Deposition process equipment and film stress adjusting method

Abstract

The invention discloses deposition process equipment and a thin film stress adjusting method. The deposition process equipment comprises a reaction cavity, a spraying plate serving as an upper electrode and a heating disc serving as a lower electrode are arranged in the reaction cavity, and the lower electrode is connected with a high-frequency power source. The deposition process equipment further comprises an insulating part which is connected with the spraying plate and is arranged between the spraying plate and the side wall of the cavity, so that the spraying plate is in an electric suspension state; one end of the impedance adjusting device is connected with the spraying plate, the other end of the impedance adjusting device is connected with the side wall of the cavity, and the impedance adjusting device is used for adjusting the impedance of the spraying plate so as to adjust the plasma field between the spraying plate and the heating disc. According to the invention, the dissipation of high-frequency energy can be reduced, and the retention time of electrons between the upper electrode and the lower electrode is prolonged, so that the film deposition rate is improved, the abnormal stress of film formation can be reduced, the finished product scrapping is reduced, and the production yield is improved.

Description

Technical Field

[0001] This invention relates to the technical field of semiconductor manufacturing, specifically to a deposition process apparatus, a method for adjusting thin film stress, and a computer-readable storage medium. Background Art

[0002] In semiconductor thin-film deposition processes, plasma-enhanced chemical vapor deposition (PECVD) typically employs a top-radio frequency (RF) input method. A spray plate, serving as the upper electrode, is connected to an RF power supply, while a heating plate, serving as the lower electrode, is grounded. However, this top-RF input method results in a significant distance between the plasma region generated at the top and the wafer at the bottom. Energy must be transferred to the wafer via plasma diffusion. During this process, some energy is adsorbed by the cavity walls or lost due to ion / radical recombination, thus reducing energy transfer efficiency.

[0003] In response, some advanced designs employ a bottom RF input approach, connecting the original heating plate to the RF power supply while grounding the spray plate. This bottom RF input structure improves energy transfer efficiency, resulting in faster deposition rates and a more stable RF circuit.

[0004] However, in the aforementioned bottom RF input scheme, because the upper electrode is grounded, the electric field generated by the RF power supply forms a fixed path along the "lower electrode → plasma → upper electrode (grounded)" path. Some RF energy is directly dissipated through the grounding loop, with approximately 10%-20% of the high-frequency energy not participating in ionization but instead being converted into Joule heat in the grounding loop. Furthermore, the grounded upper electrode reflects some high-frequency electromagnetic waves, reducing the energy coupling efficiency between electrodes and causing high-frequency energy loss. In addition, electrons in the plasma readily migrate to the grounding electrode, resulting in a short electron lifetime and hindering the improvement of the deposition rate.

[0005] Furthermore, in bottom RF input schemes, when the bottom RF energy input is high, it can lead to abnormally high stress on the deposited thin film, which can easily cause wafer breakage, damage, and thin film cracking, thus reducing production yield.

[0006] To address the aforementioned problems in the existing technology, there is an urgent need in the field for an improved thin film deposition technology that can reduce the dissipation of high-frequency energy and extend the residence time of electrons between the upper and lower electrodes, thereby increasing the thin film deposition rate. At the same time, it can also reduce abnormal stress during film formation, thereby reducing finished product scrap and improving production yield. Summary of the Invention

[0007] 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.

[0008] To overcome the aforementioned deficiencies in the prior art, the present invention provides a deposition process apparatus, a method for adjusting thin film stress, and a computer-readable storage medium, which can reduce the dissipation of high-frequency energy and extend the residence time of electrons between the upper and lower electrodes, thereby improving the thin film deposition rate. At the same time, it can also reduce abnormal stress in film formation, thereby reducing finished product scrap and improving production yield.

[0009] Specifically, the deposition process apparatus provided according to the first aspect of the present invention includes a reaction chamber, which contains a spray plate as an upper electrode and a heating plate as a lower electrode, wherein the lower electrode is connected to a high-frequency power source. The deposition process apparatus further includes: an insulating component connected to the spray plate and disposed between the spray plate and the side wall of the chamber to make the spray plate electrically levitated; and an impedance adjustment device, one end of which is connected to the spray plate and the other end of which is connected to the side wall of the chamber, for adjusting the impedance of the spray plate to adjust the plasma field between the spray plate and the heating plate.

