A plasma processing apparatus

Abstract

The utility model provides a kind of plasma processing device, the processing device includes reaction chamber, first electrode, second electrode and cover body.Reaction chamber includes first cavity, first electrode is located in the upper portion of first cavity, and first electrode includes several air holes.Second electrode is located in the lower portion of first cavity, and it is oppositely arranged with first electrode.Cover body is set on first electrode, and it extends to second electrode.Wherein, at least part of the side wall of cover body is set in the periphery of at least one air hole, so as to effectively limit the diffusion range of chemical gas in reaction chamber, so as to improve the gas concentration of local area in cover body.When plasma is excited by electric field, the frequency of molecular collision is increased, sufficient plasma is generated, ignition failure is avoided, and the stability of plasma generation is improved.

Description

Technical Field

[0001] This utility model relates to the field of wafer etching technology, and in particular to a plasma processing device. Background Technology

[0002] Plasma is a state of matter composed of positive and negative ions and free electrons generated after atoms are ionized. Its movement is mainly governed by electromagnetic forces and is crucial in dry etching. In plasma processing devices, chemical gas is diffused into the reaction chamber via the upper electrode. Then, the electric fields of the upper and lower electrodes excite electrons to continuously collide with molecules, causing them to split into electrons and positive and negative ions, thereby forming more plasma. However, with the development of dry etching, ignition failure can occur in the initial stages of plasma excitation by the electric field. Summary of the Invention

[0003] This invention provides a plasma processing device to solve the technical problem of easy ignition failure in the initial stage of plasma excited by electric field.

[0004] This invention provides a plasma processing device, comprising a reaction chamber, a first electrode, a second electrode, and a cover. The reaction chamber includes a first cavity, with the first electrode located at the upper part of the first cavity and including a plurality of vent holes. The second electrode is located at the lower part of the first cavity and is disposed opposite to the first electrode. The cover is disposed on the first electrode and extends toward the second electrode. At least a portion of the sidewall of the cover is disposed around at least one of the vent holes.

[0005] In one embodiment of the present invention, the surface of the cover is coated with a yttrium oxide coating. In one embodiment of the present invention, the cover has a retracted state and an extended state facing the second electrode.

[0006] In one embodiment of this utility model, the plasma processing device further includes a driving mechanism. The cover includes a plurality of shells sequentially connected and slidably connected to adjacent shells to form a telescopic structure. The driving mechanism is connected to the shells to drive the shells to extend and retract.

[0007] In one embodiment of this utility model, the driving mechanism includes a motor, a reel, and a traction rope. The motor is fixedly mounted on the first electrode, and the reel is rotatably mounted on the first electrode and connected to the output end of the motor. The traction rope is disposed on the reel and is connected to the end of the cover opposite to the first electrode.

[0008] In one embodiment of this utility model, a first sliding guide mechanism is further provided between adjacent covers. The first sliding guide mechanism includes a first groove and a first slider. The first groove is disposed on one of the adjacent covers, and the first slider is disposed on the other, located at the end of the cover opposite to the second electrode. The first groove and the first slider are adapted to each other.

[0009] In one embodiment of this utility model, a second sliding guide mechanism is further provided between adjacent housings. The second sliding guide mechanism includes a second sliding groove and a second slider. The second sliding groove is disposed on one of the adjacent housings and is located on the same housing as the first slider. The second slider is disposed on the other housing and is located on the same housing as the first sliding groove. The second slider is located at the end of the housing opposite to the first electrode, and the second sliding groove is adapted to the second slider.

[0010] In one embodiment of this utility model, the cover is made of quartz or ceramic material.

[0011] In one embodiment of the present invention, the plasma processing device further includes a gas supply device, which is connected to a plurality of vent holes through a plurality of pipelines, and each of the pipelines is provided with a shut-off valve.

[0012] In one embodiment of the present invention, a position sensor is further provided at the end of the cover facing the second motor.

