Focusing ring and plasma etching device

Abstract

According to the focusing ring and the plasma etching device provided by the invention, the focusing ring is divided into the focusing part and the adjusting part, the driving module drives the adjusting part to move in the horizontal direction, and the displacement of the adjusting part in the horizontal direction is transmitted into the displacement of the focusing part in the vertical direction. According to the arrangement mode, when the focusing part is continuously consumed and gradually thinned along with accumulation of plasma etching time, and a plasma shell layer becomes bent at the edge of a wafer, the purpose that the focusing part is lifted upwards is achieved by converting the displacement of the adjusting part in the horizontal direction into the displacement of the focusing part in the vertical direction, and therefore the plasma etching efficiency is improved. And finally, the upper surface height of the focusing part is adjusted to be consistent with the surface height of the wafer, so that the problem that the plasma shell layer is bent in the edge area of the wafer is effectively reduced or even avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor equipment, and in particular to a focusing ring and a plasma etching device. Background Art

[0002] Etching is a necessary step in the manufacturing process of semiconductor devices. Generally, an etching process is used to remove unnecessary parts from semiconductor devices. Among them, dry etching is a common technology in the field of integrated circuits. This process is carried out in the reaction chamber of a plasma etching device. During the process, an etching gas containing a suitable etchant is introduced into the reaction chamber, and then a high-power radio frequency voltage is applied to the etching gas introduced into the reaction chamber through the upper and lower electrodes to generate plasma, and the material on the surface of the wafer is etched by plasma to obtain the desired pattern on the wafer. However, in the etching reaction chamber, the etching rate and etching direction of the edge area of ​​the wafer are different from those of the center area of ​​the wafer, resulting in a decrease in the processing uniformity of the edge area of ​​the wafer, affecting the yield of the final chip. In order to solve this problem, a focus ring (Focus ring / Topedge ring) is usually set around the periphery of the wafer to adjust the distribution uniformity of the plasma in the reaction chamber in the middle and edge of the wafer.

[0003] However, if Figure 1 As shown in FIG. 1 , during the plasma etching of the wafer, the focus ring 21 will also be worn, causing the thickness of the focus ring 21 to gradually become thinner, and the height of the upper surface of the focus ring 21 slowly becomes lower than the upper surface of the etched wafer 20, thereby causing the plasma sheath 22 to gradually become "bent" at the edge of the wafer 20, i.e., region A. When the "bend" is presented to a certain extent, the plasma at the edge of the wafer 20 will no longer bombard and etch perpendicularly to the surface of the wafer 20. This oblique plasma etching behavior may cause the morphology of the hole at the edge of the wafer 20 to be tilted after etching, as shown in FIG. Figure 2 The groove 24 at the edge of the middle wafer is no longer vertical but tilted to the left. Summary of the invention

[0004] In view of the shortcomings of the prior art mentioned above, the purpose of the present invention is to provide a focusing ring and a plasma etching device, which are used to solve the problem in the prior art that during the plasma etching process, the thickness of the focusing ring is gradually consumed by etching and becomes thinner, causing the plasma shell to become "bent" at the edge of the wafer, affecting the wafer etching morphology and feature size, and ultimately affecting the chip yield.

[0005] To achieve the above-mentioned object and other related objects, the present invention provides a focusing ring for a plasma etching device, the focusing ring comprising:

[0006] A focusing unit located at the upper layer, an adjustment unit and a driving module located at the lower layer;

[0007] The focusing portion is annular and surrounds the periphery of the wafer during the process, and the upper surface of the focusing portion is a plane;

[0008] The driving module is used to drive the adjusting part to move in the horizontal direction;

[0009] The adjustment part transmits its horizontal displacement into the vertical displacement of the focusing part.