[0010] Furthermore, in some embodiments of the present invention, the deposition process apparatus includes a controller configured to adjust the impedance of the spray plate via the impedance adjustment device according to a first current flowing through the heating plate, so that the ratio of a second current flowing through the spray plate to the first current reaches a preset ratio, thereby forming a target plasma field.

[0011] Furthermore, in some embodiments of the present invention, the deposition process apparatus includes: a bottom matching unit connected to the high-frequency power source and the lower electrode to match the output impedance of the high-frequency power source and the input impedance of the lower electrode; a first radio frequency voltage and current sensor located in the bottom matching unit for acquiring a first current flowing through the heating plate; and a second radio frequency voltage and current sensor connected to the spray plate for acquiring a second current flowing through the spray plate.

[0012] Furthermore, in some embodiments of the present invention, the impedance adjustment device includes at least an adjustable capacitor, and by increasing the resistance value of the adjustable capacitor, the impedance of the spray plate is reduced, thereby increasing the second current.

[0013] Furthermore, in some embodiments of the present invention, the impedance adjustment device further includes a low-frequency inductor, which is connected in parallel with the adjustable capacitor to form an LC parallel circuit, so as to adjust the impedance characteristics of the impedance adjustment device at different frequencies.

[0014] Furthermore, in some embodiments of the present invention, the high-frequency power source has an operating frequency including 40MHz.

[0015] Furthermore, the method for adjusting the stress of the thin film provided by the second aspect of the present invention includes the following steps: in response to the wafer being located on a heating plate in the deposition process apparatus provided by the first aspect of the present invention, applying high-frequency power to the heating plate, which serves as a lower electrode; adjusting the impedance of a spray plate via an impedance adjustment device to adjust the plasma field between the spray plate and the heating plate; and depositing a thin film with a stress range within the normal process range based on the plasma field.

[0016] Furthermore, in some embodiments of the present invention, the step of adjusting the impedance of the spray plate via the impedance adjustment device to adjust the plasma field between the spray plate and the heating plate includes: acquiring a first current flowing through the heating plate via a first radio frequency voltage and current sensor located in the bottom matching unit; acquiring a second current flowing through the spray plate via a second radio frequency voltage and current sensor connected to the spray plate; and adjusting the impedance of the spray plate via the impedance adjustment device so that the ratio of the second current to the first current reaches a preset ratio to form a target plasma field.

[0017] Furthermore, in some embodiments of the present invention, the step of depositing a thin film with a stress range within the normal range based on the plasma field further includes: responding to the stress of the thin film deposited based on the target plasma field being abnormal stress; determining whether the abnormal stress is tensile stress or compressive stress; increasing the distance between the heating plate and the spray plate in response to the abnormal stress being compressive stress to reduce the density of the plasma field; and decreasing the distance between the heating plate and the spray plate in response to the abnormal stress being tensile stress to increase the density of the plasma field.

[0018] Furthermore, according to a third aspect of the present invention, a computer-readable storage medium is provided having computer instructions stored thereon. When the computer instructions are executed by a processor, the above-described method for adjusting thin film stress provided in the second aspect of the present invention is implemented. Attached Figure Description

[0019] 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.

[0020] Figure 1 A schematic diagram of a deposition process apparatus provided according to some embodiments of the present invention is shown;

[0021] Figure 2 A schematic diagram of the radio frequency circuit path of a deposition process apparatus provided according to some embodiments of the present invention is shown;

[0022] Figure 3A A top view of a spray plate assembly provided according to some embodiments of the present invention is shown;

[0023] Figure 3B A schematic diagram of the internal circuit of an impedance adjustment device provided according to some embodiments of the present invention is shown;

[0024] Figure 4 A flowchart of a method for adjusting thin film stress according to some embodiments of the present invention is shown.

[0025] Figure label:

[0026] 100 Deposition process equipment;

[0027] 110 Reaction Chamber;

[0028] 111. Cavity sidewall;

[0029] 120 spray plate;

[0030] 124 Second radio frequency voltage and current sensor;

[0031] 130 heating plate;

[0032] 131 High-frequency power source;

[0033] 132 Bottom Matcher;

[0034] 140 Insulating components;

[0035] 141 Sealed aluminum components;

[0036] 150 Impedance adjustment device;

[0037] 151 Adjustable capacitor;

[0038] 152 Low-frequency inductor;

[0039] 300 spray panel assembly;

[0040] 310 large baffle;

[0041] 320 heater;

[0042] 330 Connecting sheet metal;

[0043] 331 Shielding cover;

[0044] Steps S410 to S430. Detailed Implementation

[0045] 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 is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may 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.

