Etching equipment
By introducing a parallel magnetic field into the etching equipment to control the movement of plasma electrons, the problem of etching non-uniformity in Micro-LED production was solved, and the uniformity and consistency of the etching process were improved.
Patent Information
- Application Number
- CN202422717530.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-07
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2034-11-07
AI Technical Summary
In the production process of Micro-LED, there is anisotropic deviation in the etching process during plasma etching, which leads to the formation of micro-grooves on the bottom sidewalls of the feature trenches. The vertical etching rate varies with the width of the feature trenches, resulting in etching non-uniformity.
An etching apparatus is employed, comprising a vacuum chamber, a plasma generation mechanism, a workpiece holder, and magnetic components. By forming a parallel magnetic field in the process chamber, the spiral motion of electrons in the plasma is controlled, reducing the accumulation of electrons on the surface and sides of the mask layer, reducing the generation of local charging electric fields, and improving etching uniformity.
It improves the microgrooves at the bottom of the feature trenches during etching, enhances the uniformity and consistency of etching, and ensures the uniformity of the etching process.
Smart Images
Figure CN223712705U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of semiconductor processing, and in particular to an etching device. BACKGROUND
[0002] In the production process of Micro-Light Emitting Diode (Micro-LED), a plasma etching process is needed to etch the semiconductor substrate. In the etching process, the ions in the plasma are guided by the sheath field to induce anisotropic etching. The surface of the semiconductor substrate not covered by the mask will receive a large ion flux and be etched rapidly. Other surfaces, such as the vertical sidewall of the mask layer, will receive a relatively small ion flux and will not be etched.
[0003] In actual operation, it is often observed that there is a deviation from the ideal etching anisotropy, and a "micro groove" will be formed on the sidewall at the bottom of the feature groove. The vertical etching rate will also change with the feature groove width during reactive ion etching. CONTENT OF THE UTILITY MODEL
[0004] The present application provides an etching device to improve etching uniformity.
[0005] The present application provides an etching device, comprising:
[0006] A vacuum chamber comprising a process cavity, the vacuum chamber further comprising a first end and a second end;
[0007] A plasma generating mechanism arranged outside the vacuum chamber and close to the first end, the plasma generating mechanism being configured to excite plasma in the process cavity;
[0008] A workpiece holder arranged inside the vacuum chamber and close to the second end;
[0009] A magnetic assembly comprising a plurality of magnetic pieces, the plurality of magnetic pieces being arranged to intersect each other, the center axes of the plurality of magnetic pieces all coinciding, the magnetic assembly being rotationally arranged on a side of the vacuum chamber facing away from the process cavity and located on a side of the workpiece holder facing away from the plasma generating mechanism, the magnetic assembly being configured to form a planar magnetic field in the process cavity, the planar magnetic field being parallel to the workpiece holder.
[0010] In some possible embodiments, the magnetic pieces have N and S poles, the N and S poles being symmetrically arranged about the center axis of the magnetic assembly, and the rotation axis of the magnetic assembly coincides with the center axis of the magnetic assembly.
[0011] In some possible implementations, an included angle α is provided between any two adjacent magnetic elements, where 30°≤α≤150°.
[0012] In some possible implementations, the etching apparatus further includes a first driving member, which is tractively connected to the magnetic component and is used to drive the magnetic component to rotate.
[0013] In some possible implementations, the vertical distance between the magnetic component and the workpiece holder is adjustable.
[0014] In some possible implementations, the magnetic component is floating relative to the workpiece holder, and the floating direction of the magnetic component is parallel to the vertical distance direction between the magnetic component and the workpiece holder.
[0015] In some possible implementations, the etching apparatus further includes a second drive member, which is tractively connected to the magnetic component and is used to drive the magnetic component to move along the floating direction.
[0016] In some possible implementations, the planar magnetic field is configured to exert a force on the ions in the plasma that is less than the force exerted by the workpiece holder on the ions in the plasma.
