CN111850517B

CN111850517B - Lower electrode assembly and process chamber

Info

Publication number: CN111850517B
Application number: CN202010614772.XA
Authority: CN
Inventors: 王福来
Original assignee: Beijing Naura Microelectronics Equipment Co Ltd
Current assignee: Beijing Naura Microelectronics Equipment Co Ltd
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2022-10-21
Anticipated expiration: 2040-06-30
Also published as: CN111850517A

Abstract

The invention discloses a lower electrode assembly and a process chamber, wherein the lower electrode assembly comprises a bearing disc and a turntable arranged in the central area of the bearing disc, interdigital fingers are arranged on the circumference of the turntable, and the turntable can rotate relative to the bearing disc and drive the interdigital fingers to lift, wherein: the turntable comprises a pressure plate, a fixed plate and at least one height adjusting component, wherein the pressure plate and the fixed plate are vertically stacked; each height adjusting component is used for adjusting the lifting height of each interdigital through adjusting the lifting height of the height adjusting component. The lifting height of each interdigital is adjusted by adjusting the lifting height of each height adjusting assembly, so that the lifting height of each interdigital can be independently adjusted, and the influence on a process result caused by upwarping of a wafer due to inconsistent interdigital heights on the turntable is avoided.

Description

Lower electrode assembly and process chamber

Technical Field

The invention relates to the technical field of semiconductor equipment, in particular to a lower electrode assembly and a process chamber.

Background

In a semiconductor processing apparatus, a turntable multi-station type process chamber is a highly efficient apparatus frame, which is commonly used in various Chemical Vapor deposition apparatuses CVD (Chemical Vapor deposition. Fig. 1 shows a schematic structural view of a conventional turntable, and as shown in fig. 1, a lower electrode (or heater) 101 of the structure has a plurality of wafer stations (6 shown in fig. 1) uniformly distributed on the circumference, each station has a groove for receiving an interdigital, the turntable 103 has a lifting and rotating action function, an interdigital 4 for lifting up a wafer 104 corresponds to each wafer station, the interdigital 4 is fixed on the turntable 103, and the interdigital 4 can fall into the groove on the lower electrode 101 when the turntable 103 is lowered, so as to place the wafer 4 on the lower electrode 101, and the wafer 4 sequentially passes through each station (or individual station) to be subjected to a corresponding process during the whole process.

When the wafer 104 lifting device works, the turntable 103 drives the interdigital 4 to vertically lift up, and the wafer 104 is lifted to a certain height; the turntable 103 then rotates one (or more) station clockwise or counterclockwise to transfer the wafer 104 to the next station; finally, the turntable 103 is vertically dropped, the fingers 4 are dropped into the grooves of the lower electrode 101, and the wafer is placed in a new station. And circulating in sequence, and realizing a production line type multi-station production mode.

The interdigital 4 in the structure is a part for supporting the wafer 104, the interdigital 4 and the turntable 103 can be used as a fixed structure or a non-fixed structure, the function of controlling the height of the interdigital 4 or the height consistency of the two interdigital 4 is mainly achieved, the problem of process uniformity is easily caused by the height inconsistency of the two interdigital 4, and therefore the influence of the interdigital 4 on the process relative to the top surface of the lower electrode is very important when the interdigital 4 is in the groove of the lower electrode 101.

Fig. 2 shows a schematic diagram of a two-finger interdigitated structure of a prior art turntable. As shown in fig. 2, the finger structure is very simple, i.e. two long strips like fingers are passed through the middle of the wafer, and when the wafer is moved, the finger 4 is located right under the wafer.

Fig. 3 shows a schematic diagram of the connection of the prior art finger to the turntable, fig. 4 shows a schematic diagram of the relative fixed relationship of the prior art finger to the turntable, and fig. 5 shows a schematic diagram of the connection of the prior art finger to the reed. As shown in fig. 3 to 5, the turntable is composed of an upper part and a lower part, and comprises a fixed disk 1 and a pressure plate 2, wherein the fixed disk 1 plays a role in supporting and positioning the interdigital fingers 4; the pressure plate 2 is connected and matched with the fixed plate 1 through a connecting bolt 9, and the upper and lower positions of the interdigital 4 are limited; a reed 7 is arranged between the fixed disk 1 and the pressure plate 2, the reed 7 is generally of an inverted V-shaped structure and has certain compression capacity, two fulcrums at the lower end are respectively fixed on the upper surfaces of the fixed disk 1 and the interdigital 4, one fulcrum at the upper part is contacted with the bottom surface of the pressure plate 2, when the pressure plate 2 presses down the fixed disk 1, the reed 7 deforms, pressing force is generated downwards by the two fulcrums at the lower part, one fulcrum acts on the fixed disk to ensure that the reed 7 does not displace, and the other fulcrum presses down the interdigital 4 to ensure that the interdigital 4 is fixed on the fixed disk 1.