[0046] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0047] 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.

[0048] 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.

[0049] As mentioned above, in the bottom RF input scheme, because the upper electrode is grounded, the electric field generated by the RF power supply forms a fixed path along "lower electrode → plasma → upper electrode (grounded)". Some RF energy is directly dissipated through the grounding loop, and approximately 10%-20% of the high-frequency energy is not ionized but converted into Joule heat in the grounding loop. Furthermore, the grounded upper electrode reflects some high-frequency electromagnetic waves, reducing the energy coupling efficiency between electrodes and causing high-frequency energy loss. In addition, electrons in the plasma tend to migrate rapidly to the ground electrode, resulting in a short electron lifetime and hindering the improvement of deposition rate. Moreover, in the bottom RF input scheme, when the input bottom RF energy is high, it can lead to abnormally high stress in the deposited thin film, which can easily cause wafer breakage, damage, and thin film cracking, reducing production yield.

[0050] To address the aforementioned problems in the prior art, this invention provides a deposition process apparatus, a method for adjusting thin film stress, and a computer-readable storage medium, which can reduce the dissipation of high-frequency energy and extend the residence time of electrons between the upper and lower electrodes, thereby increasing the thin film deposition rate. At the same time, it can also reduce abnormal stress in film formation, thereby reducing finished product scrap and improving production yield.

[0051] In some non-limiting embodiments, the deposition process equipment provided in the first aspect of the present invention can be used to implement the thin film stress adjustment method provided in the second aspect of the present invention.

[0052] Specifically, in some non-limiting embodiments, the computer-readable storage medium provided in the third aspect of the present invention stores computer instructions thereon. When the computer instructions are executed by a processor, they can be used to implement the thin film stress adjustment method provided in the second aspect of the present invention.

[0053] The working principle of the above-described deposition process equipment will be described below with reference to some embodiments of thin film stress adjustment methods. Those skilled in the art will understand that these embodiments of thin film stress adjustment methods 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 deposition process equipment. Similarly, the deposition process equipment is also only one non-limiting implementation provided by the present invention and does not limit the entities implementing the steps in these thin film stress adjustment methods.

[0054] Please refer to Figure 1 , Figure 1 A schematic diagram of a semiconductor process apparatus provided according to some embodiments of the present invention is shown.

[0055] like Figure 1 As shown, in some embodiments of the present invention, the deposition process apparatus 100 may include a reaction chamber 110, which may include a spray plate 120 as an upper electrode and a heating plate 130 as a lower electrode. The lower electrode may be connected to a high-frequency power source 131. By inputting high-frequency power to the lower electrode through the high-frequency power source 131, a bottom RF input is formed, thereby improving energy transfer efficiency, resulting in a faster deposition rate and a more stable RF circuit.

[0056] In some preferred embodiments, the operating frequency of the high-frequency power source 131 preferably includes 40MHz. Experiments have shown that when performing a thin-film deposition process with a bottom RF input at a high-frequency power of 40MHz, the energy transfer efficiency, RF circuit stability, and deposition rate are all superior.

[0057] Those skilled in the art will understand that the high-frequency power source 131 operating at 40MHz described above is merely a non-limiting embodiment 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. In some other processes, the high-frequency power source 131 can also be adjusted to other operating frequencies to achieve the same technical effect.

[0058] Furthermore, such as Figure 1 As shown, the deposition process equipment 100 may further include an insulating component 140 and an impedance adjustment device 150. The insulating component 140 can be connected to the spray plate 120 and is disposed between the spray plate 120 and the cavity sidewall 111 (i.e., in direct contact with the cavity) to keep the spray plate 120 in an electrically levitated state. One end of the impedance adjustment device 150 can be connected to the spray plate 120, and the other end can be connected to the cavity sidewall 111, used to adjust the impedance of the spray plate 120 to adjust the plasma field between the spray plate 120 and the heating plate 130. Optionally, the insulating component 140 may specifically be a ceramic component with electrical insulating properties.

[0059] In this embodiment, by improving the spray plate, which is currently grounded in the bottom RF input mode, to be electrically floating, the plasma density can be increased, the uniformity of energy distribution can be optimized, and the adaptability of the process window can be expanded.

