A method for detecting the quality of a hot plate of a plasma deposition apparatus

Abstract

This application provides a method for detecting the quality of a hot plate in a plasma deposition apparatus. The hot plate is disposed within a housing, which is grounded. The hot plate contains metal wiring, which is part of the radio frequency (RF) circuitry of the plasma deposition apparatus. The method includes: constructing a first measurement circuit, which includes a measurement circuit and a first circuit under test, wherein the first circuit under test includes the metal wiring and the housing, the metal wiring and the housing forming a first parallel-plate capacitor; the measurement circuit outputs voltage signals at different frequencies and feeds back impedance spectra at the different frequencies; measuring the first impedance spectrum of the first parallel-plate capacitor using the measurement circuit; and determining whether the metal wiring of the hot plate is normal based on the first impedance spectrum.

Description

Technical Field

[0001] This application relates primarily to the field of semiconductor equipment, and more particularly to a method for detecting the quality of a hot plate in a plasma deposition equipment. Background Technology

[0002] In plasma-enhanced atomic layer deposition (PEALD) and plasma-enhanced chemical vapor deposition (PECVD) equipment, ceramic hot plates made of aluminum nitride or other materials are commonly used. Within the reaction chamber of PEALD and PECVD equipment, the ceramic hot plate not only performs the fundamental functions of substrate support and precise temperature control, but its internal or surface-integrated radio frequency (RF) circuitry is also a crucial component of the equipment's RF system. This RF circuitry is responsible for stably coupling the high-frequency energy output from the RF power supply to the interior of the chamber, enabling the ionization of the process gas and the controllable excitation of the plasma. It determines the plasma's density, activity, and spatial distribution, thereby affecting the film deposition rate, step coverage, and electrical properties. However, in actual hot plate production, manufacturing errors can easily lead to abnormal impedance in the RF circuitry. Abnormal impedance in the RF circuitry will directly cause malfunctions in the entire RF system, leading to difficulties in ignition, delayed ignition, or even failure to ignite. Furthermore, it will result in problems such as the inability to achieve similar process effects under the same conditions.

[0003] Therefore, how to effectively manage the processing quality of ceramic hot plates and detect whether the internal radio frequency circuits of ceramic hot plates are normal are problems that urgently need to be solved. Summary of the Invention

[0004] This application addresses the aforementioned technical problems by providing a method for detecting the quality of the hot plate in a plasma deposition apparatus, which can determine whether the internal circuitry of the hot plate is normal.

[0005] To address the aforementioned technical problems, this application provides a method for detecting the quality of a hot plate in a plasma deposition apparatus. The hot plate is housed within a grounded housing, and a metal circuit is disposed inside the hot plate. This metal circuit is part of the radio frequency circuitry of the plasma deposition apparatus. The method includes: constructing a first measurement circuit, which includes a measurement circuit and a first circuit under test. The first circuit under test includes the metal circuit and the housing, and the metal circuit and the housing form a first parallel-plate capacitor. The measurement circuit is used to output voltage signals at different frequencies and to feed back impedance spectra at the different frequencies. The measurement circuit is used to measure the first impedance spectrum of the first parallel-plate capacitor. The method also includes determining whether the metal circuitry of the hot plate is normal based on the first impedance spectrum.

[0006] In one embodiment of this application, the metal circuit has a first port for external connection, wherein the signal port of the measurement circuit is connected to the first port, and the ground port of the measurement circuit is connected to the housing; measuring the first impedance spectrum of the first parallel plate capacitor using the measurement circuit includes: the measurement circuit transmitting multiple voltage signals of different frequencies between the first port and the housing, and feeding back the impedance values ​​between the first port and the housing at the multiple different frequencies; and obtaining the first impedance spectrum based on the multiple different frequencies and the corresponding impedance values.

[0007] In one embodiment of this application, the metal circuit has a first port for external connection, wherein the measurement circuit includes an radio frequency power supply, the signal port of the measurement circuit is connected to the first port, and the ground port of the measurement circuit is connected to the housing; measuring the first impedance spectrum of the first parallel plate capacitor using the measurement circuit includes: step S3201: using the radio frequency power supply to transmit a voltage signal with a target frequency to the first port and the housing, and feeding back the incident voltage amplitude and reflected voltage amplitude at the first port; step S3202: based on the incident voltage amplitude and the reflected voltage... Amplitude calculation of reflection coefficient; Step S3203: Calculate the impedance value of the first parallel plate capacitor at the target frequency based on the reflection coefficient and the internal impedance of the RF power supply; Step S3204: Repeat steps S3201 to S3203 several times, wherein the target frequency is changed within a preset frequency range before each execution of steps S3201 to S3203; and Step S3205: After repeating steps S3201 to S3203 several times, obtain the first impedance spectrum based on the correspondence between multiple target frequencies and multiple impedance values.

[0008] In one embodiment of this application, determining whether the metal circuit of the hot plate is normal based on the first impedance spectrum includes: comparing the first impedance spectrum with a standard impedance spectrum; if the difference between the first impedance spectrum and the standard impedance spectrum exceeds a preset threshold, determining that the metal circuit of the hot plate is abnormal; wherein, the standard impedance spectrum is obtained by measuring the first parallel plate capacitor of a normal quality hot plate using the measuring circuit.

