A semiconductor plasma process monitoring apparatus and monitoring method

Abstract

The application belongs to the field of semiconductor process, and particularly relates to a semiconductor plasma process monitoring device and a monitoring method. The semiconductor plasma process monitoring device provided by the application comprises a signal sampling part, a signal analysis part, a forward transfer coefficient monitoring part, a reverse transfer coefficient monitoring part and a temperature monitoring part. The signal sampling part is provided with a forward signal sampling end, a reverse signal sampling end and two radio frequency connectors. The signal input end of the forward transfer coefficient monitoring part is connected with the forward signal sampling end. The signal input end of the reverse transfer coefficient monitoring part is connected with the reverse signal sampling end. The signal output ends of the forward transfer coefficient monitoring part, the reverse transfer coefficient monitoring part and the temperature monitoring part are connected with the signal analysis part respectively. The monitoring device can realize real-time collection of the values of the transfer coefficients on the whole transmission line and calibration analysis, so as to realize high accuracy and stability monitoring. Meanwhile, the cost of the composed device is low, and the cost and performance are considered.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology, and specifically relates to a semiconductor plasma process monitoring device and monitoring method. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] In the semiconductor industry, etching and deposition equipment are key and frequently used components in the process, and their core application is utilizing plasma for their respective processes. Because ion fluctuations are disordered, direct observation of plasma is difficult. Therefore, currently, it is impossible to strictly control and observe the concentration of plasma generated inside the cavities of etching and deposition equipment in semiconductor processes. When the plasma concentration fails to reach the required process concentration, the accuracy of the etching and deposition processes is significantly affected, leading to a decrease in chip yield and consequently impacting overall production capacity.

[0004] In existing technologies, the reference power value of the plasma excitation source panel is directly referenced. Utilizing the relationship between the panel reference power and plasma concentration, the plasma concentration can be roughly estimated by referring to the machine's operating status. However, the built-in detection circuits of current plasma excitation sources typically employ outdated circuit designs. These devices suffer from poor stability, low accuracy, aging susceptibility, and temperature sensitivity, failing to completely solve the problem of plasma concentration detection. Furthermore, as the plasma excitation source ages, its accuracy decreases further. Although the accuracy of referencing the plasma excitation source is low, this approach remains the mainstream solution due to cost constraints. Alternatively, an optical detection instrument can be mounted outside the observation window of the cavity. Using advanced optical instruments, real-time analysis of the plasma concentration inside the plasma cavity can be achieved. While this method effectively observes plasma concentration, the optical detection instrument is extremely expensive, relying on imports from Japan or Europe. The total cost of the instrument can be comparable to that of the plasma excitation source itself, making it unsuitable for mass production. Therefore, it is primarily used in laboratories during research and development and is not applicable to FAB (Feature Absorber) production lines. Existing plasma concentration monitoring and control schemes for etching and deposition generally suffer from drawbacks, where cost, accuracy, and stability cannot be simultaneously achieved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a semiconductor plasma process monitoring device and method. The monitoring device of the present invention can acquire and calibrate the transmission coefficient values ​​on the entire transmission line in real time, thereby achieving high accuracy and stability monitoring. Simultaneously, the components are inexpensive, balancing cost and performance.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] In a first aspect, the present invention provides a semiconductor plasma process monitoring device, comprising a signal sampling unit, a signal analysis unit, a forward transfer coefficient monitoring unit, a reverse transfer coefficient monitoring unit, and a temperature monitoring unit. The signal sampling unit is provided with a forward signal sampling end, a reverse signal sampling end, and two radio frequency connectors. The signal sampling unit is provided with a sampling structure that uses electromagnetic induction to sample energy signals as voltage signals. The signal input end of the forward transfer coefficient monitoring unit is connected to the forward signal sampling end, and the signal input end of the reverse transfer coefficient monitoring unit is connected to the reverse signal sampling end. The signal output ends of the forward transfer coefficient monitoring unit, the reverse transfer coefficient monitoring unit, and the temperature monitoring unit are respectively connected to the signal analysis unit.

[0008] The signal sampling unit performs sampling on the radio frequency energy transmission line, ensuring that the sampled energy signal retains its original characteristics. Through subsequent processing, analysis and calculation of this sampled signal, the transmission characteristics of the plasma generation energy transmission line can be obtained.

