CN110373654B

CN110373654B - Interdigital structure, lower electrode device and process chamber

Info

Publication number: CN110373654B
Application number: CN201810333256.2A
Authority: CN
Inventors: 张鹏; 王福来
Original assignee: Beijing Naura Microelectronics Equipment Co Ltd
Current assignee: Beijing Naura Microelectronics Equipment Co Ltd
Priority date: 2018-04-13
Filing date: 2018-04-13
Publication date: 2021-09-17
Anticipated expiration: 2038-04-13
Also published as: CN110373654A

Abstract

The invention discloses an interdigital structure, a lower electrode device and a process chamber. The interdigitated structure includes a first interdigitated member extending along a first edge region of the workpiece and formed with an escape opening to allow passage of a pick-off mechanism, the first interdigitated member being for supporting the first edge region of the workpiece. The first interdigital part only supports the first edge area of the workpiece, and the first interdigital part does not penetrate through the middle core area of the workpiece, so that the process uniformity of the workpiece can be effectively improved, the range of a process defective area can be shortened to the edge area of the workpiece, and the workpiece output rate is improved. In addition, in the actual process, the workpiece in the edge area can be cut off, so that the workpiece yield can be further improved.

Description

Interdigital structure, lower electrode device and process chamber

Technical Field

The invention relates to the technical field of semiconductor equipment, in particular to an interdigital structure, a lower electrode device comprising the interdigital structure and a process chamber comprising the lower electrode device.

Background

In semiconductor processing equipment, in order to improve the productivity of the semiconductor processing equipment, step-by-step deposition is generally performed by adopting a single wafer placing quantity increasing mode or a multi-station mobile pick-and-place mode. The mode of increasing the single wafer placing quantity is suitable for the condition that the requirement on uniformity among wafers is not high, and manual wafer taking and placing is needed, so the automation degree is not high; the multi-station mobile chip picking and placing mode is suitable for the working condition of high uniformity among chips, can load quantitative chips once according to requirements, and is suitable for the working condition of large-batch automatic production.

Fig. 1 is a schematic structural diagram of a bottom electrode device in the prior art, which can satisfy a multi-station mobile pick-and-place mode. As shown in fig. 1, the bottom electrode assembly 200 includes an interdigital structure 100, a rotation member 210, and a carrier member 220. The interdigitated structure 100 includes two interdigitated fingers 130 that are spaced apart from one another.

As shown in fig. 2, which is a schematic diagram of the structure of the fingers in the finger structure of fig. 1, the finger 130 has a strip structure similar to two fingers, and passes through the middle portion of the workpiece 300 and falls down to be located right below the workpiece 300. The critical dimensions of the structure are the length L and the width W of the finger 130, and for a workpiece 300 with a diameter of 300mm, the length L of the finger 130 is generally 125mm, and the width W is generally 9mm, in order to ensure reliable pick-and-place and structural strength.

However, the carrier and the fingers are made of different materials, for example, when the carrier is a bottom electrode, the material of the bottom electrode is generally metal aluminum with very good conductivity, and the material ceramic of the fingers is an insulator. Thus, the large difference in electrical properties of the two materials necessarily results in a significant change in the electric field distribution. That is, the fingers cause a significant electric field jump, which degrades the process results at the corresponding region on the workpiece, resulting in process uniformity degradation.

In addition, the fingers of the above structure pass through the middle part of the workpiece, so that the process uniformity of the workpiece is greatly affected, and the wafer yield is reduced. For example, for a 200mm diameter workpiece, the dimensions of a single finger are typically 125mm long and 9mm wide, counting that two fingers will result in 2250mm on the workpiece²And in the central core region of the workpiece, which is generally the main throughput region of the workpiece, this results in a reduced throughput of the workpiece.

Disclosure of Invention

The present invention is directed to at least one of the problems of the prior art, and provides an interdigital structure, a lower electrode device including the interdigital structure, and a process chamber including the lower electrode device.

In order to achieve the above object, according to a first aspect of the present invention, there is provided an interdigital structure for supporting a workpiece, comprising;

a first finger extending along a first edge region of the workpiece and formed with an escape opening allowing passage of a pick mechanism, the first finger for supporting the first edge region of the workpiece.

