Substrate processing system with capability of detecting wafer lower and method thereof

Abstract

A substrate processing system having the ability to detect whether a wafer is loosened during processing is disclosed. An embodiment of a system of the present disclosure includes a reaction chamber provided with an upper electrode and a lower electrode and configured to process a wafer; a radio frequency generator configured to generate high frequency power to process the wafer in the reaction chamber; a matching unit disposed between the reaction chamber and the generator and configured to match the high-frequency power generated from the generator for use in the reaction chamber; a phase shift detector connected in parallel to the reaction chamber and configured to detect a phase shift between a signal entering the upper electrode and a signal exiting the lower electrode; and a controller connected to the phase shift detector and configured to receive the parameters, determine and display the state of the wafer.

Description

Technical Field

[0001] The present invention relates to substrate processing systems, and more particularly, to substrate processing systems having the ability to detect whether a wafer currently being processed has been released without interfering with the processing. Background Art

[0002] During the deposition process, silicon wafers sometimes loosen (move away from their holders) due to insufficient clamping force or disturbances in plasma parameters, and wafer loosening can result in poor film uniformity and reduced yield.

[0003] By observing the reflected power of low radio frequency (LRF) during plasma enhanced chemical vapor deposition (PECVD) process, un-chucking events (referring to the event when a wafer placed on a holder in a deposition equipment moves away from the holder at the start of the process) and unclamping events (referring to the event when a wafer moves away from its holder during the process) can be detected during the deposition stage. However, there is no LRF module for plasma enhanced atomic layer deposition (PEALD) process, so it is impossible to detect poor chucking during the PEALD process by the method used in the PECVD process.

[0004] Therefore, there is a need for a system and method to detect whether a wafer in a system has been loosened (or unclamped) during a PEALD process. Summary of the invention

[0005] This summary is provided to introduce some concepts in a simplified form. These concepts are further described in detail in the detailed description of the example embodiments disclosed below. This summary is not intended to identify the key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0006] According to one embodiment, a substrate processing system having the ability to detect whether a wafer is loosened during processing may be provided, the system comprising: a reaction chamber provided with an upper electrode and a lower electrode and configured to process the wafer; a radio frequency (RF) generator configured to generate high-frequency power in the reaction chamber; a matching unit provided between the reaction chamber and the RF generator and configured to adjust the impedance of the reaction chamber so that the generated high-frequency power is more effective in processing; a phase shift detector connected in parallel to the reaction chamber and configured to detect a phase shift between a signal entering the upper electrode and a signal coming out of the lower electrode; and a controller connected to the phase shift detector and configured to receive parameters, determine and display a clamping state of the wafer.

[0007] In at least one aspect, the substrate processing system further includes a first attenuator disposed between the upper electrode and the phase shift detector and a second attenuator disposed between the phase shift detector and the lower electrode.

[0008] According to another embodiment, a method for detecting whether a chip is loosened in a substrate processing system may be provided, the method comprising: receiving a first threshold, a second threshold and a minimum time length; measuring the phase shift of the upper electrode and the lower electrode; determining whether the measured phase shift is not within the first and second thresholds and whether the duration is longer than the minimum time length, and if it is determined to be true, displaying a loosened state, and if it is determined to be false, repeating the measurement.

[0009] According to another embodiment, a substrate processing system having the ability to detect whether a wafer is loosened during processing may be provided, the system comprising: a reaction chamber provided with an upper electrode and a lower electrode and configured to process the wafer; a radio frequency (RF) generator configured to generate a high-frequency signal to process the wafer in the reaction chamber; a matching unit provided between the reaction chamber and the RF generator and configured to adjust the impedance of the reaction chamber so that the generated high-frequency power is more effective in processing; a network analysis unit connected in parallel to the reaction chamber and configured to detect a transmission coefficient of the reaction chamber; and a controller connected to the network analysis unit and configured to receive parameters and determine and display the state of the wafer.