[0009] Preferably, the forward transfer coefficient monitoring unit includes a forward sampling circuit, a forward transfer coefficient filtering circuit, a forward detection circuit, and a first analog-to-digital converter connected in sequence. The signal input terminal of the forward sampling circuit is connected to the forward signal sampling terminal, and the signal output terminal of the first analog-to-digital converter is connected to the signal analysis unit.

[0010] The forward sampling circuit acquires a sampled signal of the forward transmission signal for subsequent analysis. The forward transmission coefficient filter circuit, connected to the forward sampling circuit, filters out interference signals on this line, increasing accuracy. The forward detection circuit converts the high-frequency AC signal into a DC signal for subsequent analog-to-digital conversion. The first analog-to-digital converter, connected to the detection circuit, converts the analog signal into a digital signal for use by the subsequent signal analysis unit. The main function of the forward sampling circuit is to collect the radio frequency energy data of the forward transmission.

[0011] Preferably, the reverse transfer coefficient monitoring unit includes a reverse sampling circuit, a reverse transfer coefficient filtering circuit, a reverse detection circuit, and a second analog-to-digital converter connected in sequence. The signal input terminal of the reverse sampling circuit is connected to the reverse signal sampling terminal, and the signal output terminal of the second analog-to-digital converter is connected to the signal analysis unit.

[0012] The reverse sampling circuit acquires a sampled signal of the reverse-transmitted signal for subsequent analysis. The reverse transmission coefficient filter circuit, connected to the reverse sampling circuit, filters out interference signals on this line, increasing accuracy. The reverse detector circuit converts the high-frequency AC signal into a DC signal for subsequent analog-to-digital conversion. The second analog-to-digital converter, connected to the detector circuit, converts the analog signal into a digital signal for use by the subsequent signal analysis department. The main function of the reverse sampling circuit is to collect the radio frequency energy data of the reverse transmission.

[0013] Preferably, the temperature monitoring unit includes a temperature sensor, a temperature filtering circuit, and a third analog-to-digital converter connected in sequence, and the signal output terminal of the third analog-to-digital converter is connected to the signal analysis unit.

[0014] The temperature sensor is mainly used to monitor the real-time temperature inside the semiconductor plasma process monitoring device, quantifying the temperature into an electrical signal. A temperature filter circuit connected to the temperature sensor filters out interference signals. A third analog-to-digital converter connected to the temperature filter circuit converts the analog signal into a digital signal for use by the subsequent signal analysis department. The main function of this part is to collect the internal temperature of the invention to eliminate temperature-induced deviations in data acquisition.

[0015] Preferably, the signal sampling unit includes a sampling structure, which comprises a coupling circuit, dual directional couplers, two shared directional couplers, or an inductive sampler. Based on the principle of electromagnetic induction, the energy signal is sampled as a voltage signal, and the sampled signal parameters include voltage amplitude or frequency.

[0016] More preferably, the structure of the forward sampling line includes a microstrip branch structure, a strip branch structure, a gap waveguide structure, or a circular waveguide structure; the forward transfer coefficient filtering circuit includes a passive RLC filtering circuit; the forward detection circuit is equipped with a detector or a Schottky diode; and the first analog-to-digital converter is an analog-to-digital converter or an MCU with an analog-to-digital converter.

[0017] More preferably, the structure of the reverse sampling line includes a microstrip branch structure, a strip branch structure, a gap waveguide structure, or a circular waveguide structure; the reverse transfer coefficient filtering circuit includes a passive RLC filtering circuit; the reverse detection circuit is equipped with a detector or a diode; and the second analog-to-digital converter is an analog-to-digital converter or an MCU with an analog-to-digital converter.

[0018] More preferably, the temperature filtering circuit includes a passive RLC filtering circuit, and the third analog-to-digital converter is an analog-to-digital converter or an MCU with an analog-to-digital converter.

[0019] The circuits, analog-to-digital converters, and sensors described in this invention can all use existing circuits or devices that meet the functional requirements.

[0020] In a second aspect, the present invention provides a semiconductor plasma process monitoring method, using the semiconductor plasma process monitoring device as described in the first aspect, comprising the following steps:

[0021] S1. Connect the two RF connectors of the signal sampling unit to the RF energy transmission line to obtain RF energy data including the transfer coefficient, and output the sampling signal as a voltage signal.

[0022] S2. The forward transmission coefficient monitoring unit acquires the forward transmission signal in the sampled signal, processes it, and then transmits the forward transmission coefficient to the signal analysis unit.

[0023] S3. The reverse transmission coefficient monitoring unit acquires the reverse transmission signal in the sampled signal, processes it, and then transmits the reverse transmission coefficient to the signal analysis unit.