Preferably, the top wall of the first interdigital member is provided with a first bearing groove recessed towards the direction of the bottom wall thereof, for supporting the first edge region of the workpiece.

Preferably, the method further comprises the following steps:

a second finger detachably connected to the first finger; and,

the second finger member extends along a second edge region of the workpiece and is formed with a filling opening complementary in shape to the relief opening, the second finger member being for supporting the second edge region of the workpiece;

the first edge region and the first edge region together form the entire edge region of the workpiece.

Preferably, the top wall of the second finger is provided with a second bearing groove recessed towards the bottom wall thereof for supporting a second edge region of the workpiece.

Preferably, two open ends of the avoiding opening are provided with first matching structures;

two opening ends of the filling opening are provided with second matching structures; wherein,

the first matching structure is matched with the second matching structure so as to prevent an electric field from being directly passed through the matching structure.

Preferably, the first matching structure comprises a first step groove which is recessed from the bottom wall of the first interdigital element to the top wall of the first interdigital element, and the first step groove comprises a first step surface, a second step surface, a first connecting surface and a second connecting surface which connect the first step surface and the second step surface;

the second matching structure comprises a second stepped groove which is recessed from the top wall of the second interdigital part to the bottom wall of the second interdigital part, and the second stepped groove comprises a third stepped surface, a fourth stepped surface, a third connecting surface and a fourth connecting surface which connect the third stepped surface and the fourth stepped surface;

the first step surface is arranged opposite to the third step surface, and the first connection surface is arranged opposite to the third connection surface so as to prevent the formation of a direct path of an electric field along the radial direction of the interdigital assembly;

the second step surface and the fourth step surface are arranged oppositely, and the second connecting surface and the fourth connecting surface are arranged oppositely so as to prevent a direct path of an electric field from being formed along the thickness direction of the interdigital assembly.

Preferably, the cross section of the workpiece is circular;

the first interdigital part and the second interdigital part are both in arc structures; and,

the first interdigital part is in a major arc structure, and the second interdigital part is in a minor arc structure.

Preferably, the depth and radius of the first bearing groove are the same as those of the second bearing groove; and,

the depth of the first bearing groove is matched with the thickness of the workpiece;

the inner diameter of the first bearing groove is 3-4 mm smaller than the diameter of the workpiece;

the outer diameter of the first bearing groove is 2 mm-3 mm larger than the diameter of the workpiece.

Preferably, the corresponding central angle of the second finger is 80-120 °.

In a second aspect of the present invention, a bottom electrode device is provided, which includes the above-mentioned interdigital structure.

Preferably, the method further comprises the following steps:

the rotating part is provided with at least one mounting station along the circumferential direction, and the interdigital structures are fixedly mounted at each mounting station;

the bearing piece is provided with a rotating piece placing part in the central area and at least one interdigital groove in the edge area; wherein,

the rotating piece placing part is used for installing the rotating piece, and the rotating piece is movable and/or rotatable relative to the bearing piece;

and each interdigital groove corresponds to one first interdigital part, and when the interdigital structure comprises a second interdigital part, the second interdigital part is fixedly arranged in the interdigital groove corresponding to the first interdigital part.

In a third aspect of the present invention, a process chamber is provided, comprising the bottom electrode assembly as described above.

The invention discloses an interdigital structure, a lower electrode device and a process chamber. The first interdigital part only supports the first edge area of the workpiece, and the first interdigital part does not penetrate through the middle core area of the workpiece, so that the process uniformity of the workpiece can be effectively improved, the range of a process defective area can be shortened to the edge area of the workpiece, and the workpiece output rate is improved. In addition, in the actual process, the workpiece in the edge area can be cut off, so that the workpiece yield can be further improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram of a bottom electrode assembly in the prior art;

fig. 2 is a schematic view of the structure of the fingers in the interdigitated structure shown in fig. 1;

FIG. 3 is a schematic structural view of an interdigital structure in accordance with a first embodiment of the present invention;

FIG. 4 is a front view of a first finger of the interdigitated structure shown in FIG. 3;

fig. 5 is a schematic perspective view of a first finger of the interdigitated structure shown in fig. 3;

FIG. 6 is a partial schematic view of FIG. 5 at B;

FIG. 7 is a front view of a second finger in the interdigitated structure shown in FIG. 3;

FIG. 8 is a perspective view of a second finger of the interdigital arrangement depicted in FIG. 3;

FIG. 9 is a schematic structural diagram of a lower electrode assembly according to a second embodiment of the present invention.

