WO2015085882A1

WO2015085882A1 - Bottom electrode apparatus and plasma processing device

Info

Publication number: WO2015085882A1
Application number: PCT/CN2014/092875
Authority: WO
Inventors: 张璐; 张彦召; 陈鹏
Original assignee: 北京北方微电子基地设备工艺研究中心有限责任公司
Priority date: 2013-12-13
Filing date: 2014-12-03
Publication date: 2015-06-18
Also published as: CN104715996B; TW201523683A; CN104715996A

Abstract

A bottom electrode apparatus and a plasma processing device. The bottom electrode apparatus comprises a bearing member (201) for bearing a machined workpiece (206). The bearing member (201) is manufactured by using a conductive material, and an electric field intensity adjusting portion (202) is formed on an upper surface of the bearing member (201); the position of the electric field intensity adjusting portion (202) is corresponding to a compensation region for electric field intensity on the upper surface of the bearing member (201), and a manifestation of the electric field intensity adjusting portion (202) is corresponding to a compensation direction of the electric field intensity. With height differences between regions on the upper surface of the bearing member (201), that is, different distances from positions on the upper surface of the bearing member to the ground, electric field intensities of different regions on the upper surface of the bearing member (201) are adjusted, and differences between electric field intensities of the regions are compensated, so that distribution of plasmas relative to different regions of the machined workpiece (206) borne on the upper surface of the bearing member (201) tends to be uniform, thereby improving the uniformity of the process and the process result.

Description

Lower electrode device and plasma processing equipment

Technical field

The present invention relates to the field of microelectronic processing technology, and in particular to a lower electrode device and a plasma processing apparatus.

Background technique

At present, plasma processing equipment has been widely used in manufacturing processes of semiconductors, solar cells, and flat panel displays. There are many types of plasma processing equipment for different applications, such as capacitively coupled plasma (CCP), inductively coupled plasma (ICP), and electron cyclotron resonance plasma (ECR) types of plasma processing equipment. These types of plasma processing equipment have been widely used in physical vapor deposition (PVD), plasma etching, and plasma chemical vapor deposition (CVD).

1 is a partial cross-sectional view of a conventional plasma processing apparatus. As shown in FIG. 1, the plasma processing apparatus includes a reaction chamber 101, a lower electrode device, a radio frequency power source 103, and a matcher 102. Wherein, the cavity of the reaction chamber 101 is grounded; the lower electrode device includes a pedestal 105 disposed in a bottom region within the reaction chamber 101 for carrying the workpiece 106 to be processed; and the susceptor 105 is coupled to the pedestal 102 via the matcher 102 The RF power source 103 is electrically connected; an outer peripheral wall surrounding the base 105 is provided with an insulating ring 104 for preventing plasma etching of the susceptor 105. During the etching or deposition process, the RF power source 103 couples energy into the reaction chamber 101 through the susceptor 105 to produce a negative bias voltage that is perpendicular to the upper surface of the pedestal 105 and directed toward the pedestal 105. The field is thereby attracted to plasma etch the workpiece 106 placed on the susceptor 105.

The plasma processing apparatus described above inevitably has a problem in the practical application that the electric field generated around the susceptor 105 is distorted by the influence of the insulating ring 104 during the process, resulting in the edge of the workpiece 106 being processed. The electric field strength of the region is greater than the electric field strength of the central region, thereby causing the plasma to have a large bombardment force on the edge region of the workpiece 106 to be processed, and the etching rate is high. The rate is too fast, which in turn affects the etch uniformity of the entire workpiece 106 being processed. The above phenomenon is often referred to as an edge effect, which is embodied in various plasma processing apparatuses having a capacitively coupled discharge mode such as PECVD, PVD, and the like.

At present, the process results are generally improved by changing the plasma distribution. For example, a side magnet is added to the outside of the reaction chamber, or the plasma generated in the reaction chamber is interposed by the upper electrode device. However, these methods cannot change the distribution of the plasma in different regions, and thus cannot overcome the problem of uneven distribution of plasma in the radial direction of the susceptor. The uneven distribution of the plasma in the radial direction of the susceptor can be expressed as the above-mentioned edge effect. It can also be expressed that when the ICP type plasma source is used, the plasma is distributed more in the central region of the reaction chamber and distributed in the edge region. Less situation.

Summary of the invention

The present invention aims to at least solve one of the technical problems existing in the prior art, and proposes a lower electrode device and a plasma processing apparatus which can change the distribution of plasma in different regions, thereby overcoming the plasma in the reaction chamber. The problem of uneven distribution in the radial direction of the chamber can further improve the uniformity of the process and improve the process results.

To achieve the object of the present invention, there is provided a lower electrode device comprising a carrier for carrying a workpiece to be processed, the carrier being made of a conductive material, and an electric field strength adjusting portion formed on an upper surface of the carrier The position of the electric field strength adjusting portion corresponds to a compensation region of the electric field strength of the upper surface of the carrier, and the expression form of the electric field strength adjusting portion corresponds to the compensation direction of the electric field strength.