[0009] In one embodiment of this application, the method further includes: measuring the first impedance spectrum of the first plate capacitors of the multiple hot plates using the measurement circuit; determining whether the metal circuit of the hot plate is normal based on the first impedance spectrum, including: comparing the first impedance spectra of the first plate capacitors of the multiple hot plates, determining abnormal first impedance spectra based on statistical distribution, and determining that the metal circuit of the hot plate with the abnormal first impedance spectrum is abnormal.

[0010] In one embodiment of this application, the hot plate is further provided with a heating circuit inside, and the hot plate quality detection method further includes: constructing a second measurement circuit, the second measurement circuit including the measurement circuit and a second circuit under test, wherein the second circuit under test includes the metal circuit and the heating circuit, the metal circuit and the heating circuit constitute a second parallel plate capacitor; measuring the second impedance spectrum of the second parallel plate capacitor using the measurement circuit; and determining whether the heating circuit of the hot plate is normal based on the first impedance spectrum and the second impedance spectrum.

[0011] In one embodiment of this application, the metal circuit has a first port for external connection, and the heating circuit has a second port for external connection, wherein the signal port of the measuring circuit is connected to the first port, and the ground port of the measuring circuit is connected to the second port; measuring the second impedance spectrum of the second parallel plate capacitor using the measuring circuit includes: the measuring circuit transmitting multiple voltage signals of different frequencies between the first port and the second port, and feeding back the impedance values ​​between the first port and the second port at the multiple different frequencies; and obtaining the second impedance spectrum based on the multiple different frequencies and the corresponding impedance values.

[0012] In one embodiment of this application, determining whether the heating circuit of the hot plate is normal based on the first impedance spectrum and the second impedance spectrum includes: determining that the heating circuit is normal in response to both the first impedance spectrum and the second impedance spectrum being normal; and determining that the heating circuit is abnormal in response to both the first impedance spectrum being normal and the second impedance spectrum being abnormal.

[0013] In one embodiment of this application, the hot plate includes a plate body and a support shaft. The metal circuit includes a metal layer inside the plate body. The support shaft has a metal column electrically connected to the metal layer inside. The metal column is used to connect to the signal port of the measurement circuit. The housing is the process cavity of the plasma deposition equipment. The outer shell of the process cavity is grounded. The metal layer and the housing constitute the first parallel plate capacitor.

[0014] In one embodiment of this application, the hot plate includes a plate body and a support shaft. The metal circuit includes a metal layer inside the plate body, and the support shaft has a metal column electrically connected to the metal layer inside. The housing is a metal housing of a fixture, and the hot plate is disposed inside the metal housing. The metal housing includes a bottom plate and a top plate disposed opposite to each other. The bottom plate is used for grounding and forms the first parallel plate capacitor with the metal layer. The top plate is provided with a port connector for connecting to the signal port of the measurement circuit.

[0015] The hot plate quality inspection method of this application constructs a first measurement circuit including a measurement circuit and a first measured circuit. The measurement circuit measures the first impedance spectrum of the first parallel plate capacitor formed by the metal circuit inside the hot plate and the shell. Based on this first impedance spectrum, the normality of the metal circuit of the hot plate can be determined, thereby judging the quality of the hot plate. This method is simple and easy to implement, requires no additional modification to the structure of the hot plate and the plasma deposition equipment cavity, and is low in cost and high in efficiency. Attached Figure Description

[0016] The accompanying drawings are included to provide a further understanding of this application; they are incorporated into and constitute a part of this application. The drawings illustrate embodiments of this application and, together with this specification, serve to explain the principles of this application. In the drawings:

[0017] Figure 1 This is a cross-sectional schematic diagram of the plasma deposition apparatus used in an embodiment of this application;

[0018] Figure 2 A schematic diagram showing a tilted position of a heat plate installed inside a cavity is shown;

[0019] Figure 3 This diagram shows a top view of the hot plate when it is correctly positioned.

[0020] Figure 4 This diagram shows a top view of the hot plate when it is tilted.

[0021] Figure 5 This is an exemplary flowchart of a hot plate quality inspection method according to an embodiment of this application;

[0022] Figure 6 A schematic diagram of the first measurement loop constructed in a hot plate quality detection method according to an embodiment of this application is shown;

[0023] Figure 7 A schematic diagram of a principle structure for measuring the impedance spectrum of a line under test using a vector network analyzer is shown.

[0024] Figure 8 This is a spectrum comparison diagram of three hot plates obtained according to a hot plate quality testing method according to an embodiment of this application;

[0025] Figure 9 This is an exemplary flowchart of a hot plate quality inspection method according to another embodiment of this application;

[0026] Figure 10 A schematic diagram of the second measurement loop constructed in a hot plate quality detection method according to an embodiment of this application is shown;

[0027] Figure 11 This is a three-dimensional structural schematic diagram of a fixture according to an embodiment of this application;

[0028] Figure 12 yes Figure 11 A perspective view of the fixture in the illustrated embodiment. Detailed Implementation

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0030] As indicated in this application, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0031] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0032] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0033] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0034] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0035] Flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, various steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from these processes.