Description of the reference numerals

100: an interdigital structure;

110: a first interdigital member;

111: avoiding the opening;

112: a top wall;

113: a bottom wall;

114: a first bearing groove;

115: a first step groove;

115 a: a first step surface;

115 b: a second step surface;

115 c: a first connection face;

115 d: a second connection face;

120: a second finger;

121: filling the opening;

122: a top wall;

123: a bottom wall;

124: a second bearing groove;

125: a second step groove;

125 a: a third step surface;

125 b: a fourth step surface;

125 c: a third connection surface;

125 d: a fourth connection face;

130: interdigital fingers;

200: a lower electrode device;

210: a rotating member;

220: a carrier;

221: a rotating member placing section;

222: interdigital grooves;

300: and (5) a workpiece.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

As shown in fig. 3 to 9, a first aspect of the present invention relates to an interdigital structure 100 for clamping a workpiece 300, wherein the interdigital structure 100 includes a first finger 110, the first finger 110 extends along a first edge region of the workpiece 300, and is formed with a relief opening 111 for allowing a take-off mechanism (not shown), which is typically a robot arm, to pass through, and as shown in fig. 3, as an alternative structure of the first finger 110, the first finger 110 may have a C-shaped ring structure. The first finger 110 is configured to support a first edge region of the workpiece 300.

The interdigital structure 100 is applied to the lower electrode device 200 of the process chamber, and accordingly, the workpiece 300 is a wafer.

As shown in fig. 9, the lower electrode assembly 200 generally includes a rotating member 210 and a supporting member 220, wherein the rotating member 210 is fixedly connected to the first finger 110. The carrier 220 is typically a lower electrode or a heater to provide a wafer with a temperature required for a process, and is typically provided with a rotator-placing portion 221 at a central region thereof and an interdigital groove 222 at an edge region thereof.

Wherein the rotation member 210 is installed in the rotation member placing part 221, and is movable and/or rotatable with respect to the bearing member 220. Each first finger 110 of the finger structure 100 corresponds to a finger groove 222 so that the first finger 110 can fall into the finger groove 222 when it falls.

Specifically, during the process, the rotating member 210 drives the first finger 110 to lift up, and the pick-up mechanism (robot) picks up the wafer from the wafer cassette (not shown), and the pick-up mechanism places the wafer on the first finger 110 through the escape opening 111. Then, the rotating member 210 drives the first finger 110 to descend until the first finger 110 falls into the corresponding finger groove 222, at which time, the wafer contacts with the current station on the surface of the carrier 220, and the wafer is processed.

After the wafer is processed, the rotator 210 drives the first finger 110 to ascend, and when the wafer reaches a predetermined height, the rotator 210 drives the first finger 110 to rotate to a next station (i.e. a position corresponding to the adjacent finger groove 220), and then the above process is repeated.

However, the material of the carrier 220 is often different from that of the interdigital structure 100, and thus, the electric field generated at the position of the interdigital structure 100 during the process is different, which may affect the process uniformity of the wafer. Based on this, the inventor of the present invention has designed an interdigital structure 100 with a novel structure, in which the first interdigital element 110 supports only the first edge region of the wafer, that is, the first interdigital element 110 does not pass through the central core region of the wafer, so that the process uniformity of the wafer can be effectively improved, the range of the process defect region can be shortened to the edge region of the wafer, and the wafer yield can be improved. In addition, in the actual process, the wafer in the edge area can be cut off, so that the wafer yield can be further improved.

As a specific structure of the first finger 110, as shown in fig. 5, the top wall 112 of the first finger 110 is provided with a first bearing groove 114 recessed toward the bottom wall 113 thereof, that is, the first bearing groove 114 is a structure similar to a ring-shaped sinking platform. The first edge region of the workpiece 300 is mounted in the first carrying groove 114, and the first carrying groove 114 of the ring-shaped sinking platform structure can effectively carry the workpiece 300.