[0010] Optionally, the focusing ring includes at least two adjusting parts and at least two driving modules;

[0011] The lower surface of the focusing portion is configured as an inclined surface inclined toward the wafer;

[0012] The lower surface of the adjusting portion is a plane, and the upper surface of the adjusting portion is configured as an inclined surface inclined toward the wafer;

[0013] During the process, the upper surface of the adjusting portion and the lower surface of the focusing portion are connected by a recess and a protrusion bite mode, and the recess and the protrusion can slide relative to each other under the push of an external force;

[0014] During the process, at least two of the driving modules are arranged one by one on the outer side of the adjusting part to push the adjusting part to achieve relative sliding between the depression and the protrusion;

[0015] When the focusing ring is initially unused, the adjusting portion is engaged with the focusing portion until the sum of their thicknesses reaches a maximum, and the upper surface of the focusing portion is higher than the upper surface of the wafer.

[0016] Optionally, the upper surface of the adjusting portion is configured as an inclined surface inclined toward the center of the wafer, and the lower surface of the focusing portion is configured as an inclined surface inclined toward the center of the wafer.

[0017] Furthermore, the depression and the protrusion slide relative to each other by one step, and the height of the focusing portion increases or decreases by 0.5 mm to 3 mm.

[0018] Optionally, the upper surface of the adjusting portion is provided with a plurality of the protrusions along the inclined direction, and the lower surface of the focusing portion is provided with a plurality of the recesses along the inclined direction; or the upper surface of the adjusting portion is provided with a plurality of the recesses along the inclined direction, and the lower surface of the focusing portion is provided with a plurality of the protrusions along the inclined direction.

[0019] Optionally, a horizontal projection of the focusing portion completely covers the adjusting portion.

[0020] Furthermore, the adjusting parts are evenly arranged along the circumferential direction.

[0021] Optionally, the shapes of the protrusions and the depressions are adapted hemispherical shapes; the number of the protrusions is 3 to 15, and the number of the depressions is 3 to 15.

[0022] Optionally, when the focusing ring is initially unused and the adjustment portion and the focusing portion are engaged and connected to each other until the sum of their thicknesses reaches a maximum, the height difference between the upper surface of the focusing portion and the upper surface of the wafer is 1 to 1.5 times the thickness of the wafer.

[0023] Optionally, the sum of the lower surface areas of all the adjusting parts is 20% to 40% of the upper surface area of ​​the focusing part.

[0024] Optionally, the adjusting portion is annular and concentrically located below the focusing portion;

[0025] The lower surface of the focusing portion is evenly provided with at least three first tracks along the circumferential direction, and the first tracks extend along the radial direction of the focusing portion, and the lower surface of the focusing portion within the first tracks is provided as an inclined surface inclined toward the vertical direction along the extension direction of the first tracks;

[0026] At least three second tracks are evenly arranged on the upper surface of the adjusting portion along the circumferential direction, and the second tracks extend along the radial direction of the adjusting portion, and the upper surface of the adjusting portion within the second tracks is a horizontal plane;

[0027] The first track and the second track extend radially differently;

[0028] After the focusing part is placed on the adjusting part, all the first tracks overlap with all the second tracks in a one-to-one correspondence, and driving beads are arranged in the overlapping area so that a part of the driving beads is located in the first track and another part is located in the second track;

[0029] The driving module is used to drive the adjusting part to rotate in a horizontal direction and drive the driving bead to move along an extending direction of the first track.

[0030] Furthermore, the first track is a straight track, and the second track is a curved track.

[0031] Furthermore, four first tracks are evenly arranged on the lower surface of the focusing portion along the circumferential direction; and four second tracks are evenly arranged on the upper surface of the adjusting portion along the circumferential direction.

[0032] The present invention also provides a plasma etching device, the plasma etching device comprising:

[0033] Etching cavity;

[0034] A base serving as a lower electrode and a wafer supporter, arranged at the bottom of the etching chamber;

[0035] An upper electrode is arranged above the etching chamber and opposite to the base;

[0036] One of the base and the upper electrode is connected to a radio frequency source;

[0037] The focusing ring as described in any one of the above items is arranged around the outer circumference of the base in the etching chamber.

