Etching chamber and etching equipment

Abstract

The utility model discloses an etching chamber and etching equipment, which are applied to the technical field of semiconductors, and comprise a cavity, an electrostatic chuck and an airflow controller, the electrostatic chuck and the airflow controller are both arranged in the cavity, and the cavity is provided with an air inlet channel and an air outlet channel so as to form an air flowing direction in the cavity; the airflow controller is located on the side, close to the air inlet channel, of the electrostatic chuck in the air flowing direction. The airflow controller comprises a plurality of airflow control units and a plurality of air inlets which are distributed in an array mode, each airflow control unit is connected with at least one air inlet, and each airflow control unit is independently in communication connection with the control chip. Through the structure, each airflow control unit can work independently, when gas is introduced into the cavity, the position of etching gas entering the cavity can be accurately controlled through the airflow controller, and the etching uniformity can be improved by accurately regulating and controlling the introduction position of the etching gas.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor integrated circuit manufacturing technology, and in particular to an etching chamber and an etching device. Background Technology

[0002] Etching equipment is an important tool for the fabrication of semiconductor micro and nano devices. Its principle is to form a low-temperature plasma in a chamber containing reactive gas through glow discharge, and then etch the unmasked parts of the wafer surface. It utilizes the dual effects of physical bombardment of the substrate by active ions and chemical reaction to perform etching.

[0003] For etching equipment, etching gas needs to be introduced into the equipment for etching. Therefore, the uniformity of the distribution or flow of the etching gas in the etching equipment directly affects the uniformity of wafer etching. Thus, how to provide an etching chamber that can maximize uniformity is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] The purpose of this invention is to provide an etching chamber that can improve the uniformity of etching; another purpose of this invention is to provide an etching device that can improve the uniformity of etching.

[0005] To solve the above-mentioned technical problems, this utility model provides an etching chamber, including a chamber body, an electrostatic chuck, and an airflow controller;

[0006] Both the electrostatic chuck and the airflow controller are disposed within the cavity, which has an air inlet channel and an air outlet channel to form a gas flow direction within the cavity; in the gas flow direction, the airflow controller is located on the side of the electrostatic chuck closer to the air inlet channel.

[0007] The airflow controller includes multiple airflow control units arranged in an array and multiple air inlets. Each airflow control unit is connected to at least one of the air inlets, and each airflow control unit is individually connected to a control chip.

[0008] Optionally, the airflow control unit corresponds one-to-one with the air inlet.

[0009] Optionally, the air inlet is distributed in a honeycomb pattern on the surface of the airflow controller.

[0010] Optionally, a mass flow controller may also be included, located on the side of the airflow controller near the air intake passage in the gas flow direction.

[0011] Optionally, a gas sieve plate may also be included, located on the side of the electrostatic chuck away from the air inlet channel in the gas flow direction.

[0012] Optionally, the gas outlet channel is set at a non-central position of the gas sieve plate, and the porosity of the gas sieve plate at the position corresponding to the gas outlet channel is less than the porosity of the gas sieve plate at the position not corresponding to the gas outlet channel.

[0013] Optionally, the distance between each position in the gas sieve plate and the projection position of the gas outlet channel in the gas sieve plate is a preset distance, and the porosity of each position in the gas sieve plate is positively correlated with the magnitude of the corresponding preset distance.

[0014] Optionally, the size of the pores at each position in the gas sieve plate is positively correlated with the size of the corresponding preset distance;

[0015] And / or, the pore density at each position in the gas sieve plate is positively correlated with the magnitude of the corresponding preset distance.

[0016] Optionally, the air inlet channel is located at the top of the cavity, the air outlet channel is located at the bottom of the cavity, and the airflow controller, the electrostatic chuck, and the gas sieve plate are all horizontally arranged inside the cavity.

[0017] This invention also provides an etching apparatus, including the etching chamber described in any of the above claims.

[0018] The present invention provides an etching chamber comprising a cavity, an electrostatic chuck, and an airflow controller. The electrostatic chuck and the airflow controller are both disposed within the cavity. The cavity is provided with an air inlet channel and an air outlet channel to form a gas flow direction within the cavity. In the gas flow direction, the airflow controller is located on the side of the electrostatic chuck closer to the air inlet channel. The airflow controller includes multiple airflow control units arranged in an array and multiple air inlets. Each airflow control unit is connected to at least one air inlet, and each airflow control unit is individually communicatively connected to a control chip.