As shown in fig. 3, the interdigital structure 100 further includes a second interdigital member 120, and the second interdigital member 120 is detachably connected to the first interdigital member 110. The second finger 120 extends along a second edge region of the workpiece 300 and is formed with a fill-in opening 121 which is complementary to the shape of the relief opening 111, the second finger 120 serves to support the second edge region of the workpiece 300, and the first and second edge regions together form the entire edge region of the workpiece 300.

As a specific structure of the second finger 120, as shown in fig. 8, the top wall 122 of the second finger 120 is provided with a second bearing groove 124 recessed toward the bottom wall 123 thereof, and the second edge region of the workpiece 300 is mounted in the second bearing groove 124. The second carrying groove 124 may be a ring-shaped sinking platform structure for effectively carrying the workpiece 300.

As shown in fig. 5, 6, 7 and 8, the two open ends of the avoiding opening 111 are provided with first matching structures, the two open ends of the filling opening 121 are provided with second matching structures, and the first matching structures and the second matching structures are matched to prevent the direct passage of the electric field formed at the matching structures.

Specifically, as shown in fig. 6, the first mating structure includes a first stepped groove 115 recessed from the bottom wall 113 of the first interdigital member 110 toward the top wall 112 thereof, and the first stepped groove 115 includes a first stepped surface 115a, a second stepped surface 115b, a first connection surface 115c connecting the first stepped surface 115a and the second stepped surface 115b, and a second connection surface 115 d.

As shown in fig. 8, the second mating structure includes a second stepped groove 125 recessed from the top wall 122 of the second finger 120 toward the bottom wall 123 thereof, and the second stepped groove 125 includes a third stepped surface 125a, a fourth stepped surface 125b, a third connecting surface 125c connecting the third stepped surface 125a and the fourth stepped surface 125b, and a fourth connecting surface 125 d.

Wherein the first step surface 115a is disposed opposite to the third step surface 125a, and the first connection surface 115c is disposed opposite to the third connection surface 125c, so as to prevent the formation of a direct path of an electric field along the radial direction of the interdigital structure 100.

Second step face 115b is disposed opposite fourth step face 125b, and second connection face 115d is disposed opposite fourth connection face 125d to prevent a direct path for an electric field from being formed along the thickness direction of interdigital structure 100.

In order to improve the reliability of the workpiece 300, as shown in fig. 3, the workpiece 300 has a circular cross section, the first finger 110 and the second finger 120 have an arc-shaped ring structure, the first finger 110 has a major arc structure, and the second finger 120 has a minor arc structure. In this way, the first and second

interdigital members

110 and 120 can form a complete ring structure, and the complete ring structure can further improve the uniformity of the electric field generated during the process, and improve the yield of the workpiece 300.

In order to improve the reliability of carrying the workpiece 300, the depth and radius of the first carrying groove 114 are the same as those of the second carrying groove 124.

Specifically, as shown in fig. 5, the depth H of the first bearing groove 114 matches the thickness of the workpiece 300, for example, the depth H of the first bearing groove 114 matches the thickness of the workpiece 300, and the movement of the workpiece 300 can be effectively prevented. The inner diameter ID of the first bearing groove 114 is 3mm to 4mm smaller than the diameter of the workpiece 300, so that the workpiece 300 can be reliably rested on the first interdigital member 110, and the first interdigital member 110 does not occupy too much process space under the workpiece 300. The outer diameter OD of the first bearing groove 114 is 2mm to 3mm larger than the diameter of the workpiece 300, so that the workpiece 300 can be ensured to freely slide in the first bearing groove 114 and not to fall off the first interdigital member 110.

As shown in fig. 4, the central angle a of the second interdigital 120 may be set to 80 ° to 120 ° depending on the position of the center of gravity of the workpiece 300 and the width of the pick-up mechanism (the width of the robot arm).

In a second aspect of the present invention, as shown in fig. 9, a bottom electrode assembly 200 is provided, which includes the interdigital structure 100 described above.