[0038] As described above, the focusing ring and plasma etching device of the present invention are divided into a focusing part and an adjusting part, and the adjusting part is driven to move in the horizontal direction by a driving module, and the displacement of the adjusting part in the horizontal direction is transmitted to the displacement of the focusing part in the vertical direction. This arrangement can achieve that when the focusing part is gradually consumed and thinned as the plasma etching time accumulates, causing the plasma shell to become "bent" at the edge of the wafer, the displacement of the adjusting part in the horizontal direction is converted into the displacement of the focusing part in the vertical direction, so as to achieve the purpose of lifting the focusing part upward, and finally adjust the height of the upper surface of the focusing part to be consistent with the height of the wafer surface, thereby effectively reducing or even avoiding the problem of the plasma shell "bending" at the edge area of ​​the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The schematic diagram shows the cross-sectional structure of the plasma shell bending caused by the thinning of the focusing ring in the plasma etching device.

[0040] Figure 2 Displayed as based on Figure 1 TEM image of the tilted etched holes formed after plasma etching when the plasma shell is curved.

[0041] Figure 3 A schematic cross-sectional structure diagram showing the relative position relationship between a focus ring, a wafer and a susceptor in an etching chamber of an exemplary plasma etching device.

[0042] Figure 4 Display as Figure 3 An exploded view of the various components of the focus ring.

[0043] Figures 5 to 7 It shows a schematic diagram of the cross-sectional structure of an example of a focusing ring in which the focusing portion and the adjusting portion are engaged with each other through recesses and protrusions to achieve different states of vertical rising of the focusing portion.

[0044] Figure 8 A schematic top view of the structure showing the relative position relationship between a focus ring, a wafer and a susceptor in an etching chamber of an exemplary plasma etching device.

[0045] Fig. 9 A schematic diagram of the lower surface structure of the focusing portion of a focusing ring is shown as another example.

[0046] Fig.10 A schematic diagram of the upper surface structure of a focus ring adjustment portion is shown as another example.

[0047] Component number description

[0048] 10 Focus

[0049] 100 Focusing unit upper surface

[0050] 101 Focusing unit lower surface

[0051] 102 First Track

[0052] 103 Inclined surface

[0053] 11 Adjustment Department

[0054] 110 Adjustment unit upper surface

[0055] 111 Adjustment unit bottom surface

[0056] 112 Second Track

[0057] 113 Horizontal plane

[0058] 12 Driver Module

[0059] 13 Depression

[0060] 14 Bump

[0061] 15 Base

[0062] 16 Wafer

[0063] 17 Plasma Sheath

[0064] 20 Wafer

[0065] 21 Focus ring

[0066] 22 Plasma Shell

[0067] 23 Base

[0068] 24 grooves

[0069] 25 drive beads DETAILED DESCRIPTION

[0070] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0071] See also Figures 3 to 10 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0072] The present invention provides a focusing ring for a plasma etching device, characterized in that the focusing ring comprises: a focusing portion located at an upper layer, an adjusting portion located at a lower layer and a driving module; the focusing portion is ring-shaped and surrounds the outer circumference of a wafer during process treatment, and the upper surface of the focusing portion is a plane; the driving module is used to drive the adjusting portion to move in a horizontal direction; the adjusting portion transmits its horizontal displacement into a vertical displacement of the focusing portion.

[0073] The focusing ring is divided into a focusing part and an adjusting part, and the adjusting part is driven to move in the horizontal direction by a driving module, and the displacement of the adjusting part in the horizontal direction is transmitted to the displacement of the focusing part in the vertical direction. This setting method can realize that when the focusing part is gradually consumed and thinned as the plasma etching time accumulates, causing the plasma shell to become "bent" at the edge of the wafer, the displacement of the adjusting part in the horizontal direction is converted into the displacement of the focusing part in the vertical direction, so as to achieve the purpose of lifting the focusing part upward, and finally adjust the height of the upper surface of the focusing part to be consistent with the height of the wafer surface, thereby effectively reducing or even avoiding the problem of the plasma shell "bending" at the edge area of ​​the wafer.