[0017] In some possible implementations, the plasma generating mechanism includes a radio frequency power supply and an induction coil connected between the positive and negative terminals of the radio frequency power supply.
[0018] In some possible implementations, the etching apparatus further includes a radio frequency bias power supply, the negative terminal of which is connected to the workpiece holder.
[0019] The beneficial effects of this application are as follows: The etching equipment provided in this application, during the etching process, allows the plasma generator to generate plasma within the process chamber. Positive ions in the plasma bombard specific locations on the workpiece under the influence of an electric field. Due to their lighter mass, the electrons generated during bombardment, as well as those in the plasma, undergo spiral circular motion under the influence of the Lorentz force within a parallel magnetic field. This increases the distance electrons travel to reach the mask layer on the workpiece surface, correspondingly reducing the number of electrons reaching the surface and sides of the mask layer. This reduces the accumulation of electrons on the mask layer surface and sides, thereby lowering the possibility of localized charging electric fields. Consequently, during etching, the micro-grooves at the bottom of the feature trenches can be improved, enhancing the uniformity of the etching process. Furthermore, the magnetic component has multiple magnetic elements, which can shorten the gap time of the magnetic field at any location, improving the uniformity of the planar magnetic field distribution and further enhancing the etching uniformity. Attached Figure Description
[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 The etching principle diagram of an existing etching apparatus during the etching process of a workpiece is shown;
[0022] Figure 2 A schematic diagram of the workpiece being etched by an existing etching apparatus is shown;
[0023] Figure 3 The following are schematic diagrams of the etching apparatus in some embodiments of this application;
[0024] Figure 4 The diagram shows a schematic of the operation of the magnetic component in some embodiments of this application;
[0025] Figure 5 The magnetic field distribution diagrams generated by the magnetic components in some embodiments of this application are shown;
[0026] Figure 6 The schematic diagram of the etching workpiece in some embodiments of this application is shown;
[0027] Figure 7 A partial structural schematic diagram of the etching apparatus in some embodiments of this application is shown.
[0028] Explanation of key component symbols:
[0029] 1000 - Etching equipment;
[0030] 100 - Vacuum chamber; 110 - Process cavity; 101 - First end; 102 - Second end
[0031] 200 - Plasma generator; 210 - Radio frequency power supply; 220 - Induction coil;
[0032] 300-Workpiece Holder;
[0033] 400-RF bias power supply;
[0034] 500 - Magnetic assembly; 510 - Magnetic component; 511 - N pole; 512 - S pole;
[0035] 610 - First drive component; 620 - Second drive component;
[0036] 700-plane magnetic field;
[0037] 2000 - Workpiece; 2100 - Featured groove; 2200 - Microgroove;
[0038] 3000 - Mask layer;
[0039] M - Floating direction; L - Central axis. Detailed Implementation
[0040] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0041] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0043] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0044] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0045] like Figure 1 and Figure 2 As shown, during step etching of a semiconductor substrate, due to the electron distribution angle and the electrons moving in different directions generated by ion collisions on the semiconductor substrate surface, these electrons leave the semiconductor substrate surface under the influence of an electric field and accumulate charge on the sidewalls and surface regions of the mask layer, forming a local electric field. The presence of this local electric field deflects the ion trajectories, increasing their concentration at the bottom of the feature trenches, intensifying the etching at the bottom of the feature trenches, and forming micro-trenches at the bottom of the feature trenches, resulting in inconsistent etching uniformity in different areas.
[0046] like Figure 3 As shown, the embodiment provides an etching apparatus 1000, which can be used to perform etching operations on a workpiece 2000 to improve the uniformity of etching. The workpiece 2000 can be an epitaxial layer in the Micro-LED manufacturing process, an epitaxial layer in the Mini-Light Emitting Diode (Mini-LED) manufacturing process, or an epitaxial layer in the Light Emitting Diode (LED) manufacturing process, etc.
[0047] like Figure 3 and Figure 5 As shown, the etching apparatus 1000 may include a vacuum chamber 100, a plasma generator 200, a workpiece holder 300, and a magnetic assembly 500.
