according to claim 2.   The plasma processing apparatus according to claim 2, wherein the opening width variable member is divided into a plurality of parts in the one direction, and each opening width variable member can be moved forward and backward independently.   5. The plasma processing apparatus according to claim 2, wherein an inclined line that is inclined toward a predetermined position toward the discharge space is formed on an end surface on the forward side of the opening width variable member. In a plasma processing apparatus that applies process gas to a substrate through a discharge space,
A pair of electrodes extending in one direction alongside each other and forming the discharge space therebetween;
An inlet forming part having a process gas inlet connected to the upstream end of the discharge space,
The plasma processing apparatus according to claim 1, wherein an inclined line that is inclined toward the predetermined position toward the discharge space is formed on an inner surface of the introduction port near the predetermined position in the one direction.   The inclined strips are respectively provided at a first position near the predetermined position and a second position closer to the predetermined position than the first position, and the inclined strip at the second position is the first position. The plasma processing apparatus according to claim 5, wherein the plasma processing apparatus is inclined more greatly than the inclined line.

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