JP2013134885A - Plasma processing apparatus and plasma processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively perform plasma processing to a substrate having a protruding portion on a rear surface and a warped substrate.SOLUTION: A plasma processing apparatus 100 includes: a housing 101 housing a substrate 200; an electrode body 102 disposed on the rear side of the substrate 200 housed in the housing 101; rails 103, each of which is disposed in the housing 101, forms a transfer path A of the substrate 200, and maintains the substrate 200 during the processing; and plasma generation means 104 for generating plasma in the housing 101. The plasma processing apparatus 100 includes moving means 105 which relatively moves the rails 103 and the electrode body 102 so that the substrate 200 and the electrode body 102 are placed in contact with each other when the plasma is generated and the transfer path A is separated from the electrode body 102 when the substrate 200 is transferred.

Description

  The present invention relates to a plasma processing apparatus and a plasma processing method for irradiating a substrate with plasma and cleaning or etching the surface of the substrate.

  Plasma treatment is known as a surface treatment such as cleaning or etching of a substrate on which an electronic component is mounted. A plasma processing apparatus is known as an apparatus for performing such plasma processing. In a plasma processing apparatus, a substrate is disposed in a processing chamber (vacuum chamber) of a reduced pressure atmosphere surrounded by a casing, and plasma is generated by introducing gas and performing discharge in the processing chamber. Surface treatment of the substrate is performed by the etching action.

  Specifically, an electrode body arranged in contact with the substrate so as to cover the entire back surface of the substrate is used as one pole, and a voltage is applied using the housing (particularly the lid) as the other electrode, The surface of the substrate is surface-treated with plasma generated between the substrate and the substrate.

  Since a high voltage is applied during the plasma processing, if abnormal discharge occurs between the substrate and the electrode body or the like, problems such as damage to the substrate or occurrence of insufficient processing occur.

  Therefore, in the plasma processing apparatus described in Patent Document 1, a guide member that freely fits the shape of the substrate is disposed between the electrode body and the substrate to suppress the occurrence of abnormal discharge.

JP 2006-228773 A

  When assembling a plasma processing apparatus in a production line or the like, a rail for automatically carrying the substrate in and out of the plasma processing apparatus is disposed so as to penetrate the plasma processing apparatus, and the substrate is slid along the rail. In some cases, the substrate may be transferred.

  However, in the case of a substrate on which an electronic component is attached to the back surface, when the substrate is slid on the rail and conveyed, the interference between the electrode body arranged on the back side of the substrate and the electronic component protruding on the back surface side of the substrate is prevented Therefore, it is necessary to provide a wide space between the substrate transport path and the electrode body.

  Such a gap between the substrate and the electrode body increases the probability of occurrence of abnormal discharge and causes problems in plasma processing.

  Further, the substrate may be warped, and the state of the warp is different for each substrate. Accordingly, a gap may be generated between the substrate and the electrode body depending on the state of warping of the substrate, and the gap causes a problem in the plasma processing.

  The present invention has been made in view of the above problems, and even when a projection such as an electronic component is present on the back surface of the substrate, which is an object of plasma processing, or when the substrate is warped, the substrate and the electrode body It aims at suppressing generation | occurrence | production of the clearance gap between.

  In order to achieve the above object, a plasma processing apparatus according to the present invention is provided in a housing that houses a substrate, an electrode body that is disposed behind the substrate that is housed in the housing, and the housing. A plasma processing apparatus comprising a rail for forming a substrate transport path and holding a substrate being processed, and a plasma generating means for generating plasma in the housing, wherein the substrate and the electrode are generated during plasma generation It is characterized in that it comprises a moving means for moving the rail and the electrode body relative to each other so that the body is in contact with the substrate and the transfer path and the electrode body are separated from each other during transfer of the substrate.

  According to this, even if there are protrusions on the back surface of the substrate, the substrate can be transported without interfering with the electrode body. Further, when performing plasma treatment, a gap between the substrate and the electrode body is allowed. It becomes possible to make it as narrow as possible. Therefore, it is possible to suppress the occurrence of abnormal discharge and improve the plasma processing yield.