[0010] In at least one aspect, the substrate processing system further includes: a first low pass filter (LPF) disposed between the upper electrode and the network analysis unit, and a second LPF disposed between the network analysis unit and the lower electrode.

[0011] In at least one aspect, the network analysis unit is a vector network analyzer.

[0012] In at least one aspect, the transmission coefficient is calculated by the following formula: 21 =S out / S in , (S 21 : Transmission coefficient, S out : The signal coming out of the first LPF, S in : Signal entering the second LPF).

[0013] According to another embodiment, a method for detecting whether a wafer is loosened in a substrate processing system may be provided, the method comprising: receiving a threshold; measuring a transmittance from a reaction chamber; determining whether it is true that the measured transmittance is greater than the threshold; and if it is determined to be true, displaying looseness, and if it is determined to be false, repeating the measuring step.

[0014] According to another embodiment, a substrate processing system having the ability to detect whether a wafer is released during processing may be provided, the system comprising: a reaction chamber configured to process the wafer; a radio frequency (RF) generator configured to generate high-frequency power to process the wafer in the reaction chamber; a matching unit disposed between the reaction chamber and the RF generator and configured to adjust the impedance of the reaction chamber so that the generated high-frequency power is more effective in processing; a shielding circuit connected in series to the matching unit and configured to generate a reference voltage for calculating a slope value (b) to determine whether the wafer is released; and a controller connected to the shielding circuit and configured to monitor the reference voltage, calculate the slope value, and determine whether the wafer is released.

[0015] In at least one aspect, in the substrate processing system, the shielding circuit includes one or more resistors, one or more capacitors, one or more coils, and one or more diodes.

[0016] According to another embodiment, a method for detecting whether a wafer is loosened in a substrate processing system may be provided, the method comprising: receiving a predetermined number (N) and a threshold; measuring N reference voltages (V ref,i ) (1 ≤ i ≤N); extract N reference voltages (V ref,i ) of each of the maximum values ​​(V max,i ) (1 ≤ i ≤ N); use the following equation to calculate the moving average y n (1 ≤ n ≤ N), where Eq.) (1 ≤ n ≤ N); the slope value b is derived using the following equation, where the equation) ; Determine whether it is true that the slope value b is less than the threshold value; and if it is determined to be true, display release, and if it is determined to be false, repeat reception. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] It should be understood that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the drawings may be exaggerated relative to other elements to help improve the understanding of the illustrated embodiments of the present disclosure.

[0018] Figure 1 An overview of a substrate processing system with loose wafer detection capability according to a first system embodiment of the present disclosure is shown.

[0019] Figure 2 An example of how a substrate processing system and a method of detecting a loose wafer will work according to a first method embodiment of the present disclosure is shown.

[0020] Figure 3(a) shows a flow chart of a method for detecting a loose wafer in a substrate processing system according to a first method embodiment of the present disclosure; Figure 3 (b) in FIG. 1 shows an example of values ​​of how the method according to the first method embodiment of the present disclosure works.

[0021] Figure 4 An overview of a substrate processing system with loose wafer detection capability according to a second system embodiment of the present disclosure is shown.

[0022] Figure 5 An example of how a substrate processing system and a method of detecting a loose wafer will work according to a second method embodiment of the present disclosure is shown.

[0023] Figure 6 A flow chart of a method for detecting a loose wafer in a substrate processing system according to a second method embodiment of the present disclosure is shown.

[0024] Figure 7 An overview of a substrate processing system with loose wafer detection capability according to a third system embodiment of the present disclosure is shown.

[0025] Figure 8 (a) shows an example of a graph of high radio frequency (HRF) power generated from an RF generator for a plurality of cycles generated from the RF generator; Figure 8 (b) shows the reference voltage (V ref ) and from the reference voltage (V ref ) Each maximum value (V max ) example.

[0026] Fig. 9 A flow chart of a method for detecting a loose wafer in a substrate processing system according to a third method embodiment of the present disclosure is shown.