[0036] The plasma deposition equipment described in this application includes, but is not limited to, plasma-enhanced atomic layer deposition (PEALD) equipment and plasma-enhanced chemical vapor deposition (PECVD) equipment.

[0037] Figure 1 This is a schematic cross-sectional view of the plasma deposition apparatus used in one embodiment of this application. (Reference) Figure 1As shown, the plasma deposition apparatus includes a cavity 11, a spray head 12, and a hot plate 13. The spray head 12 is used to uniformly deliver precursors (such as a metal-organic source) and reactive gases (such as O2 or NH3 plasma sources) to the surface of a substrate (not shown) supported on the hot plate 13. The hot plate 13 includes a plate body 131 and a support shaft 132 connected to each other. The support shaft 132 is located below the plate body 131 and supports the plate body 131. A metal layer 141 is disposed within the plate body 131, and a metal pillar 142 is disposed within the support shaft 132. The first end 1421 of the metal layer 141 and the metal pillar 142 are electrically connected. The second end 1422 of the metal pillar 142 is located at the lower end of the support shaft 132 and also at the bottom of the cavity 11.

[0038] like Figure 1 As shown, the plasma deposition apparatus also includes an equipment radio frequency power supply 16 (RF power supply) and an impedance matching device 17. The equipment radio frequency power supply 16 is used to apply a high-frequency alternating electric field to the electrodes of the reaction chamber, causing the reactive gas in the chamber to ionize and generate a plasma containing electrons, ions, and active free radicals. Figure 1 Plasma 101 is illustrated between spray head 12 and hot plate 13, but is not used to limit the actual distribution range of plasma 101. Impedance matching device 17 is used to achieve conjugate matching between the plasma load impedance and the power supply output impedance within the reaction chamber, minimizing energy reflection and ensuring efficient coupling of radio frequency energy into the plasma, thus reducing energy waste. The bottom of cavity 11 is grounded, and one end of the device radio frequency power supply 16 is also grounded, so that some radio frequency energy can return to the device radio frequency power supply 16 through the ground loop.

[0039] like Figure 1 As shown, the metal layer 141 within the hot plate 13 is directly connected to the metal pillar 142 and grounded through the outer casing of the cavity 11. In some embodiments, when using an electrostatic chuck, a DC filter 19 may also be provided at the second end 1422 of the metal pillar 142. The metal layer 141 is directly connected to the metal pillar 142 and then grounded through a capacitor in the DC filter 19. Figure 1 The path of the radio frequency current is marked by a double-headed dashed line. From top to bottom, the radio frequency current starts from the output of the impedance matching device 17, passes through the spray head 12, plasma 101, metal layer 141, metal pillar 142, and finally reaches the ground of the outer shell of the cavity 11.

[0040] The radio frequency (RF) circuitry of a plasma deposition apparatus typically includes an RF power supply 16, an impedance matching circuit 17, a hot plate 13, and related transmission lines. Figure 1In the illustrated embodiment, the spray head 12 serves as the upper electrode in the radio frequency (RF) circuit. The metal layer 141 serves as the lower electrode in the RF circuit. The spray head 12 and the metal layer 141 constitute a planar capacitor. After RF power is applied to the metal layer 141 of the hot plate, a high-frequency electric field is formed between the two poles of the planar capacitor, thereby exciting gas generation and maintaining plasma. The metal layer 141 and the metal pillar 142 belong to the metal circuit inside the hot plate 13, which is part of the RF circuit of the plasma deposition equipment. When the metal circuit malfunctions, it will cause malfunction of the entire RF circuit, thereby affecting the quality of the hot plate.

[0041] After the hot plate 13 is processed, because the metal layer 141 and metal pillars 142 are laid inside the ceramic material of the hot plate 13, it is impossible to confirm whether the processing technology is normal by observation and ranging. Even slight processing differences can cause significant impedance differences in the RF circuit. For example, if the metal pillars 142 in the hot plate 13 have many impurities or a small cross-sectional area, the measured impedance value will be high. Similarly, if the thickness of the ceramic material from the metal layer 141 to the surface of the hot plate 13 is thicker or thinner than standard, or if there are many impurities or pores in the ceramic material, the measured impedance value will be higher or lower than expected. Furthermore, improper processing at the connection between the metal layer 141 and the metal pillars 142 can cause significant impedance. When the RF voltage connected to the spray head 12 (which serves as the upper electrode) remains constant, the high impedance at the connection between the metal layer 141 and the metal pillars 142 will consume a large amount of RF power, resulting in low discharge efficiency. Moreover, the same RF power cannot achieve similar process results as other devices, leading to significant differences in process results between different hot plates of the same model.

[0042] Before the hot plate 13 is installed into the cavity, impedance spectrum analysis can be used to confirm whether the impedance of the entire RF circuit is normal within the range of the RF frequency being used, and to confirm whether there are any impedance anomalies caused by processing or material selection issues. However, even if the test results show that the RF circuit of the hot plate 13 is normal, improper operation during the installation of the hot plate 13 into the cavity, causing the hot plate 13 to tilt, or one side of the hot plate 13 to be too close to the grounding bellows of the cavity, will cause changes in the parasitic capacitance between the RF circuit inside the hot plate 13 and the grounded cavity 11.