[0019] By setting up multiple airflow control units in an array within the airflow controller, and ensuring that each airflow control unit is individually connected to the control chip, each airflow control unit can operate independently. When gas is introduced into the cavity, the airflow controller can precisely control the position of the etching gas entering the cavity. This precise control of the etching gas introduction position can improve the uniformity of the etching process.

[0020] This invention also provides an etching device, which has the same beneficial effects as described above, and will not be described in detail here. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of an etching chamber provided in an embodiment of the present invention;

[0023] Figure 2 for Figure 1 A schematic diagram of the airflow controller from below;

[0024] Figure 3 A schematic diagram of a specific etching chamber provided in this embodiment of the present invention;

[0025] Figure 4 This is a diagram showing the airflow distribution within a cavity when using a symmetrical gas sieve plate in existing technology.

[0026] Figure 5 for Figure 3 A top view of the structure of the gas sieve plate;

[0027] Figure 6 for Figure 3 Airflow distribution diagram within the central cavity.

[0028] In the diagram: 1. Cavity, 2. Electrostatic chuck, 3. Airflow controller, 31. Airflow control unit, 32. Air inlet, 4. Air inlet channel, 5. Air outlet channel, 6. Wafer, 7. Gas sieve plate, 71. Air hole. Detailed Implementation

[0029] The core of this invention is to provide an etching chamber. In existing technologies, airflow controllers typically only allow selection of whether the etching gas is introduced from the center of the corresponding electrostatic chuck or from the edge of the corresponding electrostatic chuck. Simply selecting one of these two locations for the etching gas will result in uneven distribution of the etching gas within the chamber, thus causing uneven etching.

[0030] The etching chamber provided by this utility model includes a cavity, an electrostatic chuck, and an airflow controller. The electrostatic chuck and the airflow controller are both disposed in the cavity. The cavity is provided with an air inlet channel and an air outlet channel to form a gas flow direction within the cavity. In the gas flow direction, the airflow controller is located on the side of the electrostatic chuck closer to the air inlet channel. The airflow controller includes multiple airflow control units and multiple air inlets arranged in an array. Each airflow control unit is connected to at least one air inlet, and each airflow control unit is individually connected to a control chip.

[0031] By setting up multiple airflow control units in an array within the airflow controller, and ensuring that each airflow control unit is individually connected to the control chip, each airflow control unit can operate independently. When gas is introduced into the cavity, the airflow controller can precisely control the position of the etching gas entering the cavity. This precise control of the etching gas introduction position can improve the uniformity of the etching process.

[0032] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please refer to Figure 1 as well as Figure 2 , Figure 1 This is a schematic diagram of the structure of an etching chamber provided in an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the airflow controller from below.

[0034] See Figure 1 In this embodiment of the invention, the etching chamber includes a cavity 1, an electrostatic chuck 2, and an airflow controller 3. The electrostatic chuck 2 and the airflow controller 3 are both disposed within the cavity 1. The cavity 1 is provided with an air inlet channel 4 and an air outlet channel 5 to form a gas flow direction within the cavity 1. In the gas flow direction, the airflow controller 3 is located on the side of the electrostatic chuck 2 closer to the air inlet channel 4. The airflow controller 3 includes a plurality of airflow control units 31 arranged in an array and a plurality of air inlets 32. Each airflow control unit 31 is connected to at least one air inlet 32, and each airflow control unit 31 is individually communicatively connected to a control chip.

[0035] The aforementioned cavity 1 is the main structure of the etching chamber, while specific functional structures such as the electrostatic chuck 2 and the airflow controller 3 are all located inside the cavity 1. The cavity 1 is provided with an air inlet channel 4 and an air outlet channel 5. The air inlet channel 4 is used to introduce etching gas into the cavity 1, while the air outlet channel 5 is used to discharge the etched gas. Due to the arrangement of the air inlet channel 4 and the air outlet channel 5, a gas flow direction is formed within the cavity 1, pointing from the air inlet channel 4 to the air outlet channel 5.

[0036] In this embodiment, the airflow controller 3 is used to control the etching gas introduced into the cavity 1, while the electrostatic chuck 2 is used to adsorb and fix the wafer 6. Therefore, in the gas flow direction, the airflow controller 3 needs to be located on the side of the electrostatic chuck 2 closer to the air inlet channel 4, so that the etching gas is distributed and transmitted to the electrostatic chuck 2 by the airflow controller 3 to etch the wafer 6. Obviously, the etching position of the etching gas on the wafer 6 is related to the position of the airflow controller 3 introducing the etching gas into the cavity 1.