The electric field intensity adjusting portion has a positive correlation with the amount of change in the electric field strength of the installation region of the electric field strength adjusting portion in the axial direction of the carrier. Wherein the setting region of the electric field strength adjusting portion refers to a region in the upper surface of the carrier member where the electric field intensity adjusting portion is formed; and the amount of change in the electric field strength refers to after the electric field strength adjusting portion is provided The electric power of the set region of the electric field intensity adjusting portion before the electric field intensity adjusting portion is provided The amount of change in field strength.

Wherein the projection of the electric field strength adjusting portion on the upper surface of the carrier presents a closed annular structure centered on the geometric center of the upper surface of the carrier.

Wherein the number of the electric field strength adjusting portions is one; or the number of the electric field strength adjusting portions is plural, and the projection of the plurality of electric field strength adjusting portions on the upper surface of the carrier is such a form That is, the plurality of electric field intensity adjusting portions are nested with each other and the adjacent two electric field intensity adjusting portions are spaced apart from each other by a predetermined distance.

Here, the cross-sectional view of the electric field intensity adjusting portion obtained by using the normal plane of the electric field strength adjusting portion as a cutting plane appears as a regular polygon, an arc, or an irregular shape.

Here, the cross-sectional view of the electric field intensity adjusting portion obtained by taking the normal plane of the electric field intensity adjusting portion as a cutting plane is triangular, rectangular or trapezoidal.

Wherein the electric field strength adjusting portion is provided as a concave portion recessed downward from an upper surface of the carrier member; or a convex portion provided to protrude upward from an upper surface of the carrier member.

Wherein, in a case where the electric field intensity adjusting portion is provided as a concave portion, the lower electrode device further includes an insulating member, and the insulating member is disposed in the recess.

The shape of the longitudinal section of the insulating member is adapted to the shape of the longitudinal section of the recess.

Wherein, the material used for the insulating member comprises ceramic or quartz.

Wherein the upper surface of the carrier has a workpiece carrying position, the projection of the electric field strength adjusting portion on the upper surface of the carrier overlaps with the bearing position of the one workpiece; and the carrier includes Base, mechanical chuck or electrostatic chuck.

Wherein the upper surface of the carrier is arranged with a plurality of bearing positions of the workpiece to be processed, and the projection of the electric field strength adjusting portion on the upper surface of the carrier overlaps with the bearing positions of the plurality of workpieces; The lower electrode assembly further includes a support for supporting the carrier; the support includes a base, a mechanical chuck, or an electrostatic chuck.

As another aspect of the present invention, the present invention also provides a plasma processing apparatus, which A reaction chamber and a lower electrode device disposed in the reaction chamber are included, and the lower electrode device employs any of the above-described lower electrode devices of the present invention.

The invention has the following beneficial effects:

The lower electrode device provided by the present invention provides an electric field strength adjusting portion on the upper surface of the upper surface of the carrier to be compensated, so that the upper surface of the electric field strength adjusting portion and the upper surface of the carrier are different in height, that is, the electric field intensity adjusting portion is The distance between the upper surface and the bottom wall of the electrically grounded reaction chamber is different from the distance between the upper surface of the carrier and the bottom wall of the electrically grounded reaction chamber, thereby changing the position corresponding to the electric field strength adjusting portion The electric field strength is used to compensate for the difference in electric field strength between the various regions on the upper surface of the carrier, so that the distribution of the plasma relative to the respective regions of the workpiece to be processed carried by the carrier tends to be uniform, thereby improving the process. Uniformity improves process results.

The plasma processing apparatus provided by the present invention can make the distribution of the plasma to be uniform with respect to the respective regions of the workpiece to be processed carried by the carrier by using the above-mentioned lower electrode device provided by the present invention, thereby improving the uniformity of the process. Sex, improve process results.

DRAWINGS

1 is a partial cross-sectional view of a conventional plasma processing apparatus;

2A is a cross-sectional view of a lower electrode device according to a first embodiment of the present invention;

2B is a top view of a lower electrode device according to a first embodiment of the present invention;

2C is a distribution diagram of electric field strengths of substrates at different radii;

3A is a cross-sectional view of another lower electrode device according to a first embodiment of the present invention;

3B is a top plan view of another lower electrode device according to a first embodiment of the present invention;

4A is a cross-sectional view of still another lower electrode device according to a first embodiment of the present invention;

4B is a top plan view of still another lower electrode device according to the first embodiment of the present invention;

5A is a cross-sectional view of still another lower electrode device according to a first embodiment of the present invention;

FIG. 5B is a top view of still another lower electrode device according to the first embodiment of the present invention; FIG.

6A is a cross-sectional view of a lower electrode device according to a second embodiment of the present invention;

6B is a top view of a lower electrode device according to a second embodiment of the present invention;

7A is a cross-sectional view of another lower electrode device according to a second embodiment of the present invention;

7B is a top plan view of another lower electrode device according to a second embodiment of the present invention;

8A is a cross-sectional view of a lower electrode device according to a third embodiment of the present invention;

8B is a top plan view of a lower electrode device according to a third embodiment of the present invention;

9 is a cross-sectional view of a plasma processing apparatus according to an embodiment of the present invention.

detailed description

An essence of the present invention is to provide a lower electrode device including a carrier for carrying a workpiece to be processed, the carrier is made of a conductive material, and an electric field strength adjusting portion is formed on an upper surface of the carrier. The position of the electric field strength adjusting portion corresponds to a compensation region of the electric field intensity of the upper surface of the carrier, and the expression form of the electric field strength adjusting portion corresponds to the compensation direction of the electric field strength.

