Etching cavity and etching equipment
By embedding heaters and cooling pipes within the etching chamber and implementing coordinated control, the problem of uneven temperature within the chamber was solved, achieving stability and effective temperature control during the etching process.
Patent Information
- Application Number
- CN202423315856.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-02-03
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Traditional etching chamber temperature control systems are ineffective in controlling the temperature of the chamber and liner, resulting in uneven temperature distribution on the wafer surface, which affects etching rate and process stability.
Multiple heaters and cooling pipes are embedded in the etching cavity and distributed along the horizontal circumference of the cavity. The upper end of the heater is higher than the lowest end of the inner lining, and the cooling pipes surround the cavity vertically. Temperature uniformity and stability are achieved through coordinated control.
It achieves stable control of the chamber temperature, meets the temperature requirements of various processes, and improves the stability of the etching process and wafer quality.
Smart Images
Figure CN223871444U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of semiconductor etching equipment technology, and in particular to an etching cavity and etching equipment. Background Technology
[0002] In today's semiconductor integrated circuit or panel manufacturing process, it is required to precisely control the size of various materials down to the submicron level, and it must also have extremely high reproducibility. Plasma etching is a technology that can efficiently complete this work with high yield, so plasma etching has become one of the main technologies in semiconductor manufacturing.
[0003] During the etching process, the internal temperature of the etching chamber is affected by heat sources such as the lower electrode temperature, plasma concentration, and changes in radio frequency power. These temperature variations have a significant impact on the quality of the process. For example, wafer temperature control is a critical parameter. Uneven temperature distribution on the wafer surface will affect the etching rate at different locations, potentially causing process instability and damaging the wafer structure. However, traditional etching chamber temperature control systems are not effective in controlling the temperature of the chamber and liner. Therefore, improving the etching chamber to enhance temperature control of both the chamber and liner has become a pressing technical problem for those skilled in the art. Utility Model Content
[0004] In view of this, one objective of this invention is to provide an etching cavity that enables more effective control of the temperature of the chamber and its lining. Another objective of this invention is to provide an etching apparatus that includes the aforementioned etching cavity.
[0005] To achieve the above objectives, this utility model provides the following technical solution:
[0006] An etching cavity includes a wall forming a cavity and an inner liner located within the cavity, and further includes:
[0007] Multiple heaters are embedded in the wall body and are distributed horizontally around the chamber. The lower end of each heater is located on the wall body at the bottom of the chamber, and the upper end of each heater is located above the lowest end of the liner.
[0008] Multiple cooling pipes are embedded in the wall body and are distributed vertically. At least two of the cooling pipes are located at positions above and below the lowest end of the lining, respectively. The cooling pipes surround the cavity horizontally.
[0009] Optionally, in the above-mentioned etching cavity, the heater is rod-shaped, and the angle between the heater and the horizontal plane is not less than 45° and not greater than 90°.
[0010] Optionally, in the above-mentioned etching cavity, the vertical projection of the cooling pipe is annular or polygonal.
[0011] Optionally, in the above-mentioned etching cavity, the angle between the cooling pipe and the horizontal plane is no greater than 30°.
[0012] Optionally, in the above-mentioned etching cavity, the inlets of different cooling pipes are more than 30° apart in the horizontal circumferential direction of the cavity.
[0013] Optionally, in the above-mentioned etching cavity, the cooling pipes are configured as two, one of which is located 1 cm to 2 cm lower than the lowest end of the liner, and the other is located 1 cm to 2 cm lower than the top surface of the wall.
[0014] Optionally, in the above-mentioned etching cavity, the heaters are configured as four, located at the four corners of the etching cavity.
[0015] Optionally, the etching cavity described above includes multiple temperature sensors embedded within the wall.
[0016] Optionally, the etching cavity includes an over-temperature protection component embedded in the wall, the over-temperature protection component being electrically connected to the temperature sensor.
[0017] An etching apparatus comprising an etching cavity as disclosed in any of the foregoing claims.