[0060] Specifically, in this embodiment, when the upper electrode is in an electrically suspended state, there is no fixed grounding circuit between the electrodes. Therefore, electrons cannot migrate quickly to the upper electrode and are directly conducted away via the grounded upper electrode. At this time, the residence time of electrons between the electrodes is extended, i.e., the electron lifetime is increased. This significantly increases the probability of electrons colliding with reactive gas molecules, generating more ions and active groups, thereby significantly increasing the plasma density within the cavity. Furthermore, a higher plasma density means more active particles participate in the deposition reaction per unit volume, thus significantly increasing the deposition process rate.

[0061] Furthermore, a grounded upper electrode reflects some high-frequency electromagnetic waves, leading to a decrease in energy coupling efficiency between the electrodes. To address this, when the upper electrode is electrically levitated, since there is no grounding loop, almost all the high-frequency energy is used to maintain the plasma sheath between the two electrodes, increasing the energy coupling efficiency from 60%-70% when grounded to 85%-95%. In other words, under the same plasma density requirements, having the upper electrode in levitated mode reduces the input power of the high-frequency power source 131 (e.g., from 1000W to only 700W), saving energy and reducing the impact of power supply heating on equipment stability.

[0062] Furthermore, different thin-film deposition processes (such as SiO2, SiN3, and metal thin films) have significantly different plasma energy requirements. Currently, when the upper electrode is grounded, the ion bombardment energy is primarily controlled by a single parameter—the bias voltage of the lower electrode—resulting in a narrow adjustable range. Moreover, excessively high bias voltage can easily lead to excessive film stress, while excessively low bias voltage can result in incomplete reactions. To address this, when the upper electrode is electrically suspended, the process parameter window can be expanded by indirectly controlling the suspension potential. Since the potential of the suspended electrode is not fixed at 0 but dynamically changes with the high-frequency voltage of the lower electrode, gas pressure, and gas type, adjusting parameters such as the lower electrode power and gas flow rate can indirectly alter the suspension potential of the upper electrode, thereby fine-tuning the sheath voltage between the electrodes (the sheath voltage determines the ion bombardment energy).

[0063] For example, when depositing low-stress SiN3 thin films, the upper electrode's levitation potential can be slightly increased indirectly by reducing the power of the lower electrode, thereby weakening the ion bombardment intensity and preventing excessive compressive stress in the SiN3 film. In addition, during metal etching processes, the lower electrode power can be increased to indirectly decrease the upper electrode's levitation potential, thereby enhancing ion bombardment and increasing the etching rate. In other words, in this embodiment, by improving the upper electrode to an electrically suspended state, not only can abnormal stress during film formation be reduced, thus reducing finished product scrap and improving production yield, but the process window can also be expanded to achieve multi-parameter linkage control, allowing the equipment to further adapt to various process requirements from low-energy deposition to high-energy etching.

[0064] Furthermore, in some embodiments of the present invention, the deposition process apparatus 100 may also include a controller (not shown in the figures). The controller may be configured to adjust the impedance of the spray plate 120 via the impedance adjustment device 150 according to the first current flowing through the heating plate 130, so that the ratio of the second current flowing through the spray plate 120 to the first current can reach a preset ratio to form a target plasma field.

[0065] Specifically, it can be combined with Figure 2 Common understanding Figure 2 A schematic diagram of the radio frequency circuit path of a deposition process apparatus provided according to some embodiments of the present invention is shown.

[0066] like Figure 1 and Figure 2 As shown, the deposition process apparatus 100 may also include a bottom matching device 132. The bottom matching device 132 can connect the high-frequency power source 131 and the heating plate 130 serving as the lower electrode, so that the output impedance of the high-frequency power source 131 matches the input impedance of the lower electrode. In this embodiment, via the bottom matching device 132, not only can high-frequency energy be transferred to the load (lower electrode and plasma) to the maximum extent, avoiding energy waste and ensuring the energy required for the process, but it can also suppress energy reflected back to the power source, protecting the power supply and transmission components from damage.

[0067] Furthermore, a first radio frequency voltage and current sensor (VIsensor) (not shown in the figures) may also be provided in the bottom matching unit 132. The first radio frequency voltage and current sensor can be used to obtain the first current flowing through the heating plate 130. For example... Figure 2 As shown, the spray plate 120 can be connected to a second radio frequency voltage and current sensor 124 to obtain the second current flowing through the spray plate 120.