[0024] S4. The temperature monitoring unit monitors the internal temperature of the semiconductor plasma process monitoring device, processes the data, converts it into a temperature signal, and sends it to the signal analysis unit.

[0025] S5. The signal analysis unit analyzes the forward and reverse transmission coefficients in conjunction with the temperature signal. Based on whether the transmission coefficient is too high or too low, it issues a command to the plasma excitation source to increase or decrease the corresponding value until it stabilizes within the range required by the process.

[0026] Preferably, in step S5, specific data is obtained through calculation or by looking up a table for analysis. The values ​​include frequency, power, temperature, standing wave ratio, altitude, or humidity.

[0027] The beneficial effects achieved by one or more technical solutions of the present invention are as follows:

[0028] The semiconductor plasma process monitoring device and method of this invention solve the accuracy, stability, and cost problems of existing technologies. In principle, this invention replaces the inaccurate panel data from the source plasma excitation source used in existing technologies with real-time acquisition of the transfer coefficient values ​​on the entire transmission line, offering reliability and timeliness, and solving the problem of difficult self-detection of internal aging offsets in the plasma excitation source. Regarding accuracy, this invention employs sampling, voltage regulation, filtering, and detection circuit structures, combined with a high-precision MCU, reducing the error of real-time numerical monitoring to below 1%. In terms of stability, the independent module design and built-in temperature calibration algorithm maintain extremely high accuracy even in extremely harsh environments, and the built-in frequency calibration algorithm maintains high accuracy even when the frequency fluctuates. Regarding cost, the device uses conventional components, greatly reducing overall cost and improving its accessibility.

[0029] Wafers undergo a series of processes including photolithography, etching, deposition, polishing, and packaging to be processed into usable chips. Plasma plays a crucial role in the two key stages of etching and deposition; even minor variations can affect the process results. For example, current deposition and etching processes typically rely on precise calculations of plasma concentration to control the reaction time of each process step within milliseconds or even microseconds. In other words, fluctuations and changes in plasma concentration can render the pre-calculated reaction times unsuitable. From a process perspective, when the energy value of the plasma excitation source fluctuates upwards, if it cannot be adjusted to meet the process requirements in time, the plasma concentration generated in the cavity will increase, leading to over-etching or over-deposition within the same timeframe. Conversely, if the plasma excitation source fluctuates downwards, if it cannot be pulled back to the required operating state in time, the plasma concentration generated in the cavity will decrease, resulting in insufficient etching depth or insufficient deposition thickness. These two situations can significantly reduce chip yield, and in severe cases, even lead to large-scale scrapping of entire batches of chips, with varying economic losses depending on the specific circumstances. This invention can monitor the transfer coefficient in the energy transmission line of the excitation plasma generation in real time and feed the monitored data back to the host computer in real time. When the host computer receives the data, it can immediately detect whether the transfer coefficient of the entire line is too high or too low, and then issue an instruction to the plasma excitation source to increase or decrease the corresponding value until it is stable within the range required by the process, thereby maintaining the stability of the plasma concentration inside the cavity and improving the overall process yield.

[0030] The semiconductor plasma process monitoring device of the present invention can be used as a standalone instrument, or it can be installed as a module at any node of the overall transmission line, or the overall structure can be integrated into the equipment, such as inside the plasma excitation source, inside the etching and deposition equipment, or on the transmission line. Attached Figure Description

[0031] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0032] Figure 1 This is a schematic diagram of the semiconductor plasma process monitoring device of the present invention;

[0033] Figure 2 This is a schematic diagram of the forward transmission coefficient monitoring unit of the present invention;

[0034] Figure 3 This is a schematic diagram of the reverse transmission coefficient monitoring unit of the present invention;

[0035] Figure 4 This is a schematic diagram of the temperature monitoring unit of the present invention;

[0036] In the diagram, 1 is the signal sampling unit, 2 is the RF connector, 3 is the forward signal sampling end, 4 is the reverse signal sampling end, 5 is the temperature monitoring unit, 6 is the forward transfer coefficient monitoring unit, 7 is the reverse transfer coefficient monitoring unit, 8 is the signal analysis unit, 9 is the forward sampling circuit, 10 is the forward transfer coefficient filtering circuit, 11 is the forward detection circuit, 12 is the first analog-to-digital converter, 13 is the reverse sampling circuit, 14 is the reverse transfer coefficient filtering circuit, 15 is the reverse detection circuit, 16 is the second analog-to-digital converter, 17 is the temperature sensor, 18 is the temperature filtering circuit, and 19 is the third analog-to-digital converter. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples.