[0043] Figure 2 A schematic diagram showing a tilted position of a heat plate installed inside a cavity is shown. Figure 3 and Figure 4 Top-view diagrams are shown for the hot plate in the correct position and when it is tilted. For example... Figure 2 As shown, the bellows 21 is arranged around the hot plate 13. The support shaft 132 has two heating wires 152 and a metal column 142 inside. Figure 3A top view of the heating plate 13 when it is not tilted is shown, revealing that the circular outlines of the support shaft 132 and the bellows 21 are concentric. When the heating plate 13 is tilted, as... Figure 4 As shown, the circular outlines of the support shaft 132 and the bellows 21 are not concentric, indicating that the hot plate 13 is incorrectly positioned. This causes a change in the parasitic capacitance between the metal pillar 142 and the grounded cavity, thereby altering the impedance of the RF circuit. As the RF frequency increases, the impact of this parasitic capacitance on the equivalent impedance of the circuit becomes greater. Therefore, even minor installation errors causing an impedance anomaly in the overall RF circuit can result in significant deviations from the reference values ​​for various RF system parameters, such as matching conditions, making it difficult to guarantee the stability and repeatability of the process.

[0044] Based on the aforementioned technical problems, this application proposes a method for inspecting the quality of a hot plate. This method can inspect the hot plate 13 installed within a housing to confirm whether the hot plate 13 has an impedance abnormality, thereby determining the quality of the hot plate. This impedance abnormality may be due to the manufacturing process of the hot plate 13 itself, or it may be due to improper operation when installing the hot plate 13 into the housing. It should be noted that the housing here can be the outer shell of a process cavity or the outer shell of a fixture, which will be explained in detail later.

[0045] Figure 5 This is an exemplary flowchart of a hot plate quality inspection method according to an embodiment of this application. (Reference) Figure 5 As shown, the hot plate quality detection method 300 of this embodiment includes the following steps:

[0046] Step S310: Construct a first measurement circuit. The first measurement circuit includes a measurement line and a first test line. The first test line includes a metal line and a housing. The metal line and the housing constitute a first parallel plate capacitor. The measurement line is used to output voltage signals of different frequencies and to feed back impedance spectra at different frequencies.

[0047] Figure 6 A schematic diagram of the first measurement loop constructed in a hot plate quality detection method according to an embodiment of this application is shown. Figure 6 As shown, the first measurement circuit includes a measurement line 41 and a first measured line.

[0048] The measurement line 41 is any device capable of outputting voltage signals of different frequencies to the circuit under test and providing feedback on the impedance spectrum of the circuit under test at different frequencies. In some embodiments, the measurement line 41 is a vector network analyzer, but this application is not limited thereto.

[0049] Figure 7 A schematic diagram illustrating the principle of measuring the impedance spectrum of a line under test using a vector network analyzer is shown. (Reference) Figure 7As shown, the vector network analyzer 51 includes a function generator 511, a directional coupler 512, and an oscilloscope 513. The function generator 511 includes an RF power supply 5111 and an internal resistance 5112. The function generator 511 is used to generate small-amplitude RF voltage signals V(f) of different frequencies. The directional coupler 512 is connected to the circuit under test. The directional coupler 512 includes a circulator 5121, a dummy load 5122, an incident voltage probe 5123, and a reflected voltage probe 5124. The circulator 5121 can direct the incident wave to the next port output through a direction determined by a static polarization magnetic field, isolating the incident and reflected electric fields and allowing the reflected electric field to be transmitted to the branch. Figure 7 The incident wave and reflected wave are shown by dashed lines with arrows. The dummy load 5122 is a fixed impedance load connected to the branch by the circulator 5121 to absorb reflected electrical energy. The incident voltage probe 5123 and reflected voltage probe 5124 are used to measure the line voltage and output analog signals. The oscilloscope 513 is connected to both the incident voltage probe 5123 and the reflected voltage probe 5124. The oscilloscope 513 converts the analog signals measured by the incident voltage probe 5123 and the reflected voltage probe 5124 into digital signals and processes them to display the waveform, amplitude, RMS (root mean square) value, etc., showing the measurement position of the voltage probes.

[0050] The vector network analyzer 51 may also include a data processing device (not shown). The data processing device is used to manually or via the device record measured data and process it to calculate the impedance spectrum.

[0051] like Figure 6 As shown, the first circuit under test includes a metal line 42 and a housing 43. The housing 43 is grounded.

[0052] In some embodiments, the metal line 42 includes a metal layer 141. The metal layer 141 is horizontally disposed inside the disk body 131 and forms a first planar capacitor with the housing 43.

[0053] Step S320: Measure the first impedance spectrum of the first parallel plate capacitor using measurement circuit 41.

[0054] like Figure 6 As shown, the measuring line 41 is electrically connected to the first line under test. In this embodiment, the metal line 42 has a first port P1 for external connection. During measurement, the signal port PM1 of the measuring line 41 is connected to the first port P1, and the ground port PM2 of the measuring line 41 is connected to the housing 43. In some embodiments, the metal line 42 further includes a metal post 142. The metal post 142 is disposed inside the support shaft 132 and is electrically connected to the metal layer 141. The first port P1 is the second end 1422 of the metal post 142.