[0048] The vacuum chamber 100 is equipped with a process cavity 110. During the etching process, the process cavity 110 can be evacuated to provide a vacuum environment for the etching operation, and the required process gas can be injected. Additionally, the vacuum chamber 100 includes a first end 101 and a second end 102. In some embodiments, the first end 101 and the second end 102 may be distributed along the height direction of the vacuum chamber 100.
[0049] The plasma generating mechanism 200 is disposed on the side of the vacuum chamber 100 away from the process cavity 110, that is, the plasma generating mechanism 200 is disposed on the outside of the vacuum chamber 100 and close to the first end 101 of the vacuum chamber 100. In the embodiment, the plasma generating mechanism 200 can be used to excite the ionization of process gas in the process cavity 110 to generate plasma.
[0050] The workpiece holder 300 can be disposed within the process chamber 110 of the vacuum chamber 100. During the etching process, the workpiece 2000 can be placed on the workpiece holder 300, and both the workpiece holder 300 and the workpiece 2000 become negatively charged. In some embodiments, the workpiece holder 300 can be disposed near the second end 102 of the vacuum chamber 100. Positive ions in the plasma can move at high speed toward the workpiece holder 300 under the action of an electric field to bombard the corresponding position of the workpiece 2000, thereby achieving etching.
[0051] In some embodiments, the magnetic component 500 is rotatably disposed on the side of the vacuum chamber 100 opposite to the process cavity 110, and the magnetic component 500 may be located on the side of the workpiece holder 300 opposite to the plasma generating mechanism 200, that is, the magnetic component 500 may be disposed near the second end 102 of the vacuum chamber 100 and may be located below the vacuum chamber 100. In some embodiments, the magnetic component 500 may include a plurality of magnetic elements 510. The plurality of magnetic elements 510 may be radially distributed, and the center positions of each magnetic element 510 may intersect at the central axis L of the magnetic component 500, that is, the central axes of the plurality of magnetic elements 510 may coincide.
[0052] In this embodiment, the magnetic component 500 can be used to generate a planar magnetic field 700 parallel to the workpiece holder 300 in the process chamber 110. The planar magnetic field 700 may be located on the side of the workpiece holder 300 facing the plasma generating mechanism 200.
[0053] During the etching process, the workpiece 2000 can be placed on the workpiece holder 300. The process chamber 110 is evacuated and injected with process gas. The plasma generator 200 is turned on, and the workpiece 2000 and workpiece holder 300 are negatively charged. The plasma generator 200 can generate plasma within the process chamber 110. Positive ions in the plasma can bombard specific locations on the workpiece 2000 under the influence of an electric field. Due to their lighter mass, electrons generated during the bombardment and electrons in the plasma can undergo helical circular motion under the influence of the Lorentz force in a parallel magnetic field. This increases the distance that electrons travel to reach the mask layer 3000 on the surface of the workpiece 2000. Correspondingly, the number of electrons reaching the surface and sides of the mask layer 3000 is reduced, decreasing the accumulation of electrons on the surface and sides of the mask layer 3000, thereby reducing the possibility of localized charging electric fields. As a result, the micro-grooves 2200 at the bottom of the feature trenches can be improved during etching, enhancing the uniformity of the etching process. In addition, the magnetic component 500 includes multiple magnetic elements 510, which can shorten the gap time of the magnetic field at any position, improve the uniformity of the planar magnetic field distribution, and further improve the etching uniformity.
[0054] like Figure 3 As shown, in some embodiments, the plasma generating mechanism 200 may include a radio frequency power supply 210 and an induction coil 220. The induction coil 220 may be connected between the positive and negative terminals of the radio frequency power supply 210 to form a conductive circuit.
[0055] During use, the radio frequency power supply 210 can output alternating current, and the induction coil 220 can generate an induced magnetic field under the action of alternating current. The induced magnetic field can excite an induced electric field in the process cavity 110, and the process gas can be ionized under the action of the induced electric field to generate plasma.