[0074] As a specific example, Figure 3 , Figure 4 and Figure 8 As shown, the focusing ring includes: a focusing part 10 located at the upper layer, at least two adjusting parts 11 located at the lower layer, and at least two driving modules 12;

[0075] The focusing portion 10 is annular and surrounds the periphery of the wafer 16 during the process. The upper surface 100 of the focusing portion is a plane, and the lower surface 101 of the focusing portion is set as an inclined surface inclined toward the wafer 16;

[0076] The lower surface 111 of the adjusting portion is a plane, and the upper surface 110 of the adjusting portion is configured as an inclined surface inclined toward the wafer 16;

[0077] During the process, the upper surface 110 of the adjusting portion and the lower surface 101 of the focusing portion are connected by the engagement of the recess 13 and the protrusion 14, and the recess 13 and the protrusion 14 can slide relative to each other under the push of an external force;

[0078] During the process, at least two of the driving modules 12 are disposed one by one on the outside of the adjusting portion 11 to push the adjusting portion 11 to achieve relative sliding between the recess 13 and the protrusion 14;

[0079] When the focusing ring is initially unused, the adjusting portion 11 is engaged with the focusing portion 10 until the sum of their thicknesses reaches a maximum, and the upper surface of the focusing portion 10 is higher than the upper surface of the wafer 16 .

[0080] What needs to be explained here is Figure 8 In the top view, in order to facilitate understanding of the positional relationship between the adjustment part 11 and the focusing part 10, the adjustment part 11 is schematically shown in the figure. In fact, the adjustment part 11 is located below the focusing part 10 and cannot be observed in the top view.

[0081] like Figures 5 to 7 As shown in FIG. 1 , it schematically illustrates the process in which the focusing portion 10 is lifted upwards while the adjusting portion 11 is horizontally moved. Figure 5 As shown in FIG. 1 , at the beginning, the protrusion 14 on the adjusting portion 11 engages with the recess 13 on the outermost side (i.e., the right side in the figure) of the focusing portion 10, and at this time, the vertical height of the entire focusing ring is H1; Figure 6 As shown in FIG. 1 , when the adjusting portion 11 is horizontally moved to the left by three steps (i.e., the protrusion 14 of the adjusting portion 11 is moved to the left by three recesses 13), the vertical height of the entire focus ring is H2. Since the upper surface 110 of the adjusting portion is an inclined surface, the vertical height of the entire focus ring can be gradually increased as the adjusting portion 11 is horizontally moved to the left, i.e., H2>H1. Figure 7 As shown, when the adjusting portion 11 is moved horizontally to the left to engage with the innermost recess 13 of the focusing portion 10 (i.e., the leftmost side in the figure), the vertical height of the entire focusing ring is H3, reaching the highest height of the focusing ring, and at this time H3>H2.

[0082] Therefore, the present embodiment divides the focusing ring into a focusing part 10 and an adjusting part 11, and sets the lower surface 101 of the focusing part and the upper surface 110 of the adjusting part located in the upper layer as inclined surfaces inclined toward the wafer direction, and connects the two by means of a relative sliding engagement between the recess and the protrusion. This arrangement can achieve that when the focusing part 10 is gradually consumed and thinned as the plasma etching time accumulates, causing the plasma shell to become "bent" at the edge of the wafer, by pushing the driving module 12, the engagement between the recess or protrusion of the adjusting part 11 and the protrusion or recess of the focusing part 10 produces relative sliding, so that the adjusting part 11 moves toward the wafer 16, so as to achieve the purpose of driving the focusing part 10 to lift upward, and finally adjust the upper surface height of the focusing part 10 to be consistent with the wafer surface height, thereby effectively reducing or even avoiding the problem of the plasma shell "bending" at the edge area of ​​the wafer.

[0083] As an example, when the upper surface 110 of the adjusting portion is engaged with the lower surface 101 of the focusing portion through the recess 13 and the protrusion 14, the recess 13 can be provided on the lower surface 101 of the focusing portion or on the upper surface 110 of the adjusting portion, and the corresponding protrusion can be provided on the upper surface 110 of the adjusting portion or on the lower surface 101 of the focusing portion. In this embodiment, the recess 13 is provided on the lower surface 101 of the focusing portion, and the protrusion 14 is provided on the upper surface 110 of the adjusting portion.