In practical applications, the electric field strength adjusting portion may be provided in the form of a recess and/or a convex portion. Further, the electric field strength adjusting portion has a positive correlation with the amount of change in the electric field strength of the installation region of the electric field strength adjusting portion in the axial direction of the carrier. Wherein, the setting region of the electric field strength adjusting portion refers to a region in which the electric field intensity adjusting portion is formed in the upper surface of the carrier; the amount of change in electric field strength refers to the electric field strength adjusting portion after the electric field strength adjusting portion is provided The amount of change in the electric field strength of the installation region of the electric field strength adjusting portion.

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the lower electrode device and the plasma processing apparatus provided by the present invention will be described in detail below with reference to the accompanying drawings.

First embodiment

2A is a cross-sectional view of a lower electrode device according to a first embodiment of the present invention. 2B is a top plan view of a lower electrode device according to a first embodiment of the present invention. Referring to FIG. 2A and FIG. 2B together, the lower electrode device provided in this embodiment includes a carrier 201 for carrying a workpiece 206 to be processed, and the carrier 201 is made of a metal conductive material such as aluminum or other non-metallic conductive material. Production. The carrier 201 also functions as a lower electrode within the reaction chamber 204 that is electrically coupled to the RF power source 208 via a matcher 207 to couple energy into the reaction chamber 204 to create an upper surface that is perpendicular to the carrier 201. And pointing to the negative bias electric field of the carrier 201, thereby attracting plasma to etch the workpiece 206 placed on the carrier 201. An insulating ring 205 is disposed around the outer peripheral wall of the carrier 201.

In the present embodiment, the upper surface of the carrier 201 has only one workpiece bearing position, that is, the number of workpieces 206 to be processed by the carrier 201 is one, and the diameter of the workpiece 206 and the carrier 201 are The diameter of the upper surface is similar, as shown in Figure 2A. In practical applications, the carrier 201 can be embodied in the form of a base, a mechanical chuck, or an electrostatic chuck.

In the present embodiment, the electric field strength adjusting portion is provided in the form of a recess. Specifically, a concave portion 202 is formed on the upper surface of the carrier member 201, and its projection on the upper surface of the carrier member 201 overlaps with the workpiece carrying position of the workpiece. Since there is a height difference between the bottom surface of the recess 202 and the upper surface of the carrier 201, and the spacing between the bottom surface of the recess 202 and the bottom wall of the electrically grounded reaction chamber 204 is smaller than the upper surface of the carrier 201 and the bottom The spacing between the walls, such that the electric field strength of the region of the bottom surface of the recess 202 is less than the electric field strength of the orthographic projection of the recess 202 at the upper surface of the carrier 201 when the recess 202 is not formed, i.e., the recess 202 is in the carrier The electric field intensity of the orthographic projection area of the upper surface of the member 201 is smaller than the electric field intensity of the projection area when the recess 202 is not formed. Therefore, by providing the recess 202 in some areas of the upper surface of the carrier 201, the electric field strength of the region can be changed to compensate for the difference in electric field strength between the region and other regions of the upper surface of the carrier 201, thereby enabling plasma The distribution of different regions on the upper surface of the carrier member 201 tends to be uniform, thereby improving the uniformity of the process and improving the process results.

In practical applications, the area of the upper surface of the carrier 201 to be compensated for the electric field is determined according to the actual situation to provide the recess 202 in the area. For example, when the electric field intensity of the edge region of the upper surface of the carrier 201 is higher than other regions, the edge region is determined to be the region to be compensated, and the concave portion 202 is disposed in the edge region; when the electric field intensity of the central region of the upper surface of the carrier 201 is high In other regions, the central region is determined to be the region to be compensated, and the recess 202 is provided in the central region.

That is, the position where the concave portion 202 is opened on the upper surface of the carrier 201 and the workpiece 206 to be processed The distribution of the electric field in each region of the surface is correlated such that the electric field is evenly distributed relative to the surface of the workpiece 206 being machined. For example, to overcome the edge effect, the recess 202 may be disposed near the edge of the carrier 201 to reduce the electric field strength in the region, thereby compensating for the electric field strength of the edge region of the workpiece 206 to be processed and the electric field strength of the central region. The difference between them can further make the bombardment force and the etching rate of the plasma on the central region and the edge region of the workpiece 206 to be uniform, so that the etching uniformity of the entire workpiece 206 can be improved. For another example, when the plasma is distributed more in the central region of the reaction chamber 204 and less distributed in the edge region, the recess 202 may be disposed in a region near the center of the carrier 201 to reduce the electric field in the region. The strength can compensate for the difference between the electric field strength of the edge region of the workpiece 206 and the electric field strength of the central region, thereby making the distribution of the plasma in the central region and the edge region uniform, thereby improving the uniformity of the process. Sex, improve process results.