  The casing includes a base and a lid that opens and closes the casing by moving relative to the base, and the moving means includes the relative movement between the lid and the base and the rail. There may be provided interlocking means for mechanically interlocking relative movement between the electrode body and the electrode body.

  The moving means further includes urging means for urging the rail and the electrode body in a direction in which the transport path and the electrode body are separated from each other, and the interlocking means brings the lid and the base body closer to each other. The rail and the electrode body may be moved relative to each other against the urging force of the urging means by using a force generated at that time.

  According to the above, it is not necessary to provide a drive source or a drive mechanism in the vicinity of the electrode body to which a high voltage is applied, and the substrate and the electrode body are separated from each other with a simple structure and are brought into contact (including proximity). It becomes possible. Therefore, it is possible to suppress abnormal discharge that occurs due to a complicated mechanism.

  The rail is disposed on the opposite side of the electrode body with respect to the held substrate, and includes a flange portion that is disposed so as to overlap an edge of the substrate, and the moving means is a distance between the flange portion and the electrode body. The rail and the electrode body may be moved relatively until the thickness becomes equal to the thickness of the substrate.

  According to this, when the moving means relatively moves the rail and the electrode body to bring the substrate and the electrode body into contact with each other, the edge of the substrate that is in contact with the electrode body can be pressed by the flange. It is possible to correct the warpage of the substrate even if the warpage state is different for each substrate, and to suppress the generation of a gap between the substrate and the electrode body.

  The rail includes a sliding portion on which the substrate slides, and approaches the flange as much as the thickness of the substrate during plasma generation, and moves away from the flange while the substrate is transported. May be.

  According to this, it is possible to smoothly carry in and out the substrate, flexibly corresponding to substrates of different thicknesses, and it is possible to narrow the space generated at the edge of the back surface of the substrate during plasma processing. It becomes.

  In order to achieve the above object, a plasma processing method according to the present invention includes a housing for accommodating a substrate, an electrode body disposed behind the substrate accommodated in the housing, and disposed in the housing. A plasma processing method for a plasma processing apparatus, comprising a rail for forming a substrate transport path and holding a substrate being processed, and a plasma generating means for generating plasma in the housing, wherein The rail and the electrode body are relatively moved so that the substrate and the electrode body are brought into contact with each other, and the transport path and the electrode body are separated from each other during transport of the substrate. It is characterized by relatively moving the body.

  According to this, even if there are protrusions on the back surface of the substrate, the substrate can be transported without interfering with the electrode body. Further, when performing plasma treatment, a gap between the substrate and the electrode body is allowed. It becomes possible to make it as narrow as possible. Therefore, it is possible to suppress the occurrence of abnormal discharge and improve the plasma processing yield.

  According to the present invention, it is possible to suppress the occurrence of abnormal discharge during plasma processing regardless of the shape of the back surface of the substrate and the state of warpage.

FIG. 1 is a perspective view schematically showing the appearance of the plasma processing apparatus according to the embodiment. FIG. 2 is a perspective view schematically showing the plasma processing apparatus with the lid opened. FIG. 3 is a cross-sectional view schematically showing the plasma processing apparatus with the lid opened. FIG. 4 is a cross-sectional view schematically showing the plasma processing apparatus with the lid closed. FIG. 5 is a cross-sectional view schematically showing the electrode body and the substrate from the side. FIG. 6 is a perspective view schematically showing a part of the rail with the housing closed. FIG. 7 is a cross-sectional view schematically showing the rail with the housing open. FIG. 8 is a cross-sectional view schematically showing the rail with the housing closed.

  Next, embodiments of a plasma processing apparatus and a plasma processing method according to the present invention will be described with reference to the drawings. The following embodiments are merely examples of a plasma processing apparatus and a plasma processing method according to the present invention. Accordingly, the scope of the present invention is defined by the wording of the claims with reference to the following embodiments, and is not limited to the following embodiments.

  FIG. 1 is a perspective view schematically showing the appearance of the plasma processing apparatus according to the embodiment.

  FIG. 2 is a perspective view schematically showing the plasma processing apparatus with the lid opened.

  FIG. 3 is a cross-sectional view schematically showing the plasma processing apparatus with the lid opened.

  FIG. 4 is a cross-sectional view schematically showing the plasma processing apparatus with the lid closed.