The above prior art has the following disadvantages:

1. the reed only plays a downward role on the interdigital, when the groove of the fixed disk is deformed or the matching between the interdigital and the groove is poor, the two interdigital have the condition of one high and one low, which leads to the upwarping of the wafer above the interdigital and influences the process result.

2. The reed has elasticity inefficacy condition itself, because whole set of mechanism is in high temperature corrosion environment, uses the leaf spring to have the inefficacy risk for a long time.

Disclosure of Invention

The invention provides a lower electrode assembly and a process chamber, which can enable each interdigital to independently complete height adjustment and solve the problem of inconsistent height of the interdigital.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a lower electrode assembly, including a carrier plate and a turntable disposed in a central region of the carrier plate, wherein fingers are disposed on a circumferential direction of the turntable, and the turntable is capable of rotating relative to the carrier plate and driving the fingers to move up and down, wherein:

the turntable comprises a pressure plate, a fixed plate and at least one height adjusting assembly, wherein the pressure plate and the fixed plate are vertically stacked, and the height adjusting assembly is arranged between the pressure plate and the fixed plate;

each height adjusting assembly is used for adjusting the lifting height of the interdigital through adjusting the lifting height of the height adjusting assembly.

Preferably, at least one positioning groove is formed along the circumferential direction of the fixed disk, and each positioning groove is used for accommodating one interdigital;

the pressure plate is used for pressing the interdigital into the positioning groove;

every height adjusting element all corresponds and sets up in one in the constant head tank for through adjusting itself is in the lift height in the constant head tank adjusts the lift height of interdigital.

Preferably, each height adjusting assembly comprises an adjusting block and a pair of adjusting screws, the adjusting screws are respectively connected to two ends of the adjusting block through threads and penetrate through the adjusting block, and the tail ends of the adjusting screws are in contact with the groove bottom in the positioning groove.

Preferably, the constant head tank includes the edge first cell body and the perpendicular to of the radial setting of fixed disk the second cell body of first cell body, first cell body with the crossing and the plane at the two place of second cell body with the plane at fixed disk place is parallel, first cell body is used for holding the finger, the second cell body is used for placing the regulating block, the top of regulating block is equipped with the recess, the recess is located in the first cell body, a part of finger set up in first cell body with in the recess.

Preferably, a pair of first through holes is formed in two ends of the adjusting block, each first through hole is used for being in threaded connection with one adjusting screw, and the tail end of each adjusting screw is in contact with the bottom of the second groove body so as to adjust the adjusting block to ascend or descend;

the pressure plate is provided with a plurality of second through holes, each second through hole is coaxial with one first through hole, and the top end of the adjusting screw is arranged in the second through hole.

Preferably, the middle part undercut of second cell body forms deep groove structure, the regulating block is the font of falling several, locate at the middle part of regulating block in the deep groove structure, set up in the both sides of regulating block the tank bottom of second cell body.

Preferably, a plurality of screw holes are formed in the surface of the pressure plate along the circumferential direction of the pressure plate, and the pressure plate is connected with the fixed plate through screws located in the screw holes.

Preferably, the depth of the deep groove structure is smaller than the thickness of the fixed disk.

Preferably, the carrier plate is provided with at least one finger groove for receiving the finger when the finger is lowered.

According to another aspect of the present invention, a process chamber is provided comprising the lower electrode assembly.

The invention has the beneficial effects that:

1. the lifting height of each interdigital is adjusted by adjusting the lifting height of each height adjusting assembly, so that the lifting height of each interdigital can be independently adjusted, and the influence on a process result caused by upwarping of a wafer due to inconsistent height of the interdigital on the turntable is avoided.

