Semiconductor etching equipment

Abstract

A semiconductor etching device comprises: a processing chamber; the at least two magnet assemblies are arranged around the side wall of the processing chamber from top to bottom, each magnet assembly comprises a magnet and a magnet support for supporting the magnet, and the distribution characteristic of a magnetic field generated by the magnet is adjusted by the material of the magnet support; the at least two radio frequency coil areas are located above the top of the processing chamber, and the radio frequency power of each radio frequency coil area is independently adjusted.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment manufacturing, and more particularly to semiconductor etching equipment. Background Technology

[0002] In semiconductor manufacturing, plasma etching is a crucial step in achieving circuit patterning. Particularly in inductively coupled plasma etching (ICP-E), the uneven distribution of radio frequency (RF) power and airflow often results in weak etching at the chip edges and center, while the central area exhibits a highly etched "donut shape." This unevenness severely impacts device performance and reliability. Traditional methods primarily improve etching uniformity by adjusting airflow and RF power; however, these methods have limitations and cannot fundamentally solve the etching problems caused by uneven RF and airflow distribution.

[0003] Specifically, existing technologies face the following pressing technical problems that need to be addressed:

[0004] Firstly, how to more effectively adjust and control the energy distribution of plasma to achieve uniformity during the etching process.

[0005] Secondly, how to improve etching uniformity through non-traditional means (i.e., not simply relying on airflow and radio frequency power adjustment).

[0006] Third, how to integrate new etching equipment into existing semiconductor manufacturing processes to improve production efficiency and device performance.

[0007] Therefore, there is an urgent need for a plasma etching device that can achieve a more uniform etching effect during the plasma etching process through non-traditional means, especially to solve the problem of reducing the "donut-shaped" etching unevenness in inductively coupled plasma etching. Summary of the Invention

[0008] To overcome the problems faced by existing technologies, this invention proposes a novel semiconductor etching device. The core of this device is to coordinate the distribution and intensity of plasma through a multi-zone planar coil at the top and a multi-turn permanent magnet around the etching cavity.

[0009] The present invention provides a semiconductor etching apparatus, including but not limited to a processing chamber, at least two magnet assemblies and at least two radio frequency coil regions.

[0010] The at least two magnet assemblies are arranged from top to bottom around the sidewall of the processing chamber, wherein each magnet assembly includes a magnet and a magnet support for supporting the magnet, the material of the magnet support adjusting the magnetic field distribution characteristics generated by the magnet.

[0011] The at least two radio frequency coil regions are located above the top of the processing chamber, wherein the radio frequency power of each radio frequency coil region is independently adjusted.

[0012] In one embodiment, etching uniformity can be adjusted by selecting the material of the magnet holder and independently adjusting the radio frequency power of each radio frequency coil region.

[0013] In one embodiment, the at least two magnet assemblies include at least a first magnet assembly and a second magnet assembly.

[0014] The first magnet assembly includes a first magnet and a first magnet support, the first magnet support being made of a first material.

[0015] The second magnet assembly includes a second magnet and a second magnet support, the second magnet support being composed of a second material.

[0016] Wherein, the magnetic permeability of the first material is less than that of the second material; and the magnetic field strength generated by the first magnet is greater than that generated by the second magnet.

[0017] In one embodiment, the first material is a non-magnetic material; the second material is a soft magnetic material.

[0018] In one embodiment, the first material is aluminum; the second material is soft iron.

[0019] In one embodiment, the first magnet holder has a groove in which the first magnet is embedded; the second magnet holder has a groove in which the second magnet is embedded.

[0020] In one embodiment, the at least two radio frequency coil regions include at least a first radio frequency coil region and a second radio frequency coil region; the first radio frequency coil region is located at the center of the top of the processing chamber, and the second radio frequency coil region is located in the outer peripheral region surrounding the first radio frequency coil region; the first radio frequency coil region is correspondingly provided with a first radio frequency coil, and the second radio frequency coil region is correspondingly provided with a second radio frequency coil.

[0021] In one embodiment, the first radio frequency coil is planar spiral; the second radio frequency coil is planar spiral.

[0022] In one embodiment, the current flowing through the first RF coil and the second RF coil is independently adjustable.

[0023] In one embodiment, the semiconductor etching apparatus further includes a dielectric window, a stage, an exhaust port, and an intake port.

[0024] The media window serves as the top of the processing chamber.

[0025] The stage is located inside the processing chamber and is used to support the wafer.

[0026] The air extraction port is located at the bottom of the processing chamber.

[0027] The air inlet is located at the top of the processing chamber.