In this embodiment, the width of the electric field region affected by the recess 202 is positively correlated with the width d of the recess 202. Specifically, the larger the width d, the larger the width of the electric field region affected by the recess 202 is. Conversely, the smaller the width d, the smaller the width of the electric field region affected by the recess 202. The width d of the recess 202 refers to the width of the recess 202 along the radial direction of the carrier 201 in the upper surface of the carrier 201; the width of the affected electric field region refers to the influence of the recess 202. The width of the electric field region along the radial direction of the carrier 201.

In the present embodiment, the depth h of the bottom surface of the recess 202 relative to the upper surface of the carrier 201 has a positive correlation with the amount of change in the electric field strength at the region corresponding to the recess 202. That is, the larger the depth h, the larger the amount of decrease in the electric field intensity at the region corresponding to the recess 202; conversely, the smaller the depth h, the smaller the amount of decrease in the electric field strength at the region corresponding to the recess 202.

It can be seen from the above that with the lower electrode device provided in this embodiment, the position and/or the depth h and/or the width d of the recess 202 on the upper surface of the carrier 201 can be determined according to actual process requirements, and the compensation by the recess 202 The effect is to make the electric field strength at different positions of the workpiece 206 to be uniform, so as to better adapt to the requirements of different processes.

Preferably, the recess 202 can be closed with the center of the upper surface of the carrier 201 as a geometric center. The annular structure, correspondingly, the electric field region affected by the recess 202 is also annular, and the electric field strength between the annular region and other regions tends to be uniform by compensating the electric field strength in the annular region.

Please refer to FIG. 2C, which is a schematic diagram of electric field strength at different radii of the substrate during the process. Among them, the curve 1 is a schematic curve of the electric field intensity obtained by the process of using the carrier without the recess, and the curve 2 is a schematic curve of the electric field intensity obtained by the process of the carrier provided with the recess. In the case where the substrate is placed on the upper surface of the carrier and disposed coaxially therewith, the comparison curve 1 and the curve 2 show that on the upper surface of the carrier, at a position centered on the center thereof at a radius of 50 mm By providing the annular recess, the electric field strength at the position corresponding to the recess on the substrate (i.e., at a position centered at the geometric center of the substrate at a radius of 50 mm) can be reduced.

In practical applications, the recess of the annular structure may also be centered on the geometric center of the upper surface of the carrier. Moreover, the structure of the recess is not limited to the closed loop structure provided by the embodiment, but any other structure such as a non-closed arc, a strip, or the like may be employed. Further, a cross-sectional view of the concave portion obtained by cutting the normal plane of the concave portion is a regular polygon, an arc shape or an irregular shape. That is, the shape of the longitudinal section of the recess may be a regular polygon, an arc, or other shape. The longitudinal sectional shape of the concave portion refers to a closed portion of the concave portion which is formed by cutting the concave portion perpendicular to the normal plane of the upper surface of the carrier and the projection of the upper surface of the carrier in the normal plane. Graphics. For the convenience of processing, the shape of the longitudinal section of the recess may be set to a rectangular shape.

It should be noted that although the number of the recesses 202 in the embodiment is one, the present invention is not limited thereto. In practical applications, the recesses may be two or more, and two or more recesses may be used according to specific conditions. Choose the right arrangement. For example, if a plurality of recesses are formed by the above-described annular structure, the radii of the plurality of recesses may be different and nested with each other and the adjacent two recesses may be spaced apart from each other by a certain distance. For example, as shown in FIGS. 3A and 3B, the recesses 202 are three, and the three recesses 202 are closed annular structures having unequal radii with each other, and are nested with each other to be centered on the geometric center of the upper surface of the carrier 201 and mutually Concentric rings of a certain distance. The shape of the longitudinal section of each recess 202 is a rectangle.

Moreover, the width d of the three recesses 202 may be the same as shown in FIGS. 3A and 3B; alternatively, the width d of the three recesses 202 may also be different, for example, in the radial direction of the carrier 201, and along the self-supporting member 201. The center is oriented toward the edge, and the widths of the three recesses 202 are d1, d2, and d3, respectively, and d1 < d2 < d3, as shown in FIGS. 4A and 4B. The width d of the three recesses 202 is respectively provided, and the width of the electric field region affected by each recess 202 can be correspondingly obtained.

In addition, the depths h of the three recesses 202 may be the same as shown in FIGS. 3A and 3B; or the depths h of the three recesses 202 may be different, as shown in FIGS. 4A and 4B, the depths of the three recesses 202 are respectively h1. , h2 and h3, and in the radial direction of the carrier 201 in the direction from the center of the carrier 201 toward the edge, the depths of the three recesses 202 gradually increase, that is, h1 < h2 < h3. In a practical application, the depth h of the three recesses 202 may be set according to the compensation amount of the desired electric field strength at the position corresponding to the three recesses 202; and the setting of the three recesses 202 may be determined according to the desired compensation position. position.

In practical applications, the number of recesses may be set according to actual needs. The shape of the projection of the recess on the upper surface of the carrier 201 and the shape of the longitudinal section of the recess are similar to the embodiment shown in connection with FIGS. 2A to 2C. This will not be repeated here. Further, the projection shape of the concave portion on the upper surface of the carrier 201 and the shape of the longitudinal section of the concave portion may be the same or different.