2. Every altitude mixture control subassembly all includes regulating block and a pair of adjusting screw, runs through the degree of depth of regulating block through adjusting a pair of adjusting screw, makes the regulating block can be raised and reduce for the fixed disk to adjust the lift height of interdigital, this subassembly can adjust the interdigital height at any time, has increased the convenience that the interdigital goes up and down the altitude mixture control, simultaneously because the relation of connection between each part of this altitude mixture control subassembly is rigid connection, can not appear the shape change because of the temperature variation, can avoid appearing the condition of inefficacy because of the temperature variation.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The invention will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present invention have been illustrated in the accompanying drawings, it is to be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Fig. 1 shows a schematic structure of a conventional turntable.

Fig. 2 shows a schematic diagram of a two-finger interdigitated structure of a prior art turntable.

Fig. 3 shows a schematic diagram of the connection of the conventional finger to the rotary table.

Fig. 4 is a schematic diagram showing the fixed relationship of the conventional finger to the turntable.

Figure 5 shows a schematic view of a prior art finger to reed connection.

FIG. 6 illustrates a schematic structural view of a height adjustment assembly according to one embodiment of the present invention.

Fig. 7 shows a partial enlarged view at I in fig. 6.

Figure 8 illustrates a cross-sectional view of a height adjustment assembly along the direction of the interdigitation in accordance with one embodiment of the present invention.

Figure 9 illustrates a cross-sectional view of a height adjustment assembly in a vertical interdigitating direction, in accordance with one embodiment of the present invention.

Description of the reference numerals:

1. fixing the disc; 2. pressing a plate; 3. an adjusting block; 4. interdigital fingers; 5. an adjusting screw; 6. a screw; 7. a reed; 8. positioning a projection; 9. a connecting bolt; 101. a lower electrode; 103. a turntable; 104. a wafer.

Detailed Description

Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

According to an embodiment of the invention, the lower electrode assembly comprises a bearing disc and a rotating disc arranged in the central area of the bearing disc, wherein fingers are arranged on the circumference of the rotating disc, and the rotating disc can rotate relative to the bearing disc and drive the fingers to lift, wherein: the turntable comprises a pressure plate, a fixed plate and at least one height adjusting assembly, wherein the pressure plate and the fixed plate are vertically stacked, and the height adjusting assembly is arranged between the pressure plate and the fixed plate; each height adjusting component is used for adjusting the lifting height of each interdigital through adjusting the lifting height of the height adjusting component. The lifting height of each interdigital is adjusted by adjusting the lifting height of each height adjusting assembly, so that the lifting height of each interdigital can be independently adjusted, and the influence on a process result caused by upwarping of a wafer due to inconsistent interdigital heights on the turntable is avoided.

As an example, during the process of installing the fingers, when most fingers are in the same plane, the height of each finger can be finely adjusted by the finger height adjusting assembly, and the height difference of the top end of each finger can be adjusted within the range of +/-0.2 mm as required, so that the fingers not in the plane can achieve the coplanarity requirement.

As an example, the lower portion of the rotating disc is provided with a rotating member, the rotating disc is connected with the central region of the carrying disc through the rotating member, and the rotating member is used for driving the rotating disc to rotate and move up and down relative to the carrying disc.

As an example, the periphery of the rotating disc is provided with at least one mounting station, and each mounting station is provided with a pair of fingers;

as a preferred scheme, at least one positioning groove is formed in the circumferential direction of the fixed disc, and each positioning groove is used for accommodating one interdigital; the pressing disc is used for pressing the fingers in the positioning grooves; every altitude mixture control subassembly all corresponds and sets up in a constant head tank for through adjusting the self height of going up and down in the constant head tank, adjust the height of going up and down of interdigital.

Be provided with at least one station in the circumference of fixed disk, the marginal area of every station is equipped with at least one constant head tank, and the constant head tank of fixed disk is used for holding an interdigital, can support and fix a position the interdigital, and the pressure disk compresses tightly the interdigital in the constant head tank, restricts the upper and lower position of interdigital, and height adjusting part is used for adjusting the lift height of interdigital, through set up a height adjusting part in every constant head tank, can adjust every interdigital height alone.

As preferred scheme, each height adjustment subassembly all includes regulating block and a pair of adjusting screw, and a pair of adjusting screw passes through threaded connection in the both ends of regulating block and runs through the regulating block respectively, and adjusting screw's tail end and the tank bottom contact in the constant head tank.

