Process chambers and semiconductor processing equipment

Abstract

The application discloses a process chamber and a semiconductor processing equipment. The process chamber comprises a vacuum cavity and a radio frequency coil surrounding the outside of the vacuum cavity, and further comprises a Faraday shield between the vacuum cavity and the radio frequency coil, and a shield wall of the Faraday shield is provided with an axial special-shaped through slot, wherein an opening of the special-shaped through slot close to a first end of the radio frequency coil is smaller than an opening of the special-shaped through slot away from a second end of the radio frequency coil. The application can provide sufficient radial electric field in the cavity during the ignition stage to ensure smooth ignition, and can also inhibit the leakage of the excess radial electric field near the radio frequency coil during the process stage, so that the plasma discharge efficiency in the cavity is improved, and the corrosion damage of the plasma to the inner wall of the chamber is reduced.

Description

Technical Field

[0001] This invention relates to the technical field of semiconductor manufacturing, and more specifically to a process chamber and a semiconductor processing apparatus. Background Technology

[0002] Semiconductor processing equipment can be used to manufacture devices such as integrated circuits, micromechanical devices, and flat panel displays through plasma processing. Figure 1 As shown, in the existing inductively coupled plasma (ICP) process equipment, namely ICP equipment 100, the Faraday shield 110 has a wall with a straight groove 111 of equal width, and the groove size at the radio frequency coil 120 and other locations is the same.

[0003] This can lead to excessive shielding of the external electric field by the narrow slot size of the I-shaped straight slot 111 during the ignition stage, resulting in insufficient electric field released into the cavity and making ignition difficult. If the slot width of the I-shaped straight slot 111 is directly increased, although the ignition electric field requirement can be met, the radial electric field in the coil area will continue to leak out in large quantities during the steady-state process stage, resulting in a concentrated strong radial electric field on the coil and inner wall. This can cause problems such as reduced plasma discharge efficiency, arcing, plasma displacement, erosion and wear of the inner wall of the cavity, and metal sputtering contamination of the wafer.

[0004] To address the aforementioned problems in the prior art, there is an urgent need in the field for an improved process chamber that can provide sufficient radial electric field to the chamber during the ignition stage to ensure successful ignition, while also suppressing excessive radial electric field leakage near the RF coil during the process stage. This not only improves the plasma discharge efficiency within the chamber but also reduces the corrosive damage of the plasma to the inner wall of the chamber. Summary of the Invention

[0005] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed descriptions that follow.

[0006] To overcome the aforementioned deficiencies in the prior art, the present invention provides a process chamber and a semiconductor processing apparatus that can provide sufficient radial electric field to the chamber during the ignition stage to ensure smooth ignition, while also suppressing excessive radial electric field leakage near the RF coil during the process stage. This not only improves the plasma discharge efficiency within the chamber but also reduces the corrosion damage of the plasma to the inner wall of the chamber.

[0007] Specifically, the process chamber provided according to the first aspect of the present invention includes a vacuum chamber and a radio frequency coil surrounding the vacuum chamber. The process chamber further includes a Faraday shield located between the vacuum chamber and the radio frequency coil, wherein the wall of the Faraday shield is provided with an axially shaped through-slot, wherein the opening of the shaped through-slot near a first end of the radio frequency coil is smaller than the opening of its second end away from the radio frequency coil.

[0008] Furthermore, in some embodiments of the present invention, the irregularly shaped through-slot includes any one of the following: T-shaped, inverted T-shaped, V-shaped, inverted V-shaped, I-shaped, Y-shaped, inverted Y-shaped, and double V-shaped, wherein the radio frequency coil is located on the periphery of the narrow end of any of the irregularly shaped through-slots.

[0009] Furthermore, in some embodiments of the present invention, the process chamber further includes: an adjustment plate, movably disposed between the vacuum chamber and the irregularly shaped through-slot in the Faraday shield, for adjusting the opening ratio of the irregularly shaped through-slot during the ignition stage and the process stage of plasma processing in the vacuum chamber.

[0010] Furthermore, in some embodiments of the present invention, the process chamber includes a drive mechanism connected to the adjustment plate. The drive mechanism drives the adjustment plate to a first position during the ignition stage to open the irregular through slot, thereby increasing the opening ratio of the irregular through slot. During the process stage, the drive mechanism drives the adjustment plate to a second position to partially block the irregular through slot, thereby reducing the opening ratio of the irregular through slot.

[0011] Furthermore, in some embodiments of the present invention, the minimum opening size formed by the adjustment plate and the irregular through slot during the ignition stage is determined at least based on the radio frequency power provided by the radio frequency coil, wherein the lower the radio frequency power, the larger the corresponding minimum opening size, so as to compensate for the radial electric field in the vacuum cavity.

[0012] Furthermore, in some embodiments of the present invention, the minimum opening size formed by the adjustment plate and the irregular through slot during the ignition stage is determined based on the intracavity gas pressure in the vacuum cavity. The larger the radial electric field required for ignition determined by the intracavity gas pressure via the Paschen curve, the larger the corresponding minimum opening size is, in order to compensate for the radial electric field in the vacuum cavity.