[0018] The etching cavity provided by this utility model has the following beneficial effects:
[0019] The etching chamber has multiple heaters and multiple cooling pipes inside its wall. The heaters are distributed horizontally around the chamber, and the cooling pipes surround the chamber horizontally. The upper end of the heater is located above the lowest end of the liner, and the lower end is located at the bottom of the corresponding chamber wall. At least two cooling pipes are located above the lowest end of the liner and below the lowest end of the liner, respectively. This arrangement allows for better synergistic control of the uniformity of the wall temperature and the liner temperature through the heaters and cooling pipes, achieving stable temperature regulation of the chamber and meeting the temperature control requirements of various processes. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in 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 embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the etching cavity provided in an embodiment of the present invention;
[0022] Figure 2 This is a schematic diagram of the bottom surface of the etching cavity provided in this embodiment of the present invention;
[0023] Figure 3 This is a cross-sectional view of the etching cavity provided in an embodiment of the present invention;
[0024] Figure 4 yes Figure 3 Enlarged view of point A in the middle;
[0025] Figure 5 yes Figure 3 Enlarged view of point B in the middle;
[0026] Figure 6 This is a schematic diagram of the first cooling pipe according to an embodiment of the present utility model;
[0027] Figure 7 This is a schematic diagram of the second cooling pipe according to an embodiment of the present utility model;
[0028] Figure 8 This is a simulation result diagram of the longitudinal gradient temperature field control of the lining according to one embodiment;
[0029] Figure 9 This is a simulation result diagram of the longitudinal gradient temperature field control of the lining according to another embodiment.
[0030] The diagram is marked as follows:
[0031] 100, Cavity cover; 200, Wall; 300, Liner; 401, First heater; 402, Second heater; 403, Third heater; 404, Fourth heater; 510, First cooling pipe; 520, Second cooling pipe; 600, Annular heater; 701, First temperature sensor; 702, Second temperature sensor; 703, Third temperature sensor; 704, Fourth temperature sensor; 800, Over-temperature protection component. Detailed Implementation
[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0033] In the description of this application, the references to terms such as "one embodiment," "some embodiments," "example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. 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 those different embodiments or examples.
[0034] In the description of this specification, 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 limitation, 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.
[0035] See Figures 1-7This invention provides an etching chamber that can be used in etching equipment, such as a plasma etching machine. The etching chamber includes a wall 200 forming a chamber and a liner 300 located within the chamber. The chamber is the space where etching operations are performed. The liner 300 is a bushing-type component installed within the chamber, isolating the highly corrosive process environment and thus protecting the wall 200 and other components. The etching chamber also includes multiple heaters and multiple cooling pipes embedded within the wall 200, where "multiple" means more than one. These heaters are distributed horizontally around the chamber, with the lower ends of the heaters located at the bottom of the wall 200 corresponding to the bottom of the chamber, and the upper ends of the heaters located above the lowest end of the liner 300. These cooling pipes are distributed vertically, with at least two cooling pipes located above and below the lowest end of the liner 300, respectively. The cooling pipes surround the chamber horizontally; that is, for a single cooling pipe, the cooling pipe is arranged around the chamber.
[0036] The etching chamber of this invention has multiple heaters and multiple cooling pipes inside the wall 200. The heaters are distributed along the horizontal circumference of the chamber, and the cooling pipes surround the chamber along the horizontal circumference. The upper end of the heater is located above the lowest end of the liner 300, and the lower end is located at the bottom of the corresponding chamber of the wall 200. At least two cooling pipes are located above the lowest end of the liner 300 and below the lowest end of the liner 300, respectively. With this arrangement, the heaters and cooling pipes can better coordinate and control the uniformity of the wall temperature and the liner temperature, achieve stable temperature regulation of the chamber, and meet the temperature control requirements of various processes.
[0037] In some embodiments, the heater may be configured as a rod, and the angle between the heater and the horizontal plane may be set to be not less than 45° and not greater than 90°. Figure 1 In the exemplary embodiment shown, there may be four heaters: a first heater 401, a second heater 402, a third heater 403, and a fourth heater 404. Each heater is arranged perpendicular to the horizontal plane. Figure 3As shown, the upper end of the heater can be located at the height of the middle of the corresponding lining 300. It should be noted that different heaters can have the same height or different heights, as long as the upper end of the heater is higher than the lowest point of the lining 300. Furthermore, the angles between different heaters and the horizontal plane can be the same or different. For example, all four heaters can be set at a 70° angle to the horizontal plane, or two of the four heaters can be set at a 70° angle to the horizontal plane, and the other two at a 90° angle. Additionally, when two different heaters are inclined relative to the horizontal plane, the inclination directions of the two heaters relative to the horizontal plane can be the same or different. However, to facilitate temperature control, the distance between each heater and the inner surface of the wall 200 should be set as uniform as possible. Various types of heaters can be selected, such as cylindrical heaters or resistance wire heaters. Of course, in other embodiments, the heaters can also be configured with other structural forms; for example, the heater can be plate-shaped, with the plate-shaped heater parallel or approximately parallel to the wall surface of the wall 200.
