Coil structure of etching machine and etching machine

Abstract

The invention provides a coil structure of an etching machine table and the etching machine table. The coil structure comprises a first coil unit, a second coil unit, at least one first variable resistor and at least one second variable resistor, the first coil unit is concentrically arranged in the second coil unit, and the first coil unit and the second coil unit are insulated from each other; the first coil unit is electrically connected with the at least one first variable resistor, and the second coil unit is electrically connected with the at least one second variable resistor.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor equipment, and in particular to a coil structure and etching machine for an etching apparatus. Background Technology

[0002] Inductively Coupled Plasma (ICP) etching utilizes inductive coupling to generate high-density plasma, combining physical bombardment with chemical reactions to achieve high-precision selective etching of materials.

[0003] The radio frequency power supply in the etching machine generates an alternating magnetic field through coils, breaking down the etching gas (such as BCl3) and ionizing it into a high-density plasma containing ions, electrons, and active free radicals. Ions in the plasma bombard the material surface under the acceleration of the electric field, while active free radicals react chemically with the material; these two actions work together to remove the material. Using photoresist as a mask, the plasma removes only the unmasked material, thus achieving etching.

[0004] However, the etching equipment provided by the relevant technology has the problem of uneven etching rate during etching. Summary of the Invention

[0005] This disclosure provides a coil structure and an etching machine for an etching apparatus, which can effectively improve the uniformity of the etching rate. The technical solution is as follows: In a first aspect, embodiments of this disclosure provide a coil structure for an etching machine, the coil structure comprising: a first coil unit, a second coil unit, at least one first variable resistor, and at least one second variable resistor; The first coil unit is concentrically arranged within the second coil unit, and the first coil unit and the second coil unit are mutually insulated; The first coil unit is electrically connected to the at least one first variable resistor, and the second coil unit is electrically connected to the at least one second variable resistor.

[0006] Optionally, the first coil unit includes a plurality of first coils arranged concentrically, and the second coil unit includes a plurality of second coils arranged concentrically, wherein the first coils and the second coils are arranged concentrically; Two adjacent first coils of the plurality of first coils are connected, two adjacent second coils of the plurality of second coils are connected, and adjacent first coils and second coils are insulated from each other.

[0007] Optionally, the spacing between any two adjacent coils is equal, and either of the two adjacent coils is the first coil or the second coil.

[0008] Optionally, the spacing between any two adjacent coils is greater than or equal to 15 mm.

[0009] Optionally, the width of the first coil or the second coil is 8~12mm, and the thickness of the first coil or the second coil is 4~6mm.

[0010] Optionally, the first coil or the second coil includes multiple coil segments, and the multiple coil segments of each first coil or the second coil are distributed at intervals; The first coil unit and the second coil unit further include a connecting unit; The coil segments of two adjacent first coils or two adjacent second coils are connected by the connecting unit.

[0011] Optionally, the plurality of first coils are electrically connected to one of the first variable resistors; The plurality of second coils are electrically connected to the plurality of second variable resistors respectively, and each second coil is electrically connected to one second variable resistor.

[0012] Optionally, the first coil unit and the second coil unit further include a plurality of support columns; The plurality of support columns are distributed and arranged, and the plurality of support columns support the plurality of first coils and the plurality of second coils; The plurality of support columns supporting the plurality of first coils are electrically connected to the at least one first variable resistor, and the plurality of support columns supporting the plurality of second coils are electrically connected to the at least one second variable resistor.

[0013] Optionally, both the first coil unit and the second coil unit are copper structures with surface coatings, and the surface of the copper structure has a first coating and a second coating in sequence; The first plating layer is a nickel layer, and the second plating layer is a gold or silver layer.

[0014] Optionally, the thickness of the first coating is 8~12μm, and the thickness of the second coating is 2~4μm.

[0015] Secondly, embodiments of this disclosure provide an etching apparatus, the etching apparatus including a radio frequency power supply and a coil structure, the radio frequency power supply and the coil structure being electrically connected, the coil structure being a coil structure as described in any of the first aspects.

[0016] The beneficial effects of the technical solutions provided in this disclosure are: In related technologies, due to the action of the coil, the gas molecules in the inner ring rotate faster than those in the outer ring (the inner ring has a shorter stroke), and the proportion of the coil unit area in the inner ring is greater than that in the outer ring (that is, the ratio of the inner ring void area to the inner ring coil area is smaller). This results in the outer ring having a lower molecular dissociation ability than the inner ring, causing a difference in plasma concentration between the inner and outer rings, and an inconsistent etching rate between the inner and outer rings.