[0013] Furthermore, in some embodiments of the present invention, the minimum opening size formed by the adjusting plate and the irregular through slot during the ignition stage is determined based on the type of plasma excitation gas introduced into the vacuum cavity. The more difficult it is for the plasma excitation gas to ignite and discharge, the larger the corresponding minimum opening size is, in order to compensate for the radial electric field in the vacuum cavity.

[0014] Furthermore, in some embodiments of the present invention, the process chamber further includes: a controller connected to the drive mechanism, configured to: in response to the introduction of plasma excitation gas into the vacuum chamber, control the drive mechanism to move the adjustment plate to the first position to release sufficient radial electric field into the vacuum chamber via the irregular through-slot for ignition; determine whether the ignition stage is completed based on changes in process parameters; and in response to the completion of the ignition stage, control the drive mechanism to move the adjustment plate to the second position to block the outward diffusion of excess radial electric field within the vacuum chamber via the adjustment plate.

[0015] Furthermore, in some embodiments of the present invention, the step of determining whether the ignition stage is completed based on changes in process parameters includes: determining that the ignition stage is completed in response to the plasma density in the vacuum cavity reaching a preset standard, or in response to a sudden change signal in the radio frequency current of the radio frequency coil, or in response to the process duration reaching a preset conversion duration.

[0016] Furthermore, the semiconductor processing apparatus provided according to the second aspect of the present invention includes: the process chamber provided in the first aspect of the present invention, the interior of which is used for plasma processing; and an air inlet disposed above the process chamber for introducing process gas into the process chamber, wherein the process gas includes plasma excitation gas. Attached Figure Description

[0017] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related properties or features may have the same or similar reference numerals.

[0018] Figure 1A schematic diagram of the external structure of a Faraday shield with a straight groove of equal width in the shape of a 1, provided for the prior art.

[0019] Figure 2 A schematic cross-sectional view of a semiconductor processing apparatus provided according to some embodiments of the present invention is shown.

[0020] Figure 3 A schematic diagram of the external structure of a process chamber provided according to some embodiments of the present invention is shown.

[0021] Figures 4A-4C A schematic diagram of the external structure of a process chamber provided according to other embodiments of the present invention is shown.

[0022] Figure 5A This is a schematic diagram of the radial electric field distribution within the vacuum cavity corresponding to the Faraday shield with a straight groove structure of equal width in the form of a "1".

[0023] Figure 5B A schematic diagram of the radial electric field distribution within the vacuum cavity corresponding to the Faraday shield of the T-shaped irregular through-slot provided by the present invention.

[0024] Figure 6 A schematic diagram of the external structure of a process chamber provided according to other embodiments of the present invention is shown.

[0025] Figure 7A A schematic diagram of the position of the adjustment plate during the ignition stage is shown, according to some embodiments of the present invention.

[0026] Figure 7B A schematic diagram of the position of the adjustment plate during the process stage is shown, according to some embodiments of the present invention.

[0027] Figure 8A A flowchart of a method for adjusting the position of an adjustment plate according to some embodiments of the present invention is shown.

[0028] Figure 8B A structural block diagram of a controller provided according to some embodiments of the present invention is shown.

[0029] Figure 9A This diagram illustrates the global temperature distribution of the vacuum cavity corresponding to the Faraday shield with the I-shaped irregular through-slot provided by the present invention.

[0030] Figure 9B This diagram shows a partially magnified temperature field of a vacuum cavity directly opposite the slotted area of ​​the I-shaped through-slot provided by the present invention.

[0031] Figure label: 100 ICP devices; 110 Faraday shield; 111. Straight groove in the shape of a 1; 200 and 600 semiconductor processing equipment; 210 Process chamber; 211 Vacuum cavity; 212 Radio frequency coil; 213 Faraday shield; 220 air intake; 221 Top cover plate; 230 base plate; 300, 410~430 irregular through-slots; 610 Adjustment plate; 611 Auxiliary through slot; 800 controller; 801 memory; 802 processor; 910 Slotted area; 920 Non-grooved area. Detailed Implementation

[0032] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention will be presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a thorough understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood as the orientations shown in the relevant paragraphs and accompanying drawings. These relative terms are for illustrative purposes only and do not imply that the described apparatus must be manufactured or operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0035] It is understood that although terms such as "first," "second," and "third" may be used herein to describe various components, regions, layers, and / or parts, these components, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers, and / or parts. Therefore, the first components, regions, layers, and / or parts discussed below may be referred to as second components, regions, layers, and / or parts without departing from some embodiments of the present invention.

[0036] As mentioned above, such as Figure 1 As shown, in the existing ICP equipment 100, the Faraday shield 110 has a uniformly wide I-shaped straight slot 111 structure on its wall, with the slot size at the RF coil 120 and other locations being consistent. This can lead to excessive shielding of the external electric field by the narrow I-shaped straight slot 111 when the cavity is in the ignition stage, resulting in insufficient electric field released into the cavity and making ignition difficult. If the slot width of the I-shaped straight slot 111 is directly increased, although the ignition electric field requirement can be met, when the cavity is in the steady-state process stage, the radial electric field in the coil area will continuously leak out in large quantities due to the excessively wide slot width, resulting in a concentrated strong radial electric field on the coil and the inner wall of the wall. This can cause problems such as reduced plasma discharge efficiency, arcing, plasma displacement, erosion and wear of the inner wall of the cavity, and metal sputtering contamination of the wafer.