As an example, the height adjusting assembly is a rigid mechanism, that is, the assemblies have a definite relative motion relationship, and the condition that the spring force fails to adjust the height of the finger as in the prior art, and the condition that the spring force fails to adjust the height of the finger as well as the condition that the spring force fails to adjust the height of the finger due to temperature change cannot occur. In the use, if the high nonconformity condition appears in the individual interdigital, through adjusting the degree of depth that a pair of adjusting screw runs through the regulating block, make adjusting screw's tail end and the tank bottom contact of constant head tank to make the regulating block drive the interdigital and raise for the fixed disk, thereby adjust the interdigital and go up and down the height, a pair of screw symmetry sets up in the both ends of regulating block, can adjust the interdigital and go up and down the height simultaneously, can also adjust the levelness of interdigital. The method is suitable for adjusting and compensating the condition of inconsistent interdigital height caused by deformation of the fixed disk and the pressure disk, avoids the wafer upwarping caused by inconsistent interdigital height, and ensures the process result.

As preferred scheme, the constant head tank includes the first cell body that radially sets up along the fixed disk and the second cell body of the first cell body of perpendicular to, and first cell body and second cell body are crossing and the plane at the two place is parallel with the plane at fixed disk place, and first cell body is used for holding the interdigital, and the second cell body is used for placing the regulating block, and the top of regulating block is equipped with the recess, and the recess is located first cell body, and the partly of interdigital sets up in first cell body and recess.

Specifically, first cell body can support and fix a position the interdigital, and the second cell body is used for placing the regulating block, and the interdigital can pass the recess of regulating block, sets up in the top of regulating block, runs through the length of regulating block through adjusting a pair of adjusting screw, makes adjusting screw's tail end and the tank bottom contact of second cell body to the regulating block drives the interdigital and raises and reduce for the fixed disk.

The width of first cell body and recess is unanimous with the width of interdigital, and the position correspondence setting of first cell body and recess can be with the partly firm setting in first cell body and recess of interdigital, adjusts the lift height of regulating block through a pair of adjusting screw to drive the interdigital, carry out the high regulation of going up and down to it.

As an example, the first slot is used for accommodating the finger, the second slot is used for placing the adjusting block, and the depth of the first slot is smaller than that of the second slot, so that the finger can be arranged above the adjusting block.

As an example, the periphery of the lower surface of the pressure plate is provided with at least one positioning protrusion, the fingers are provided with positioning grooves, and each positioning protrusion is connected with one positioning groove in a matching manner and used for limiting the fingers to be fixed relative to the pressure plate.

As a preferred scheme, a pair of first through holes are formed in the two ends of the adjusting block, each first through hole is used for being in threaded connection with an adjusting screw, and the tail end of each adjusting screw is in contact with the bottom of the second groove body so as to adjust the adjusting block to ascend or descend; a plurality of second through holes are formed in the pressure plate, each second through hole is coaxially arranged with one first through hole, and the top end of the adjusting screw is arranged in the second through hole.

Specifically, adjusting screw passes through the regulating block through first through-hole to adjusting screw's tail end and the tank bottom contact of second cell body, in order to adjust the lift height of regulating block. Through the second on the pressure disk, can rotate adjusting screw to adjust the lift height of regulating block, increase the convenience that the fork goes up and down altitude mixture control.

As preferred scheme, the middle part of second cell body is sunken downwards and is formed the deep trouth structure, and the regulating block is the font of falling several, and in the deep trouth structure was located to the middle part of regulating block, the tank bottom of second cell body was set up to the both sides of regulating block.

The lifting height of the interdigital can be adjusted by adjusting the lifting height of the adjusting block relative to the deep groove structure. The two sides of the adjusting block are erected at the bottom of the second groove body, the lifting heights of the two sides of the adjusting block can be symmetrically adjusted, and the levelness of the interdigital is correspondingly adjusted.

Preferably, the surface of the pressure plate is provided with a plurality of screw holes along the circumferential direction, and the pressure plate is connected with the fixed plate through screws in the screw holes. A plurality of screws that circumference set up on through the pressure disk make pressure disk and fixed disk be connected, guarantee pressure disk and fixed disk circumference connected's compactness.

Preferably, the depth of the deep groove structure is smaller than the thickness of the fixed disc. The lifting height of the interdigital can be adjusted by adjusting the lifting height of the adjusting block.

Preferably, the carrier plate is provided with at least one finger recess for receiving a finger when the finger is lowered.