Preferably, FIG. 5A is a cross-sectional view of still another lower electrode device according to the first embodiment of the present invention. FIG. 5B is a top plan view of still another lower electrode device according to the first embodiment of the present invention. Referring to FIGS. 5A and 5B together, the lower electrode assembly further includes an insulating member 203 disposed in each of the recesses 202 to further ensure insulation between the internal space of the recess 202 and the ground. The material used for the insulating member 203 includes ceramic or quartz.

In the present embodiment, the shape of the longitudinal section of the insulating member 203 is adapted to the shape of the longitudinal section of the recess 202 (i.e., the shape is the same and the insulating member 203 can be fitted into the recess 202) so that the insulating member 203 can be filled or embedded. The manner completely fills the internal space of the entire recess 202. Of course, the shape of the longitudinal section of the insulating member 203 and the recess 202 may be different. In this case, the insulating member 203 does not completely fill the internal space of the entire recess 202.

It should be noted that, in practical applications, the number of the insulating members may be the same as the number of the recesses, or may be less than the number of the recesses, that is, the insulating members may be disposed in all the recesses, or may be selectively in the plurality of recesses. Insulating members are disposed in the recesses. Of course, when there is only one recess, it is optional to provide an insulating member or not to provide an insulating member. Further, the shape of the longitudinal section of the insulating member in the different recesses may be the same or different, and it is preferable to match the longitudinal cross-sectional shape of the insulating member with the longitudinal cross-sectional shape of the recess.

Second embodiment

6A is a cross-sectional view of a lower electrode device according to a second embodiment of the present invention. FIG. 6B is a top view of a lower electrode device according to a second embodiment of the present invention. Referring to FIG. 6A and FIG. 6B together, the difference between the present embodiment and the first embodiment is that the electric field strength adjusting portion can be configured as a concave portion and a convex portion in the lower electrode device provided in this embodiment. The form, in particular, not only has a recess 202 formed on the upper surface of the carrier member 201, but also has a convex portion 209. The structure and arrangement of the recess 202 are similar to those of the first embodiment described above, and are not described herein again. Only the structure and arrangement of the convex portion 209 will be described below.

Specifically, there is a height difference between the top surface of the protrusion 209 and the upper surface of the carrier 201, and the spacing between the top surface of the protrusion 209 and the bottom wall of the electrically grounded reaction chamber 204 is greater than the carrier 201. The spacing between the upper surface and the bottom wall is such that the electric field strength of the region of the top surface of the protrusion 209 is less than the electric field strength of the top projection 209 at the top projection of the upper surface of the carrier 201 when the top portion 209 is not formed. Therefore, by providing the convex portion 209 in some regions of the upper surface of the carrier 201, the electric field intensity of the region can be changed to compensate for the difference in electric field strength between the region and other regions of the upper surface of the carrier 201, thereby enabling plasma The distribution of the body in the different regions of the workpiece 206 carried by the carrier 201 tends to be uniform, thereby improving the uniformity of the process and improving the process results.

Similar to the concave portion, the region of the upper surface of the carrier 201 where the electric field is to be compensated can be determined according to the actual situation, and the convex portion 209 is disposed in the region to uniformly distribute the electric field with respect to the surface of the workpiece 206 to be processed. For example, in order to overcome the edge effect, the convex portion 209 may be disposed close to the carrier 201 a region of the heart to increase the electric field strength in the region, thereby compensating for the difference between the electric field strength of the edge region of the workpiece 206 to be processed and the electric field strength of the central region, thereby allowing the plasma to be respectively applied to the workpiece 206 to be processed. The bombardment force and etching rate of the central region and the edge region tend to be uniform, so that the etching uniformity of the entire workpiece 206 can be improved. For another example, when the plasma is distributed more in the central area of the reaction chamber, and the distribution of the edge area is less, the convex portion 209 may be disposed near the edge of the carrier 201 to increase the electric field in the area. The strength can compensate for the difference between the electric field intensity of the edge region of the workpiece 206 and the electric field strength of the central region, so that the distribution of the plasma in the central region and the edge region tends to be uniform, thereby improving the uniformity of the process. Improve process results.

Similar to the concave portion, the width of the electric field region affected by the convex portion 209 is positively correlated with the width D of the convex portion 209. Specifically, the larger the width D, the width of the electric field region affected by the convex portion 209. The larger the width D is, the smaller the width of the electric field region affected by the convex portion 209 is. Here, the width D of the convex portion 209 refers to the width of the convex portion 209 along the radial direction of the carrier 201 in the upper surface of the carrier 201.

Similar to the concave portion, there is a positive correlation between the height H of the top surface of the convex portion 209 with respect to the upper surface of the carrier 201 and the amount of change in electric field strength at the region corresponding to the convex portion 209. That is, the larger the height H is, the larger the amount of increase in the electric field intensity at the region corresponding to the convex portion 209 is. On the contrary, the smaller the height H is, the smaller the amount of increase in the electric field intensity at the region corresponding to the convex portion 209 is.