[0038] Example 1

[0039] like Figure 1As shown, a semiconductor plasma process monitoring device includes a signal sampling unit 1, a signal analysis unit 8, a forward transfer coefficient monitoring unit 6, a reverse transfer coefficient monitoring unit 7, and a temperature monitoring unit 5. The signal sampling unit 1 incorporates a coupling circuit as a sampling structure to sample energy signals as voltage signals using electromagnetic induction. The signal sampling unit 1 includes a forward signal sampling terminal 3, a reverse signal sampling terminal 4, and two radio frequency connectors 2. The signal input terminal of the forward transfer coefficient monitoring unit 6 is connected to the forward signal sampling terminal 3, and the signal input terminal of the reverse transfer coefficient monitoring unit 7 is connected to the reverse signal sampling terminal 4. The signal output terminals of the forward transfer coefficient monitoring unit 6, the reverse transfer coefficient monitoring unit 7, and the temperature monitoring unit 5 are respectively connected to the signal analysis unit 8.

[0040] like Figure 2 As shown, the forward transfer coefficient monitoring unit 6 includes a forward sampling circuit 9, a forward transfer coefficient filtering circuit 10, a forward detection circuit 11, and a first analog-to-digital converter 12 connected in sequence. The signal input terminal of the forward sampling circuit 9 is connected to the forward signal sampling terminal 3, and the signal output terminal of the first analog-to-digital converter 12 is connected to the signal analysis unit 8. The forward sampling circuit 9 uses a conventional microstrip branch structure, the forward transfer coefficient filtering circuit 10 uses a conventional passive RLC filtering circuit, the forward detection circuit 11 uses a conventional detector, and the first analog-to-digital converter 12 is a conventional analog-to-digital converter.

[0041] like Figure 3 As shown, the reverse transfer coefficient monitoring unit 7 includes a reverse sampling circuit 13, a reverse transfer coefficient filtering circuit 14, a reverse detection circuit 15, and a second analog-to-digital converter 16 connected in sequence. The signal input terminal of the reverse sampling circuit 13 is connected to the reverse signal sampling terminal 4, and the signal output terminal of the second analog-to-digital converter 16 is connected to the signal analysis unit 8. The reverse sampling circuit 13 uses a conventional microstrip branch structure, the reverse transfer coefficient filtering circuit 14 uses a conventional passive RLC filtering circuit, the reverse detection circuit 15 uses a conventional detector, and the second analog-to-digital converter 16 is a conventional analog-to-digital converter.

[0042] like Figure 4 As shown, the temperature monitoring unit 5 includes a temperature sensor 17, a temperature filtering circuit 18, and a third analog-to-digital converter 19 connected in sequence. The signal output terminal of the third analog-to-digital converter 19 is connected to the signal analysis unit 8. The temperature sensor 17 is a conventional temperature sensor, the temperature filtering circuit 18 is a conventional passive RLC filter circuit, and the third analog-to-digital converter 19 is a conventional analog-to-digital converter.

[0043] Example 2

[0044] A semiconductor plasma process monitoring method, using the semiconductor plasma process monitoring device as described in Example 1, includes the following steps:

[0045] S1. Connect the two RF connectors 2 of the signal sampling unit 1 to the RF energy transmission line to obtain RF energy data including the transfer coefficient, and output the sampling signal as a voltage signal.

[0046] S2. The forward transmission coefficient monitoring unit 6 acquires the forward transmission signal in the sampled signal, processes it, and then transmits the forward transmission coefficient to the signal analysis unit 8.

[0047] S3. The reverse transmission coefficient monitoring unit 7 acquires the reverse transmission signal in the sampled signal, processes it, and then transmits the reverse transmission coefficient to the signal analysis unit 8.

[0048] S4, Temperature monitoring unit 5 monitors the internal temperature of the semiconductor plasma process monitoring device, processes the data and converts it into a temperature signal, which is then transmitted to signal analysis unit 8;

[0049] S5 and the signal analysis unit 8 combine the temperature signal to correct and analyze the forward and reverse transmission coefficients. Based on the value of the transmission coefficient being too high or too low, they issue instructions to the plasma excitation source to increase or decrease the corresponding value until it stabilizes within the range required by the process.