[0038] In some embodiments, four heaters may be provided, located at the four corners of the etching chamber. The horizontal cross-section of the etching chamber may be rectangular. In this case, one heater can be provided at each of the four corners of the etching chamber, that is, each heater is located at the intersection of two walls of the chamber, so that the heating requirements of the entire chamber can be met with a smaller number of heaters. Of course, in other embodiments, the number of heaters may be different, such as six or eight, and the horizontal cross-section of the etching chamber may be non-rectangular, for example, the horizontal cross-section of the etching chamber may be circular.
[0039] In some embodiments, two cooling pipes may be provided, one of which is located 1 cm to 2 cm below the lowest end of the liner 300, and the other is located 1 cm to 2 cm below the top surface of the wall 200. Figure 1 In the exemplary embodiment shown, two cooling pipes may be embedded inside the wall 200, namely a first cooling pipe 510 and a second cooling pipe 520, as shown below. Figure 3 and Figure 4 As shown, the first cooling pipe 510 is separated from the top surface of the wall 200, i.e., the surface where the lining 300 overlaps, by a first distance C1, which can be set to 2 cm. Figure 3 and Figure 5As shown, the second cooling pipe 520 is located at a second distance C2 below the lowest end of the liner 300, and the second distance C2 can be set to 2 cm. Of course, in other embodiments, the number of cooling pipes can be set to other values, such as three, four, etc. When there are more than two cooling pipes, the first distance C1 can be understood as the vertical distance between the highest cooling pipe and the top surface of the wall 200, and the second distance C2 can be understood as the vertical distance between the lowest cooling pipe and the lowest end of the liner 300.
[0040] exist Figure 3 In the exemplary embodiment shown, the liner 300 can be configured as an inverted hat shape, with its outer flange overlapping the top surface of the wall 200 and being pressed tightly by the cavity cover 100, and the central through-hole of the liner 300 fitting around the outer edge of the lower electrode. In some embodiments, an annular heater 600 can be embedded inside the lower electrode, such as... Figure 1 As shown, the annular heater 600 can be concentrically arranged with the circular lower electrode, that is, the center of the annular heater 600 coincides with the center of the upper surface of the lower electrode. It can be understood that the heat provided by the annular heater 600 can be transferred to the inner liner 300 through the outer edge of the lower electrode, thereby enabling better temperature control of the inner liner 300.
[0041] In some embodiments, the angle between the cooling pipes and the horizontal plane can be set to no more than 30°. That is, when the cooling pipes are arranged around the chamber in a horizontal circumferential direction, all points of the cooling pipes can be located in the same horizontal plane or in the same inclined plane, and the angle between the inclined plane and the horizontal plane is no more than 30°. It should be noted that when the angles between two different cooling pipes and the horizontal plane are both greater than 0°, the inclined planes in which the two cooling pipes are located can be parallel to each other or not.
[0042] In some embodiments, the vertical projection of the cooling pipes can be configured as an annular or polygonal shape. The cooling pipes circumferentially surround the chamber, thus their projection on the horizontal plane forms an approximately closed shape, which can be annular, or a polygon such as a quadrilateral, pentagon, or hexagon. It should be noted that the vertical projections of two different cooling pipes can have the same shape or different shapes; see [reference needed]. Figure 6 and Figure 7 When the vertical projection of the first cooling pipe 510 is set to a circular shape, the vertical projection of the second cooling pipe 520 can be set to a hexagon.
[0043] The fluid medium in the cooling pipes can be a liquid, gas, or a gas-liquid mixture. Examples include water, dichloromethane, liquid ammonia, electronic fluorinated liquids such as perfluorotripropylamine, nitrogen, and air. To facilitate temperature control, the flow direction of the fluid medium in two adjacent cooling pipes can be set to opposite directions. See [link to relevant documentation]. Figure 6 and Figure 7 When the fluid medium in the first cooling pipe 510 flows counterclockwise, the fluid medium in the second cooling pipe 520 can be configured to flow clockwise.