[0055] According to this embodiment, step S320 includes:

[0056] Step S321: The measuring line 41 transmits multiple voltage signals of different frequencies between the first port P1 and the housing 43, and feeds back the impedance values ​​between the first port P1 and the housing 43 at multiple different frequencies; and

[0057] Step S322: Obtain the first impedance spectrum based on multiple different frequencies and their corresponding impedance values.

[0058] In another specific embodiment, step S320 includes:

[0059] Step S3201: Use an RF power supply to transmit a voltage signal with a target frequency to the first port P1 and the housing 43, and feed back the incident voltage amplitude and reflected voltage amplitude at the first port P1.

[0060] The measurement circuit 41 here can be a vector network analyzer 51, and the RF power supply is the RF power supply 5111 in the vector network analyzer 51. The signal port PM1 of the vector network analyzer 51 is connected to the first port P1, and the ground port PM2 of the vector network analyzer 51 is connected to the housing 43. It should be noted that the RF power supply in step S3201 is not... Figure 1 The device RF power supply 16 shown is not the RF power supply used for impedance spectrum measurement; the two are distinguished by their names. Specifically, the RF power supply 5111 can be used to transmit a voltage signal V(f) with a target frequency f between the first port P1 and the housing 43, and the amplitude of the incident voltage at that frequency f at the first port P1 can be measured using the directional coupler 512 and the oscilloscope 513 in the vector network analyzer 51. and reflected voltage amplitude .

[0061] Step S3202: Calculate the reflection coefficient based on the incident voltage amplitude and the reflected voltage amplitude.

[0062] In some embodiments, a formula may be used. Calculate the reflection coefficient .

[0063] Step S3203: Calculate the impedance value of the first parallel plate capacitor at the target frequency based on the reflection coefficient and the internal impedance of the RF power supply.

[0064] The internal impedance of the RF power supply 5111 It is known, for example, to be 50 ohms. The impedance of the first parallel-plate capacitor at a certain target frequency can be calculated using conventional methods in the art.

[0065] .in, This represents the impedance value of the measured port (first port P1) at frequency f.

[0066] Step S3204: Repeat steps S3201 to S3203 several times, wherein the target frequency is changed within a preset frequency range before each execution of steps S3201 to S3203.

[0067] In some embodiments, the preset frequency range includes all frequencies that the device's RF power supply 16 can cover during the process of the hot plate 13. This application does not limit this preset frequency range; for example, it can be below 100MHz. Changing the target frequency each time establishes a correspondence between different target frequencies and impedance values.

[0068] Step S3205: After repeatedly executing steps S3201 to S3203 several times, the first impedance spectrum is obtained based on the correspondence between multiple target frequencies and multiple impedance values.

[0069] Step S330: Determine whether the metal circuitry of the hot plate is normal based on the first impedance spectrum. This includes comparing the first impedance spectrum with the standard impedance spectrum and determining whether the internal circuitry is normal based on the comparison result. The standard impedance spectrum is obtained by measuring the first parallel plate capacitance of a normal-quality hot plate using the measurement circuit 41 of this application. This standard impedance spectrum can be provided by the hot plate manufacturer or obtained by an engineer testing a standard hot plate. A difference threshold can be set; if the difference between the impedance spectrum of the tested hot plate and the standard impedance spectrum is greater than this difference threshold, the metal circuitry of the tested hot plate is determined to be abnormal. Specifically, the impedance of the tested hot plate and the standard impedance can be compared frequency by frequency.

[0070] It should be noted that, theoretically, the impedance spectra of different heat plates of the same model should be the same, or the error should be within a preset range. Therefore, the impedance spectra of multiple heat plates under test can be obtained according to steps S310 to S320, and the first impedance spectra of the first plate capacitor of the multiple heat plates under test can be compared in step S330. The abnormal first impedance spectra can be judged according to the statistical distribution, and the metal circuit of the heat plate with the abnormal first impedance spectrum can be judged to be abnormal.

[0071] Figure 8 This is a spectrum comparison diagram of three hot plates obtained according to a hot plate quality testing method according to an embodiment of this application. The three hot plates are numbered 001, 002, and 003, with the same model but different serial numbers. The horizontal axis represents frequency in MHz. The vertical axis represents the S11 parameter in dB. The S11 parameter is the logarithmic reflection coefficient modulus (…). ), . Figure 8The spectrum diagrams shown indicate that the S11 parameters of disks 002 and 003 are similar, while the S11 parameter of disk 001 is significantly different from that of the other two disks. Based on this comparison, it can be determined that the metal circuitry of disk 001 is abnormal. Furthermore, when disk 001 is actually installed in the cavity of the plasma deposition equipment, it fails to ignite normally under the same RF power compared to the other hot disks, verifying the correctness of the judgment result of hot disk quality detection method 300.

[0072] The S11 parameter used here is only an example; other parameters obtained from impedance spectrum measurements can also be used for comparison.

[0073] According to the hot plate quality detection method 300 described above, when it is not possible to directly measure the radio frequency circuit body, the metal circuit of the hot plate 13 can be detected through the constructed first measurement circuit to determine whether the hot plate is qualified. This method is simple and easy to implement, does not require additional modification to the structure of the hot plate 13 and the cavity 11, and is low in cost and high in efficiency.