[0028] The semiconductor etching apparatus of the present invention has the following beneficial technical effects:

[0029] Firstly, it improves etching uniformity: through the coordinated control of dual-zone planar coils and permanent magnets, the uniformity of the etching process is significantly improved, reducing the "donut-shaped" phenomenon.

[0030] Secondly, it improves device performance: uniform etching can improve the performance of semiconductor devices and reduce device failures caused by uneven etching.

[0031] Third, it enhances production efficiency: The semiconductor etching equipment of the present invention can be seamlessly integrated into the existing semiconductor manufacturing process without significant adjustments to the production process, thereby improving production efficiency.

[0032] Fourth, it reduces manufacturing costs: Due to the improved etching uniformity, material waste and device rework caused by uneven etching can be reduced, thereby reducing the overall manufacturing cost.

[0033] In summary, this invention provides a new solution for the semiconductor etching field through innovative radio frequency and permanent magnet coordinated control technology, which can effectively improve etching quality and production efficiency, and has significant practical application value and broad market prospects. Attached Figure Description

[0034] The above-described invention and the following detailed description will be better understood when read in conjunction with the accompanying drawings. It should be noted that the drawings are merely examples of the claimed invention. In the drawings, the same reference numerals represent the same or similar elements.

[0035] Figure 1 A plasma etching apparatus according to an embodiment of the present invention is shown;

[0036] Figure 2 A top view of the inner and outer radio frequency coils according to an embodiment of the present invention is shown;

[0037] Figure 3 A schematic diagram illustrating the principle of how the magnetic field curvature changes when the same magnet is replaced with different support materials, according to an embodiment of the present invention;

[0038] Figure 4 A schematic diagram illustrating the flexible alteration of the total magnetic field distribution shape using two magnets and two supports according to an embodiment of the present invention is shown.

[0039] Figure 5 A schematic diagram of the etching rate distribution before and after dual magnetic field constraint according to an embodiment of the present invention is shown. Detailed Implementation

[0040] The following detailed description of the features and advantages of the present invention provides sufficient information for any person skilled in the art to understand and implement the invention. Furthermore, based on the specification, claims, and drawings disclosed herein, those skilled in the art can easily understand the related objectives and advantages of the invention. Although the description of the invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may arise based on the claims of the invention. To provide a thorough understanding of the invention, numerous specific details will be included in the following description. The invention may also be implemented without using these details. Moreover, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood as the orientations shown in the relevant paragraphs and accompanying drawings. These relative terms are for illustrative purposes only and do not imply that the described apparatus must be manufactured or operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0043] It is understood that while terms such as "first," "second," and "third" may be used herein to describe various components, channels, assemblies, regions, layers, and / or parts, these components, channels, assemblies, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, channels, assemblies, regions, layers, and / or parts. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0045] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of scope in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0046] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0047] This invention proposes a novel semiconductor etching apparatus, the core of which is to coordinate the distribution and intensity of plasma through a multi-zone planar coil at the top and a multi-turn permanent magnet around the etching cavity.

[0048] The following are the main features of the technical solution of the present invention:

[0049] Multi-zone planar coil design:

[0050] The design features a multi-region planar coil at the top (e.g., a dual-region planar coil), where the RF power of each region can be adjusted independently as needed. This design allows for finer control over the plasma energy distribution during the etching process.

[0051] Permanent magnet configuration:

[0052] Multiple rings of permanent magnets (e.g., two rings) are arranged around the etching cavity, and the strength of each ring can be adjusted as needed. The arrangement of permanent magnets can effectively change the intensity distribution of the plasma, thereby improving the uniformity of etching.

[0053] Innovative applications of permanent magnet materials and fixed structure materials:

[0054] Permanent magnets can be made of neodymium iron boron and other high-performance magnet materials to provide a strong and stable magnetic field.

[0055] The fixing material of the permanent magnet (i.e. the material of the magnet support) can be selected from materials with different magnetic permeability, such as aluminum, iron, and soft magnetic materials. By adjusting the fixing material, the penetration depth of the magnetic field strength can be adjusted, thereby affecting the overall distribution of the magnetic field strength and ultimately the distribution of the plasma.

[0056] Coordinated control of magnetic field and radio frequency:

[0057] By combining the adjustment of radio frequency power and the magnetic field generated by the permanent magnet, precise control of the plasma etching process can be achieved. Adjusting the magnetic field can affect the energy distribution of the plasma, while adjusting the radio frequency power can further refine this distribution.

[0058] Through the above technical solution, the present invention can effectively improve the etching uniformity in the semiconductor etching process, reduce the "donut shape" phenomenon caused by uneven distribution of radio frequency and airflow, thereby improving the performance and reliability of semiconductor devices.