[0017] In this embodiment, the coil is divided into a first coil unit and a second coil unit. The first coil unit is concentrically arranged within the second coil unit, meaning the first coil unit is the inner coil and the second coil unit is the outer coil. Unlike the integrated design of related technologies, the first and second coil units are insulated from each other. The first coil unit is electrically connected to at least one first variable resistor, and the second coil unit is electrically connected to at least one second variable resistor. During operation, by adjusting the resistance values ​​of at least one first variable resistor and at least one second variable resistor, the surface current of the inner and outer coils can be changed. This allows control over the molecular dissociation capabilities of the inner and outer coils, ensuring consistent plasma concentrations and thus consistent etching rates, effectively improving etching rate uniformity. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the coil structure of an etching machine provided in an embodiment of this disclosure; Figure 2 This is a structural block diagram of a coil structure of an etching machine provided in an embodiment of this disclosure; Figure 3 This is a structural block diagram of an etching machine provided in an embodiment of this disclosure.

[0020] Explanation of reference numerals in the attached figures: 100: First coil unit; 200: Second coil unit; 300: First variable resistor; 400: Second variable resistor; 101: First coil; 201: Second coil; 1000: Coil segment; 2000: Connection unit; 2001: Connecting column; 2002: Connecting strip; 3000: Support column; 10: Radio frequency power supply; 20: Coil structure. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0022] Figure 1 This is a schematic diagram of the coil structure of an etching machine provided in an embodiment of this disclosure. See also... Figure 1 The coil structure includes: a first coil unit 100 and a second coil unit 200.

[0023] The first coil unit 100 is concentrically arranged within the second coil unit 200, and the first coil unit 100 and the second coil unit 200 are mutually insulated.

[0024] Figure 2 This is a structural block diagram of a coil structure for an etching machine according to an embodiment of this disclosure. See also... Figure 2 The coil structure also includes at least one first variable resistor 300 and at least one second variable resistor 400.

[0025] The first coil unit 100 is electrically connected to the at least one first variable resistor 300, and the second coil unit 200 is electrically connected to the at least one second variable resistor 400.

[0026] In related technologies, due to the action of the coil, the gas molecules in the inner ring rotate faster than those in the outer ring (the inner ring has a shorter stroke), and the proportion of the coil unit area in the inner ring is greater than that in the outer ring (that is, the ratio of the inner ring void area to the inner ring coil area is smaller). This results in the outer ring having a lower molecular dissociation ability than the inner ring, causing a difference in plasma concentration between the inner and outer rings, and an inconsistent etching rate between the inner and outer rings.

[0027] In this embodiment, the coil is divided into a first coil unit and a second coil unit. The first coil unit is concentrically arranged within the second coil unit, meaning the first coil unit is the inner coil and the second coil unit is the outer coil. Unlike the integrated design of related technologies, the first and second coil units are insulated from each other. The first coil unit is electrically connected to at least one first variable resistor, and the second coil unit is electrically connected to at least one second variable resistor. During operation, by adjusting the resistance values ​​of at least one first variable resistor and at least one second variable resistor, the surface current of the inner and outer coils can be changed. This allows control over the molecular dissociation capabilities of the inner and outer coils, ensuring consistent plasma concentrations and thus consistent etching rates, effectively improving etching rate uniformity.

[0028] like Figure 1 As shown, the first coil unit 100 includes a plurality of first coils 101 arranged concentrically, and the second coil unit 200 includes a plurality of second coils 201 arranged concentrically, wherein the first coils 101 and the second coils 201 are arranged concentrically.

[0029] Two adjacent first coils 101 are connected, and two adjacent second coils 201 are connected. Adjacent first coils 101 and second coils 201 are insulated from each other.

[0030] In this implementation, both the first coil unit 100 and the second coil unit 200 are composed of multiple coils. By having multiple coils in both the inner and outer rings, the uniform distribution of plasma is improved, thereby enhancing the uniformity of the etching rate.

[0031] In this embodiment of the present disclosure, the first coil unit 100 includes 2 to 4 first coils 101 arranged concentrically. The second coil unit 200 includes 3 to 5 second coils 201 arranged concentrically.

[0032] For example, such as Figure 1 As shown, the first coil unit 100 includes two first coils 101 arranged concentrically. The second coil unit 200 includes three second coils 201 arranged concentrically.

[0033] like Figure 1 As shown, the spacing between any two adjacent coils is equal, and either of the two adjacent coils is the first coil 101 or the second coil 201.