[0037] To address the aforementioned problems in the prior art, the present invention provides a process chamber and a semiconductor processing apparatus that can provide sufficient radial electric field to the chamber during the ignition stage to ensure smooth ignition, while also suppressing excessive radial electric field leakage near the RF coil during the process stage. This not only improves the plasma discharge efficiency within the chamber but also reduces the corrosion damage of the plasma to the inner wall of the chamber.

[0038] In some non-limiting embodiments, the process chamber provided in the first aspect of the present invention can be configured in the semiconductor processing equipment provided in the second aspect of the present invention.

[0039] The working principle of the above-described process chamber will be described below with reference to some embodiments of semiconductor processing equipment. Those skilled in the art will understand that these embodiments of semiconductor processing equipment are merely non-limiting implementations provided by the present invention, intended to clearly demonstrate the main concepts of the invention and provide specific solutions convenient for public implementation, rather than limiting all operating methods or functions of the process chamber. Similarly, the process chamber is also only one non-limiting implementation provided by the present invention and does not constitute a limitation on other functional components in these semiconductor processing equipment.

[0040] Please refer to Figure 2 . Figure 2 A schematic cross-sectional view of a semiconductor processing apparatus provided according to some embodiments of the present invention is shown.

[0041] like Figure 2 As shown, in some embodiments of the present invention, the semiconductor processing equipment 200 mainly includes a process chamber 210 and an air inlet 220.

[0042] Specifically, the process chamber 210 is entirely placed on the base plate 230, and its interior is used for plasma processing. This process chamber 210 can adapt to the timing requirements of various plasma processes such as plasma thin film deposition, plasma etching, plasma surface cleaning, and plasma surface modification, and can be configured with corresponding structures and accessories, which are not limited here. An air inlet 220 is provided at the top of the process chamber 210. This air inlet 220 can be located above the process chamber 210 via the chamber cover plate 221, and is used to introduce process gas from above the process chamber 210. The process gas includes at least a plasma excitation gas. The plasma excitation gas does not participate in the chemical reactions mentioned above, such as thin film deposition and etching; it is responsible for being broken down by the electric field to generate plasma. For example, argon (Ar) can be used as the plasma excitation gas.

[0043] Optionally, the process gas may also include precursors required for the deposition process, etching gases required for the etching process, etc. For example, when the semiconductor processing equipment 200 performs a deposition process, the process gas introduced through the gas inlet 220 may include silicon precursor SiH4, oxidizing gas N2O, and plasma excitation gas Ar. When the semiconductor processing equipment 200 performs an etching process, the process gas introduced through the gas inlet 220 may include fluorine-based etching reactive gas SF6 and plasma excitation gas Ar.

[0044] Continue as Figure 2 As shown, in some embodiments, the process chamber 210 includes a vacuum chamber 211, a radio frequency coil 212 surrounding the vacuum chamber 211, and a Faraday shield 213.

[0045] Specifically, the vacuum cavity 211 can be a quartz cavity. The quartz vacuum cavity 211 can isolate the electric field but not shield the alternating magnetic field. For example, when a high-frequency radio frequency of 13.56 MHz is supplied to the external radio frequency coil 212, an alternating magnetic field and an alternating radial radio frequency electric field are generated simultaneously. Since quartz is a silicon dioxide insulating medium and is non-conductive, it can prevent the radio frequency electric field of the radio frequency coil 212 from directly contacting the plasma. The radio frequency coil 212 is a metal coil, such as a copper coil. Without the insulation of the quartz cavity, the metal conductor of the coil would directly contact the plasma, resulting in leakage, arcing, and metal sputtering from the coil onto the wafer. Furthermore, since the propagation of the alternating magnetic field does not require a conductor, the insulating, non-magnetic quartz material cannot prevent magnetic field lines from passing through. The alternating magnetic field generated by the radio frequency coil 212 can penetrate the quartz cavity without loss, enter the cavity, and ionize the plasma excitation gas, completing the normal ignition of the ICP plasma.

[0046] The Faraday Ring 213 is a shaped metal shielding electrode, fabricated using the Faraday shielding principle. Within the vacuum cavity 211 undergoing plasma processing, high-frequency radio waves generate stray electric fields and parasitic discharges. Based on the principle that a closed metal conductor can isolate internal and external electric fields (i.e., the Faraday shielding effect), by enclosing or surrounding the vacuum cavity 211 with the Faraday Ring 213, excess internal electric fields can be prevented from leaking out, thereby confining the plasma.

[0047] Optionally, the Faraday shield 213 can be made of metal materials such as aluminum, stainless steel, or copper. Correspondingly, the upper cover 221 and the bottom plate 230 can be made of the same metal material as the Faraday shield 213 to enhance the shielding effect against the electric field.

[0048] Furthermore, please refer to [the relevant documentation / reference]. Figure 3 A shared understanding. Figure 3 A schematic diagram of the external structure of a process chamber provided according to some embodiments of the present invention is shown.