In this embodiment, the convex portion 209 can adopt a closed annular structure centered on the geometric center of the upper surface of the bearing member 201. Correspondingly, the electric field region affected by the convex portion 209 is also annular, and the electric field strength is performed in the annular region. Compensation to make the electric field strength region between the annular region and other regions uniform. Of course, in practical applications, the convex portion of the annular structure may not be centered on the geometric center of the upper surface of the carrier.

It should be noted that, in practical applications, if it is required to cool the workpiece 206 placed on the carrier 201 during the process, it is usually required to be between the upper surface of the carrier 201 and the lower surface of the workpiece 206 to be processed. Cooling gas (also known as back-blowing gas) is introduced into the gap to realize the processing of the workpiece The temperature of the piece 206 is lowered. In this case, in order to ensure that the cooling gas can be uniformly diffused to the respective regions of the workpiece 206 to be processed, in particular the edge regions, it is ensured that the cooling gas does not leak from the gap between the carrier 201 and the workpiece 206 to be processed. To go out, the convex portion 209 must be disposed outside the outlet of the cooling gas passage on the upper surface of the carrier 201, and the workpiece 206 to be processed is supported by the convex portion 209, that is, the inner diameter of the convex portion 209 should be smaller than that of the workpiece 206 to be processed. The diameters and the two are disposed substantially concentrically to enclose the cooling gas in the inner side wall of the convex portion 209, the region within the upper surface of the carrier 201 located within the convex portion 209, and the lower surface of the workpiece 206 to be processed. The area located within the convex portion 209 is enclosed by a space.

As shown in FIG. 7A and FIG. 7B, a plurality of convex portions 209 having a ring structure may be provided as needed. The plurality of protrusions 209 have different radii and are nested with each other and the adjacent two protrusions 209 are spaced apart from each other by a certain distance, that is, the plurality of protrusions 209 are respectively disposed on the upper surface of the carrier 201 with different radii. The circumference is such that the electric field strength at the plurality of circumferences can be increased to compensate for the difference in electric field strength between the region corresponding to the plurality of circumferences on the surface of the workpiece 206 to be processed and other regions.

Moreover, the widths D of the different convex portions 209 may be the same or different, for example, in the radial direction of the carrier 201, and in the direction from the center of the carrier 201 toward the edge, the widths of the three convex portions 209 are respectively D1. D2 and D3, and D1 < D2 < D3, as shown in Fig. 7B. The width D of the three convex portions 209 is respectively provided, and the width of the electric field region affected by each convex portion 209 can be obtained correspondingly.

Further, the heights H of the different convex portions 209 may be the same or different. For example, as shown in FIG. 7A, the heights of the three convex portions 209 are H1, H2, and H3, respectively, and the heights of the three convex portions 209 gradually increase in the radial direction of the carrier 201 in the direction from the center of the carrier 201 toward the edge. , that is, H1 < H2 < H3. In practical applications, the height H of the three convex portions 209 can be set according to the amount of compensation of the desired electric field strength at the corresponding position on the three carriers 201.

Similar to the recess 202, in practice, each of the protrusions 209 may employ any other structure other than a closed arc shape, a strip shape, or the like, in addition to a closed loop structure, and each protrusion 209 may be employed. The longitudinal section shape can be a polygon, an arc, or any other shape. Set this up The shape of the convex portion 209, that is, the cross-sectional view of the convex portion 209 obtained by cutting the normal plane of the convex portion 209 is a regular polygonal shape, an arc shape or an irregular shape. That is, the shape of the longitudinal section of the convex portion 209 may be a regular polygon, an arc, or other shape. The longitudinal sectional shape of the convex portion 209 refers to the cross section of the convex portion 209 which is obtained by cutting the convex portion 209 perpendicular to the normal plane of the upper surface of the carrier portion 209 and the upper surface of the carrier member at the normal plane. The closed pattern formed by the projections in the middle. Further, the projection shape of the convex portion 209 on the upper surface of the carrier 201 and the shape of the longitudinal section of the convex portion 209 may be the same or different.

It can be understood that, in the embodiment, for the case where the cooling gas needs to be introduced into the gap between the upper surface of the carrier and the lower surface of the workpiece to be processed, the convex portion at the outermost side should adopt a closed annular structure, and The height is greater than the height of the other protrusions to ensure that the cooling gas is enclosed in the inner side wall of the convex portion 209, the region within the upper surface of the carrier 201 located within the convex portion 209, and the lower surface of the workpiece 206 to be processed. The area located within the convex portion 209 is enclosed by a space.

It can also be understood that, in practical applications, only the concave portion or only the convex portion may be provided on the upper surface of the carrier according to a specific case, or the concave portion and the convex portion may be provided at the same time. It is easy to understand that the convex portion can increase the electric field strength of the region in which it is located, and conversely, the concave portion can reduce the electric field strength of the region in which it is located. However, if the concave portion and the convex portion are simultaneously provided on the upper surface of the carrier member, the height difference between the region corresponding to the convex portion and the region where the concave portion is located can be increased on the upper surface of the carrier member, thereby increasing the adjustment range of the electric field strength. .