[0034] That is, the distance between two adjacent first coils 101 is equal to the distance between two adjacent second coils 201, which is equal to the distance between adjacent first coils 101 and second coils 201.

[0035] The above-mentioned equidistant design facilitates the design and manufacture of the coil.

[0036] In other examples, the spacing between two adjacent first coils 101 can be greater than the spacing between two adjacent second coils 201, thereby improving the problem of inconsistent area ratios between the inner and outer coils.

[0037] exist Figure 1 In the structure shown, the spacing between any two adjacent coils is greater than or equal to 15 mm.

[0038] In this implementation, the spacing between two adjacent coils is designed to be greater than or equal to 15mm, thereby ensuring that no electromagnetic interference is generated between the coils.

[0039] For example, the spacing between any two adjacent coils is 20 mm.

[0040] By designing the spacing between the two coils to be 20mm, electromagnetic interference between the coils can be avoided, while ensuring the ability to dissociate etching gas molecules.

[0041] In this embodiment of the disclosure, the width and thickness of the first coil 101 and the second coil 201 can be the same.

[0042] Wherein, the width of the first coil 101 or the second coil 201 refers to its width in the radial direction, and the thickness of the first coil 101 or the second coil 201 refers to its thickness in the axial direction.

[0043] In this embodiment of the disclosure, the width of the first coil 101 or the second coil 201 is 8~12mm, and the thickness of the first coil 101 or the second coil 201 is 4~6mm.

[0044] In this implementation, designing the first coil 101 and the second coil 201 according to the above dimensions can ensure the mechanical strength of the coils and their ability to dissociate etching gas molecules.

[0045] For example, the width of the first coil 101 or the second coil 201 is 10 mm, and the thickness of the first coil 101 or the second coil 201 is 5 mm.

[0046] like Figure 1 As shown, the first coil 101 or the second coil 201 includes a plurality of coil segments 1000, and the plurality of coil segments 1000 of each first coil 101 or second coil 201 are distributed at intervals.

[0047] The first coil unit 100 and the second coil unit 200 further include a connecting unit 2000; the coil segments 1000 of two adjacent first coils 101 or two adjacent second coils 201 are connected through the connecting unit 2000.

[0048] In this implementation, each turn of the coil is divided into multiple segments, thereby optimizing the high-frequency current distribution, suppressing eddy current interference, and improving plasma uniformity.

[0049] For example, the first coil 101 or the second coil 201 includes three coil segments 1000, all of which are of the same length.

[0050] like Figure 1 As shown, two adjacent first coils 101 are connected by a connecting unit 2000. Two adjacent second coils 201 are connected by a connecting unit 2000.

[0051] One connecting unit 2000 is connected to the ends of two coil segments 1000 located in adjacent turns.

[0052] Each coil segment 1000 can be connected to the connection unit 2000 at both ends, or only at one end.

[0053] like Figure 1 As shown, the connecting unit 2000 includes a connecting post 2001 and a connecting strip 2002. The connecting post 2001 is threaded into a threaded hole at the end of the coil segment 1000. The two ends of the connecting strip 2002 are connected to the connecting post 2001 at the ends of two adjacent coil segments 1000.

[0054] like Figure 1 As shown, the connecting post 2001 is arranged along the axial direction of the coil, and the connecting strip 2002 is perpendicular to the connecting post 2001, and the connecting strip 2002 intersects the radial and axial directions of the coil.

[0055] In this embodiment of the disclosure, the plurality of first coils 101 are electrically connected to a first variable resistor 300.

[0056] The plurality of second coils 201 are electrically connected to the plurality of second variable resistors 400 respectively, and each second coil 201 is electrically connected to one second variable resistor 400.

[0057] In this implementation, by setting more resistors in the outer ring, more precise adjustment can be achieved for the multi-turn coils in the outer ring, so that the plasma concentration around each coil in the outer ring is comparable to the plasma concentration around the coils in the inner ring.

[0058] In other embodiments, the plurality of first coils 101 may be electrically connected to the plurality of first variable resistors 300 respectively. Alternatively, the plurality of second coils 201 may be electrically connected to a second variable resistor 400.

[0059] The variable resistor can be a sliding resistor or other resistors whose resistance value is easily adjustable.

[0060] See you again Figure 1 The first coil unit 100 and the second coil unit 200 also include a plurality of support columns 3000.

[0061] The plurality of support columns 3000 are distributed and arranged, and the plurality of support columns 3000 support the plurality of first coils 101 and the plurality of second coils 201.

[0062] The plurality of support columns 3000 supporting the plurality of first coils 101 are electrically connected to the at least one first variable resistor 300, and the plurality of support columns 3000 supporting the plurality of second coils 201 are electrically connected to the at least one second variable resistor 400.