[0027] Fig.10 (a) in FIG. 4 shows an example of obtaining the slope value b in the case of (N = 4); Fig.10 (b) in FIG. 1 shows another example of obtaining the slope value b in the case of (N = 4). DETAILED DESCRIPTION

[0028] Although certain embodiments and examples are disclosed below, those skilled in the art will appreciate that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention and their obvious modifications and equivalents. Therefore, it is intended that the scope of the disclosed invention should not be limited by the specifically disclosed embodiments described below.

[0029] As used herein, the term "substrate" may refer to any one or more underlying materials, including any one or more underlying materials that may be modified or on which a device, circuit, or film may be formed. A "substrate" may be continuous or non-continuous; rigid or flexible; solid or porous; and combinations thereof. A substrate may be in any form, such as a powder, a plate, or a workpiece. A plate-like substrate may include wafers of various shapes and sizes. A substrate may be made of semiconductor materials, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.

[0030] For example, a substrate in powder form can be used in drug manufacturing. The porous substrate can include a polymer. Examples of workpieces can include medical devices (such as stents and syringes), jewelry, tool equipment, components for battery manufacturing (such as anodes, cathodes, or separators), or components of photovoltaic cells, etc.

[0031] The continuous substrate may extend beyond the boundaries of the processing chamber in which the deposition process occurs. In some processes, the continuous substrate may be moved through the processing chamber so that the process continues until the end of the substrate is reached. The continuous substrate may be provided from a continuous substrate feed system to allow the continuous substrate to be manufactured and output in any suitable form.

[0032] Non-limiting examples of continuous substrates may include sheets, nonwoven films, rolls, foils, meshes, flexible materials, bundles of continuous filaments or fibers (eg, ceramic fibers or polymer fibers).The continuous substrate may also include a carrier or sheet on which a discontinuous substrate is mounted.

[0033] The illustrations presented herein are not meant to be actual views of any particular material, structure, or device but are merely idealized representations used to describe embodiments of the present disclosure.

[0034] The specific embodiments shown and described are illustrations of the present invention and its best mode and are not intended to limit the scope of these aspects and embodiments in any way. In fact, for the sake of brevity, the traditional manufacturing, connection, preparation and other functional aspects of the system may not be described in detail. In addition, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or physical connections between various elements. Many alternative or additional functional relationships or physical connections may exist in actual systems, and / or may not exist in some embodiments.

[0035] It should be understood that the configuration and / or method described herein are exemplary in nature, and these specific embodiments or examples should not be considered restrictive, because many variations are possible. The specific routine or method described herein can represent one or more of any number of processing strategies. Therefore, the various actions shown can be performed in the order shown, in other orders, or omitted in some cases.

[0036] The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various processes, systems and configurations, and other features, functions, acts and / or properties disclosed herein, and any and all equivalents thereof.

[0037] Figure 1 The substrate processing system 100 is shown, which includes a reaction chamber 110, a radio frequency (RF) generator 115, a matching unit 114, and a monitoring block 120. The reaction chamber 110 may include an upper electrode 111 and a lower electrode 112. The upper electrode 111 may be a showerhead, and the lower electrode 112 may be a susceptor. A wafer 113 may be placed on the lower electrode 112.

[0038] The RF generator 115 generates RF power. The matching unit 114 may be configured to adjust the impedance of the reaction chamber 110 so that the generated RF power is more effective in wafer processing, and the lower electrode 112 is grounded to the ground 130.

[0039] The substrate processing system 100 may further include a radio frequency (RF) filter 150. The RF filter 150 may be connected at one end to the lower electrode 112 and to the ground 130, such as Figure 1 shown.

[0040] The monitoring block 120 may include a phase shift detector 123 and a controller 124 coupled to the phase shift detector 123. The monitoring block 120 may be connected in parallel to the reaction chamber 110. Additional attenuators 121, 122 may be connected in series to the phase shift detector 123, such as Figure 1 shown.