Third embodiment

8A is a cross-sectional view of a lower electrode device according to a third embodiment of the present invention. 8B is a top plan view of a lower electrode device according to a third embodiment of the present invention. Referring to FIG. 8A and FIG. 8B together, the difference between the present embodiment and the first and second embodiments is that the lower electrode device provided in this embodiment has a carrier representation form for carrying multiple processed parts. a tray 301 of the workpiece, that is, a bearing position of a plurality of workpieces to be processed is arranged on the upper surface of the tray 301, and a bearing position of each workpiece to be processed is used to carry a workpiece to be processed, and an electric field strength adjusting portion is in the tray a projection of an upper surface of the 301 overlaps with the plurality of workpiece bearing positions; and the lower electrode devices of the foregoing first and second embodiments The carrier has only one workpiece carrying position and is used to carry one workpiece to be processed.

Specifically, the diameter of the upper surface of the tray 301 is much larger than the diameter of the workpiece 305 to be processed. As shown in FIG. 8B, a plurality of load-bearing positions are provided on the tray 301, and respectively at the circumferences of different radii of the upper surface of the tray 301. Evenly arranged, a plurality of workpieces 305 to be processed are placed in a plurality of bearing positions in a one-to-one correspondence. Moreover, the tray 301 is made of a metal conductive material such as aluminum or other non-metallic conductive material for use as a lower electrode in the reaction chamber 304, and is electrically connected by sequentially connecting the matching unit 306 and the RF power source 307. Coupled into the reaction chamber 304. In addition, a support member 303 is provided in the reaction chamber 304 for supporting the carrier 301, which includes a base, a mechanical chuck or an electrostatic chuck.

In the process of loading the workpiece 305 into the reaction chamber 304, a plurality of workpieces 305 are first placed on the respective carrying positions of the tray 301; then the tray 301 is transferred to the support in the reaction chamber 304. 303, thereby completing the loading of the workpiece 305 to be processed. It can be seen that, in addition to the function of the lower electrode, the carrier in the present embodiment has the workpiece 305 being processed between the inside and the outside of the reaction chamber 304, as compared with the first and second embodiments described above. Features.

A recess 302 is provided on the upper surface of the tray 301 at a position corresponding to each of the load carrying positions. The structure of the recess 302 is similar to that of the first and second embodiments described above, but the arrangement thereof is slightly different. Specifically, since the tray 301 carries a plurality of workpieces 305 to be processed, when selecting the arrangement of the recesses, the distribution of the electric field strength of different regions of the same workpiece 305 should be considered, and the workpieces 305 being processed differently The distribution of electric field strength between. That is, if there is a difference in electric field strength between different regions of the same workpiece 305, recesses should be provided in the respective regions of each workpiece 305 for the difference to compensate for different regions of the same workpiece 305. There is a difference in electric field strength between. If there is a difference in electric field strength between different workpieces 305, a recess 302 should be provided for the difference in the region of the corresponding workpiece 305 to compensate for the difference in electric field strength between the different workpieces 305. Of course, even if the electric field strength is different between the same and different workpieces 305, the difference can be compensated by designing the structure and the position of the recess 302.

For example, in the present embodiment, the plurality of workpieces 305 to be processed are evenly arranged two times at the circumference of the upper surface of the upper surface of the carrier 301. For the arrangement of the workpieces 305 to be processed, four annular recesses 302 may be respectively disposed on the upper surface of the carrier 301, and the four recesses 302 are nested with each other and processed on the circumference corresponding to the same radius. At the bottom of the workpiece 305, two annular recesses 302 are respectively assigned, so that not only the amount of change in electric field strength between the workpieces 305 on the circumference of the same radius can be made the same, but also the radius of each recess 302 can be changed. The affected area position of the workpiece 305 to be processed.

It can be understood that, in practical applications, the plurality of carrying positions provided on the tray 301 may be arranged in one turn, or may be arranged in more circles, and is not necessarily limited to two turns in the embodiment.

In summary, the lower electrode device provided by the embodiment of the present invention provides an electric field strength adjusting portion on the upper surface of the upper surface of the carrier to be compensated, so that the upper surface of the electric field strength adjusting portion and the upper surface of the carrier have a height difference, that is, The distance between the upper surface of the electric field strength adjusting portion and the bottom wall of the electrically grounded reaction chamber 204 is different from the distance between the upper surface of the carrier and the bottom wall of the electrically grounded reaction chamber 204. Varying the electric field strength at the position corresponding to the electric field strength adjusting portion to compensate for the difference in electric field strength between the respective regions on the upper surface of the carrier, so that the distribution of the plasma relative to each region of the workpiece to be processed carried by the carrier can be made It tends to be uniform, which in turn can improve the uniformity of the process and improve the process results.

As another technical solution, FIG. 9 is a cross-sectional view of a plasma processing apparatus according to an embodiment of the present invention. Referring to FIG. 9, the plasma processing apparatus is an inductively coupled plasma processing apparatus including a reaction chamber 401, a lower electrode device 405, a lower electrode RF power source 403, a lower electrode matcher 402, an inductive coupling coil 407, and a coil matcher 408. And coil RF power supply 409. Wherein, the cavity of the reaction chamber 401 is grounded; the inductive coupling coil 407 is disposed above the top wall of the reaction chamber 401, and is electrically connected to the coil RF power source 409 via the coil matcher 408 in sequence; the lower electrode device 405 is generally of a flat structure. a bottom region disposed in the reaction chamber 401 as a carrier carrying the workpiece 406 to be processed, and the lower electrode device 405 is electrically connected to the lower electrode RF power source 403 via the lower electrode matching device 402; surrounding the lower electrode device 405 An outer peripheral wall is provided with an insulating ring 404, The electrode device 405 for preventing plasma etching. The lower electrode device 405 can employ the lower electrode device provided by the above embodiments of the present invention.