[0037] See Figure 2 In this embodiment, the airflow controller 3 includes a plurality of airflow control units 31 arranged in an array, and each airflow control unit 31 is connected to at least one of the air inlets 32. Each airflow control unit 31 can individually control the airflow through its connected air inlet 32. Each airflow control unit 31 can at least control whether the etching gas flows from its connected air inlet 32 ​​to the electrostatic chuck 2. Typically, the airflow control unit 31 can control the flow rate or volume of the etching gas flowing from its connected air inlet 32 ​​to the electrostatic chuck 2. Typically, the airflow controller 3 in this embodiment is disc-shaped, with an array of air inlets 32 arranged on its surface facing the electrostatic chuck 2. An array of airflow control units 31 is arranged inside the airflow controller 3, and each airflow control unit 31 is connected to at least one of the air inlets 32 for control. Optionally, in this embodiment, the airflow control units 31 and the air inlets 32 can correspond one-to-one to ensure maximum flexibility in controlling the etching gas flowing into each air inlet 32.

[0038] The aforementioned airflow control unit 31 typically includes a drive motor and a damper connected to the drive motor. The drive motor controls the opening and closing degree of the damper to control the flow rate or velocity of the etching gas passing through each air inlet 32. The specific structure of the airflow control unit 31 can be customized according to actual conditions and is not specifically limited here. The airflow controller 3 provided in this embodiment can control the etching gas to flow from any air inlet 32 ​​to the electrostatic chuck 2, thereby achieving precise control of the etching position on the surface of the wafer 6.

[0039] Specifically, in this embodiment, the air inlets 32 can be distributed in a honeycomb pattern on the surface of the airflow controller 3. That is, every six adjacent air inlets 32 on the surface of the airflow controller 3 can serve as vertices of a regular hexagon, forming a regular hexagonal distribution. More air inlets 32 can be periodically distributed in regular hexagonal patterns, thus forming a honeycomb structure. In this case, the distribution density of air inlets 32 in each area of ​​the surface of the airflow controller 3 is the same. Since each airflow control unit 31 can be controlled independently in this embodiment, the etching gas can be controlled to be released to the electrostatic chuck 2 at the same flow rate in each area of ​​the surface of the airflow controller 3, thereby ensuring the uniformity of etching.

[0040] In this embodiment, each airflow control unit 31 needs to communicate with the control chip individually to enable independent operation of each airflow control unit 31. The specific details of the control chip can be set according to the actual situation and are not specifically limited here.

[0041] Specifically, in this embodiment, the etching chamber may further include a mass flow controller (MFC), which is located on the side of the airflow controller 3 near the air inlet channel 4 in the gas flow direction. The MFC can be specifically disposed within the air inlet channel 4 to control the total amount of etching gas entering the chamber 1. The airflow controller 3 is responsible for controlling the flow rate of the etching gas entering different areas of the chamber 1 to ensure etching uniformity. In this embodiment, the etching gas first passes through the mass flow controller, which controls the overall flow rate of the etching gas entering the chamber 1; then, the etching gas passes through the airflow controller 3, which controls the flow rate of the etching gas sprayed onto different positions of the wafer 6 through various airflow control units 31; finally, the etching gas etches the wafer 6 adsorbed on the surface of the electrostatic chuck 2.

[0042] In this embodiment, the control values ​​of each airflow control unit 31 can be calculated by the difference in uniformity (including but not limited to key dimensions, depth, and etching angle) between the two wafers 6. The specific values ​​can be set according to the actual situation and are not specifically limited here.

[0043] The etching chamber provided in this embodiment features an array of multiple airflow control units 31 arranged in an array within the airflow controller 3. Each airflow control unit 31 is individually connected to a control chip, allowing each airflow control unit 31 to operate independently. When gas is introduced into the chamber 1, the airflow controller 3 can precisely control the position of the etching gas entering the chamber 1. This precise control of the etching gas introduction position improves the uniformity of the etching process.

[0044] The specific details of the etching chamber provided by this utility model will be described in detail in the following embodiments.

[0045] Please refer to Figures 3 to 6 , Figure 3 A schematic diagram of a specific etching chamber provided in this embodiment of the present invention; Figure 4 This is a diagram showing the airflow distribution within a cavity when using a symmetrical gas sieve plate in existing technology. Figure 5 for Figure 3 A top view of the structure of the gas sieve plate; Figure 6 for Figure 3 Airflow distribution diagram within the central cavity.

[0046] Unlike the above-described embodiments, this embodiment further defines the structure of the etching chamber. The remaining details have been described in detail in the above embodiments and will not be repeated here.