[0041] The phase shift detector 123 monitors and detects how much phase shift may occur in the signal passing through it. The measured phase shift can be displayed in analog or digital form. The phase shift detector 123 may include an oscilloscope. The attenuators 121, 122 can attenuate or reduce the amplitude of the signal passing through it. A high voltage probe (not shown) can be used instead of an attenuator. The attenuator is used to reduce the signal strength, thereby reducing any damage caused by the high power signal to the phase shift detector 123.

[0042] The controller 124 may receive parameters such as a first threshold value (minimum value), a second threshold value (maximum value), and a minimum time length (in seconds). Figure 2 An example is shown of how to use the measured (monitored) phase shift values ​​to determine whether a wafer is loosened.

[0043] The first and second thresholds (A and B) define the minimum and maximum values ​​(in degrees), respectively, so any phase shift between B and A will be considered a properly clamped wafer. On the other hand, any phase shift greater than the maximum value (A) can be considered loose. The parameter minimum time length is the minimum duration of the phase shift, which is used to determine the loose state of the wafer.

[0044] For example, Figure 2 As shown, the first threshold may be [22 degrees], and the second threshold may be [25 degrees]. The minimum time length may be [3 cycles] (for simplicity, this parameter is set to the number of cycles this time).

[0045] Then, the controller 124 measures and monitors the phase shift value picked up from the phase shift detector 123. The periods D1 to D5 last for a minimum time length, and periods D1 and D2 may be examples of "unclamped wafer", D3 and D4 are examples of "released wafer", and D5 is an example of "clamped wafer".

[0046] During D1, there are 3 phase shift values, such as [25 degrees], [28 degrees], and [30 degrees]. Although [28 degrees] and [30 degrees] are greater than the second threshold, the offset value of the first cycle of D1, [25 degrees], is equal to the second threshold. This means that the controller 124 may not determine that the wafer is to be released after D1. However, D2 contains phase shift values ​​such as [28 degrees], [29 degrees], and [30 degrees], and they are all greater than the second threshold. After D2, the controller 124 can determine that the wafer is released.

[0047] Although the unclamping event and the unclamping event are completely different, in the present disclosure, "unclamping" may be used to refer to both the unclamping event and the unclamping event.

[0048] D3 includes three phase shift values, such as [23 degrees], [27 degrees], and [26 degrees]. Although [27 degrees] and [26 degrees] are greater than the second threshold, [23 degrees] is less than the second threshold. Therefore, the controller 124 may not determine to release the wafer after D3. However, D4 includes phase shift values ​​such as [28 degrees], [26 degrees], and [30 degrees]. Since all three values ​​are greater than the second threshold, the controller 124 may determine to release the wafer after D4.

[0049] D5 includes three phase shift values, for example, [23 degrees], [24 degrees], and [23 degrees]. Since they are all within the gap between the first threshold and the second threshold, the controller 124 may not determine to release the wafer after D5.

[0050] Figure 3 (a) shows a method of determining whether a wafer is loosened.

[0051] At the beginning of step 301 of the method, the controller 124 may receive parameters such as a first threshold, a second threshold, and a minimum time length. The effect of each parameter may be Figure 2As described above. In step 302 of the method, once the parameters are set, the controller 124 may begin measuring (or monitoring) the phase shift degree picked up from the phase shift detector 123. In step 303 of the method, for each new input of the phase shift value (in degrees), the controller 124 may determine whether the measured phase shift value 1) is not within the gap between the first threshold and the second threshold (condition I) and 2) the phase shift value continues to be equal to or longer than a minimum time length (condition II).

[0052] Figure 3 (b) shows a diagram with the description Figure 3 An example of how the method in (a) works for values.

[0053] The first threshold is set to [10 degrees] and the second threshold is set to [14 degrees]. The minimum time length is set to [3 cycles]. In cycle 1, a phase shift value of [14 degrees] is received, but the time length of cycle 1 is only [1 cycle] (only [14 degrees] so far), so a measurement can be performed (step 302). In cycle 2, a new offset value of [16 degrees] is received, but the time length of cycle 2 is [2 cycles] ([14 degrees], [16 degrees], so the measurement (step 302) can continue.