[0013] The beneficial effects of this invention are as follows: The plasma processing device proposed in this invention, by setting a cover on the first electrode, with at least a portion of the cover's sidewalls located around at least one vent, effectively limits the diffusion range of chemical gases within the reaction chamber, causing the chemical gases to concentrate in a localized area between the first and second electrodes, thereby increasing the gas concentration in that localized area. When the plasma is excited by an electric field, the high gas concentration in the localized area within the cover increases the frequency of molecular collisions, making the collisions between electrons and molecules more complete, thus making it easier to generate sufficient plasma, avoiding ignition failure, and improving the stability of plasma generation. Attached Figure Description

[0014] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0015] In the attached diagram: Figure 1This is a schematic diagram of the plasma processing device provided in one embodiment of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the plasma processing device provided in one embodiment of the present invention. Figure 2 ; Figure 3 This is a bottom view of the first electrode and its installation in one embodiment of the present invention; Figure 4 This is a top view of the cover structure provided in one embodiment of the present utility model; Figure 5 yes Figure 4 AA-direction cross-sectional view of the structure; Figure 6 for Figure 4 BB-direction cross-sectional view of the structure.

[0016] The attached figures are labeled as follows: 100. Reaction chamber; 110. First chamber; 200. First electrode; 210. Vent; 300. Second electrode; 400. Cover; 410. Shell; 411. First shell; 412. Second shell; 413. Third shell; 500. Drive mechanism; 510. Motor; 520. Reel; 530. Traction rope; 600. First sliding guide mechanism; 610. First slide groove; 620. First slider; 700. Second sliding guide mechanism; 710. Second slide groove; 720. Second slider; 800. Gas supply device; 810. Pipeline; 820. Shut-off valve; 900. Position sensor. Detailed Implementation

[0017] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0018] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0019] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0020] Please see Figures 1 to 6 This utility model provides a plasma processing device, which is mainly used for dry etching processes. For example... Figure 1 As shown, the processing apparatus includes a reaction chamber 100, a first electrode 200, a second electrode 300, and a housing 400. The reaction chamber 100 serves as the main body and core working area of ​​the entire apparatus, forming a essentially closed vacuum environment within which plasma is excited and maintained. In this embodiment, the internal space of the reaction chamber 100 is planned to include at least one first cavity 110. The first cavity 110 is the core area for performing the dry etching reaction. The first electrode 200 is fixedly installed in the upper space of the first cavity 110. The first electrode 200 is a radio frequency (RF) electrode, its function being to receive RF power provided by an external RF power supply for exciting chemical gases to generate plasma within the first cavity 110. The second electrode 300 is fixedly installed in the lower space of the first cavity 110. The second electrode 300 is typically used to support the workpiece to be processed, i.e., to support the wafer. The second electrode 300 can be a ground electrode or a bias electrode. The second electrode 300 is disposed opposite to the upper first electrode 200, forming a discharge region between them for generating plasma. The first electrode 200 includes several vent holes 210. Several vents 210 are connected to a gas supply device 800 outside the reaction chamber 100 via gas communication pipes. The gas supply device 800 can be an existing process gas supply system of an existing plasma processing device, used to inject precisely controlled chemical gas into the first chamber 110 through the vents 210.

[0021] Please see Figure 2 and Figure 3A cover 400 is disposed on the first electrode 200 and extends toward the second electrode 300. Specifically, the cover 400 is fixedly installed on the lower part of the first electrode 200, located on the side facing the second electrode 300, and extends toward the second electrode 300, forming an open chamber structure. The cover 400 can be fixedly installed on the first electrode 200 by means of snap-fit ​​or integral fixing, but is not limited thereto. The cover 400 can be a square cover or a circular cover. At least a portion of the sidewall of the cover 400 is disposed around at least one vent hole 210. Specifically, taking a circular cover 400 as an example, the sidewall of the cover 400 is a surrounding cylindrical structure, and at least one vent hole 210 is completely surrounded within the circular cross-sectional area enclosed by the sidewall of the cylindrical structure. The number of vent holes 210 surrounded by the cover 400 is not limited; it can be one or more, and can be determined comprehensively based on the number and distribution area of ​​the vent holes 210 distributed on the first electrode 200. The semi-enclosed cavity structure formed by the enclosure 400 and the first electrode 200 effectively restricts the diffusion range of chemical gas within the reaction chamber 100, causing the chemical gas to concentrate in a localized area between the first electrode 200 and the second electrode 300, thereby increasing the gas concentration in that localized area. When plasma is excited by an electric field in the area between the first electrode 200 and the second electrode 300, the high concentration of chemical gas in the vents 210 surrounding the area increases the frequency of molecular collisions, resulting in more complete collisions between electrons and molecules. This makes it easier to generate sufficient plasma, preventing ignition failure in the initial stages of the etching reaction and improving the stability of plasma generation.