Specifically, each finger of the turntable corresponds to one finger groove, so that the finger can fall into the finger groove when falling. A process chamber according to an embodiment of the present invention includes the lower electrode assembly described above. The process chamber of the embodiment of the invention comprises the lower electrode assembly. In the process chamber of the embodiment, the lower electrode assembly is provided with the interdigital height adjusting assembly, and the lifting height of each interdigital is adjusted by adjusting the lifting height of each height adjusting assembly, so that the lifting height of each interdigital can be independently adjusted, and the influence on the process result caused by the upwarp of the wafer due to the inconsistent height of the interdigital on the turntable is avoided.

Examples

Fig. 6 shows a schematic structural view of a height adjusting assembly according to an embodiment of the present invention, fig. 7 shows a partially enlarged view at I in fig. 6, and fig. 8 shows a cross-sectional view of the height adjusting assembly in the interdigital direction according to an embodiment of the present invention.

As shown in fig. 6 to 9, the lower electrode assembly of this embodiment includes a bearing disc and a rotating disc disposed in a central region of the bearing disc, wherein fingers 4 are disposed in a circumferential direction of the rotating disc, the rotating disc is capable of rotating relative to the bearing disc and driving the fingers 4 to ascend and descend, the bearing disc is provided with at least one finger groove, and when the fingers 4 descend, the finger groove is used for accommodating the fingers 4. Wherein: the turntable comprises a pressure plate 2 and a fixed plate 1 which are vertically stacked, and at least one height adjusting component arranged between the pressure plate 2 and the fixed plate 1; each height adjusting component is used for adjusting the lifting height of the interdigital fingers 4 by adjusting the lifting height of the height adjusting component.

The circumference of pressure disk 2 lower surface is equipped with at least one location arch 8, and fork 4 is equipped with positioning groove, and every location arch 8 is connected with a positioning groove cooperation for it is fixed for pressure disk 2 to restrict fork 4.

At least one positioning groove is formed along the circumferential direction of the fixed disk 1, and each positioning groove is used for accommodating an interdigital; the pressure plate 2 is used for pressing the interdigital 4 in the positioning groove; every altitude mixture control subassembly all corresponds and sets up in a constant head tank for through adjusting the self height of going up and down in the constant head tank, adjust the height of going up and down of interdigital. Every height adjusting assembly all includes regulating block 3 and a pair of adjusting screw 5, and a pair of adjusting screw 5 just runs through regulating block 3 through threaded connection in the both ends of regulating block 3 respectively, and adjusting screw 5's tail end contacts with the tank bottom in the constant head tank.

The constant head tank includes the first cell body of the radial setting along fixed disk 1 and the second cell body of the first cell body of perpendicular to, and first cell body and second cell body are crossing and the plane at the two place is parallel with the plane at fixed disk 1 place, and first cell body is used for holding fork 4, and the second cell body is used for placing regulating block 3, and the top of regulating block 3 is equipped with the recess, and the recess is located first cell body, and the partly of fork 4 sets up in first cell body and recess. A pair of first through holes are formed in the two ends of the adjusting block 3, each first through hole is used for being in threaded connection with an adjusting screw 5, and the tail end of each adjusting screw 5 is in contact with the bottom of the second groove body so as to adjust the adjusting block 3 to ascend or descend; a plurality of second through holes are formed in the pressure plate 2, each second through hole is coaxially arranged with one first through hole, and the top end of the adjusting screw 5 is arranged in each second through hole.

The middle part undercut of second cell body forms deep groove structure, and regulating block 3 is for falling a few font, and in the deep groove structure was located at the middle part of regulating block 3, the tank bottom of second cell body was set up to the both sides of regulating block 3, and the degree of depth of deep groove structure is less than the thickness of fixed disk 1.

The surface of the pressure plate 2 is provided with a plurality of screw holes along the circumferential direction, and the pressure plate 2 is connected with the fixed plate 1 through screws 6 positioned in the screw holes.

When the lower electrode assembly is installed, the adjusting block 3 needs to be placed in the second groove body of the positioning groove in advance, the first groove body of the positioning groove is used for installing the interdigital 4, at the moment, the groove bottom of the groove of the adjusting block 3 is lower than the bottom surface of the first groove body, and the interdigital 4 is installed in the first groove body and the groove along the length direction of the interdigital 4; then, the pressure plate 2 is pre-installed, the pressure plate 2 does not need to be pressed, and the height of the far end of each finger 4 is inconsistent (or higher or lower) because a gap exists between the pressure plate 2 and the fixed plate 1 and the surface flatness influences the matching of the pressure plate and the fixed plate and the plane of the finger.