[0054] In loop 3, a new offset value [17 degrees] is received, and "condition II" is satisfied starting from loop 3. Among the three offset values ​​([14 degrees], [16 degrees], [17 degrees]) in the time length of loop 3, [16 degrees] & [17 degrees] are not within the gap between the first and second thresholds. Therefore, in step 302 of the method, the controller 124 can be configured to continue measuring the phase shift value.

[0055] In loop 4, a new value [15 degrees] is received, and the time length of loop 4 has 3 shift values ​​[16 degrees], [17 degrees], [15 degrees]. All values ​​are not between the first and second thresholds. Therefore, in step 304 of the method, the controller 124 can display "Release".

[0056] Once the wafer is removed from its correct position, the unclamped wafer will not usually return to the "clamped" state. Therefore, when the controller 124 displays "unclamped", it may not be necessary to continue. However, in some specific systems with different requirements, the unclamped wafer may return to the clamped state. Therefore, in some cases, in steps 304 and 302 of the method, the controller 124 can be configured to continue measuring after displaying "unclamped".

[0057] Assume that the controller 124 can be configured to Figure 3Continuing after loop 4 of (b) in FIG. 5 . In loop 5, a new value [14 degrees] is received. Since [14 degrees] does not satisfy “Condition I”, the controller 124 can be configured to continue measuring without displaying “Release”. In loops 6, 7, and 8, values ​​[13 degrees], [12 degrees], and [11 degrees] are received, respectively. None of them meet “Condition I”.

[0058] In loops 9 and 10, the values ​​[15 degrees] and [17 degrees] are received, respectively. Since [11 degrees] is included in the time length of loops 9 and 10, the controller 124 can be configured to measure the phase shift value and not display "release" until loop 10.

[0059] In loops 11 and 12, new values ​​[21 degrees] and [20 degrees] are received. Because the phase shift values ​​in the time lengths of loop 11 ([15 degrees], [17 degrees], [21 degrees]) and loop 12 ([17 degrees], [21 degrees], [20 degrees]) meet "Condition 1", the controller 124 can be configured to display "Release" after loops 11 and 12. Therefore, if Figure 3 As shown in (b) in FIG. 1 , using the parameters of the first threshold [10 degrees], the second threshold [14 degrees] and the minimum time length [3 cycles], the controller 124 can be configured to display “Release” only after cycles 4, 11 and 12.

[0060] Figure 4 A second embodiment of the present disclosure is shown. The substrate processing system 400 includes a reaction chamber 410, a radio frequency (RF) generator 415, a matching unit 414, and a monitoring module 420. The reaction chamber 410 may include an upper electrode 411 and a lower electrode 412. The upper electrode 411 may be a showerhead, and the lower electrode 412 may be a susceptor. A wafer 413 may be placed on the lower electrode 412. The substrate processing system 400 may also include an RF filter 450, which is connected to the lower electrode 412 at one end and to the ground 430 at the other end, as shown in FIG. Figure 4 shown.

[0061] The RF generator 415 may generate RF power. The matching unit 414 may be configured to adjust the impedance of the reaction chamber 410 so that the generated RF power is more effective in wafer processing, and the lower electrode 412 is grounded to the ground 430 .

[0062] The monitoring block 420 may include a network analysis unit 423 and a controller 424 coupled to the network analysis unit 123. The monitoring module 420 may be connected in parallel to the reaction chamber 410. And low pass filters (LPFs) 421, 422 may be connected in series to the network analysis unit 423, such as Figure 4 shown.

[0063] The network analysis unit 423 can be configured to monitor and measure the amplitude and phase characteristics of the signal by using the scattering parameter (S parameter) theory. Since explaining the S parameter theory will deviate from the subject matter of the present disclosure, only the results of the theory (i.e., the formula for obtaining the transmission coefficient) will be used. The formula for obtaining the transmission coefficient of the forward transmission can be expressed as S 21 =S transmitted / S incident . [Equation 1] (S 21 : Transmission coefficient, S transmitted : The signal entering the device under test, S incident : Signal coming out of the device under test).