[0084] As an example, the number of the recesses 13 and the number of the protrusions 14 are set according to actual needs. Generally, the number of the recesses 13 or protrusions 14 on the lower surface 101 of the focusing portion is greater than the number of the recesses 14 or protrusions 14 on the upper surface 110 of the adjusting portion. In this embodiment, the number of protrusions 14 is selected to be 3 to 15, and the number of the recesses 13 is selected to be 3 to 15. In addition, there is no excessive restriction on the shapes of the recesses 13 and the protrusions 14, as long as the two can be engaged and can slide relative to each other under the push of external force. Based on the convenience of process processing, in this embodiment, the shapes of the protrusions 14 and the recesses 13 are preferably adapted hemispherical.

[0085] Based on the consideration of the allowable conditions for reducing the "bending" of the plasma shell at the edge of the wafer, the depression 13 and the protrusion 14 are selected to slide relative to each other by one step, that is, the height of the focusing portion 10 rises or falls by 0.5mm to 3mm, that is, the adjustment portion 11 controls the step distance of the focus portion 10 to rise or fall by 0.5mm to 3mm. Figure 6For example, when the protrusion 14 of the adjusting portion 11 moves horizontally to the left, the focusing portion 10 is lifted upward by 0.5mm to 3mm, and when the protrusion 14 of the adjusting portion 11 moves horizontally to the right, the focusing portion 10 is lowered by 0.5mm to 3mm. The step distance of the adjusting portion 11 controlling the focus portion 10 to rise or fall is jointly determined by the inclination angle of the inclined surfaces of the two and the distance between adjacent protrusions 14 or adjacent recesses 13, which can be obtained by calculation.

[0086] like Figure 4 As shown, as a preferred example, the upper surface 110 of the adjusting portion is set as an inclined surface inclined toward the center of the wafer, and the lower surface 101 of the focusing portion is set as an inclined surface inclined toward the center of the wafer. More preferably, the upper surface 110 of the adjusting portion and the lower surface 101 of the focusing portion have the same inclination angle to achieve optimal stability between the two in the bite state. In this embodiment, the inclination angle of the upper surface 110 of the adjusting portion and the lower surface 101 of the focusing portion is selected to be 30° to 60°.

[0087] like Figure 8 As shown, as a preferred example, the horizontal projection of the focusing portion 10 completely covers the adjusting portion 11. This is to prevent the adjusting portion 11 from occupying a larger area of ​​the entire focusing ring during the plasma etching process, thereby preventing some adverse effects on the etching effect.

[0088] like Figure 8 As shown, as another preferred example, the adjusting parts 11 are evenly arranged along the circumferential direction. The evenly arranged adjusting parts 11 along the circumferential direction can realize that when the driving module 12 drives the adjusting parts 11, since the inclined surfaces of the adjusting parts 11 and the focusing parts 10 are both inclined toward the wafer direction, the horizontal components of the driving force cancel each other out, so that the lower adjusting parts 11 can ensure the static state of the upper focusing parts 10 when they move horizontally toward the wafer direction.

[0089] As an example, the sum of the areas of the lower surfaces 111 of all the adjusting parts is 20% to 40% of the area of ​​the upper surface 100 of the focusing part. Figure 8 As shown, three adjusting parts 11 are provided, and the sum of the areas of the three adjusting part lower surfaces 111 of the three adjusting parts 11 is 20% to 40% of the area of ​​the focusing part upper surface 100 .

[0090] As an example, the shape of the adjusting portion 11 can be set to be a wedge-shaped body, but there is no excessive restriction on whether the adjusting portion 11 is a regular wedge-shaped body, as long as the upper surface 110 of the adjusting portion and the lower surface 101 of the focusing portion can be engaged with each other.

[0091] As an example, the adjustment portion 11 and the focusing portion 10 of the focusing ring are made of the same material, which may be a semiconductor material such as quartz, silicon, silicon nitride, or silicon carbide.