[0049] like Figure 2 and Figure 3 As shown, the Faraday shield 213 is located between the vacuum chamber 211 and the radio frequency coil 212. The wall of the Faraday shield 213 has an axial irregular through-slot 300. By opening the axial through-slot in the wall of the Faraday shield 213, the complete circumferential conductive path can be cut off, thereby suppressing the annular current of the Faraday shield, greatly reducing the eddy current loss generated by magnetic field induction, and ensuring that the coil magnetic field can efficiently penetrate into the quartz vacuum chamber 211.

[0050] Furthermore, such as Figure 3As shown in the magnified area I, the opening d1 of the irregular through-slot 300 near the first end of the RF coil 212 is smaller than the opening d2 of its second end away from the RF coil 212. In the above-mentioned non-I-shaped irregular through-slot 300 structure, segmented differentiated slotting is adopted to separately address the two conflicting requirements existing in the prior art.

[0051] Specifically, the ICP process discharge mode comprises two stages. The first stage is the ignition stage in Electrostatic Mode (E-mode), where a radial electric field breaks down the plasma-excited gas inside the cavity to complete plasma ignition. A sufficiently strong radial electric field is required for successful ignition in this step. After ignition, once the plasma density within the vacuum chamber 211 reaches a certain level, the second stage begins.

[0052] The second stage is the stable process stage under Helicon Mode (H-mode), which relies on the alternating magnetic field of the RF coil 212 to maintain the plasma within the cavity. In this second stage, the RF power input to the RF coil 212 is intended to be entirely converted into the alternating magnetic field to continuously generate the plasma required for the process. However, in this steady-state stage, if an E-mode electric field remains, some RF energy will be converted into excess radial electric field, leading to disordered outward and inward radiation leakage. Furthermore, this energy does not participate in the effective process reaction and is considered energy loss. Therefore, with the same input power, less effective energy is used to maintain the plasma, thus reducing the plasma's process efficiency. In addition, the radial electric field strongly accelerates electrons and ions within the cavity, significantly increasing the kinetic energy of charged particles. Therefore, the high-energy particles generated in E-mode will corrode and damage the inner wall of the vacuum cavity 211, especially the cavity wall near the RF coil 212, where corrosion is most severe.

[0053] In this regard, in the above-described embodiment of the present invention, by aligning the narrow end of the irregularly shaped through-slot 300 with the RF coil 212, the shielding body at the Faraday shield 213 corresponding to the RF coil 212 is made almost complete. This avoids the negative effects caused by electric field leakage due to the excessive width of the traditional I-shaped slot in the second-stage steady-state process. Furthermore, in areas far from the RF coil 212, the RF electric field generated by coil coupling is naturally weaker. To address this, by increasing the opening of the irregularly shaped through-slot 300 corresponding to the area far from the RF coil 212, the shielding failure area in this region is increased, allowing for the release of more radial electric field inward for end compensation. This ensures that the overall radial electric field strength within the cavity meets the requirements for the first-stage ignition.

[0054] Next, please combine Figures 4A-4C . Figures 4A-4CA schematic diagram of the external structure of a process chamber provided according to other embodiments of the present invention is shown.

[0055] In some alternative embodiments, the irregularly shaped slot 300 may include any of the following: T-shaped, inverted T-shaped, V-shaped, inverted V-shaped, I-shaped, Y-shaped, inverted Y-shaped, and double V-shaped. The radio frequency coil 212 is located around the narrow end of any of the irregularly shaped slots 300. Exemplarily, Figure 3 The T-shaped irregular through-slot 300 is shown. Figure 4A The V-shaped irregular through-slot 410 is shown. Figure 4B The double V-shaped irregular through-slot 420 is shown. Figure 4C An I-shaped through-slot 430 is shown. In any of the embodiments shown above, since the electric field strength generated by the RF coil 212 is weaker at the upper and / or lower ends of the region far from the RF coil 212, the radial electric field required for ignition in the first stage of ICP discharge can be maintained by increasing the slot size of the through-slot corresponding to this region. Furthermore, in any of the embodiments shown above, the RF coil 212 is located on the periphery of the narrow end of the through-slot 300, 410, 420, or 430, thereby suppressing the negative impact of the radial electric field near the RF coil 212 in the steady-state second stage.

[0056] Those skilled in the art will understand that the various irregularly shaped slots listed above are merely non-limiting embodiments of the present invention, intended to clearly demonstrate the main concept of the invention and provide a specific solution that is easy for the public to implement, rather than being used to limit the scope of protection of the present invention. Optionally, in other embodiments, those skilled in the art can also use other slotted structures of different shapes to segmentally design the slots in the Faraday shield based on the concept of the present invention, in order to achieve the same technical effect.