[0063] In this implementation, the support column 3000 not only provides support but also serves as an electrical connection.

[0064] In this embodiment of the disclosure, each coil corresponds to at least one support post 3000, and the support post 3000 can be connected to the threaded hole of the coil by threads.

[0065] The support column 3000 and the connecting column 2001 connect opposite sides of the coil, with the support column 3000 positioned along the axial direction of the coil.

[0066] In this embodiment of the disclosure, the first coil unit 100 and the second coil unit 200 are both copper structures with surface coatings, and the surface of the copper structure has a first coating and a second coating in sequence. The first plating layer is a nickel layer, and the second plating layer is a gold or silver layer.

[0067] In this implementation, the main body of the coil unit is copper, the outermost surface is a gold or silver layer to ensure that the surface current is large enough, and the nickel layer increases the adhesion of the metal.

[0068] The coil segment 1000, the connecting unit 2000, and the support column 3000 are all made of the aforementioned materials.

[0069] In this embodiment of the disclosure, the thickness of the first coating is 8~12μm, and the thickness of the second coating is 2~4μm.

[0070] In this implementation, using a nickel layer of the aforementioned thickness ensures adhesion, while using a gold or silver layer of the aforementioned thickness ensures conductivity.

[0071] For example, the thickness of the first coating is 10 μm and the thickness of the second coating is 3 μm.

[0072] The following is an exemplary description of the fabrication and use of this coil structure: Step 1: Use precision machining equipment to cut the low-impurity brass into multiple coil segments.

[0073] For example, 15 coil segments can be formed, and these 15 coil segments can be spliced ​​together to form five coils.

[0074] Optionally, this step also includes cutting the connecting unit and support column, and then splicing them together to form five coils.

[0075] Step 2: The processed coil undergoes surface coating treatment.

[0076] For example, a layer of nickel is first plated on the copper surface to increase the adhesion of subsequent metals; then a layer of gold / silver is plated to ensure that the surface current is large enough.

[0077] Step 3: Connect the coil to an adjustable resistor, and then connect it to the RF power supply.

[0078] Step 4: During each wafer etching cycle, inspect the etching rate of the inner ring corresponding to the wafer region and the outer ring corresponding to the die region. Based on the etching rate feedback from the inner and outer rings, adjust the resistance values ​​of the first variable resistor and / or the second variable resistor.

[0079] The above adjustments can be made in steps until the etching rates of the inner and outer rings are equal.

[0080] It should be noted that the above adjustment process may require multiple batches of wafers to complete.

[0081] Etching equipment with this coil structure is applied to the etching of patterned sapphire substrates to etch yurt patterns onto the sapphire surface. Each sapphire substrate contains millions of patterns, and variations in pattern size will result in differences in the epitaxial wavelength. Uneven plasma concentration within the etching chamber can cause size differences between the inner and outer coil patterns. By dividing the coil into inner and outer coils and controlling the resistance value of each coil, the etching rate can be controlled, thus ensuring a consistent etching rate within the chamber and guaranteeing the uniformity of the patterns on the patterned sapphire substrate.

[0082] Figure 3 This is a structural block diagram of an etching apparatus provided in an embodiment of this disclosure. See also... Figure 3The etching apparatus includes an RF power supply 10 and a coil structure 20, the RF power supply 10 and the coil structure 20 being electrically connected, and the coil structure 20 being as follows: Figure 1 or Figure 2 The coil structure described above.

[0083] In related technologies, due to the action of the coil, the gas molecules in the inner ring rotate faster than those in the outer ring (the inner ring has a shorter stroke), and the proportion of the coil unit area in the inner ring is greater than that in the outer ring (that is, the ratio of the inner ring void area to the inner ring coil area is smaller). This results in the outer ring having a lower molecular dissociation ability than the inner ring, causing a difference in plasma concentration between the inner and outer rings, and an inconsistent etching rate between the inner and outer rings.

[0084] In this embodiment, the coil is divided into a first coil unit and a second coil unit. The first coil unit is concentrically arranged within the second coil unit, meaning the first coil unit is the inner coil and the second coil unit is the outer coil. Unlike the integrated design of related technologies, the first and second coil units are insulated from each other. The first coil unit is electrically connected to at least one first variable resistor, and the second coil unit is electrically connected to at least one second variable resistor. During operation, by adjusting the resistance values ​​of at least one first variable resistor and at least one second variable resistor, the surface current of the inner and outer coils can be changed. This allows control over the molecular dissociation capabilities of the inner and outer coils, ensuring consistent plasma concentrations and thus consistent etching rates, effectively improving etching rate uniformity.