[0092] The purpose of this embodiment is to reduce the problem of the plasma shell bending at the edge of the wafer by adjusting the height of the upper surface of the focusing portion 10. Therefore, when the focusing ring is not used initially, the thickness of the adjusting portion 11 and the focusing portion 10 that are engaged with each other and the maximum thickness (such as Figure 7 In the engaged state shown in the figure), the upper surface of the focusing portion 10 is higher than the upper surface of the wafer 16, so that after the upper surface of the focusing portion 10 is consumed and thinned, the upper surface of the focusing portion 10 can be kept within a reasonable height range with the upper surface of the wafer 16 through the horizontal movement of the adjusting portion 11. In the present embodiment, preferably, when the sum of the thicknesses of the adjusting portion 11 and the focusing portion 10 engaged with each other reaches the maximum, the height difference between the upper surface height of the focusing portion 10 and the upper surface height of the wafer 16 is 1 to 1.5 times the thickness of the wafer 16. It should be noted here that when the sum of the thicknesses of the adjusting portion 11 and the focusing portion 10 engaged with each other is the minimum (as shown in the figure), the upper surface of the focusing portion 10 is higher than the upper surface of the wafer 16, so that the upper surface of the focusing portion 10 is kept within a reasonable height range with the upper surface of the wafer 16 through the horizontal movement of the adjusting portion 11. Figure 5 As shown), the lower surface 101 of the focusing portion may be in contact with the surface of the base 15 (as shown Figure 3 As shown), it can also be higher than the surface of the base 15 and in a suspended state. The specific selection is made according to design requirements and no excessive restrictions are made here.

[0093] As another specific example, Fig. 9 and Fig.10 As shown, the focusing ring includes: a focusing portion 10 located at the upper layer, an adjusting portion 11 located at the lower layer, and a driving module; the adjusting portion 11 is annular and concentrically located below the focusing portion 10;

[0094] like Fig. 9 As shown, at least three first tracks 102 are evenly arranged on the lower surface of the focusing portion 10 along the circumferential direction, and the first tracks 102 extend along the radial direction of the focusing portion 10, and at the same time, the lower surface of the focusing portion 10 within the first tracks 102 is arranged as an inclined surface 103 inclined toward the vertical direction along the extension direction of the first tracks 102;

[0095] like Fig.10 As shown, at least three second tracks 112 are evenly arranged on the upper surface of the adjusting portion 11 along the circumferential direction, and the second tracks 112 extend along the radial direction of the adjusting portion 11, and the upper surface of the adjusting portion 11 within the second tracks 112 is a horizontal surface 113;

[0096] The first track 102 and the second track 112 extend radially in different ways;

[0097] After the focusing part 10 is placed on the adjusting part 11, all the first tracks 102 overlap with all the second tracks 112 in a one-to-one correspondence, and driving beads 25 are arranged in the overlapping area, so that a part of the driving beads 25 is located in the first track 102, and another part is located in the second track 112;

[0098] The driving module is used to drive the adjusting portion 11 to rotate in a horizontal direction and drive the driving ball 25 to move along an extending direction of the first track 102 .

[0099] When the driving module drives the adjusting part 11 to rotate in the horizontal direction, since the radial extension modes of the first track 102 and the second track 112 are different, the driving beads 25 located in the overlapping area of ​​the first track 102 and the second track 112 will move along the extension direction of the first track 102 due to the horizontal rotation of the adjusting part. At this time, since the surface inside the first track 102 is an inclined surface 103 and the surface inside the second track 112 is a horizontal surface 113, the driving beads 25 can move uphill / downhill in the first track 102 as the driving beads 25 move, while the adjusting part 11 does not move in the height direction, so the vertical distance between the focusing part 10 and the adjusting part 11 gradually changes (depending on the rotation direction of the adjusting part 11, the vertical distance gradually increases or decreases). Thus, when the focusing portion 10 is continuously consumed and gradually becomes thinner as the plasma etching time accumulates, causing the plasma shell to become "bent" at the edge of the wafer, the driving module drives the adjusting portion 11 to rotate in the horizontal direction to increase the vertical distance between the focusing portion 10 and the adjusting portion 11, thereby achieving the purpose of lifting the focusing portion 10, and finally adjusting the upper surface height of the focusing portion 10 to be consistent with the surface height of the wafer, thereby effectively reducing or even avoiding the problem of "bending" of the plasma shell in the edge area of ​​the wafer.