[0022] In one embodiment of this invention, the surface of the cover 400 is coated with a yttrium oxide coating. Specifically, the yttrium oxide coating is applied to the inner and outer sidewalls of the cover 400, effectively preventing the plasma and chemical gases generated during plasma treatment from corroding the surface of the cover 400. This significantly extends the service life of the cover 400 and reduces maintenance and replacement costs due to corrosion.

[0023] Please see Figure 1 and Figure 2In one embodiment of this invention, the cover 400 has a contracted state and an extended state facing the second electrode 300. The cover 400 employs a telescopic structure design. In the initial stage of the dry etching reaction, the cover 400 extends towards the second electrode 300, forming a larger cavity structure. This concentrates the chemical gas within a local area of ​​the cover 400, reducing the diffusion rate of the chemical gas to the first cavity 110 outside the cover 400. The increased local gas concentration within the cover 400 increases the frequency of molecular collisions, leading to more complete collisions between electrons and molecules, thereby generating sufficient plasma. This prevents ignition failure in the initial stage of the etching reaction and improves the reliability of plasma generation. The extended state of the cover 400 makes the plasma generation area more concentrated, reducing the disordered diffusion of plasma within the reaction chamber 100. After successful ignition, the cover 400 contracts, expanding the plasma's effective range and allowing the plasma to diffuse more evenly throughout the entire first cavity 110. The structure of the shrinkage cover 400 is reduced, the space occupied by the cover 400 in the first cavity 110 is reduced, the etching effect on the wafer on the second electrode 300 is reduced, the plasma is ensured to be uniformly distributed in the first cavity 110, and the etching non-uniformity caused by insufficient local plasma is reduced.

[0024] Please see Figure 1 and Figure 2 In one embodiment of this utility model, the plasma processing device further includes a driving mechanism 500. The cover 400 includes multiple shells 410 sequentially nested and connected, with adjacent shells 410 slidably connected to form a telescopic structure. In the initial stage of ignition, the cover 400 can extend towards the second electrode 300, entering an extended state to increase the local gas concentration. The cover 400 can also retract away from the second electrode 300 to ensure uniform distribution of plasma in the first cavity 110, ensuring uniform wafer etching. The telescopic structure of the plasma processing device provides greater flexibility, allowing it to adjust the relative position and shape of the cover 400 according to different processing requirements and stages. The number of shells 410 is not limited; it can be two sets of nested telescopic structures or three sets of sequentially nested telescopic structures, but is not limited thereto. The driving mechanism 500 is a power driving mechanism for controlling the extension and retraction of multiple shells 410. The driving mechanism 500 is connected to the shells 410 to drive the extension and retraction of the shells 410. The drive mechanism 500 can be a cylinder drive mechanism, a ball screw drive mechanism, or a traction mechanism, but is not limited thereto.

[0025] Specifically, please refer to Figure 5In this embodiment, taking three circular covers 410 as an example, the cover 400 includes a first cover 411, a second cover 412, and a third cover 413 coaxially and sequentially nested. The diameters of the first cover 411, the second cover 412, and the third cover 413 increase sequentially. The upper end of the first cover 411 is fixedly connected to the first electrode 200. The second cover 412 is slidably connected to the outside of the first cover 411, forming a relative telescopic structure with the first cover 411. The third cover 413 is slidably connected to the outside of the second cover 412, forming a relative telescopic structure with the second cover 412. The power output end of the drive mechanism 500 is fixedly connected to the third cover 413. By driving the third cover 413 to rise and fall, the third cover 413 is telescopic relative to the second cover 412, and the second cover 412 is telescopic relative to the first cover 411.