Through screwing two adjusting screw 5 of installing on regulating block 3, adjusting screw 5 passes through threaded connection with regulating block 3, when adjusting screw 5 screwed out the first through-hole of regulating block 3 downwards, the tail end of adjusting screw 5 contacts with the tank bottom of second cell body, adjusting screw 5 can't pass the tank bottom of second cell body downwards, be raised regulating block 3 for the deep groove structure, the bottom surface of interdigital 4 breaks away from with the bottom surface of first cell body this moment, go up and down to suitable height with adjusting interdigital 4, adjust each interdigital 4 on the fixed disk 1 in proper order, make every interdigital 4 top surface be in the coplanar, adjust every interdigital 4's top difference in height to within a range of +/-0.2 mm as required. The lower electrode subassembly of this embodiment, through the degree of depth of adjusting a pair of adjusting screw through the regulating block, make the regulating block drive the interdigital and raise for the fixed disk, can adjust the lift height of interdigital at any time, increased the convenience of interdigital lift altitude mixture control.

While embodiments of the present invention have been described above, the above description is intended to be exemplary, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the illustrated embodiments.

Claims

1. The utility model provides a lower electrode subassembly, its characterized in that, including bear the dish with set up in bear the regional carousel in center of dish, the circumference of carousel is equipped with the interdigital, the carousel can for bear the dish and rotate and drive the interdigital goes up and down, wherein:

the turntable comprises a pressing plate (2) and a fixed plate (1) which are vertically stacked, and at least one height adjusting component arranged between the pressing plate (2) and the fixed plate (1);

each height adjusting assembly is used for adjusting the lifting height of each interdigital by adjusting the lifting height of the height adjusting assembly;

at least one positioning groove is formed in the circumferential direction of the fixed disc (1), and each positioning groove is used for accommodating one interdigital;

the pressing disc (2) is used for pressing the interdigital (4) in the positioning groove;

each height adjusting assembly is correspondingly arranged in one positioning groove and used for adjusting the lifting height of the interdigital through adjusting the lifting height of the interdigital in the positioning groove;

every the altitude mixture control subassembly all includes regulating block (3) and a pair of adjusting screw (5), a pair of adjusting screw (5) respectively through threaded connection in the both ends of regulating block (3) just run through regulating block (3), the tail end of adjusting screw (5) with tank bottom contact in the constant head tank.

2. The lower electrode assembly according to claim 1, wherein the positioning groove comprises a first groove body and a second groove body, the first groove body and the second groove body are arranged along the radial direction of the fixed disc (1), the first groove body and the second groove body are intersected, the plane where the first groove body and the second groove body are located is parallel to the plane where the fixed disc (1) is located, the first groove body is used for containing the interdigital (4), the second groove body is used for placing the adjusting block (3), a groove is formed in the top of the adjusting block (3), the groove is located in the first groove body, and a part of the interdigital (4) is arranged in the first groove body and the groove.

3. The lower electrode assembly according to claim 2, wherein a pair of first through holes are formed at two ends of the adjusting block (3), each first through hole is used for being in threaded connection with one adjusting screw (5), and the tail end of each adjusting screw (5) is in contact with the bottom of the second groove body so as to adjust the ascending or descending of the adjusting block (3);

a plurality of second through holes are formed in the pressure plate (2), each second through hole is coaxial with one first through hole, and the top end of the adjusting screw (5) is arranged in the second through hole.

4. The lower electrode assembly according to claim 3, wherein the middle of the second groove body is recessed downwards to form a deep groove structure, the adjusting block (3) is in an inverted T shape, the middle of the adjusting block (3) is arranged in the deep groove structure, and two sides of the adjusting block (3) are arranged on the bottom of the second groove body in an overlapping mode.

5. The lower electrode assembly according to claim 1, wherein a plurality of screw holes are provided in the surface of the pressure plate (2) in the circumferential direction thereof, and the pressure plate (2) is connected to the fixed disk (1) by screws (6) located in the screw holes.

6. A lower electrode assembly according to claim 4, characterized in that the depth of the deep groove structure is smaller than the thickness of the fixed disk (1).

7. The lower electrode assembly of claim 1, wherein the carrier tray is provided with at least one finger groove for receiving the fingers as the fingers are lowered.

8. A process chamber comprising the lower electrode assembly of any of claims 1-7.