[0068] exist Figure 2 In the illustrated embodiment, the input path and feedback path in the radio frequency circuit are shown. In this embodiment, via the first radio frequency voltage and current sensor and the second radio frequency voltage and current sensor 124, combined with the controller, the real-time ratio of the second current flowing through the spray plate 120 to the first current flowing through the heating plate 130 can be obtained, and then compared with a preset ratio to perform subsequent adjustment of the impedance of the spray plate 120.

[0069] Next, please refer to Figure 3A , Figure 3A A top view of a spray plate assembly provided according to some embodiments of the present invention is shown.

[0070] like Figure 3AAs shown, in some optional embodiments, a large baffle 310 may be provided above the spray plate 12 in the spray plate assembly 300 to distribute the gas so that the gas flows evenly onto the spray plate 120. A heater 320 may be provided on the outside of the large baffle 310 to control the temperature of the spray plate 120 to heat it to the temperature required by the process.

[0071] Furthermore, such as Figure 3A As shown, the impedance adjustment device 150 may include at least an adjustable capacitor 151, for example, an adjustable vacuum capacitor (the capacitor's range can be 1400pF). Optionally, the adjustable capacitor 151 can be connected to the spray plate 120 via a copper connecting sheet metal 330. The adjustable capacitor 151 can also be fixed to the shielding cover 331 of the cavity. The shielding cover 331 can be used to isolate the reaction chamber 110 from electromagnetic, physical, and chemical interference from the external environment, thereby ensuring equipment safety and process stability. In this embodiment, by increasing the resistance value of the adjustable capacitor 151, the impedance of the spray plate 120 can be reduced, thereby increasing the second current flowing through the spray plate 120.

[0072] Based on this, such as Figure 3A As shown, in some preferred embodiments, the impedance adjustment device 150 may further include a low-frequency inductor 152. Optionally, the low-frequency inductor 152 may be connected to the heater 320. The low-frequency inductor 152 is connected in parallel with the adjustable capacitor 151 to form an LC parallel circuit to adjust the impedance characteristics of the impedance adjustment device 150 at different frequencies.

[0073] Can be combined Figure 3B It is generally understood that in an LC parallel circuit, by simultaneously adjusting the adjustable capacitor 151 and the low-frequency inductor 152, finer impedance adjustment can be achieved over a wider frequency range. Compared to a circuit with only one adjustable capacitor 151, impedance adjustment mainly relies on capacitance changes. In some RF applications with complex impedance characteristics (such as requiring specific impedance responses at different frequencies), the adjustment range and accuracy are limited. For example, in an RF loop, an LC parallel circuit can better match the impedance of loads such as the spray plate assembly 300, reduce signal reflection, and improve RF energy transmission efficiency, while a single-capacitor circuit is relatively less effective in this regard.

[0074] Specifically, such as Figure 3B As shown, since the spray plate assembly 300 is connected to the second radio frequency voltage and current sensor 124, the voltage and current flowing through the spray plate assembly 300 can be monitored in real time via the second radio frequency voltage and current sensor 124, according to Ohm's law. (U represents voltage, I represents current) Calculate the current actual impedance value of the spray plate assembly 300. Then, compare the measured actual impedance value with the target impedance value, and adjust the adjustable capacitor 151 based on the difference. If the actual impedance value is higher than the target impedance value, the capacitance of the adjustable capacitor 151 can be appropriately increased to lower the resonant frequency of the LC parallel circuit, thus reducing the impedance of the LC circuit at the operating frequency and consequently lowering the equivalent impedance of the spray plate assembly 300. Conversely, if the actual impedance value is lower than the target impedance value, the capacitance of the adjustable capacitor 151 can be appropriately decreased to increase the impedance of the LC parallel circuit at the operating frequency, thereby increasing the equivalent impedance of the spray plate assembly 300 and achieving precise impedance adjustment.

[0075] Furthermore, preferably, during testing, the adjustable capacitor 151 can be pre-rotated according to the required target capacitance value. For example, the resistance of the adjustable capacitor 151 can be adjusted in the range of 10-100pF to pass high frequency, and then connected to the second radio frequency voltage and current sensor 124 to measure the second current flowing through the spray plate 120.

[0076] Continue back Figure 3A In some embodiments, a sealing aluminum component 141 may be provided between the spray plate 120 and the insulating component 140 to cooperate with other components to achieve cavity sealing.