[0047] See Figure 3 In this embodiment of the invention, the etching chamber further includes a gas sieve plate 7, which is located on the side of the electrostatic chuck 2 away from the air inlet channel 4 in the gas flow direction.

[0048] The aforementioned gas sieve plate 7 has vents 71, which are specifically positioned on the side of the electrostatic chuck 2 near the outlet channel 5 in the gas flow direction. That is, after the etching gas etches the wafer 6 adsorbed by the electrostatic chuck 2, it passes through the gas sieve plate 7 and exits through the outlet channel 5. In this embodiment, the outlet channel 5 can be a gas channel defined by a dry pump (dry vacuum pump), meaning that the etching gas introduced into the cavity 1 in this embodiment can ultimately be discharged from the cavity 1 through the dry pump, wherein the pipe for setting the dry pump is the aforementioned outlet channel 5.

[0049] In this embodiment, the gas outlet channel 5 is positioned at a non-central location corresponding to the gas sieve plate 7. The porosity of the gas sieve plate 7 at the location corresponding to the gas outlet channel 5 is less than the porosity of the gas sieve plate 7 at locations not corresponding to the gas outlet channel 5. Since other accessories need to be installed directly below the center of the electrostatic chuck 2, to save space within the etching chamber, the aforementioned gas outlet channel 5, for example defined by a dry pump, typically needs to be positioned at a non-central location corresponding to the gas sieve plate 7. That is, the projection of the gas outlet channel 5 onto the gas sieve plate 7 is usually offset from the center of the gas sieve plate 7. See also... Figure 4 It is obvious that, generally speaking, the gas flow rate is faster closer to the outlet channel 5. However, when the projection of the outlet channel 5 onto the gas sieve plate 7 deviates from the center of the gas sieve plate 7, it means that the gas flow rate is not faster closer to the center of the gas sieve plate 7, but rather faster closer to the off-center position corresponding to the outlet channel 5. This will lead to non-uniformity in the flow rate of the etching gas in the cavity 1 as it flows towards the wafer 6. That is, the etching gas flow rate is faster closer to the outlet channel 5 and slower farther away from the outlet channel 5, thus causing non-uniformity in the etching on the surface of the wafer 6. In other words, the uneven gas extraction uniformity causes abnormal etching uniformity on the surface of the wafer 6, with faster etching near the outlet channel 5 and slower etching further away from the outlet channel 5.

[0050] See Figure 5 as well as Figure 6In this embodiment, the porosity of the gas sieve plate 7 corresponding to the gas outlet channel 5 is set to be less than the porosity of the gas sieve plate 7 not corresponding to the gas outlet channel 5. The porosity is the ratio of the area occupied by the pores 71 per unit area of ​​the gas sieve plate 7. Obviously, the larger the porosity, the easier it is for gas to pass through, and the smaller the porosity, the more difficult it is for gas to pass through. In this embodiment, the porosity of the gas sieve plate 7 corresponding to the gas outlet channel 5 is set to be less than the porosity of the gas sieve plate 7 not corresponding to the gas outlet channel 5. That is, gas is more difficult to pass through the gas sieve plate 7 corresponding to the gas outlet channel 5, while gas passes through the gas sieve plate 7 not corresponding to the gas outlet channel 5 more easily. This balances the flow rate of gas at different positions in the cavity 1, ensures the uniformity of the etching gas distribution in the cavity 1, and thus ensures the uniformity of etching.

[0051] Specifically, in this embodiment, the distance between each position in the gas sieve plate 7 and the projected position of the gas outlet channel 5 in the gas sieve plate 7 is a preset distance, and the porosity of each position in the gas sieve plate 7 is positively correlated with the magnitude of the corresponding preset distance. That is, in this embodiment, the porosity of each position in the gas sieve plate 7 gradually increases along the direction away from the projected position of the gas outlet channel 5 in the gas sieve plate 7. The farther away from the projected position of the gas outlet channel 5 in the gas sieve plate 7, the greater the porosity of the corresponding position in the gas sieve plate 7; conversely, the closer to the projected position of the gas outlet channel 5 in the gas sieve plate 7, the smaller the porosity of the corresponding position in the gas sieve plate 7. In this embodiment, the porosity of each position in the gas sieve plate 7 and the corresponding preset distance can be linearly positively correlated or non-linearly positively correlated. The porosity of each region in the gas sieve plate 7 usually needs to be set according to the simulation results of the simulation software, and no specific limitation is made here.