[0056] In some embodiments, the etching apparatus 1000 further includes a radio frequency bias power supply 400, the negative terminal of which can be connected to the workpiece holder 300. During the etching process, the radio frequency bias power supply 400 can be turned on to make the workpiece holder 300 and the workpiece 2000 negatively charged, so that positive ions in the plasma can bombard specific positions of the workpiece 2000 under the action of the electric field to achieve etching.
[0057] like Figures 3 to 5 As shown, in some embodiments, the magnetic element 510 may have an S pole 512 and an N pole 511, which may be respectively disposed at both ends of the magnetic element 510 and symmetrically arranged about the central axis L of the magnetic element 510. The magnetic element 510 can be rotatably disposed relative to the vacuum chamber 100. Furthermore, the axis of rotation of the magnetic element 510 may coincide with its own central axis. Additionally, the magnetic element 510 may be coaxially disposed with the workpiece holder 300. In this embodiment, the central axis of the magnetic element 510 may coincide with the central axis L of the magnetic assembly 500.
[0058] In some embodiments, the etching apparatus 1000 further includes a first driving member 610. The magnetic component 500 can be connected to the output shaft of the first driving member 610 via a structure such as a bracket. Thus, the first driving member 610 can drive the magnetic component 500 to rotate about its central axis L. In some embodiments, the first driving member 610 can be a high-precision motor.
[0059] During the etching process, the magnetic component 500 can be driven by the first driving element 610 to rotate around the central axis L. The rotation speed of the magnetic component 500 can be set as needed. As a result, the magnetic component 500 can form a uniform planar magnetic field 700 within the process cavity 110, so that electrons in all parts of the process cavity 110 (including electrons in the plasma and electrons generated during the bombardment process) can basically perform helical circular motion under the action of the planar magnetic field 700.
[0060] In some embodiments, the magnetic component 500 may include two, three, or five or more magnetic components 510, the specific number of which can be set as needed and is not specifically limited here, thereby shortening the gap time of the magnetic field at any position. In some embodiments, an included angle α, 30°≤α≤150°, may be configured between any two adjacent magnetic components 510. On the one hand, this can avoid mutual interference between the magnetic fields formed by adjacent magnetic components 510, and on the other hand, it can minimize the gap time of the magnetic field at any position, improving the uniformity of the planar magnetic field distribution. For example, the included angle α between any two adjacent magnetic components 510 may be set to 30°, 50°, 55°, 60°, 62°, 65°, 75°, 86°, 90°, 105°, 110°, 125°, 130°, 136°, 140°, 145°, 150° or any other angle from 30° to 150°.
[0061] In other embodiments, the magnetic component 500 may also include a magnetic element 510.
[0062] like Figure 3 and Figure 7 As shown, in some embodiments, the length N1 of the magnetic component 510 may be greater than the length N2 of the workpiece holder 300. This reduces the influence of the electric field carried by the workpiece holder 300 on the planar magnetic field 700 formed by the magnetic component 500, ensuring the uniformity of the planar magnetic field 700 at all positions and ensuring etching uniformity.
[0063] Of course, in some other embodiments, the length N1 of the magnetic element 510 may also be less than or equal to the length N2 of the workpiece holder 300.
[0064] like Figure 3As shown, in some embodiments, the vertical distance between the magnetic component 500 and the workpiece holder 300 is adjustable. Therefore, the magnetic field strength distribution above the workpiece holder 300 can be adjusted as needed, and the vertical distance between the position of the electrons undergoing helical circular motion and the workpiece holder 300 can be adjusted as needed.
[0065] In some embodiments, the magnetic component 500 may be floated relative to the vacuum chamber 100, and the floating direction M of the magnetic component 500 may be parallel to the direction of the vertical distance between the magnetic component 500 and the workpiece holder 300, that is, the floating direction M may be perpendicular to the planar magnetic field 700. Therefore, the distribution of the magnetic field strength generated by the magnetic component 500 in the process cavity 110 can be adjusted as needed, thereby adjusting the distance between the planar magnetic field 700 and the workpiece holder 300.