[0074] In some embodiments, such as Figure 1 As shown, the heating plate 13 also includes a heating layer 151 and a heating wire 152 for heating. The heating layer 151 is located within the plate body 131 and can be a horizontally arranged heating wire. The heating wire 152 is located within the support shaft 132. The first end 1521 of the heating wire 152 is connected to the heating layer 151, and the second end 1522 of the heating wire 152 is located at the lower end of the support shaft 132 for connecting to other external devices.

[0075] Figure 9 This is an exemplary flowchart of a hot plate quality inspection method according to another embodiment of this application. (See reference...) Figure 9 As shown, the hot plate quality inspection method 700 of this embodiment includes the following steps:

[0076] Step S710: Construct a second measurement circuit. The second measurement circuit includes a measurement line and a second measured line. The second measured line includes a metal line and a heating line, which together constitute a second parallel plate capacitor.

[0077] Figure 10 A schematic diagram of the second measurement loop constructed in a hot plate quality detection method according to an embodiment of this application is shown. Figure 10 As shown, the second measurement circuit includes a measurement line 41 and a second measured line. The measurement line 41 can be connected to... Figure 6 The measurement circuit 41 is the same as the one in the previous test, therefore the same designation is used. The second circuit under test includes the metal circuit 42 and the heating circuit 44. The housing 43 is grounded.

[0078] In some embodiments, the metal line 42 includes a metal layer 141. The heating line 44 includes a heating layer 151. The metal layer 141 and the heating layer 151 constitute a second parallel plate capacitor.

[0079] Step S720: Measure the second impedance spectrum of the second parallel plate capacitor using a measuring circuit.

[0080] like Figure 10 As shown, the measuring line 41 is electrically connected to the second measured line. In this embodiment, the metal line 42 has a first port P1 for external connection. The heating line 44 has a second port P2 for external connection. During measurement, the signal port PM1 of the measuring line 41 is connected to the first port P1, and the ground port PM2 of the measuring line 41 is connected to the second port P2. In some embodiments, the metal line 42 further includes a metal post 142. The metal post 142 is disposed inside the support shaft 132 and electrically connected to the metal layer 141. The first port P1 is the second end 1422 of the metal post 142. The heating line 44 further includes a heating connection 152. The heating connection 152 is disposed inside the support shaft 132 and connected to the heating layer 151. The second port P2 is the second end 1522 of the heating connection 152.

[0081] The measurement process for the second impedance spectrum is similar to that for the first impedance spectrum. In some embodiments, step S720 includes:

[0082] Step S721: The measuring line 41 transmits multiple voltage signals of different frequencies between the first port P1 and the second port P2, and feeds back the impedance values ​​between the first port P1 and the second port P2 at multiple different frequencies; and

[0083] Step S722: Obtain the second impedance spectrum based on multiple different frequencies and their corresponding impedance values.

[0084] Step S720 can use the vector network analyzer 51 described above as the measurement line 41. The specific measurement process can be referred to the previous description and will not be repeated here.

[0085] Step S730: Determine whether the heating circuit 44 of the hot plate is normal based on the first impedance spectrum and the second impedance spectrum.

[0086] In some embodiments, step S730 includes:

[0087] Step S731: If the first impedance spectrum is normal and the second impedance spectrum is normal, then the heating circuit 44 is considered to be normal.

[0088] Step S732: If the first impedance spectrum is normal and the second impedance spectrum is abnormal, then the heating circuit 44 is determined to be abnormal.

[0089] After obtaining the first impedance spectrum and the second impedance spectrum according to steps S710 to S730, it can be determined whether the heating circuit 44 is normal. If both the first and second impedance spectra are normal, it indicates that both the metal circuit 42 and the heating circuit 44 are normal, and the hot plate is of good quality. If the first impedance spectrum is normal, but the second impedance spectrum is abnormal, it indicates that the metal circuit 42 is normal, but the heating circuit 44 is abnormal. If the first impedance spectrum is abnormal, but the second impedance spectrum is normal, it indicates that the metal circuit 42 is abnormal, and the heating circuit 44 is uncertain. In any case, any abnormal impedance spectrum indicates that the hot plate has a quality problem.

[0090] The steps in the hot plate quality testing method of this application can be flexibly applied to suit different measurement scenarios and purposes.

[0091] For example, by measuring the first impedance spectrum of the hot plate that has been installed in the cavity, it is possible to simultaneously determine the impedance anomalies caused by problems with the metal wiring of the hot plate and the tilting of the hot plate installation position.

[0092] For example, for the same hot plate, before installing it into the cavity, measure either the first impedance spectrum or the second impedance spectrum. If either the first or second impedance spectrum is normal, it indicates that the metal circuitry is normal. Then, install the hot plate into the cavity and measure the first impedance spectrum again. If the result is abnormal, it indicates that the impedance abnormality is caused by the tilting of the hot plate.

[0093] For example, when the heating plate is installed in the cavity, the first impedance spectrum and the second impedance spectrum are measured respectively. If the first impedance spectrum is normal, but the second impedance spectrum is abnormal, it indicates that there is an abnormality in the heating circuit.