[0077] This concludes the basic description of the deposition process equipment 100 provided in the first aspect of the present invention. Next, we will discuss... Figure 4 To further illustrate the method for adjusting thin film stress based on deposition process equipment 100, wherein, Figure 4 A flowchart of a method for adjusting thin film stress according to some embodiments of the present invention is shown.

[0078] like Figure 4 As shown, in some embodiments of the present invention, the method for adjusting thin film stress mainly includes steps S410 to S430. First, step S410 includes applying high-frequency power to the heating plate, which serves as the lower electrode, in response to the wafer being located on the heating plate in the deposition process equipment.

[0079] Specifically, it can be combined with Figure 1It is understood that in some embodiments, the reaction chamber 110 of the deposition process apparatus 100 includes a spray plate 120 serving as an upper electrode and a heating plate 130 serving as a lower electrode. When the wafer is transferred to the heating plate 130 within the reaction chamber 110, high-frequency power can be input to the lower electrode via a high-frequency power source 131, forming a bottom RF input. Optionally, the operating frequency of the high-frequency power source 131 is preferably 40MHz. Experiments have shown that when performing a thin film deposition process with bottom RF input at a high-frequency power of 40MHz, the energy transfer efficiency, the stability of the RF circuit, and the deposition rate are all superior. The 40MHz high-frequency energy is transferred from the high-frequency power source 131 to the bottom matching unit 132, and then to the heating plate 130. The bottom matching unit 132 may include a first RF voltage-current sensor for measuring the first current from the bottom matching unit 132 to the heating plate 130.

[0080] like Figure 4 As shown, next, step S420 can be performed to adjust the impedance of the spray plate via the impedance adjustment device, thereby adjusting the plasma field between the spray plate and the heating plate.

[0081] Specifically, as shown in Figure 3, the spray plate 120 may include a sealed aluminum component 141 and a ceramic insulating component 140 underneath. A low-frequency inductor 152 and a high-frequency adjustable capacitor 151 are connected to the spray plate assembly 300, and a second radio frequency voltage and current sensor 124 can be connected to the downstream of the adjustable capacitor 151 to measure a second current flowing through the spray plate 120.

[0082] After obtaining the first current flowing through the heating plate 130 via the first radio frequency voltage and current sensor, and the second current flowing through the spray plate 120 via the second radio frequency voltage and current sensor, the actual current ratio between the two can be obtained. Then, the impedance of the spray plate 120 is adjusted via the impedance adjustment device 150 so that the ratio of the second current to the first current reaches a preset ratio, thereby forming the target plasma field.

[0083] Then, step S430 can be performed to deposit a thin film with a stress range within the normal process range based on the plasma field.

[0084] Furthermore, adjusting the impedance of the spray plate 120 alone is not highly sensitive to the process window. In other words, adjusting the capacitance of the adjustable capacitor 151 alone can only achieve the effect of adjusting the impedance. However, in actual process runs, a larger process window is more conducive to ensuring mass production yield and reducing the risk of failure. If the process window is small, even a slight deviation in parameters (such as an extra second in reaction time) can lead to device failure, directly lowering the yield of a single batch, or even resulting in the scrapping of the entire batch. Increasing the process window, even if parameters fluctuate within a certain range (such as temperature ±2℃, deposition thickness ±10%), can still meet the electrical performance and physical specifications of the device, thereby ensuring that the yield remains stable within the target range.

[0085] In some preferred embodiments, the process gap between the spray plate 120 and the heating plate 130 can be adjusted simultaneously with the impedance adjustment of the spray plate 120. The change in the process gap will affect parameters such as RF energy and deposition rate. Therefore, adjusting both in combination can result in a wider process window, thereby increasing the process window and improving sensitivity.

[0086] Specifically, in some optional embodiments, step S430 may further include the following process steps. When the stress of the film deposited based on the target plasma field is detected to be abnormal stress, it can be determined whether the abnormal stress is tensile stress or compressive stress. When the abnormal stress is determined to be compressive stress, the distance between the heating plate 130 and the spray plate 120 can be increased to reduce the density of the plasma field between the two electrodes. When the abnormal stress is determined to be tensile stress, the distance between the heating plate 130 and the spray plate 120 can be decreased to increase the density of the plasma field between the two electrodes. In this embodiment, by combining the impedance adjustment of the spray plate 120 with the process gap adjustment between the spray plate 120 and the heating plate 130, the stress of the deposited film can be reduced, so that a film with a stress range within the normal process range can be deposited based on the plasma field after dual adjustment.