[0064] The network analysis unit 423 may be a vector network analyzer. The LPFs 421 and 422 may be configured to allow low frequency signals to pass through while attenuating high frequency signals.

[0065] The controller 424 may be configured to receive parameters such as threshold values. Figure 5 An example is shown of how to use the measured (monitored) transmission coefficient to determine whether a wafer is loose.

[0066] Curve 501 may be a transmission coefficient curve from [Equation 1] when the wafer 413 may be normally clamped, and curve 502 may be a transmission coefficient curve when the wafer 413 may be loosened. Figure 5 As shown, the y-axis is amplitude, the x-axis is frequency, and the slope of curve 502 is greater than the slope of curve 501 .

[0067] Curve 503 may be a received parameter (threshold). Any transmission coefficient curve having a slope greater than the threshold curve 503 may be determined as a loose wafer, and any transmission coefficient curve having a slope less than the threshold curve 503 may be determined as a clamped wafer.

[0068] LPF421, 422 will attenuate the signal with frequency greater than 1MHz, so Figure 5 The frequency range can be 1Hz~1MHz. For better loosening detection, the spectrum will vary from system to system.

[0069] Figure 6 A second method embodiment of how to determine whether a wafer is loosened is shown.

[0070] Initially, in step 601 of the method, the controller 424 may receive parameters such as a threshold curve value. In step 602 of the method, once the parameters are set, the controller 124 may begin measuring (or monitoring) the transmission coefficient picked up from the network analysis unit 423. The network analysis unit 423 may use the following [Equation 2] to obtain the transmission coefficient. It can be seen that Equation 2 is derived from Equation 1.

[0071] Transmission coefficient = S out / S in ,

[0072] (S out : The signal coming out of the first LPF421, S in : The signal entering the second LPF 422) [Equation 2]

[0073] After obtaining the transmission coefficient, in step 603 of the method, the controller 424 may be configured to determine whether it is true that the measured transmission coefficient is greater than a threshold value, which means whether the slope of the newly measured transmission coefficient curve is greater than the slope of the threshold curve.

[0074] If the measured transmission coefficient is greater than the threshold, the controller 424 may be configured to display "Release" in step 604 of the method. If the measured transmission coefficient is equal to or less than the threshold, the controller 424 may be configured to continue measuring the transmission coefficient without displaying "Release" in step 602 of the method.

[0075] Once the wafer is removed from its correct position, a unclamped wafer will not typically return to a "clamped" state. Therefore, when the controller 424 displays "unclamped", it may not be necessary to continue. However, in some specific systems with different requirements, a unclamped wafer may return to a clamped state. Therefore, as with steps 604 and 602 of the method, in some cases, the controller 424 may be configured to continue measuring after displaying "unclamped".

[0076] Figure 7 The third embodiment of the present disclosure is shown. The substrate processing system 700 includes a reaction chamber 710, a radio frequency (RF) generator 715, and a shielding circuit 721 connected to a matching unit 714. The reaction chamber 710 may include an upper electrode 711 and a lower electrode 712. The upper electrode 711 may be a showerhead, and the lower electrode 712 may be a susceptor. A wafer 713 may be placed on the lower electrode 412.

[0077] The RF generator 715 generates RF power. The matching unit 714 may be configured to adjust the impedance of the reaction chamber 110 so that the generated RF power is more effective in wafer processing, and the lower electrode 712 is grounded to the ground 730.

[0078] The shielding circuit 721 may include one or more resistors, one or more capacitors, one or more coils, and one or more diodes, and the shielding circuit 721 may generate a voltage called a reference voltage (V ref The controller 722 may be connected to the shielding circuit 721, and the controller 722 may be configured to measure and monitor the reference voltage and calculate a slope value for determining whether the wafer 713 is released.

[0079] Figure 8 (a) shows an example of a high radio frequency (HRF) power graph of multiple cycles generated by an RF generator, Figure 8 (b) shows the reference voltage monitored by the controller 722 and each maximum value (V max ) example.