[0044] In some embodiments, the inlets of different cooling pipes are spaced at least 30° apart horizontally around the chamber. When the cooling pipes circumferentially surround the chamber, the inlets and outlets are relatively close, and both are locations where they connect to external pipes; that is, the cooling pipes are connected to the fluid circulation system via external pipes. To centrally house the external pipes in the same area of the etching chamber, the inlets of different cooling pipes can be vertically distributed. However, considering the need for operating space for pipe installation and removal, the inlets of different cooling pipes can be set to be spaced at least 30° apart horizontally around the chamber. For example, in... Figure 1 In the exemplary embodiment shown, the inlet positions of the first cooling pipe 510 and the second cooling pipe 520 are 180° apart in the horizontal circumferential direction of the chamber, i.e., they are diagonally arranged. Similarly, the outlet positions of the first cooling pipe 510 and the second cooling pipe 520 are 180° apart in the horizontal circumferential direction of the chamber.
[0045] In some embodiments, the etching cavity may include a plurality of temperature sensors embedded within the wall 200. Figure 1 In the exemplary embodiment shown, four temperature sensors can be configured, namely a first temperature sensor 701, a second temperature sensor 702, a third temperature sensor 703, and a fourth temperature sensor 704. The temperature sensors can be as follows: Figure 1 The temperature sensors are positioned near the heater. However, in other embodiments, the number and location of the temperature sensors can be flexibly configured as needed, as long as they are embedded within the wall 200 and can detect the temperature of the corresponding area. It is easy to understand that the temperature sensors are electrically connected to the temperature control unit. The temperature control unit establishes the current temperature field within the chamber using the temperature information collected by the temperature sensors, and adjusts the temperature based on the difference between the current temperature field and the target temperature field, causing the current temperature field to transform into the target temperature field.
[0046] In some embodiments, the etching chamber may include an over-temperature protection component 800 embedded in the wall 200, which is electrically connected to a temperature sensor. The over-temperature protection component 800 can improve the safety of the equipment and prevent overheating. Feedback communication is established between the over-temperature protection component 800 and the temperature sensor. When the temperature value detected by the temperature sensor exceeds a set value (e.g., 65°C), the over-temperature protection component 800 is triggered and sends an alarm signal to the temperature control unit. Upon receiving the alarm signal, the temperature control unit can reduce the temperature by, for example, shutting down the heater or increasing the flow rate of the fluid medium in the cooling pipes.
[0047] In some embodiments, to more accurately establish the target temperature field, each heater and each cooling pipe can be controlled independently. For example, the temperature control unit can control the first heater 401 and the third heater 403 to turn on for heating while controlling the second heater 402 and the fourth heater 404 to turn off for not heating; it can control the first heater 401 to heat to 45°C and the third heater 403 to heat to 50°C. As another example, the temperature control unit can control the mass flow rate of the fluid medium in the first cooling pipe 510 to be 0.02 kg / s to 0.03 kg / s, and control the mass flow rate of the fluid medium in the second cooling pipe 520 to be 0.06 kg / s to 0.07 kg / s.
[0048] See Figure 1 and Figure 3In some embodiments, the etching cavity may include a first heater 401, a second heater 402, a third heater 403, a fourth heater 404, a first cooling pipe 510, a second cooling pipe 520, a first temperature sensor 701, a second temperature sensor 702, a third temperature sensor 703, and a fourth temperature sensor 704 embedded within the wall 200. Taking a gradient temperature field with a uniformly decreasing temperature from top to bottom established in one embodiment as an example, the first cooling pipe 510, relative to the upper layer, can control the initial temperature of the longitudinal top of the four walls (front, back, left, and right) of the wall 200 and the liner 300, while the temperature at the bottom of the wall 200 is controlled by the second cooling pipe 520, relative to the lower layer. Different fluid mass flow rate adjustments in the cooling pipes can effectively reduce the non-uniformity and fluctuation of the longitudinal temperature gradient of the wall and the liner. During equipment operation, for a temperature-controlled area k within the etching chamber, a temperature sensor acquires the current real-time temperature Txk of that area and reports it to the temperature control unit. The temperature control unit compares the current real-time temperature Txk with the target temperature T: if the difference is less than a preset temperature threshold range ε, the current real-time temperature is considered to meet the control requirements; if the difference is greater than the preset temperature threshold range ε, the temperature control unit executes the temperature control procedure. During the temperature control procedure, the temperature control unit further determines the relationship between the current real-time temperature Txk and the target temperature T: if Txk < T, meaning the temperature-controlled area k is currently relatively cold, it then determines whether the difference between the current real-time temperature Txk and the target temperature T is three times the preset temperature threshold range ε, and decides which temperature control method to use based on the magnitude of the difference. If the difference between the current real-time temperature Txk and the target temperature T is less than three times the preset temperature threshold range ε, then only the fluid mass flow rate of the cooling pipe needs to be reduced. If the difference between the current real-time temperature Txk and the target temperature T is greater than three times the preset temperature threshold range ε, then the heating power of the heater needs to be increased to meet the temperature increase. After one judgment and adjustment, the temperature sensor will again capture the current real-time temperature Txk of the temperature control area k and execute the temperature control logic flow again until the current real-time temperature Txk and the target temperature T meet the judgment of the preset temperature threshold range ε, that is, the difference is less than the preset temperature threshold range ε. If Txk > T, that is, the temperature control area k is currently relatively hot, its control and judgment logic can be compared with that when the temperature control area k is currently relatively cold, except that the control mode of the cooling pipe and the heater is reversed.