[0059] Figure 1 A plasma etching apparatus according to an embodiment of the present invention is shown. The plasma etching apparatus of the present invention includes, but is not limited to, a processing chamber 101, a dielectric window 102, a first radio frequency coil 103, a second radio frequency coil 104, a first magnet 105, a first magnet support 107, a second magnet 106, a second magnet support 108, a stage 109, an air inlet 111, and an air outlet 112.

[0060] The air inlet 111 is located at the top of the processing chamber 101, and the air outlet 112 is located at the bottom of the processing chamber 101. Gas enters through the air inlet 111 and is extracted through the air outlet 112.

[0061] In one embodiment, the gas may include one or more of the following: oxygen, nitrogen, argon, CF4, etc.

[0062] The processing chamber 101 is equipped with a stage 109, which is used to support the wafer 110.

[0063] The top of the processing chamber 101 has a medium window 102.

[0064] The media window 102 may include media materials such as ceramics and quartz.

[0065] The area above the dielectric window 102 is divided into multiple radio frequency (RF) coil regions. In one embodiment, the area above the dielectric window 102 can be divided into two RF coil regions, with a first RF coil 103 corresponding to the first RF coil region and a second RF coil 104 corresponding to the second RF coil region. The first RF coil region is located at the center, and the second region is located on the outer periphery surrounding the first RF coil region.

[0066] After the RF power supply is connected to the matching unit, it is connected to the first RF coil 103 and the second RF coil 104 to provide ionization power.

[0067] In one embodiment, the RF power supply is specified as 5000W, 13.56MHz.

[0068] The first radio frequency coil 103 and the second radio frequency coil 104 generate a radio frequency electric field, which ionizes the reactive gas in the processing cavity to generate plasma.

[0069] In one embodiment, the first RF coil 103 and the second RF coil 104 are respectively inner and outer RF coils. For example, the first RF coil 103 is the inner RF coil, and the second RF coil 104 is the outer RF coil.

[0070] In one embodiment, the ratio of the current flowing through the first RF coil 103 and the second RF coil 104 is adjustable.

[0071] In one embodiment, the currents of the first RF coil 103 and the second RF coil 104 can be independently adjusted, thereby enabling independent adjustment of the RF power of each region to achieve finer etching control.

[0072] Figure 2 A top view of the inner and outer radio frequency coils according to an embodiment of the present invention is shown. Figure 2 As shown, the first group of RF coils 103 is the inner RF coil, which is planar and spiral-shaped. The second group of RF coils 104 is the outer RF coil, which is planar and spiral-shaped.

[0073] It should be noted that the present invention can provide two or more radio frequency coil regions, each region corresponding to a radio frequency coil. The regions can be divided into layers from the inside out, or distributed in blocks. The arrangement of each radio frequency coil can be planar spiral, or other suitable shapes.

[0074] return Figure 1The plasma etching apparatus of the present invention further includes at least a first magnet assembly and a second magnet assembly disposed from top to bottom around the sidewall of the processing chamber. The first magnet assembly includes a first magnet 105 and a first magnet support 107. The second magnet assembly includes a second magnet 106 and a second magnet support 108.

[0075] A first magnet 105 is disposed around the side wall of the processing chamber 101. A first magnet support 107 is used to support the first magnet 105.

[0076] The first magnet holder 107 has a groove for accommodating the first magnet 105. The first magnet holder 107 is made of a first material.

[0077] The second magnet 106 is disposed around the side wall of the processing chamber 101, and is located below the first magnet 105. The second magnet bracket 108 is used to support the second magnet 106.

[0078] The second magnet holder 108 has a groove for accommodating the second magnet 106. The second magnet holder 108 is made of a second material.

[0079] The selection of the first and second material types is used to adjust the total magnetic field distribution generated by the first and second magnets, thereby adjusting the plasma distribution.

[0080] In one embodiment, the permeability of the first material is less than that of the second material; the magnetic field strength generated by the first magnet is greater than that generated by the second magnet.

[0081] In one embodiment, the first material is a non-magnetic material and the second material is a soft magnetic material.

[0082] In one embodiment, the first material is aluminum. Since aluminum has almost no magnetic permeability and is close to vacuum permeability, it has a strong magnetic field but a shallow penetration depth.

[0083] In one embodiment, the second material is soft iron. Because soft iron has high magnetic permeability, the magnetic field is relatively weak, but the magnetic field string is longer, and the penetration depth is therefore deeper.

[0084] In one embodiment, the surface magnetic field strength of the first magnet is approximately 1000 Gauss.

[0085] In one embodiment, the surface magnetic field strength of the second magnetic field is approximately 500 Gauss.