  As shown in these drawings, a plasma processing apparatus 100 is an apparatus that irradiates plasma on the surface of a substrate 200 as an object to be processed, and performs plasma processing such as cleaning and etching on the surface of the substrate 200. 101, an electrode body 102, a rail 103, a plasma generating means 104, and a moving means 105. The plasma processing apparatus 100 includes a vacuum suction means such as a vacuum pump that evacuates the inside of the housing 101, a gas supply means that introduces plasma processing gas into the housing 101, and the like. Omitted. Further, the plasma processing apparatus 100 includes an external rail 139 for carrying the substrate 200 into the housing 101 and carrying the substrate 200 in the housing 101 out of the housing 101.

  The vacuum suction means includes a vacuum exhaust pipe, a vacuum valve, a pressure adjustment valve, and the like that connect the vacuum pump and the housing 101.

  The gas supply means includes an argon gas cylinder, a gas introduction pipe connected to the nitrogen gas cylinder and the housing 101, and the like.

  In the case of the present embodiment, the plasma processing apparatus 100 irradiates the bonding pad provided on the substrate 200 with plasma in order to improve the bonding strength between the bonding pad and the bonding wire, for example, when the bare chip is directly wire bonded. This is a device for cleaning.

  The housing 101 is a vacuum container that can accommodate the substrate 200 and can maintain the space accommodating the substrate 200 in a vacuum, and includes a base 111 and a lid 112 provided above the base 111. .

  The base 111 is a container in which the electrode body 102 and the rail 103 are accommodated, and has rigidity capable of withstanding atmospheric pressure. The base 111 is insulated from the electrode body 102.

  The lid body 112 is a lid (or door) capable of opening and closing the housing 101 by moving relative to the base body 111 and has rigidity capable of withstanding atmospheric pressure. Further, the lid body 112 is configured to be movable forward and backward with respect to the base body 111 by a driving source (not shown) such as a motor. That is, when the substrate 200 is loaded into the casing 101 or when the substrate 200 is unloaded from the casing 101, the lid body 112 is lifted with respect to the base 111, and when performing plasma treatment, The lid 112 is lowered until the lid 112 abuts. Although not shown, a sealing member such as an O-ring is interposed between the base body 111 and the lid body 112 in order to maintain the airtightness of the housing 101.

  The lid body 112 also functions as an electrode body when performing plasma treatment. That is, when a voltage is applied between the lid body 112 and the electrode body 102, plasma is generated between the lid body 112 and the electrode body 102. In the case of the present embodiment, the lid body 112 is grounded.

  FIG. 5 is a cross-sectional view schematically showing the electrode body and the substrate from the side.

  The electrode body 102 functions as one electrode body for generating plasma in the housing 101, and is a plate-shaped (block-shaped) member formed of a conductive material such as metal, for example.

  In the case of the present embodiment, a protrusion 201 made of an electronic component such as a connector is present on the back surface of the substrate 200, and the electrode body 102 is provided with a recess 121 that accommodates the protrusion 201.

  As described above, since the electrode body 102 includes the recessed portion 121 corresponding to the protruding portion 201, the substrate 200 can be brought into contact with the electrode body 102 without a gap.

  The plasma generating means 104 is a device that generates plasma by applying a voltage between the electrode body 102 and the lid body 112. In the case of the present embodiment, the plasma generation means 104 includes a high-frequency power supply unit that applies a high-frequency voltage between the electrode body 102 and the lid body 112, and a high-frequency reflection applied between the electrode body 102 and the lid body 112. And an automatic matching unit that prevents interference by waves.

  FIG. 6 is a perspective view schematically showing a part of the rail with the housing closed.

  FIG. 7 is a cross-sectional view schematically showing the rail with the housing open.

  FIG. 8 is a cross-sectional view schematically showing the rail with the housing closed.

  As shown in these drawings, the rail 103 is a member that forms a transport path A (see FIG. 2) when the substrate 200 is carried in and out, and as a member that holds the substrate 200 when performing plasma processing. Also works. The rail 103 extends over the entire inside of the housing 101 in the conveyance direction of the substrate 200 (X-axis direction in the drawing), and is attached to the base 111 so as to be movable forward and backward with respect to the electrode body 102. Yes. The rail 103 is formed of an insulator such as ceramics.