[0057] Continue back Figure 3 As shown, exemplarily, in some optional embodiments, the lateral slot range of the opening d1 of the irregular through-slot 300 near the first end (i.e., the narrow end) of the RF coil 212 can be 0.1~10mm. The narrow end of the irregular through-slot 300 is only used to cut off the complete circumferential conductive path, that is, only used to suppress annular eddy currents. Therefore, the lateral slot range of the narrow end should not be too large. Preferably, only a narrow slit of 0.5~1mm can be retained at the first end of the irregular through-slot 300 corresponding to the RF coil 212, and the shielding body of the Faraday shield 213 is almost complete, thereby significantly blocking the radial electric field spillover phenomenon in the second stage of steady state and reducing the negative problems caused by the residual electric field in E-mode.

[0058] Next, please refer to the following: Figure 5A and Figure 5B . Figure 5A This is a schematic diagram of the radial electric field distribution within the vacuum cavity corresponding to the Faraday shield with a straight groove structure of equal width in the form of a "1". Figure 5B A schematic diagram of the radial electric field distribution within the vacuum cavity corresponding to the Faraday shield of the T-shaped irregular through-slot provided by the present invention.

[0059] like Figure 5A As shown, in the Faraday shield 110 with a straight slot structure of equal width (I-shape), the electric field of the vacuum cavity is mainly concentrated near the radio frequency coil. However, as... Figure 5B As shown, in the Faraday shield 213 with T-shaped through slot, the electric field of the vacuum cavity is mainly concentrated in the upper region away from the radio frequency coil. Therefore, it can effectively reduce the possibility of high-energy particles corroding and damaging the inner wall of the cavity due to excessively strong radio frequency electric field near the radio frequency coil, which could lead to vacuum cavity failure.

[0060] Furthermore, according to simulation results, the volume-average radial electric field in the vacuum cavity corresponding to the Faraday shield with a straight slot is approximately 5.6 V / m. However, in the vacuum cavity corresponding to the Faraday shield with a T-shaped through slot, the volume-average radial electric field increases to approximately 35 V / m. Therefore, the above-mentioned embodiments provided by this invention can significantly improve the ignition performance of ICP (first-stage E-mode discharge).

[0061] Next, please refer to Figure 6 . Figure 6 A schematic diagram of the external structure of a process chamber provided according to other embodiments of the present invention is shown.

[0062] like Figure 6 As shown, in some other embodiments, the process chamber of the semiconductor processing equipment 600 may also include an adjustment plate 610. The adjustment plate 610 is movably disposed between the vacuum chamber 211 and the irregularly shaped through-slot 300 in the Faraday shield 213, and is used to adjust the opening ratio of the irregularly shaped through-slot 300 during the initiation and process stages of plasma processing in the vacuum chamber 211.

[0063] Specifically, the process chamber may also include a drive mechanism (not shown in the figures) connected to the adjusting plate 610 for moving the adjusting plate 610, thereby changing the position of the adjusting plate 610. The adjusting plate 610 and the Faraday shield 213 may be made of the same material.

[0064] Furthermore, it can be combined with Figure 7A and Figure 7B . Figure 7A A schematic diagram of the position of the adjustment plate during the ignition stage is shown, according to some embodiments of the present invention. Figure 7B A schematic diagram of the position of the adjustment plate during the process stage is shown, according to some embodiments of the present invention.

[0065] like Figure 7A As shown, in some embodiments, when the semiconductor processing equipment 600 is in the ignition stage of the electric field mode (i.e., the first stage of ICP discharge), the drive mechanism drives the adjustment plate 610 to move to a first position, opening the irregularly shaped through slot 300 to increase the opening ratio of the irregularly shaped through slot 300. Exemplarily, in... Figure 7A In the illustrated embodiment, the ignition performance is maintained by increasing the opening ratio of the T-shaped through-slot 300 during the ignition stage.

[0066] like Figure 7B As shown, in some embodiments, when the semiconductor processing equipment 600 is in a stable process stage under magnetic field mode (i.e., the second stage of ICP discharge), the drive mechanism drives the adjustment plate 610 to move to a second position, partially blocking the irregularly shaped through-slot 300 to reduce the opening ratio of the irregularly shaped through-slot 300. Exemplarily, in... Figure 7A In the illustrated embodiment, the negative impact of the radial electric field (such as corrosion of the inner wall of the cavity) is reduced by decreasing the opening ratio of the enlarged T-shaped through groove 300 during the process stage.

[0067] In some alternative embodiments, the opening ratio of the irregular through-slot can be adjusted by adjusting the longitudinal position (i.e., height) of the adjusting plate 610. Exemplarily, the driving mechanism can drive the adjusting plate 610 to rise during the ignition stage to open the irregular through-slot 300, and drive the adjusting plate 610 to fall during the process stage to block the irregular through-slot 300.

[0068] In some alternative embodiments, the opening ratio of the irregular through slot can be adjusted by adjusting the lateral position of the adjusting plate 610. For example, the driving mechanism can drive the adjusting plate 610 to the left during the ignition stage to open the irregular through slot 300, and drive the adjusting plate 610 to the right during the process stage to block the irregular through slot.