During the etching or deposition process, the coil RF power supply 409 provides RF power to the inductive coupling coil 407 to ionize the process gas entering the reaction chamber 401 to form a plasma; the lower electrode RF power source 403 passes through the lower electrode assembly 405. Energy is coupled into the reaction chamber 401 to produce a negative bias electric field that is perpendicular to the upper surface of the lower electrode assembly 405 and directed toward the lower electrode assembly 405, thereby attracting the plasma etch to the lower electrode assembly 405. The workpiece 406 is machined.

It should be noted that although the plasma processing apparatus in this embodiment is an inductively coupled plasma processing apparatus, the present invention is not limited thereto, but in practical applications, the plasma processing apparatus may also be a capacitively coupled plasma. Body processing equipment, electron cyclotron resonance plasma processing equipment, and the like.

The plasma processing apparatus provided by the embodiment of the present invention can use the lower electrode device provided by the above embodiments of the present invention, so that the distribution of plasma in different regions tends to be uniform, thereby improving the uniformity of the process and improving. Process results.

It is to be understood that the above embodiments are merely exemplary embodiments employed to explain the principles of the invention, but the invention is not limited thereto. Various modifications and improvements can be made by those skilled in the art without departing from the spirit and scope of the invention. These modifications and improvements are also considered to be within the scope of the invention.

Claims

A lower electrode device comprising a carrier for carrying a workpiece to be processed, the carrier being made of a conductive material, characterized in that an electric field strength adjusting portion is formed on an upper surface of the carrier, the electric field intensity adjustment The position of the portion corresponds to a compensation region of the electric field strength of the upper surface of the carrier, and the expression of the electric field strength adjusting portion corresponds to the compensation direction of the electric field strength.
The lower electrode device according to claim 1, wherein the amount of change in the electric field strength of the electric field strength adjusting portion in the axial direction of the carrier and the electric field strength in the electric field strength adjusting portion is positive. Corresponding correspondence, where

The installation region of the electric field strength adjusting portion refers to a region in the upper surface of the carrier that is formed with the electric field strength adjusting portion;

The amount of change in the electric field intensity refers to the amount of change in the electric field intensity of the installation region of the electric field intensity adjusting portion after the electric field intensity adjusting portion is provided and before the electric field intensity adjusting portion is provided.
The lower electrode device according to claim 2, wherein the projection of the electric field strength adjusting portion on the upper surface of the carrier is a closed annular structure centered on a geometric center of the upper surface of the carrier.
The lower electrode device according to claim 3, wherein the number of the electric field intensity adjusting portions is one; or

The number of the electric field strength adjusting portions is plural, and the projection of the plurality of electric field strength adjusting portions on the upper surface of the carrier exhibits a form in which the plurality of electric field intensity adjusting portions are nested with each other and The adjacent two electric field strength adjusting portions are spaced apart from each other by a certain distance.
The lower electrode device according to claim 1, wherein said electric field strength A cross-sectional view of the electric field strength adjusting portion obtained by cutting the normal plane of the adjusting portion is a regular polygon, an arc, or an irregular shape.
The lower electrode device according to claim 5, wherein the cross-sectional view of the electric field intensity adjusting portion obtained by using the normal plane of the electric field intensity adjusting portion as a cutting plane is triangular, rectangular or trapezoidal.
The lower electrode device according to claim 1, wherein the electric field strength adjusting portion is provided as a recess recessed downward from an upper surface of the carrier; or is disposed upward from an upper surface of the carrier Raised convex.
The lower electrode device according to claim 7, wherein in the case where the electric field intensity adjusting portion is provided as a concave portion, the lower electrode device further includes an insulating member, and the insulating member is disposed in the groove Inside.
The lower electrode device according to claim 8, wherein a shape of a longitudinal section of the insulating member is adapted to a shape of a longitudinal section of the recess.
The lower electrode device according to claim 8, wherein the material used for the insulating member comprises ceramic or quartz.
The lower electrode device according to claim 1, wherein an upper surface of the carrier has a workpiece carrying position, and a projection of the electric field strength adjusting portion on an upper surface of the carrier and the one The workpiece carrying positions are overlapped; and the carrier comprises a base, a mechanical chuck or an electrostatic chuck.
The lower electrode device according to claim 1, wherein said carrier member is upper The surface is arranged with a plurality of bearing positions of the workpiece to be processed, and the projection of the electric field strength adjusting portion on the upper surface of the carrier overlaps with the plurality of workpiece bearing positions; and

The lower electrode assembly further includes a support for supporting the carrier; the support includes a base, a mechanical chuck, or an electrostatic chuck.
A plasma processing apparatus comprising a reaction chamber and a lower electrode device disposed in the reaction chamber, wherein the lower electrode device employs the lower electrode device according to any one of claims 1-12.