  In the case of the present embodiment, the rail 103 includes a flange portion 131 and a sliding portion 132, and the flange portion 131 and the sliding portion 132 can independently move forward and backward with respect to the electrode body 102. It is attached to the base 111.

  The flange 131 is a portion that is disposed on the opposite side of the electrode body 102 with respect to the held substrate 200 and is disposed so as to overlap the edge of the substrate 200 disposed in the housing 101. In the case of the present embodiment, the flange 131 is a portion that protrudes laterally from the main body 134 and extends over the entire inner side of the housing 101 in the conveyance direction of the substrate 200 (X-axis direction in the drawing). Exist. In addition, the flange 131 is disposed above the upper end surface of the electrode body 102 while the substrate 200 is being transported (when the lid 112 is separated from the base body 111 and the housing 101 is opened). During plasma generation (when the lid body 112 is in contact with the base body 111 and the housing 101 is closed), the upper end surface of the electrode body 102 and the lower end surface of the flange 131 are approximately the same as the thickness of the substrate 200. It will be in a state approaching.

  As described above, the substrate 200 can be disposed on the electrode body 102 as a pressed body, and a gap can be prevented from being generated between the electrode body 102 and the substrate 200, even when the carried substrate 200 is warped. Then, it becomes possible to correct the warpage and bring the substrate 200 into close contact with the electrode body 102.

  The sliding part 132 is a part that supports the edge of the substrate 200 from below, and the edge of the substrate 200 slides when the substrate 200 is carried in and out. The sliding portion 132 is disposed on the side of the electrode body 102 and extends over the entire inside of the housing 101 in the transport direction of the substrate 200 (X-axis direction in the drawing). In the case of the present embodiment, the sliding portion 132 protrudes from the electrode body 102 and protrudes from the external rail while the substrate 200 is being transported (when the cover body 112 is separated from the base body 111 and the housing 101 is opened). The upper end surface of 139 and the upper end surface of the sliding portion 132 are arranged on the same horizontal plane, and the lower end surface of the flange portion 131 is separated from the thickness of the substrate 200. On the other hand, during plasma generation (when the lid body 112 is in contact with the base body 111 and the housing 101 is closed), the upper end surface of the electrode body 102 and the upper end surface of the sliding portion 132 are arranged on the same horizontal plane. In other words, the state is close to the flange 131 as much as the thickness of the substrate 200.

  As described above, during the transfer of the substrate 200, the substrate 200 can be smoothly transferred to and from the external rail 139. During plasma generation, the edge of the substrate 200 is supported from below, thereby causing abnormal discharge. It is possible to reduce the space in which the occurrence occurs.

  The flange 131 is attached to a columnar shaft 133 attached to the base 111 in an upright state so as to be slidable in the vertical direction (Z-axis direction) via the main body 134. The sliding portion 132 is disposed so as to sandwich the main body 134 and is slidably attached to the main body 134 in the vertical direction (Z-axis direction). That is, the flange 131 and the sliding portion 132 are attached to the shaft 133 so as to be slidable in the vertical direction independently. The vertical stroke of the collar 131 is longer than the stroke of the sliding part 132. Thereby, even when the thickness of the board | substrate 200 differs, it can respond flexibly.

  The moving means 105 abuts the substrate 200 and the electrode body 102 during plasma generation, and separates the transport path A formed by the rail 103 from the electrode body 102 while the substrate 200 is transported. And the electrode body 102 are relatively moved.

  In the case of the present embodiment, the moving means 105 includes an interlocking means 151 that mechanically interlocks the relative movement between the lid body 112 and the base body 111 and the relative movement between the rail 103 and the electrode body 102, and the rail 103 and the electrode body. An urging means 152 that urges the rail 103 and the electrode body 102 in a direction away from the illuminator 102 is provided.

  The interlocking means 151 is a mechanism for moving the rail 103 and the electrode body 102 relatively against the urging force of the urging means 152 using the force generated when the lid body 112 and the base body 111 approach each other. Specifically, the interlocking means 151 is a columnar member attached to the lower surface of the lid body 112 in a hanging manner. When the lid body 112 approaches the base body 111, the base body 111 moves to the tip of the rail 103 of the protruding body. The tip of the interlocking unit 151 comes into contact, and thereafter, the rail 103 is pushed down in conjunction with the movement of the lid 112.