[0087] 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.

[0088] Those skilled in the art will further appreciate that the steps of the methods or algorithms described in connection with the embodiments disclosed herein can 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 so 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.

[0089] 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.

[0090] In summary, the present invention provides a deposition process apparatus, a method for adjusting thin film stress, and a computer-readable storage medium, which can reduce the dissipation of high-frequency energy and extend the residence time of electrons between the upper and lower electrodes, thereby improving the thin film deposition rate. At the same time, it can also reduce abnormal stress in film formation, thereby reducing finished product scrap and improving production yield.

[0091] 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 deposition process apparatus, comprising a reaction chamber, wherein the interior includes a spray plate serving as an upper electrode and a heating plate serving as a lower electrode, wherein, The lower electrode is connected to a high-frequency power source, characterized in that the deposition process equipment further includes: An insulating component, connecting the spray plate and disposed between the spray plate and the cavity sidewall, so that the spray plate is in an electrically levitated state; and An impedance adjustment device, one end of which is connected to the spray plate and the other end of which is connected to the side wall of the cavity, is used to adjust the impedance of the spray plate in order to adjust the plasma field between the spray plate and the heating plate.

2. The deposition process equipment as described in claim 1, characterized in that, include: The controller is configured to adjust the impedance of the spray plate via the impedance adjustment device according to the first current flowing through the heating plate, so that the ratio of the second current flowing through the spray plate to the first current reaches a preset ratio, thereby forming a target plasma field.

3. The deposition process equipment as described in claim 2, characterized in that, include: A bottom matching circuit connects the high-frequency power source and the lower electrode to match the output impedance of the high-frequency power source with the input impedance of the lower electrode. A first radio frequency voltage and current sensor, located in the bottom matching unit, is used to acquire the first current flowing through the heating plate; as well as A second radio frequency voltage and current sensor is connected to the spray plate to obtain a second current flowing through the spray plate.

4. The deposition process equipment as described in claim 2, characterized in that, The impedance adjustment device includes at least an adjustable capacitor. By increasing the resistance of the adjustable capacitor, the impedance of the spray plate is reduced, thereby increasing the second current.

5. The deposition process equipment as described in claim 4, characterized in that, The impedance adjustment device further includes a low-frequency inductor, which is connected in parallel with the adjustable capacitor to form an LC parallel circuit, so as to adjust the impedance characteristics of the impedance adjustment device at different frequencies.

6. The deposition process equipment as described in claim 1, characterized in that, The high-frequency power source operates at frequencies including 40MHz.

7. A method for adjusting thin film stress, characterized in that, The following steps are involved: In response to the wafer being located on a heating pad in the deposition process apparatus as described in any one of claims 1 to 6, high-frequency power is applied to the heating pad, which serves as the lower electrode; The impedance of the spray plate is adjusted by the impedance adjustment device to adjust the plasma field between the spray plate and the heating plate. as well as Based on the plasma field, a thin film with a stress range within the normal process range is deposited.

8. The adjustment method as described in claim 7, characterized in that, The step of adjusting the impedance of the spray plate via an impedance adjustment device to adjust the plasma field between the spray plate and the heating plate includes: The first current flowing through the heating plate is obtained via a first radio frequency voltage and current sensor located in the bottom matching unit; A second current flowing through the spray plate is obtained via a second radio frequency voltage and current sensor connected to the spray plate; and The impedance of the spray plate is adjusted by the impedance adjustment device so that the ratio of the second current to the first current reaches a preset ratio, thereby forming a target plasma field.

9. The adjustment method as described in claim 8, characterized in that, The step of depositing a thin film with a stress range within the normal range based on the plasma field further includes: The stress in response to the thin film deposited in the target plasma field is abnormal stress; Determine whether the abnormal stress is tensile or compressive; In response to the abnormal stress being compressive stress, the distance between the heating plate and the spray plate is increased to reduce the density of the plasma field; and In response to the abnormal stress being tensile stress, the distance between the heating plate and the spray plate is reduced to increase the density of the plasma field.

10. A computer-readable storage medium storing computer instructions thereon, characterized in that, When the computer instructions are executed by the processor, the method for adjusting the thin film stress as described in any one of claims 7 to 9 is implemented.

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