[0100] The driving method of the adjusting part 11 by the driving module is not excessively restricted. Any driving module that can enable the adjusting part 11 to rotate in the horizontal direction (including counterclockwise rotation and / or clockwise rotation) is acceptable, for example, it can be a meshing gear driving mode or a motor driving mode.

[0101] like Fig. 9 and Fig.10 As shown, four first tracks 102 are evenly arranged on the lower surface of the focusing portion 10 along the circumferential direction; and four second tracks 112 are evenly arranged on the upper surface of the adjusting portion 11 along the circumferential direction.

[0102] Preferably, if Fig. 9 and Fig.10 As shown, the first track 102 is a straight track, and the second track 112 is an arc track. The second track 112 is set as an arc track, which can amplify the rotation control of the adjustment part 11 and facilitate precision control. For example, when the adjustment part 11 is driven by a motor to rotate, the focus part 10 rises in the form of an arc plus a straight track, and the design of the inclined surface in the straight track realizes two mechanical amplification methods, so the precision control requirements of the motor can be reduced; and if a motor with fine rotation precision control is used to control the rotation of the adjustment part 11, after amplification, the control process can be further amplified, which is more conducive to control, and then the setting of components such as sensors can be reduced by setting the start-up time of the adjustment part 11 and the motor to be linked (or the two form a strong correlation), and the instability is also reduced. Of course, the first track 102 can also be another arc track different from the second track 112, so that the upper and lower arc tracks can cooperate to amplify the rotation of the adjustment part 11 again, so that the control process of the rising precision of the focus part 10 becomes longer, which is more conducive to precision control.

[0103] like Figure 3 As shown, this embodiment also provides a plasma etching device, and the plasma etching device includes:

[0104] an etching chamber (not shown);

[0105] A base 15 serving as a lower electrode and a wafer carrier is disposed at the bottom of the etching chamber;

[0106] An upper electrode is arranged above the etching chamber and opposite to the base 15;

[0107] The base 15 and one of the upper electrodes are connected to a radio frequency source;

[0108] The focusing ring described in this embodiment is arranged around the outer circumference of the base 15 in the etching chamber.

[0109] The plasma etching device has the same technical effects as the above-mentioned focusing ring, which will not be discussed again here.

[0110] As an example, the plasma etching apparatus is suitable for any etching apparatus that needs to use a focusing ring to adjust the uniformity of the plasma sheath, such as an ICP etching apparatus, a CCP etching apparatus, and the like.

[0111] In summary, the present invention provides a focusing ring and a plasma etching device, which divides the focusing ring into a focusing part and an adjusting part, and drives the adjusting part to move in the horizontal direction through a driving module, and transmits the displacement of the adjusting part in the horizontal direction to the displacement of the focusing part in the vertical direction. This arrangement can achieve that when the focusing part is gradually consumed and thinned as the plasma etching time accumulates, causing the plasma shell to become "bent" at the edge of the wafer, the displacement of the adjusting part in the horizontal direction is converted into the displacement of the focusing part in the vertical direction, so as to achieve the purpose of lifting the focusing part upward, and finally adjust the height of the upper surface of the focusing part to be consistent with the height of the wafer surface, thereby effectively reducing or even avoiding the problem of "bending" of the plasma shell in the edge area of ​​the wafer. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0112] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A focusing ring for a plasma etching device, characterized in that: The focusing ring comprises: a focusing part located at an upper layer, an adjusting part located at a lower layer and a driving module; The focusing portion is annular and surrounds the periphery of the wafer during the process, and the upper surface of the focusing portion is a plane; The driving module is used to drive the adjusting part to move in the horizontal direction; The adjustment part transmits its horizontal displacement into the vertical displacement of the focusing part.