[0052] Specifically, in this embodiment, the size of the pores 71 at each location in the gas sieve plate 7 is positively correlated with the corresponding preset distance; and / or, the density of the pores 71 at each location in the gas sieve plate 7 is positively correlated with the corresponding preset distance. That is, in this embodiment, the porosity at each location in the gas sieve plate 7 can be positively correlated with the corresponding preset distance by adjusting the size of the pores 71 in different regions of the gas sieve plate 7, adjusting the distribution density of the pores 71, or adjusting both simultaneously. To facilitate the simulation of the gas sieve plate 7, the porosity of the gas sieve plate 7 is usually adjusted by adjusting the size of the pores 71 in different regions. In this embodiment, the pores 71 can be circular, strip-shaped, or any other shape, and are not specifically limited.

[0053] In this embodiment, the cavity 1 is typically cylindrical, with the air inlet channel 4 usually located at the top of the cavity 1 and the air outlet channel 5 usually located at the bottom of the cavity 1. The airflow controller 3, the electrostatic chuck 2, and the gas sieve plate 7 are all horizontally arranged inside the cavity 1. Corrosion gas propagates downwards within the cavity 1. The cavity 1 is also typically equipped with electrode plates or other functional structures for point-discharge. Further details regarding the remaining structures within the cavity 1 can be found in existing technologies and will not be elaborated upon here.

[0054] The etching chamber provided in this embodiment of the present invention, by setting a gas sieve plate 7 with asymmetrically distributed pores 71, can avoid abnormal etching uniformity on the surface of the wafer 6 caused by different gas extraction uniformity, and further improve the uniformity of etching the wafer 6.

[0055] The following describes an etching apparatus provided by an embodiment of the present invention. The etching apparatus described below can be referred to in correspondence with the etching chamber described above.

[0056] In this embodiment, the etching apparatus includes an etching chamber as provided in any of the above-described embodiments. The specific structure of the etching chamber has been described in detail in the above-described embodiments and will not be repeated here. Other structures of the etching apparatus, such as the gas chamber, can be found in the prior art and will not be described further here.

[0057] Since the etching apparatus provided in this embodiment specifically uses the etching chamber provided in the above embodiment, the etching apparatus can have higher etching uniformity, thereby enabling the fabrication of higher quality semiconductor devices.

[0058] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0059] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0060] The etching chamber and etching apparatus provided by this utility model have been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. An etch chamber, comprising: The chamber, the electrostatic chuck and the gas flow controller are provided in the chamber, the chamber is provided with an air inlet channel and an air outlet channel to form a gas flow direction in the chamber, the gas flow controller is located on the side of the electrostatic chuck close to the air inlet channel along the gas flow direction. The gas flow controller comprises a plurality of gas flow control units and a plurality of air inlets arranged in an array, each gas flow control unit is connected to at least one air inlet, and each gas flow control unit is individually connected to a control chip. The gas flow control unit corresponds to the air inlet.

2. The etch chamber of claim 1, wherein, The air inlets are arranged in a honeycomb pattern on the surface of the gas flow controller.

3. The etch chamber of claim 1, wherein, A mass flow controller is further included, and the mass flow controller is located on the side of the gas flow controller close to the air inlet channel along the gas flow direction.

4. The etch chamber of claim 1, wherein, A gas screen plate is further included, and the gas screen plate is located on the side of the electrostatic chuck away from the air inlet channel along the gas flow direction.

5. The etch chamber of claim 1, wherein, The air outlet channel is arranged corresponding to a non-central position of the gas screen plate, the porosity of the gas screen plate corresponding to the position of the air outlet channel is less than the porosity of the gas screen plate not corresponding to the position of the air outlet channel.

6. The etch chamber of claim 5, wherein, The distance between each position of the gas screen plate and the projection position of the air outlet channel in the gas screen plate is a preset distance, and the porosity of each position of the gas screen plate is positively correlated with the size of the corresponding preset distance.

7. The etch chamber of claim 6, wherein, The size of the gas hole in each position of the gas screen plate is positively correlated with the size of the corresponding preset distance.

8. The etch chamber of claim 7, wherein, The density of the gas hole in each position of the gas screen plate is positively correlated with the size of the corresponding preset distance. The air inlet channel is arranged at the top of the chamber, the air outlet channel is arranged at the bottom of the chamber, and the gas flow controller, the electrostatic chuck and the gas screen plate are horizontally arranged inside the chamber.

9. The etch chamber of claim 5, wherein, The etching chamber comprises the etching chamber according to any one of claims 1 to 9.

10. An etching apparatus, characterized by, ​

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