  The biasing means 152 is a device that biases the rail 103 and the electrode body 102 in a direction in which the transport path A and the electrode body 102 are separated from each other. In the case of the present embodiment, the urging means 152 is a spring that urges the electrode body 102 and the rail 103 via the base 111 and is provided inside the main body 134 of the rail 103 or inside the sliding portion 132. The biasing means 152 that is a spring is disposed in the space defined. The biasing means 152 always generates a force between the rail 103 and the electrode body 102 via the base body 111 in the direction in which the rail 103 protrudes with respect to the base body 111.

  The plasma processing apparatus 100 configured as described above performs plasma processing as follows.

  First, in a state where the housing 101 is opened (FIGS. 2, 3, and 7), the urging means 152 functions in the direction in which the rail 103 is pushed up, and the upper end surface of the external rail 139 and the sliding portion 132 are The upper end surface is disposed in the same plane. In this state, the substrate 200 is slid along the external rail 139 and the rail 103 by a loader such as a pusher, and is carried into the housing 101.

  In this carrying-in process, for example, even when a protrusion 201 such as a connector is present on the back surface of the substrate 200 (see FIG. 5), the transport path A of the substrate 200 is lifted, and a gap is formed between the transport path A and the electrode body 102. Since this occurs, the substrate 200 can be carried in without the electrode body 102 and the protrusion 201 interfering with each other.

  Next, the lid 112 is moved in the direction of the base 111 by a driving source in order to close the casing 101. When the lid 112 approaches the base 111, the moving means 105 comes into contact with the tip of the main body 134 of the rail 103 (the state shown in FIG. 7), and is linked to the movement of the lid 112. The main body 134 is pushed down together with the collar 131. Then, the flange 131 of the rail 103 comes into contact with the surface of the edge of the substrate 200, and the substrate 200 and the sliding portion 132 are pushed down until the substrate 200 comes into contact with the upper surface of the electrode body 102 (state shown in FIG. 8).

  By the above, the rail and the electrode body 102 can be relatively moved so that the substrate 200 and the electrode body 102 are brought into contact with each other before the plasma is generated, so that the electrode body 102 and the substrate 200 can be brought into close contact with each other. Further, in the case where the protruding portion 201 exists on the back surface of the substrate 200, if the recessed portion 121 corresponding to the protruding portion 201 is provided in the electrode body 102, the generation of a gap is suppressed as much as possible and the substrate 200 and the electrode The body 102 can be brought into close contact. Further, when the substrate 200 is warped, the warp of the substrate 200 is corrected, and the generation of a gap due to the warp of the substrate 200 is suppressed.

  In the above state, since the lid body 112 and the base body 111 are in contact with each other and the housing 101 is in a sealed state, the inside of the housing 101 is evacuated using vacuum suction means.

  Next, when a predetermined vacuum state is reached, a gas generating means introduces a plasma generating gas such as argon into the inside of the casing 101, and the plasma generating means 104 provides a gap between the electrode body 102 and the lid. Apply high frequency voltage. As a result, a high frequency voltage is applied to the plasma generating gas introduced to the inside of the casing 101, and plasma is generated in the casing 101. Then, the plasma generated in the housing 101 is irradiated on the surface of the substrate 200 to clean the surface of the substrate 200.

  When the cleaning with plasma is completed, the inside of the housing 101 is opened to the atmosphere, and the lid 112 is moved away from the base body 111 by a driving source in order to open the housing 101. As described above, the interlocking unit 151 is lifted with the movement of the lid body 112, and the rail 103 moves relative to the electrode body 102 by the urging force of the urging unit 152 and advances upward. When the upper end surface of the external rail 139 and the upper end surface of the sliding portion 132 are in the same plane, the advancement of the sliding portion 132 is stopped, but the main body 134 and the collar portion 131 are in the state shown in FIG. Further advance to.

  As described above, since the housing 101 is opened and the upper end surface of the external rail 139 and the upper end surface of the sliding portion 132 are arranged in the same plane, the substrate 200 is moved by using the unloader or the like. And it is carried out while sliding with respect to the external rail 139.