2. The focusing ring according to claim 1, characterized in that: The focusing ring includes at least two adjusting parts and at least two driving modules; The lower surface of the focusing portion is configured as an inclined surface inclined toward the wafer; The lower surface of the adjusting portion is a plane, and the upper surface of the adjusting portion is configured as an inclined surface inclined toward the wafer; During the process, the upper surface of the adjusting portion and the lower surface of the focusing portion are connected by a recess and a protrusion bite mode, and the recess and the protrusion can slide relative to each other under the push of an external force; During the process, at least two of the driving modules are arranged one by one on the outer side of the adjusting part to push the adjusting part to achieve relative sliding between the depression and the protrusion; When the focusing ring is initially unused, the adjusting portion is engaged with the focusing portion until the sum of their thicknesses reaches a maximum, and the upper surface of the focusing portion is higher than the upper surface of the wafer.

3. The focusing ring according to claim 2, characterized in that: The upper surface of the adjusting portion is configured as an inclined surface inclined toward the center of the wafer, and the lower surface of the focusing portion is configured as an inclined surface inclined toward the center of the wafer.

4. The focusing ring according to claim 3, characterized in that: The depression and the protrusion slide relative to each other by one step, and the height of the focusing portion increases or decreases by 0.5 mm to 3 mm.

5. The focusing ring according to claim 2, characterized in that: The upper surface of the adjusting portion is provided with a plurality of the protrusions along the inclined direction, and the lower surface of the focusing portion is provided with a plurality of the recesses along the inclined direction; or the upper surface of the adjusting portion is provided with a plurality of the recesses along the inclined direction, and the lower surface of the focusing portion is provided with a plurality of the protrusions along the inclined direction.

6. The focusing ring according to claim 2, characterized in that: The horizontal projection of the focusing portion completely covers the adjusting portion.

7. The focusing ring according to any one of claims 2 to 6, characterized in that: The adjusting parts are evenly arranged along the circumferential direction.

8. The focusing ring according to claim 2, characterized in that: The protrusion and the depression are in a matching hemispherical shape; The number of the protrusions is 3 to 15, and the number of the depressions is 3 to 15.

9. The focusing ring according to claim 2, characterized in that: When the focusing ring is initially unused, the adjusting portion and the focusing portion are engaged and connected to a maximum thickness, and the height difference between the upper surface of the focusing portion and the upper surface of the wafer is 1 to 1.5 times the thickness of the wafer.

10. The focusing ring according to claim 2, characterized in that: The sum of the lower surface areas of all the adjusting parts is 20% to 40% of the upper surface area of ​​the focusing part.

11. The focusing ring according to claim 1, characterized in that: The adjusting portion is annular and concentrically located below the focusing portion; At least three first tracks are evenly arranged on the lower surface of the focusing portion along the circumferential direction, and the first tracks extend along the radial direction of the focusing portion, and the lower surface of the focusing portion in the first tracks is arranged as an inclined surface inclined toward the vertical direction along the extension direction of the first tracks; At least three second tracks are evenly arranged on the upper surface of the adjusting portion along the circumferential direction, and the second tracks extend along the radial direction of the adjusting portion, and the upper surface of the adjusting portion within the second tracks is a horizontal plane; The first track and the second track extend radially differently; After the focusing part is placed on the adjusting part, all the first tracks overlap with all the second tracks in a one-to-one correspondence, and driving beads are arranged in the overlapping area so that a part of the driving beads is located in the first track and another part is located in the second track; The driving module is used to drive the adjusting part to rotate in a horizontal direction and drive the driving bead to move along an extending direction of the first track.

12. The focusing ring according to claim 11, characterized in that: The first track is a straight track, and the second track is a curved track.

13. The focusing ring according to claim 11, characterized in that: The lower surface of the focusing portion is evenly provided with four first tracks along the circumferential direction; the upper surface of the adjusting portion is evenly provided with four second tracks along the circumferential direction.

14. A plasma etching device, characterized in that: The plasma etching device comprises: Etching cavity; A base serving as a lower electrode and a wafer supporter, arranged at the bottom of the etching chamber; An upper electrode is arranged above the etching chamber and opposite to the base; One of the base and the upper electrode is connected to a radio frequency source; The focusing ring as described in any one of claims 1 to 13 is arranged around the outer periphery of the base in the etching chamber.

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