[0086] It should be noted that the plasma etching apparatus of the present invention may also include a third magnet assembly and more magnet assemblies. These magnet assemblies may have a structure similar to that of the first magnet assembly and the second magnet assembly.

[0087] This invention cleverly utilizes the magnetic properties of different support materials to adjust the penetration depth of the magnetic field, thereby affecting the plasma distribution: the aluminum support maintains a strong but localized magnetic field, while the iron support generates a weaker but more widespread magnetic field. The combination of the two allows for more precise control of the plasma. In other words, by selecting different support materials, this invention can flexibly adjust the spatial distribution characteristics of the magnetic field, thereby synergistically controlling the plasma distribution.

[0088] Figure 3 This diagram illustrates the principle of how the magnetic field curvature changes when the same magnet is replaced with different support materials, according to an embodiment of the present invention. Figure 3 As shown, the dashed line represents the magnetic field strength distribution when the support material is aluminum, and the solid line represents the magnetic field strength distribution when the support material is soft iron.

[0089] Figure 4 A schematic diagram illustrating the flexible alteration of the total magnetic field distribution shape using two magnets and two supports, according to an embodiment of the present invention, is shown. Figure 4 As shown, the total magnetic field can be adjusted by adjusting the first magnetic field and the second magnetic field.

[0090] Figure 5 A schematic diagram showing the etching rate distribution before and after dual magnetic field confinement according to an embodiment of the present invention is illustrated. Figure 5 As shown, the etching rate tends to be uniform everywhere after constraint.

[0091] The terminology and expressions used above are for descriptive purposes only, and the invention should not be limited to these terms and expressions. The use of these terms and expressions does not mean excluding any illustrative and descriptive equivalent features (or parts thereof), and it should be recognized that various modifications that may exist should also be included within the scope of the claims. Other modifications, variations, and substitutions may also exist. Accordingly, the claims should be considered to cover all such equivalents.

[0092] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the present application requires more features than those mentioned in the claims.

[0093] Similarly, it should be noted that although the present invention has been described with reference to the specific embodiments described above, those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and various equivalent changes or substitutions can be made without departing from the spirit of the present invention. Therefore, any changes or modifications to the above embodiments within the scope of the essential spirit of the present invention will fall within the scope of the claims of this application.

Claims

1. A semiconductor etching apparatus, characterized by comprising: Comprising: a processing chamber; at least two magnet assemblies arranged from top to bottom around the sidewall of the processing chamber, wherein each magnet assembly comprises a magnet and a magnet holder supporting the magnet, the material of the magnet holder adjusts the magnetic field distribution characteristics generated by the magnet; at least two RF coil regions above the top of the processing chamber, wherein the RF power of each RF coil region is independently adjusted.

2. The semiconductor etching apparatus of claim 1, wherein The adjustment of etching uniformity is achieved by the material selection of the magnet holder and the independent adjustment of the RF power of each RF coil region.

3. The semiconductor etching apparatus of claim 1, wherein The at least two magnet assemblies at least include a first magnet assembly and a second magnet assembly; The first magnet assembly comprises: a first magnet; a first magnet holder composed of a first material; The second magnet assembly comprises: a second magnet; a second magnet holder composed of a second material; Wherein, the magnetic permeability of the first material is less than that of the second material; the magnetic field strength generated by the first magnet is greater than that generated by the second magnet.

4. The semiconductor etching apparatus of claim 3, wherein The first material is a non-magnetic material; the second material is a soft magnetic material.

5. The semiconductor etching apparatus of claim 3, wherein The first material is aluminum; the second material is soft iron.

6. The semiconductor etching apparatus of claim 3, wherein The first magnet holder has a recess, and the first magnet is embedded in the recess; the second magnet holder has a recess, and the second magnet is embedded in the recess.

7. The semiconductor etching apparatus of claim 1, wherein The at least two RF coil regions at least include a first RF coil region and a second RF coil region; the first RF coil region is located at the center of the top of the processing chamber, and the second RF coil region is located at the outer peripheral region around the first RF coil region; The first RF coil region is correspondingly provided with a first RF coil, and the second RF coil region is correspondingly provided with a second RF coil.

8. The semiconductor etching apparatus of claim 7, wherein, The first RF coil is a planar spiral; the second RF coil is a planar spiral.

9. The semiconductor etching apparatus of claim 7, wherein, The current flowing through the first RF coil and the second RF coil is independently adjustable.

10. The semiconductor etching apparatus of claim 1, wherein, Further comprising: a dielectric window as the top of the processing chamber; a carrier located inside the processing chamber for supporting a wafer; an exhaust port located at the bottom of the processing chamber; an air inlet located at the top of the processing chamber.

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