[0085] In this embodiment of the disclosure, the etching equipment is an ICP etching equipment, and the radio frequency power supply 10 and the coil structure 20 constitute the plasma source of the ICP etching equipment.

[0086] Optionally, the etching apparatus also includes a reaction chamber. The reaction chamber includes a chamber body and a stage located within the chamber body, and the aforementioned coil structure 20 is also located within the chamber body.

[0087] The cavity body is a closed space for the etching reaction, and the stage is used to place the wafer to be etched.

[0088] Optionally, the etching apparatus also includes a gas delivery system. The gas delivery system includes a gas source unit, a flow control unit, and gas pipelines, used to deliver etching gas into the cavity body.

[0089] Optionally, the etching equipment also includes a temperature control system for controlling the etching temperature within the cavity body.

[0090] Optionally, the etching apparatus also includes a vacuum system for controlling the gas pressure inside the cavity body.

[0091] Optionally, the etching machine also includes a control system. The control system includes a control unit and a sensor unit.

[0092] The control unit is used to control etching-related parameters, such as gas flow rate, radio frequency power, temperature, pressure, and time.

[0093] The sensor unit may include temperature sensors, pressure sensors, gas concentration sensors, etc., to provide real-time feedback of parameters within the cavity body.

[0094] In this embodiment of the disclosure, the control unit is further configured to control the resistance values ​​of at least one first variable resistor 300 and at least one second variable resistor 400 to make the etching rates of the inner and outer rings consistent.

[0095] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the element or object preceding “comprising” or “including” encompasses the element or object listed following “comprising” or “including” and its equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0096] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A coil structure for an etching machine, characterized in that, The coil structure includes: a first coil unit (100), a second coil unit (200), at least one first variable resistor (300) and at least one second variable resistor (400). The first coil unit (100) is concentrically arranged within the second coil unit (200), and the first coil unit (100) and the second coil unit (200) are mutually insulated; The first coil unit (100) is electrically connected to the at least one first variable resistor (300), and the second coil unit (200) is electrically connected to the at least one second variable resistor (400).

2. The coil structure according to claim 1, characterized in that, The first coil unit (100) includes a plurality of first coils (101) arranged concentrically, and the second coil unit (200) includes a plurality of second coils (201) arranged concentrically, wherein the first coils (101) and the second coils (201) are arranged concentrically; Two adjacent first coils (101) of the plurality of first coils (101) are connected, two adjacent second coils (201) of the plurality of second coils (201) are connected, and adjacent first coils (101) and second coils (201) are insulated from each other.

3. The coil structure according to claim 2, characterized in that, The spacing between any two adjacent coils is equal, and either of the two adjacent coils is the first coil (101) or the second coil (201).

4. The coil structure according to claim 3, characterized in that, The distance between any two adjacent coils is greater than or equal to 15mm.

5. The coil structure according to any one of claims 2 to 4, characterized in that, The width of the first coil (101) or the second coil (201) is 8~12mm, and the thickness of the first coil (101) or the second coil (201) is 4~6mm.

6. The coil structure according to any one of claims 2 to 4, characterized in that, The first coil (101) or the second coil (201) includes a plurality of coil segments (1000), and the plurality of coil segments (1000) of each first coil (101) or second coil (201) are spaced apart; The first coil unit (100) and the second coil unit (200) further include a connecting unit (2000); The coil segments (1000) of two adjacent first coils (101) or two adjacent second coils (201) are connected by the connecting unit (2000).

7. The coil structure according to any one of claims 2 to 4, characterized in that, The plurality of first coils (101) are electrically connected to one of the first variable resistors (300); The plurality of second coils (201) are electrically connected to the plurality of second variable resistors (400), and each second coil (201) is electrically connected to one second variable resistor (400).

8. The coil structure according to any one of claims 1 to 4, characterized in that, Both the first coil unit (100) and the second coil unit (200) are copper structures with surface coatings, and the copper structure surface has a first coating and a second coating in sequence; The first plating layer is a nickel layer, and the second plating layer is a gold or silver layer.

9. The coil structure according to claim 8, characterized in that, The thickness of the first coating is 8~12μm, and the thickness of the second coating is 2~4μm.

10. An etching machine, characterized in that, The etching apparatus includes a radio frequency power supply (10) and a coil structure (20), the radio frequency power supply (10) and the coil structure (20) being electrically connected, and the coil structure (20) being a coil structure as described in any one of claims 1 to 9.

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