  As described above, even when the substrate 200 is unloaded, the electrode body 102 and the transport path A are separated from each other. Therefore, even if the protruding portion 201 exists on the back surface of the substrate 200, the electrode body 102 interferes. It can be carried out without.

  In addition, this invention is not limited to the said embodiment. For example, another embodiment realized by arbitrarily combining the components described in this specification and excluding some of the components may be used as an embodiment of the present invention. In addition, the present invention includes modifications obtained by making various modifications conceivable by those skilled in the art without departing from the gist of the present invention, that is, the meaning described in the claims. It is.

  For example, in the rail 103, not only the flange portion 131 and the sliding portion 132 can move independently, but also the rail portion 131 and the sliding portion 132 are fixed, or the rail 103 does not have the flange portion 131. Etc. may be adopted.

  Further, although the moving unit 105 has been described as interlocking with the movement of the lid 112 or the like, the moving unit 105 may be a unit that relatively moves the rail 103 and the electrode body 102 independently. For example, an air actuator can be used to move the rail 103 with respect to the electrode body 102.

  In the above embodiment, the plasma processing apparatus 100 has been described as being intended for cleaning the substrate with plasma. However, for the purpose of forming a via hole or the like in the substrate 200, the substrate is etched using plasma. A dry etching apparatus that performs the above process may be used.

  The present invention can be used for a plasma processing apparatus and a plasma processing method, and in particular, can be applied to a plasma processing apparatus and a plasma processing method for performing plasma processing on a substrate having a protrusion on the back surface or a substrate having a warp.

DESCRIPTION OF SYMBOLS 100 Plasma processing apparatus 101 Case 102 Electrode body 103 Rail 104 Plasma generating means 105 Moving means 111 Base body 112 Cover body 121 Recessed part 131 Gutter part 132 Sliding part 133 Shaft 134 Main body 139 External rail 151 Interlocking means 152 Energizing means 152 Substrate 201 Projection

Claims (6)

A housing that accommodates a substrate, an electrode body that is disposed behind the substrate that is accommodated in the housing, and a rail that is disposed in the housing, forms a substrate transport path, and holds the substrate being processed And a plasma processing apparatus comprising plasma generating means for generating plasma in the housing,
Moving means for relatively moving the rail and the electrode body so that the substrate and the electrode body are in contact with each other during plasma generation, and the transfer path and the electrode body are separated from each other during transfer of the substrate. A plasma processing apparatus comprising: The casing includes a base and a lid that opens and closes the casing by moving relative to the base.
The plasma processing apparatus according to claim 1, wherein the moving means includes interlocking means for mechanically interlocking relative movement between the lid and the base and relative movement between the rail and the electrode body. The moving means further includes
Urging means for urging the rail and the electrode body in a direction in which the transport path and the electrode body are separated from each other;
The interlocking means is
The plasma processing apparatus according to claim 2, wherein the rail and the electrode body are moved relative to each other against a biasing force of the biasing unit using a force generated when the lid and the base body approach each other. . The rail is
It is disposed on the opposite side of the electrode body with respect to the held substrate, and includes a flange portion disposed so as to overlap the edge of the substrate,
The moving means is
The plasma processing apparatus according to claim 1, wherein the rail and the electrode body are relatively moved until an interval between the flange portion and the electrode body becomes equal to a thickness of the substrate. The rail is
5. The slide portion according to claim 4, wherein the slide portion is a slide portion on which the substrate slides, and approaches the flange portion as much as the thickness of the substrate during plasma generation, and moves away from the flange portion while the substrate is transported. Plasma processing equipment. A housing that accommodates a substrate, an electrode body that is disposed behind the substrate that is accommodated in the housing, and a rail that is disposed in the housing, forms a substrate transport path, and holds the substrate being processed And a plasma processing method for a plasma processing apparatus comprising plasma generating means for generating plasma in the housing,
Relatively moving the rail and the electrode body so that the substrate and the electrode body abut before plasma generation,
A plasma processing method in which the rail and the electrode body are relatively moved so as to separate the transport path and the electrode body during transport of the substrate.

Images