[0080] At the same time of the HRF power cycle 810, a reference voltage 820 appears. But for the shielding circuit 721, the top of the voltage 821 may not be as flat as the top of the HRF power 811. From this uneven top 821, a maximum value 822 can be derived.

[0081] Fig. 9 A third method embodiment of the present disclosure is explained.

[0082] In steps 910 and 911 of the method, the controller 722 may be configured to receive parameters such as a predetermined number N and a slope determination threshold, and the controller 722 may also be configured to measure N reference voltages (V ref,1 , V ref,2 , V ref,3 , …V ref,N-1 , V ref,N ).

[0083] After the N reference voltage measurements, in step 912 of the method, the controller 722 may be configured to extract the maximum value (V max,1 , V max,2 , V max,3 , … , V max,N-1 , V max,N ). Then, in step 913 of the method, the controller 722 can be configured to calculate y using the equation shown below [Equation 3] n .

[0084] [Equation 3] ;

[0085] Then, in step 914 of the method, the controller 722 may be configured to derive the slope value b using the equation [Equation 4] shown below,

[0086] [Equation 4] .

[0087] Then, in step 915 of the method, the controller 722 may be configured to determine whether it is true that the slope value b is lower than the threshold value, and if it is determined to be true, the controller 722 may be configured to display "Release" in step 916 of the method. If it is not determined to be true, the controller 722 may be configured to continue measuring the reference voltage.

[0088] Fig.10 (a) in FIG. 1 shows an example of obtaining the slope value b in the case of (N = 4).

[0089] For simplicity, we can show the calculation of y n and slope value b, while omitting the V ref The curve graph obtains V max The process of value.

[0090] In step 913 of the method, each y is derived using Equation 3 as follows n (1≤n≤4) value.

[0091]

[0092] Then, in step 914 of the method, b is derived as follows using Equation 4 below.

[0093]

[0094] Therefore, for V max For the values ​​[10, 9, 10, 10] and N = 4, the slope value b will be -0.058.

[0095] Fig.10 (b) in FIG. 4 shows another example where N = 4.

[0096] For V max The values ​​[10, 9, 8, 7], the slope value b is derived as follows.

[0097] In step 913 of the method, each y is derived using Equation 3 as follows n (1≤n≤4) value.

[0098]

[0099] Then, in step 914 of the method, b is derived using Equation 4 as follows.

[0100]

[0101]

[0102] For V maxFor the values ​​[10, 9, 8, 7] and N = 4, the slope value b will be -0.5.

[0103] When the wafer is well clamped, the slope value b may be zero (0) or very close to zero (0). The threshold for determining whether may vary depending on the specifics of the system and requirements.

[0104] If the threshold can be set to '-0.1', then Fig.10 The slope value (-0.05833) of (a) is greater than the threshold, while Fig.10 The slope value (-0.5) of (b) in is less than the threshold value. Therefore, in step 915 of the method, the controller 722 may be configured to determine whether b is lower than the threshold value.

[0105] exist Fig.10 In the case of (b), in step 916 of the method, the controller 722 can be configured to display "Release". Fig.10 In (a), in step 911 of the method, the controller 722 may be configured to measure a reference voltage.

[0106] The configuration of the above system and method is only an illustration of the application of the principles of the present invention, and many other embodiments and modifications may be made without departing from the spirit and scope of the present invention defined in the claims. Therefore, the scope of the present invention should not be determined with reference to the above description, but should be determined with reference to the full scope of the appended claims and their equivalents.

Claims

1. A substrate processing system having the capability to detect whether a wafer has become loose during processing, the system comprising: a reaction chamber provided with an upper electrode and a lower electrode and configured to process a wafer; a radio frequency (RF) generator configured to generate high frequency power in the reaction chamber; a matching unit disposed between the reaction chamber and the RF generator and configured to adjust the impedance of the reaction chamber so that the generated high frequency power is more effective in the process; a phase shift detector connected in parallel to the reaction chamber and configured to detect a phase shift between a signal entering the upper electrode and a signal exiting the lower electrode; as well as A controller is connected to the phase shift detector and is configured to receive the parameters and determine and display a clamping state of the wafer.