[0094] In some embodiments, Figure 6 and Figure 10 The housing 43 can be specifically implemented as a process cavity of a plasma deposition apparatus, with the outer shell of the process cavity grounded. Therefore, the hot plate can be placed inside the process cavity, and then the first impedance spectrum and / or the second impedance spectrum can be measured. In other embodiments, instead of placing the hot plate inside the process cavity, the hot plate is placed in a fixture, and the quality of the hot plate is detected outside the process cavity via the fixture.

[0095] Figure 11 This is a three-dimensional structural schematic diagram of a fixture according to an embodiment of this application. Figure 12 yes Figure 11 A perspective view of the fixture in the illustrated embodiment. (Refer to...) Figure 11 and Figure 12As shown, the fixture 900 of this embodiment includes a metal housing 910 with an internal accommodating space 920 for accommodating the hot plate 13 to be tested. The metal housing 910 includes a bottom plate 911 and a top plate 912 disposed opposite to each other. The bottom plate 911 is used for grounding and supporting the substrate surface of the hot plate 13. The bottom plate 911 and the metal layer 141 in the hot plate 13 can form a first parallel plate capacitor. The top plate 912 is provided with a port connector 930 for connecting to the signal port of the measurement line 41. The measurement line 41 can be the vector network analyzer 51 described above.

[0096] The following combination Figure 1 Hot plate 13 and Figure 12 Explain the compatibility between the hot plate 13 and the fixture 900. In Figure 1 In the design, the hot plate 13 has a substrate bearing surface, which is the upper surface of the hot plate 13. During semiconductor processing, the substrate is placed on this substrate bearing surface. It should be noted that the substrate bearing surface is not limited to a single plane. For example, to secure the substrate, the substrate bearing surface typically includes edge protrusions that limit the substrate's position, confining it within the edge protrusions. Figure 1 and Figure 12 When using the fixture testing hot plate 13, Figure 1 The hot plate 13 is inverted so that its substrate bearing surface faces down and is placed on the base plate 911. The second end 1422 of the support shaft 132 of the hot plate 13 faces upward and is connected to the port connector 930. This inverted hot plate placement method facilitates stable placement of the hot plate and, since the port connector 930 is located above the fixture 900, facilitates the connection of circuits.

[0097] It can also be achieved using fixtures. Figure 6 and Figure 10 The two measurement methods shown construct a first measurement loop and a second measurement loop, respectively. For example, when constructing the first measurement loop, the first port P1 is connected to the signal port PM1 of the measurement line 41 via the port connector 930, and the ground port PM2 of the measurement line 41 and the base plate 911 share a common ground. When constructing the second measurement loop, the first port P1 is connected to the signal port PM1 of the measurement line 41 via the port connector 930, and the second port P2 is connected to the ground port PM2 of the measurement line 41 via the port connector 930.

[0098] The preceding explanation of the hot plate quality inspection method can be used to illustrate the method of using fixture 900 for hot plate quality inspection, and will not be elaborated further.

[0099] Using the fixture 900 provided in this application embodiment, the hot plate 13 can be stably supported on the base plate 911, and the first port P1 and / or the second port P2 of the hot plate 13 can be connected to the measurement circuit 41 through the port connector 930 to construct the first measurement circuit and / or the second measurement circuit, which can conveniently and quickly detect whether the radio frequency circuit of the hot plate 13 is abnormal.

[0100] It should be noted that the metal casing 910 has electromagnetic field shielding and a sealed design. That is, after the hot plate 13 is placed on the base plate 911, the receiving space 920 is a sealed shielded space. The hot plate 13 is not affected by external electromagnetic fields within this receiving space 920, which is equivalent to simulating the actual use scenario of the hot plate 13, thereby ensuring the accuracy and practicality of the impedance detection results.

[0101] In some embodiments, a dielectric layer 940 is provided on the upper surface of the base plate 911. The dielectric layer 940 is made of an insulating material to insulate the hot plate 13 from the metal base plate 911 while supporting the hot plate 13. The plate body 131 is made of ceramic material, and its substrate bearing surface is easily damaged. Therefore, the dielectric layer 940 is made of a cushioning material with a certain degree of plasticity to protect the substrate bearing surface from damage, while also needing a certain degree of hardness to prevent deformation when supporting the hot plate 13. In some embodiments, the dielectric layer 940 can be made of Teflon, resin, plastic, etc.

[0102] This application uses specific terms to describe embodiments of the application. Terms such as "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0103] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the present application requires more features than those mentioned. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0104] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used to describe embodiments are sometimes modified by the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in this application are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

Claims

1. A method for detecting the quality of a hot plate in a plasma deposition apparatus, wherein the hot plate is disposed within a housing, the housing is grounded, and a metal circuit is disposed inside the hot plate, the metal circuit being part of the radio frequency circuitry of the plasma deposition apparatus, characterized in that... include: A first measurement circuit is constructed, which includes a measurement line and a first test line. The first test line includes the metal line and the housing. The metal line and the housing form a first parallel plate capacitor. The measurement line is used to output voltage signals of different frequencies and to feed back the impedance spectrum at the different frequencies. The first impedance spectrum of the first parallel plate capacitor is measured using the aforementioned measurement circuit; and Determining whether the metal circuitry of the hot plate is normal based on the first impedance spectrum includes: Compare the first impedance spectrum with the standard impedance spectrum. If the difference between the first impedance spectrum and the standard impedance spectrum exceeds a preset threshold, it is determined that the metal circuit of the hot plate is abnormal. The standard impedance spectrum is obtained by measuring the first parallel plate capacitance of a normal quality hot plate using the measurement circuit.