[0069] like Figure 7B As shown, in some embodiments, an axial auxiliary slot 611 may be provided in the adjustment plate 610. Optionally, the auxiliary slot 611 can be a straight slot structure. Since the metal Faraday shield is a continuously conductive cylinder, the alternating magnetic field of the RF coil will induce a large-area annular eddy current on the complete, unopened metal cylinder, thereby losing RF power, reducing plasma coupling efficiency, and also weakening the penetration ability of the coil's alternating magnetic field into the vacuum cavity, resulting in the inability to stably maintain plasma in H-mode. To address this, by opening a small auxiliary slot 611 in the adjustment plate 610, after the second end (wide end) of the second-stage irregular slot 300 is completely covered, the conductive closed loop can still be cut off and eddy currents suppressed after the opening of the first end (narrow end) of the irregular slot 300, while minimizing the leakage of harmful radial electric field.

[0070] like Figure 7A or Figure 7B As shown, in some embodiments, the minimum opening size formed by the adjusting plate 610 and the irregular through-slot 300 during the ignition stage can be determined based on process parameters.

[0071] Specifically, in some alternative embodiments, the minimum opening size may be determined at least based on the radio frequency power provided by the radio frequency coil 212. The lower the radio frequency power, the larger the corresponding minimum opening size, in order to compensate for the radial electric field within the vacuum cavity.

[0072] For example, in a high-power scenario of 1000W, the radio frequency energy is stronger, so only a smaller opening size (e.g., raised to a height of 5mm) is needed to output a sufficient radial electric field for ignition. However, in a low-power scenario of 100W, the plasma excitation gas and the pressure inside the chamber remain constant, and the radio frequency energy is lower, making it more difficult to break down the plasma excitation gas. Therefore, a larger opening size (e.g., continuously raised to a height of 20mm) can be used to release a sufficient radial electric field to compensate for the overall radial electric field within the chamber, thus enabling successful ignition in E-mode.

[0073] In other embodiments, the minimum opening size may be determined based on the intracavity pressure within the vacuum chamber 211. The larger the radial electric field required for ignition, determined by the intracavity pressure via the Paschen curve, the larger the corresponding minimum opening size, in order to compensate for the radial electric field within the vacuum chamber.

[0074] Specifically, the Paschen curve describes the minimum breakdown voltage required for a gas to undergo a breakdown discharge (i.e., change from an insulating state to a conductive state, generating plasma / glow) between two parallel electrode plates. Vb With air pressure p ×Polar spacing d (Right now pd The functional relationship between the product and the product. pd (Air pressure × electrode spacing) is the horizontal axis, and the breakdown voltage is... Vb With the vertical axis as the ordinate, the Paschen curve is a U-shaped (or V-shaped) curve that first decreases and then increases. The lowest point on the curve is the minimum breakdown voltage point, corresponding to the operating condition where ignition is easiest. Therefore, based on the Paschen curve and the gas pressure inside the cavity, the minimum radial electric field required for ignition can be determined. The larger the required minimum radial electric field, the larger the corresponding minimum opening size.

[0075] For example, when the cavity pressure is within a first range (e.g., below 10 Pa), this pressure corresponds to the left branch of the U-shaped Paschen curve. The lower the pressure, the further to the upper left of the U-shaped curve, and correspondingly, the larger the required radial electric field. Therefore, when the cavity pressure is within the first range, the lower the cavity pressure, the larger the minimum radial electric field required for ignition, and the larger the corresponding minimum opening size, thus compensating for the radial electric field within the vacuum cavity. Conversely, when the cavity pressure is within a second range (e.g., above 100 Pa), this pressure corresponds to the right branch of the U-shaped Paschen curve. The higher the pressure, the further to the upper right of the U-shaped curve, and correspondingly, the larger the required radial electric field. Therefore, when the cavity pressure is within the second range, the higher the cavity pressure, the larger the minimum radial electric field required for ignition, and the larger the corresponding minimum opening size, thus compensating for the radial electric field within the vacuum cavity.

[0076] In other embodiments, the minimum opening size can be determined based on the plasma-excited gas introduced into the vacuum chamber. The more difficult it is for the plasma-excited gas to ignite, the larger its corresponding minimum opening size, in order to compensate for the radial electric field within the vacuum chamber. Gases that are easier to ignite (such as argon) have smaller corresponding minimum opening sizes. Gases that are more difficult to ignite (such as fluorine-based etching gases) require appropriately enlarged minimum opening sizes to compensate for the radial electric field strength and complete ionization.

[0077] In some optional embodiments, the minimum opening size of the irregular through-slot 300 in the Faraday shield within the process chamber where a specific plasma process is performed can be calibrated based on at least one of the three process parameters described above.

[0078] Further, please see Figure 8A . Figure 8A A flowchart of adjusting the position of the adjustment plate according to some embodiments of the present invention is shown.

[0079] In some embodiments, the process chamber may further include a controller (not shown in the figures). The controller is connected to the drive mechanism and configured to perform actions such as Figure 8A The steps S810~S830 are shown.

[0080] Specifically, step S810 can be executed first: in response to the introduction of plasma excitation gas into the vacuum cavity, the control drive mechanism moves the adjustment plate to a first position to release a sufficient radial electric field into the vacuum cavity for ignition via the irregularly shaped through-slot. Here, the "first position" refers to the adjustment position of the adjustment plate 610 corresponding to the minimum opening size of the irregularly shaped through-slot 300. This adjustment position can be determined based on at least one of the following: the radio frequency power provided by the radio frequency coil, the intracavity pressure within the vacuum cavity, and the type of plasma excitation gas. Through the opening region of the irregularly shaped through-slot 300 corresponding to the minimum opening size, the irregularly shaped through-slot 300 can be used only to suppress annular eddies during the ignition stage, while simultaneously providing a sufficient radial electric field for ignition within the cavity.