2. The substrate processing system according to claim 1, further comprising: a first attenuator disposed between the upper electrode and the phase shift detector; as well as A second attenuator is disposed between the phase shift detector and the lower electrode.

3. A method for detecting whether a wafer is loosened in a substrate processing system according to any one of claims 1 to 2, the method comprising: receiving a first threshold, a second threshold, and a minimum time length; Measuring the phase shift between the upper electrode and the lower electrode; determining if the measured degree of phase shift is not within first and second thresholds, and the measured degree of phase shift persists as long as a minimum length of time is true; and If the determination is true, the release state is displayed, and if the determination is false, the measuring step is repeated.

4. A substrate processing system having the capability to detect whether a wafer has become loose during processing, the system comprising: a reaction chamber provided with an upper electrode and a lower electrode and configured to process a wafer; a radio frequency (RF) generator configured to generate a high frequency signal to process the wafer in the reaction chamber; a matching unit disposed between the reaction chamber and the RF generator and configured to adjust the impedance of the reaction chamber so that the generated high frequency power is more effective in the process; a network analysis unit connected in parallel to the reaction chamber and configured to detect a transmission coefficient of the reaction chamber; as well as A controller is connected to the network analysis unit and is configured to receive the parameters and determine and display the release status of the wafer.

5. The substrate processing system according to claim 4, comprising: a first low pass filter (LPF) disposed between the upper electrode and the network analysis unit; as well as The second LPF is arranged between the network analysis unit and the lower electrode.

6. The substrate processing system according to any one of claims 4 to 5, wherein: The network analysis unit is a vector network analyzer.

7. The substrate processing system according to any one of claims 4 to 5, wherein: The transmission coefficient is calculated by the following formula: S 21 =S out / S in , (S 21 : Transmission coefficient, S out : The signal coming out of the first LPF, S in : signal entering the second LPF).

8. A method for detecting whether a wafer is loosened in a substrate processing system according to any one of claims 4 to 5, the method comprising: Receiving threshold; measuring the transmission coefficient from the reaction chamber; determining whether it is true that the measured transmission coefficient is greater than a threshold value; as well as If the determination is true, release is displayed, and if the determination is false, the measuring step is repeated.

9. The method according to claim 8, wherein: The transmission coefficient is calculated by the following formula: S 21 =S out / S in , (S 21 : Transmission coefficient, S out : The signal coming out of the first LPF, S in : Signal entering the second LPF).

10. A substrate processing system having the capability to detect whether a wafer has become loose during processing, the system comprising: a reaction chamber configured to process a wafer; a radio frequency (RF) generator configured to generate high frequency power to process the wafer in the reaction chamber; a matching unit disposed between the reaction chamber and the RF generator and configured to adjust the impedance of the reaction chamber so that the generated high frequency power is more effective in the process; a shielding circuit connected in series to the matching unit and configured to generate a reference voltage for calculating a slope value (b) to determine whether the wafer is released; as well as A controller is connected to the shielding circuit and configured to monitor the reference voltage, calculate the slope value, and determine whether the wafer is released.

11. The substrate processing system according to claim 10, wherein: The shielding circuit includes one or more resistors, one or more capacitors, one or more coils and one or more diodes.

12. A method for detecting whether a wafer is loosened in the substrate processing system according to claim 10, the method comprising: receiving a predetermined number (N) and a threshold value; Measure N reference voltages (V ref,i ) (1 ≤ i ≤ N); Extract N reference voltages (V ref,i ) of each of the maximum values ​​(V max,i ) (1 ≤ i ≤ N); Calculate the moving average y using equation 1 n (1 ≤ n ≤ N), where Equation 1) (1 ≤n ≤ N); The slope value b is derived using Equation 2, where Equation 2) ; Determine whether the slope value b is less than a threshold value; and If the determination is true, release is displayed, and if the determination is false, the measuring step is repeated.

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