2. The hot plate quality inspection method as described in claim 1, characterized in that, The metal circuit has a first port for external connection, wherein the signal port of the measurement circuit is connected to the first port, and the ground port of the measurement circuit is connected to the housing; Measuring the first impedance spectrum of the first parallel plate capacitor using the aforementioned measurement circuit includes: The measuring circuit transmits multiple voltage signals of different frequencies between the first port and the housing, and feeds back the impedance values ​​between the first port and the housing at the multiple different frequencies; and The first impedance spectrum is obtained based on the multiple different frequencies and their corresponding impedance values.

3. The hot plate quality inspection method as described in claim 1, characterized in that, The metal circuit has a first port for external connection, wherein the measurement circuit includes an radio frequency power supply, the signal port of the measurement circuit is connected to the first port, and the ground port of the measurement circuit is connected to the housing; Measuring the first impedance spectrum of the first parallel plate capacitor using the aforementioned measurement circuit includes: Step S3201: Use the radio frequency power supply to transmit a voltage signal with a target frequency to the first port and the housing, and feed back the incident voltage amplitude and reflected voltage amplitude at the first port; Step S3202: Calculate the reflection coefficient based on the incident voltage amplitude and the reflected voltage amplitude; Step S3203: Calculate the impedance value of the first parallel plate capacitor at the target frequency based on the reflection coefficient and the internal impedance of the radio frequency power supply; Step S3204: Repeat steps S3201 to S3203 several times, wherein before each execution of steps S3201 to S3203, the target frequency is changed within a preset frequency range; and Step S3205: After repeatedly executing steps S3201 to S3203 several times, the first impedance spectrum is obtained according to the correspondence between multiple target frequencies and multiple impedance values.

4. The hot plate quality inspection method as described in claim 1, characterized in that, Also includes: The first impedance spectrum of the first parallel plate capacitor of multiple hot plates was measured using the aforementioned measurement circuit. Determining whether the metal circuit of the hot plate is normal based on the first impedance spectrum includes: comparing the first impedance spectra of the first plate capacitors of multiple hot plates, determining the abnormal first impedance spectrum based on statistical distribution, and determining that the metal circuit of the hot plate with the abnormal first impedance spectrum is abnormal.

5. The hot plate quality inspection method as described in claim 1, characterized in that, The heating plate is also equipped with heating circuitry, and the method for detecting the quality of the heating plate further includes: Construct a second measurement circuit, the second measurement circuit including the measurement line and the second measured line, wherein the second measured line includes the metal line and the heating line, the metal line and the heating line constitute a second parallel plate capacitor; The second impedance spectrum of the second parallel plate capacitor is measured using the aforementioned measuring circuit; and The heating circuit of the hot plate is determined to be normal based on the first impedance spectrum and the second impedance spectrum.

6. The hot plate quality inspection method as described in claim 5, characterized in that, The metal circuit has a first port for external connection, the heating circuit has a second port for external connection, wherein the signal port of the measuring circuit is connected to the first port, and the grounding port of the measuring circuit is connected to the second port; Measuring the second impedance spectrum of the second parallel plate capacitor using the aforementioned measurement circuit includes: The measuring line transmits multiple voltage signals of different frequencies between the first port and the second port, and feeds back the impedance values ​​between the first port and the second port at the multiple different frequencies; and The second impedance spectrum is obtained based on the multiple different frequencies and their corresponding impedance values.

7. The hot plate quality inspection method as described in claim 6, characterized in that, Determining whether the heating circuit of the hot plate is normal based on the first impedance spectrum and the second impedance spectrum includes: If both the first impedance spectrum and the second impedance spectrum are normal, then the heating circuit is determined to be normal; and If the first impedance spectrum is normal and the second impedance spectrum is abnormal, then the heating circuit is determined to be abnormal.

8. The hot plate quality inspection method as described in claim 1, characterized in that, The hot plate includes a plate body and a support shaft. The metal circuit includes a metal layer inside the plate body. The support shaft has a metal post inside that is electrically connected to the metal layer. The metal post is used to connect to the signal port of the measurement circuit. The housing is the process chamber of the plasma deposition equipment. The outer shell of the process chamber is grounded, and the metal layer and the housing constitute the first parallel plate capacitor.

9. The hot plate quality inspection method as described in claim 1, characterized in that, The hot plate includes a plate body and a support shaft. The metal circuit includes a metal layer inside the plate body. The support shaft has metal pillars that are electrically connected to the metal layer. The housing is a metal housing of the fixture, and the heating plate is disposed inside the metal housing. The metal housing includes a bottom plate and a top plate disposed opposite each other. The base plate is used for grounding and forms the first parallel plate capacitor with the metal layer; the top plate is provided with a port connector, which is used to connect to the signal port of the measurement line.

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