[0066] In some embodiments, the etching apparatus 1000 further includes a second drive member 620. The first drive member 610 can notify a structure such as a support to be connected to the output end of the second drive member 620. The second drive member 620 can be used to drive the first drive member 610 to move along the floating direction M of the magnetic component 500, thereby causing the magnetic component 500 to move along the floating direction M. In some embodiments, the second drive member 620 may be a cylinder.
[0067] In other embodiments, the second drive element 620 may also be an electric cylinder, a hydraulic cylinder, or an electric push rod.
[0068] like Figure 3 and Figure 6 As shown, the etching equipment 1000 provided in this application, with its magnetic component 500, can form an auxiliary planar magnetic field 700 within the process chamber 110. Electrons generated during the bombardment of the workpiece 2000 by electrons in the plasma and positive ions can undergo spiral circular motion under the influence of the planar magnetic field 700, extending the distance and time for electrons to reach the surface and sidewalls of the mask layer 3000. This reduces the probability of localized electric fields, thereby reducing the probability of microgrooves 2200 appearing at the bottom of the feature trench 2100, resulting in more uniform etching of each part of the feature trench 2100 and improving the uniformity of the etching. Furthermore, since the positive ions in the plasma have a relatively large mass, the force exerted by the planar magnetic field 700 on the ions in the plasma is much smaller than the force exerted by the workpiece holder 300 on the ions in the plasma. Therefore, the positive ions in the plasma are almost unaffected by the planar magnetic field 700 and can normally bombard the workpiece 2000 to obtain the feature trench 2100.
[0069] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0070] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.
Claims
1. An etching apparatus, characterized in that, include: A vacuum chamber, including a process cavity, the vacuum chamber further including a first end and a second end; A plasma generating mechanism is disposed outside the vacuum chamber and close to the first end. The plasma generating mechanism is used to generate plasma in the process chamber. A workpiece holder is disposed within the vacuum chamber and is positioned near the second end; A magnetic assembly includes multiple magnetic elements arranged intersecting each other, with their central axes coinciding. The magnetic assembly is rotatably disposed on the side of the vacuum chamber away from the process cavity and on the side of the workpiece holder away from the plasma generating mechanism. The magnetic assembly is used to form a planar magnetic field parallel to the workpiece holder in the process cavity.
2. The etching apparatus according to claim 1, characterized in that, The magnetic component has an N pole and an S pole, which are symmetrically arranged about the central axis of the magnetic component, and the rotation axis of the magnetic component coincides with the central axis of the magnetic component.
3. The etching apparatus according to claim 1, characterized in that, An included angle α is provided between any two adjacent magnetic components, where 30°≤α≤150°.
4. The etching apparatus according to any one of claims 1 to 3, characterized in that, The etching apparatus further includes a first driving member, which is tractively connected to the magnetic component and is used to drive the magnetic component to rotate.
5. The etching apparatus according to claim 1, characterized in that, The vertical distance between the magnetic component and the workpiece holder is adjustable.
6. The etching apparatus according to claim 5, characterized in that, The magnetic component is floating relative to the workpiece holder, and the floating direction of the magnetic component is parallel to the vertical distance between the magnetic component and the workpiece holder.
7. The etching apparatus according to claim 6, characterized in that, The etching apparatus further includes a second driving member, which is tractively connected to the magnetic component and is used to drive the magnetic component to move along the floating direction.
8. The etching apparatus according to claim 1, characterized in that, The planar magnetic field is configured such that the force exerted on the ions in the plasma is less than the force exerted on the ions in the plasma by the workpiece holder.
9. The etching apparatus according to claim 1, characterized in that, The plasma generating mechanism includes a radio frequency power supply and an induction coil, with the induction coil connected between the positive and negative terminals of the radio frequency power supply.
10. The etching apparatus according to claim 1, characterized in that, The etching apparatus also includes an RF bias power supply, the negative terminal of which is connected to the workpiece holder.