[0081] Then, steps S820 and S830 can be executed. Step S820: Determine whether the ignition stage is complete based on the changes in process parameters. Step S830: In response to the completion of the ignition stage, control the drive mechanism to move the adjustment plate to the second position to block the outward diffusion of excess radial electric field in the vacuum chamber via the adjustment plate.

[0082] Specifically, after the ignition stage is completed, the controller can control the drive mechanism to automatically adjust the adjustment plate 610 to the adjustment position with a small opening ratio corresponding to the irregular through slot 300. Further, during the execution of step S820, the judgment means for automatic adjustment may include any one of the following: changes in plasma density in the vacuum chamber, sudden changes in the radio frequency current of the radio frequency coil, and the process time reaching a preset conversion time.

[0083] For example, assuming that during the ignition stage of the fluorine-based etching process, the plasma characteristic spectral lines in the cavity are acquired in real time using an optical emission spectrometer (OES), thereby indirectly obtaining the plasma density within the cavity. In step S810, the adjustment plate 610 is kept in the first position (e.g., with a rise height of 20 mm). When the plasma density in the vacuum cavity is detected to reach a preset standard, the controller determines that the ignition stage in E-mode is complete, and the cavity switches to H-mode. At this time, the controller outputs a control signal to control the drive mechanism to move the adjustment plate 610 to the second position (e.g., to completely cover the wide end of the irregular through-slot 300) to narrow the slot as a whole, thereby suppressing excess radial electric field leakage during the stabilization process stage.

[0084] For example, suppose that during the ignition phase of a high-power SiO2 etching process, the RF power supply operates in a matched state. Before ignition, the RF current of the RF coil is stably maintained at 10A. When the plasma excitation gas breaks down to form plasma, the cavity load impedance changes abruptly, and the RF current drops instantly to 8A, showing a significant abrupt change. The controller detects this current step change signal and determines that ignition is complete.

[0085] For example, based on statistics from a large number of batches of repetitive mass production etching processes, it is assumed that the fixed duration of the complete E-mode to H-mode conversion under this operating condition is 1 second. Taking the moment when the RF power-on and the adjustment board 610 is adjusted to the first position corresponding to the minimum opening size as the timing start point, after the timer counts down for 1 second, the end of the ignition stage can be directly determined without the need for additional sensor signals.

[0086] Please refer to Figure 8B . Figure 8B A structural block diagram of a controller provided according to some embodiments of the present invention is shown.

[0087] like Figure 8B As shown, in some non-limiting embodiments, the controller 800 includes a memory 801 and a processor 802. Here, the memory 801 includes, but is not limited to, a computer-readable storage medium storing computer instructions. The processor 802 is connected to the memory 801 and configured to execute the computer instructions stored in the memory 801 to implement the adjustment plate position adjustment method provided above according to the present invention.

[0088] Next, please combine Figure 9A and Figure 9B . Figure 9A This diagram illustrates the global temperature distribution of the vacuum cavity corresponding to the Faraday shield with the I-shaped irregular through-slot provided by the present invention. Figure 9B This diagram shows a partially magnified temperature field of a vacuum cavity directly opposite the slotted area of ​​the I-shaped through-slot provided by the present invention.

[0089] like Figure 9AAs shown, the slotting of the Faraday shield leads to temperature non-uniformity inside the vacuum cavity due to the difference in heat transfer methods between the slotted region 910 and the non-slotted region 920. In the non-slotted region 920, efficient heat dissipation is achieved through heat conduction via the gap between the vacuum cavity and the Faraday shield, resulting in a lower overall temperature. However, in the slotted region 910, the metal shielding layer is broken, preventing heat conduction through the metal gap. Heat dissipation relies solely on the thermal radiation of air convection, easily leading to heat accumulation and the formation of high-temperature zones within the cavity. Within a certain temperature range, the higher the temperature of the inner wall of the vacuum cavity, the higher the deactivation coefficient of active groups (such as H) on the wall surface. The non-uniformity of the distribution of active groups on the inner wall of the cavity further affects the non-uniformity of the process.

[0090] In this regard, in the embodiments provided by the present invention, by adjusting the opening area of ​​the irregular through-slot 300 to the minimum opening size during the ignition stage using the adjusting plate 610, it is possible to ensure that more metal cover is retained while the cavity can ignite normally, thereby increasing the heat exchange area between the outer wall of the cavity and the Faraday shield for gap heat conduction. This maximizes the effective area for gap heat conduction, thereby increasing the proportion of channels for efficient heat dissipation. Therefore, in the above embodiments, the influence of the opening in the Faraday shield on the vacuum cavity temperature can also be suppressed, resulting in an overall reduction in the cavity wall temperature.