[0049] It should be noted that the preset capture frequency f of the current real-time temperature Txk of the temperature control zone k is issued by the temperature control unit. For cases with small temperature differences, the original temperature control parameters can be corrected. This avoids the problem of independent operation of the heating and cooling modules and their increasing energy consumption, effectively improving the coordination and consistency of temperature control and its environmental friendliness.
[0050] See Figure 8 This demonstrates a longitudinal temperature gradient field (reflected by the longitudinal temperatures at eight different locations on the lining) with a uniformly decreasing temperature from top to bottom, established by synchronously adjusting the heating power of each heater. Synchronous adjustment of the heating power of each heater means that the first heater 401, the second heater 402, the third heater 403, and the fourth heater 404 are set to isothermal conditions. See also... Figure 9 This demonstrates a longitudinal temperature gradient field in the lining with a uniform temperature decrease from top to bottom, established by differentially controlling the power of each heater, in comparison to... Figure 9 and Figure 8 It is evident that differentiated power control for each heater can improve the radial uniformity of the temperature field, reducing the temperature difference by half compared to isothermal conditions. It should be noted that... Figure 8 and Figure 9 In the diagram, the vertical axis represents the temperature value, and the horizontal axis represents the distance value (with the highest point of the lining as the reference, the downward distance is a positive value). The eight different locations selected are eight locations scattered on the horizontal plane.
[0051] This utility model also provides an etching apparatus, which includes the etching cavity disclosed in the above embodiments. Since the etching cavity disclosed in the above embodiments has the aforementioned technical effects, the etching apparatus having this etching cavity also has the aforementioned technical effects, and will not be described in detail here. It should be understood that the etching apparatus also includes other components such as a pre-vacuum chamber and a gas supply system. These components and their connection relationships with the etching cavity are prior art, and therefore will not be described in detail here.
[0052] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. An etching cavity, comprising a wall (200) forming a cavity and a liner (300) located within the cavity, characterized in that, Also includes: Multiple heaters (401~404) are embedded in the wall (200). The multiple heaters (401~404) are distributed horizontally around the chamber. The lower end of the heater is located at the bottom of the chamber corresponding to the wall (200), and the upper end of the heater is located above the lowest end of the liner (300). Multiple cooling pipes (510, 520) are embedded in the wall (200). The multiple cooling pipes (510, 520) are distributed vertically. At least two of the cooling pipes are located at positions above the lowest end of the lining (300) and below the lowest end of the lining (300), respectively. The cooling pipes surround the cavity in the horizontal circumference of the cavity.
2. The etching cavity according to claim 1, characterized in that, The heater is rod-shaped, and the angle between the heater and the horizontal plane is not less than 45° and not greater than 90°.
3. The etching cavity according to claim 1, characterized in that, The vertical projection of the cooling pipes is circular or polygonal.
4. The etching cavity according to claim 3, characterized in that, The angle between the cooling pipe and the horizontal plane shall not exceed 30°.
5. The etching cavity according to claim 1, characterized in that, The inlets of the different cooling pipes are more than 30° apart in the horizontal circumferential direction of the chamber.
6. The etching cavity according to claim 1, characterized in that, The cooling pipes are configured as two, one of which is located 1 cm to 2 cm lower than the lowest end of the lining (300), and the other is located 1 cm to 2 cm lower than the top surface of the wall (200).
7. The etching cavity according to claim 1, characterized in that, The heaters are configured as four and located at the four corners of the etching cavity.
8. The etching cavity according to any one of claims 1 to 7, characterized in that, It includes multiple temperature sensors (701~704) embedded in the wall (200).
9. The etching cavity according to claim 8, characterized in that, It includes an over-temperature protection component (800) embedded in the wall (200), and the over-temperature protection component (800) is electrically connected to the temperature sensor (701~704).
10. An etching apparatus, characterized in that, Includes the etching cavity as described in any one of claims 1 to 9.