[0026] Please see Figure 1 and Figure 2 In one embodiment of this utility model, the driving mechanism 500 adopts a traction mechanism. The driving mechanism 500 includes a motor 510, a reel 520, and a traction rope 530. The motor 510 serves as the power source of the driving mechanism 500 and is fixedly installed on the upper part of the first electrode 200. The reel 520 is rotatably installed on the first electrode 200 and connected to the output end of the motor 510. The traction rope 530 is provided on the reel 520 and is connected to the end of the cover 400 away from the first electrode 200. Specifically, the traction rope 530 passes through the first electrode 200 and connects to the third cover 413. When the cover 400 needs to extend, the motor 510 drives the reel 520 to rotate, and the traction rope 530 wound on the reel 520 is lowered. Under the action of gravity, the first cover 411, the second cover 412, and the third cover 413 extend, and the cover 400 is lowered to the extended state. Conversely, when the enclosure 400 needs to retract, the traction rope 530 pulls the third enclosure 413 upward, and the enclosure 400 retracts to its retracted state. This drive mechanism 500 has only a portion of the traction rope 530 located in the space between the first electrode 200 and the second electrode 300, avoiding excessive space occupied by other components in the space between the first electrode 200 and the second electrode 300, thereby reducing interference with the plasma distribution. It also avoids interference from additional mechanical components in the electric field, thus improving the uniformity of the electric field.

[0027] Please see Figure 5In one embodiment of this utility model, a first sliding guide mechanism 600 is further provided between adjacent housings 410. The first sliding guide mechanism 600 is used for sliding guidance during sliding movement between adjacent housings 410. The first sliding guide mechanism 600 includes a first sliding groove 610 and a first slider 620. The first sliding groove 610 is disposed on one of the adjacent housings 410, and the first slider 620 is disposed on the other, located at the end of the housing 410 away from the second electrode 300. The first sliding groove 610 and the first slider 620 are adapted to each other. Specifically, taking the adjacent housings 410 as the first housing 411 and the second housing 412 as an example, along the axial direction of the housing 400, the first sliding groove 610 is fixedly installed on the outer side wall of the first housing 411, and the first slider 620 is fixedly installed on the inner side wall of the second housing 412, located at the end of the second housing 412 away from the second electrode 300. The first cover 411 and the second cover 412 can be T-shaped groove structures or ball bearing structures, etc., but are not limited to these, as long as they can ensure smooth relative sliding of the first cover 411 and the second cover 412. The number of adjacent covers 410 is not limited; they can be two symmetrically arranged sets or multiple sets arranged circumferentially at intervals. Similarly, the first sliding guide mechanism 600 between the second cover 412 and the third cover 413 is similar and will not be described in detail here.

[0028] Please see Figure 6 In one embodiment of this utility model, a second sliding guide mechanism 700 is further provided between adjacent housings 410 to further improve the stability of sliding movement and extension / retraction between adjacent housings 410 and avoid extension / retraction jamming. The first sliding guide mechanism 600 and the second sliding guide mechanism 700 have similar structures. The second sliding guide mechanism 700 includes a second sliding groove 710 and a second slider 720. The second sliding groove 710 is disposed on one of the adjacent housings 410 and is located on the same housing 410 as the first slider 620. The second slider 720 is disposed on the other housing and is located on the same housing 410 as the first sliding groove 610. The second slider 720 is located at the end of the housing 410 away from the first electrode 200, and the second sliding groove 710 and the second slider 720 are adapted to each other. Specifically, taking the adjacent housings 410 as the first housing 411 and the second housing 412 as examples, along the axial direction of the housing 400, the second sliding groove 710 is fixedly installed on the inner side wall of the second housing 412, and the second slider 720 is fixedly installed on the outer side wall of the first housing 411, located at the end of the first housing 411 opposite to the first electrode 200. Similarly, the first sliding guide mechanism 600 between the second housing 412 and the third housing 413 is similar, and will not be described in detail here.

[0029] In one embodiment of this utility model, the cover 400 is made of quartz or ceramic material. Quartz or ceramic material has high heat resistance and thermal stability, and can reduce electric field interference between the first electrode 200 and the second electrode 300.