[0091] In summary, the present invention provides a process chamber and a semiconductor processing apparatus that can provide sufficient radial electric field to the chamber during the ignition stage to ensure smooth ignition, while also suppressing excessive radial electric field leakage near the RF coil during the process stage. This not only improves the plasma discharge efficiency within the chamber but also reduces the corrosion damage of the plasma to the inner wall of the chamber.

[0092] Although the methods described above are illustrated and depicted as a series of actions for the sake of simplicity, it should be understood and appreciated that these methods are not limited by the order of the actions, as some actions may occur in a different order and / or concurrently with other actions from the illustrations and descriptions herein or not illustrated and described herein but which may be understood by those skilled in the art, according to one or more embodiments.

[0093] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps are described above in a generalized manner in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be construed as departing from the scope of the invention.

[0094] The various illustrative logic modules and circuits described in conjunction with the embodiments disclosed herein may be implemented or performed using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but in alternatives, it may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0095] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor such that the processor can read and write information to / from the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside as discrete components in the user terminal.

[0096] In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functionality may be stored or transmitted as one or more instructions or code on or through a computer-readable medium. A computer-readable medium includes both computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium accessible to a computer. By way of example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a computer. Any connection is also legitimately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of a medium. As used in this article, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs. Disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of these should also be included within the scope of computer-readable media.

[0097] The prior description of this disclosure is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A process chamber, comprising a vacuum chamber and a radio frequency coil surrounding the outside of the vacuum chamber, characterized in that, The process chamber further includes: A Faraday shield is located between the vacuum cavity and the radio frequency coil. The wall of the Faraday shield is provided with an axial irregularly shaped through groove, wherein the opening of the irregularly shaped through groove at the first end near the radio frequency coil is smaller than the opening at the second end away from the radio frequency coil.

2. The process chamber as described in claim 1, characterized in that, The irregularly shaped through-slot includes any one of the following: T-shaped, inverted T-shaped, V-shaped, inverted V-shaped, I-shaped, Y-shaped, inverted Y-shaped, and double V-shaped, wherein the radio frequency coil is located on the periphery of the narrow end of any of the irregularly shaped through-slots.

3. The process chamber as described in claim 1, characterized in that, Also includes: An adjustment plate is movably disposed between the vacuum cavity and the irregularly shaped through-slot in the Faraday shield, and is used to adjust the opening ratio of the irregularly shaped through-slot during the ignition stage and the process stage of plasma processing in the vacuum cavity.

4. The process chamber as described in claim 3, characterized in that, The device includes a drive mechanism connected to the adjustment plate. During the ignition stage, the drive mechanism drives the adjustment plate to a first position to open the irregularly shaped through slot, thereby increasing the opening ratio of the irregularly shaped through slot. During the process stage, the drive mechanism drives the adjustment plate to a second position to partially block the irregularly shaped through slot, thereby reducing the opening ratio of the irregularly shaped through slot.

5. The process chamber as described in claim 3, characterized in that, The minimum opening size formed by the adjustment plate and the irregular through slot during the ignition stage is determined at least based on the radio frequency power provided by the radio frequency coil. The lower the radio frequency power, the larger the corresponding minimum opening size, in order to compensate for the radial electric field inside the vacuum cavity.

6. The process chamber as described in claim 3 or 5, characterized in that, The minimum opening size formed by the adjustment plate and the irregular through-slot during the ignition stage is determined based on the intracavity pressure in the vacuum cavity. The larger the radial electric field required for ignition, determined by the intracavity pressure via the Paschen curve, the larger the corresponding minimum opening size, in order to compensate for the radial electric field in the vacuum cavity.

7. The process chamber as described in claim 3 or 5, characterized in that, The minimum opening size formed by the adjustment plate and the irregular through slot during the ignition stage is determined based on the type of plasma excitation gas introduced into the vacuum cavity. The more difficult it is for the plasma excitation gas to ignite and discharge, the larger the corresponding minimum opening size, in order to compensate for the radial electric field inside the vacuum cavity.

8. The process chamber as described in claim 4, characterized in that, Also includes: The controller, connected to the drive mechanism, is configured to: In response to the introduction of plasma excitation gas into the vacuum chamber, the drive mechanism is controlled to move the adjustment plate to the first position so as to release a sufficient radial electric field into the vacuum chamber through the irregular through slot to initiate ignition. Determine whether the ignition stage is complete based on changes in process parameters; as well as In response to the completion of the ignition stage, the drive mechanism is controlled to move the adjustment plate to the second position to block the outward diffusion of excess radial electric field within the vacuum cavity via the adjustment plate.

9. The process chamber according to claim 8, characterized in that, The step of determining whether the ignition stage is completed based on changes in process parameters includes: The ignition stage is determined to be complete when the plasma density in the vacuum chamber reaches a preset standard, or when the radio frequency current of the radio frequency coil shows a sudden change signal, or when the process duration reaches a preset conversion duration.

10. A semiconductor processing apparatus, characterized in that, include: The process chamber as described in any one of claims 1 to 9 is used for plasma process treatment; as well as An air inlet is located above the process chamber and is used to introduce process gas into the process chamber, wherein the process gas includes plasma excitation gas.

Images