The bottom electrode assembly 200 of the present embodiment has the structure of the interdigital structure 100 described above, and the first interdigital device 110 supports the first edge region of the workpiece 300, that is, the first interdigital device 110 does not penetrate the central core region of the workpiece 300, so that the process uniformity of the workpiece 300 can be effectively improved, the range of the process defect region can be shortened to the edge region of the workpiece 300, and the throughput of the workpiece 300 can be improved. In addition, in the actual process, the workpiece 300 in the edge area can be cut off, so that the yield of the workpiece 300 can be further improved.

As shown in fig. 9, the lower electrode assembly 200 further includes a rotating member 210 and a supporting member 220. At least one mounting station is arranged on the circumferential direction of the rotating member 210, and the interdigital structure 100 is fixedly mounted on each mounting station. The carrier 220 is provided with a rotation element placement part 221 in a central region and at least one interdigital groove 222 in an edge region thereof.

The rotating member 210 is mounted on the rotating member placing portion 221, and the rotating member 210 is movable and/or rotatable with respect to the bearing member 220. Each first finger 110 of the finger structure 100 corresponds to a finger groove 222 so that the first finger 110 can fall into the finger groove 222 when it falls. Also, when the interdigital structure 100 includes a second finger 120, the second finger 120 can be fixedly mounted within the corresponding finger groove 222 of the first finger 110.

A third aspect of the present invention relates to a process chamber (not shown) including the bottom electrode assembly 200 described above.

The process chamber configured in this embodiment has the bottom electrode assembly 200 described above and the interdigital structure 100 described above, wherein the first interdigital device 110 supports the first edge region of the workpiece 300, i.e., the first interdigital device 110 does not penetrate the central core region of the workpiece 300, so that the process uniformity of the workpiece 300 can be effectively improved, the range of the process defect region can be reduced to the edge region of the workpiece 300, and the throughput of the workpiece 300 can be improved. In addition, in the actual process, the workpiece 300 in the edge area can be cut off, so that the yield of the workpiece 300 can be further improved.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.

Claims

1. An interdigitated structure for supporting a workpiece, comprising:

a first finger extending along a first edge region of the workpiece and formed with an escape opening allowing passage of a pick-off mechanism, the first finger for supporting the first edge region of the workpiece;

a second finger detachably connected to the first finger; and,

the first edge region and the second edge region together form an entire edge region of the workpiece.

2. The interdigital structure of claim 1, wherein the top wall of the first interdigital member is provided with a first carrier groove recessed toward the bottom wall thereof for supporting the first edge region of the workpiece.

3. The interdigital structure of claim 2, wherein the top wall of the second interdigital member is provided with a second bearing groove recessed in the direction of the bottom wall thereof, for supporting a second edge region of the workpiece.

4. The interdigital structure of claim 2,

two opening ends of the avoidance opening are provided with first matching structures;

5. The interdigital structure of claim 4,

the first matching structure comprises a first step groove which is recessed from the bottom wall of the first interdigital part to the top wall of the first interdigital part, and the first step groove comprises a first step surface, a second step surface, a first connecting surface and a second connecting surface which connect the first step surface and the second step surface;

the first step surface and the third step surface are arranged oppositely, and the first connecting surface and the third connecting surface are arranged oppositely so as to prevent a direct path of an electric field from being formed along the radial direction of the interdigital structure;

the second step surface and the fourth step surface are arranged oppositely, and the second connecting surface and the fourth connecting surface are arranged oppositely so as to prevent a direct path of an electric field from being formed along the thickness direction of the interdigital structure.

6. The interdigital structure of any one of claims 3 to 5,

the cross section of the workpiece is circular;

7. The interdigital structure of claim 6,

the depth and the radius of the first bearing groove are the same as those of the second bearing groove; and,

8. The interdigital structure of claim 6 wherein the corresponding central angle of the second interdigital member is from 80 ° to 120 °.

9. A bottom electrode assembly comprising an interdigitated structure according to any one of claims 1 to 8.

10. The bottom electrode assembly of claim 9, further comprising:

11. A process chamber comprising the lower electrode assembly of claim 9 or 10.