[0030] Please see Figure 1 In one embodiment of this utility model, the plasma processing device further includes a gas supply device 800. The gas supply device 800 is connected to a plurality of vent holes 210 through a plurality of pipes 810, and each pipe 810 is provided with a shut-off valve 820. A single set of vent pipes 810 can be connected to one vent hole 210 or to multiple vent holes 210, as long as the gas flow control of the vent holes 210 can be achieved. During the initial stage of ignition, the vent holes 210 located inside the enclosure 400 are supplied with chemical gas, while the vent holes 210 located on the first electrode 200 outside the enclosure 400 are not supplied with chemical gas. By optimizing the gas distribution, the ignition success rate is improved.

[0031] Please see Figure 1 In one embodiment of this utility model, a position sensor 900 is further provided at the end of the cover 400 facing the second electrode 300. Specifically, the position sensor 900 is provided at the end of the third cover 413 facing the second electrode 300 to detect the distance between the third cover 413 and the second electrode 300, avoid collision between the cover 400 and the second electrode 300, and ensure a safe distance between the cover 400 and the wafer.

[0032] This invention proposes a plasma processing device that, by placing a cover below the first electrode, with the projection of the cover onto the first electrode covering at least part of the vent holes, effectively limits the diffusion range of chemical gases within the reaction chamber. This concentrates the chemical gases in a localized area between the first and second electrodes, thereby increasing the gas concentration in that localized area. When the plasma is excited by an electric field, the high gas concentration in the localized area within the cover increases the frequency of molecular collisions, leading to more complete collisions between electrons and molecules. This makes it easier to generate sufficient plasma, preventing ignition failure and improving the stability of plasma generation. This addresses the technical problem of low molecular or ion concentrations in the reaction chamber during the initial stage of electric field-excited plasma, which easily leads to ignition failure.

[0033] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A plasma processing device, characterized in that, include: A reaction chamber, the reaction chamber comprising a first chamber; The first electrode is located at the upper part of the first cavity, and the first electrode includes several vent holes; The second electrode is located at the lower part of the first cavity and is disposed opposite to the first electrode; A cover is disposed on the first electrode and extends toward the second electrode; Wherein, at least a portion of the sidewall of the cover is disposed around at least one of the ventilation holes.

2. The processing apparatus according to claim 1, characterized in that, The surface of the cover is coated with a yttrium oxide coating.

3. The processing apparatus according to claim 1, characterized in that, The cover has a retracted state and an extended state facing the second electrode.

4. The processing apparatus according to claim 3, characterized in that, The plasma processing device further includes a driving mechanism. The cover includes a plurality of shells that are sequentially connected and slidably connected to adjacent shells to form a telescopic structure. The driving mechanism is connected to the shells to drive the shells to extend and retract.

5. The processing apparatus according to claim 4, characterized in that, The driving mechanism includes a motor, a reel, and a traction rope. The motor is fixedly mounted on the first electrode, and the reel is rotatably mounted on the first electrode and connected to the output end of the motor. The traction rope is provided on the reel and is connected to the end of the cover that is away from the first electrode.

6. The processing apparatus according to claim 4, characterized in that, A first sliding guide mechanism is also provided between adjacent covers. The first sliding guide mechanism includes a first slide groove and a first slider. The first slide groove is provided on one of the adjacent covers, and the first slider is provided on the other and located at the end of the cover away from the second electrode. The first slide groove and the first slider are adapted to each other.

7. The processing apparatus according to claim 6, characterized in that, A second sliding guide mechanism is also provided between adjacent covers. The second sliding guide mechanism includes a second slide groove and a second slider. The second slide groove is disposed on one of the adjacent covers and is located on the same cover as the first slider. The second slider is disposed on the other cover and is located on the same cover as the first slide groove. The second slider is located at the end of the cover away from the first electrode, and the second slide groove is adapted to the second slider.

8. The processing apparatus according to claim 1, characterized in that, The cover is made of quartz or ceramic.

9. The processing apparatus according to claim 1, characterized in that, The plasma processing device also includes a gas supply device, which is connected to several ventilation holes through several pipelines, and each pipeline is equipped with a shut-off valve.

10. The processing apparatus according to claim 3, characterized in that, A position sensor is also provided at the end of the cover facing the second electrode.

Images