[0050] In step S2, the forward sampling circuit 9 is used to acquire the sampled signal of the forward transmission signal, the forward transmission coefficient filter circuit 10 is used to filter out the interference signal on the line, the forward detection circuit 11 is used to convert the high-frequency AC signal into a DC signal, and the first analog-to-digital converter 12 is used to convert the analog signal into a digital signal for use by the signal analysis unit 8.

[0051] In step S3, the reverse sampling circuit 13 is used to acquire the sampled signal of the reverse transmission signal, the reverse transmission coefficient filter circuit 14 is used to filter out the interference signal on the line, the reverse detector circuit 15 is used to convert the high-frequency AC signal into a DC signal, and the second analog-to-digital converter 16 is used to convert the analog signal into a digital signal for use by the signal analysis unit 8.

[0052] In step S4, the temperature sensor 17 is used to monitor the real-time temperature inside the semiconductor plasma process monitoring device, the temperature is quantified into an electrical signal, the temperature filter circuit 18 is used to filter out interference signals, and the third analog-to-digital converter 19 is used to convert the analog signal into a digital signal for use by the signal analysis unit 8.

[0053] In step S5, specific data is obtained through calculation or by looking up tables for analysis. The values ​​include frequency, power, temperature, standing wave ratio, altitude, or humidity.

[0054] Example 3

[0055] like Figure 1As shown, a semiconductor plasma process monitoring device includes a signal sampling unit 1, a signal analysis unit 8, a forward transfer coefficient monitoring unit 6, a reverse transfer coefficient monitoring unit 7, and a temperature monitoring unit 5. The signal sampling unit 1 uses a dual directional coupler as a sampling structure to sample energy signals as voltage signals using electromagnetic induction. The signal sampling unit 1 has a forward signal sampling terminal 3, a reverse signal sampling terminal 4, and two radio frequency connectors 2. The signal input terminal of the forward transfer coefficient monitoring unit 6 is connected to the forward signal sampling terminal 3, and the signal input terminal of the reverse transfer coefficient monitoring unit 7 is connected to the reverse signal sampling terminal 4. The signal output terminals of the forward transfer coefficient monitoring unit 6, the reverse transfer coefficient monitoring unit 7, and the temperature monitoring unit 5 are respectively connected to the signal analysis unit 8.

[0056] like Figure 2 As shown, the forward transfer coefficient monitoring unit 6 includes a forward sampling circuit 9, a forward transfer coefficient filtering circuit 10, a forward detection circuit 11, and a first analog-to-digital converter 12 connected in sequence. The signal input terminal of the forward sampling circuit 9 is connected to the forward signal sampling terminal 3, and the signal output terminal of the first analog-to-digital converter 12 is connected to the signal analysis unit 8. The forward sampling circuit 9 uses a conventional strip-branch structure, the forward transfer coefficient filtering circuit 10 uses a conventional passive RLC filtering circuit, the forward detection circuit 11 uses a conventional Schottky diode, and the first analog-to-digital converter 12 is a conventional MCU with an analog-to-digital converter.

[0057] like Figure 3 As shown, the reverse transfer coefficient monitoring unit 7 includes a reverse sampling circuit 13, a reverse transfer coefficient filtering circuit 14, a reverse detection circuit 15, and a second analog-to-digital converter 16 connected in sequence. The signal input terminal of the reverse sampling circuit 13 is connected to the reverse signal sampling terminal 4, and the signal output terminal of the second analog-to-digital converter 16 is connected to the signal analysis unit 8. The reverse sampling circuit 13 uses a conventional strip-branch structure, the reverse transfer coefficient filtering circuit 14 uses a conventional passive RLC filtering circuit, the reverse detection circuit 15 uses a conventional Schottky diode, and the second analog-to-digital converter 16 is a conventional MCU with an integrated analog-to-digital converter.

[0058] like Figure 4 As shown, the temperature monitoring unit 5 includes a temperature sensor 17, a temperature filtering circuit 18, and a third analog-to-digital converter 19 connected in sequence. The signal output terminal of the third analog-to-digital converter 19 is connected to the signal analysis unit 8. The temperature sensor 17 is a conventional temperature sensor, the temperature filtering circuit 18 is a conventional passive RLC filtering circuit, and the third analog-to-digital converter 19 is a conventional MCU with an analog-to-digital converter.

[0059] Example 4

[0060] like Figure 1As shown, a semiconductor plasma process monitoring device includes a signal sampling unit 1, a signal analysis unit 8, a forward transfer coefficient monitoring unit 6, a reverse transfer coefficient monitoring unit 7, and a temperature monitoring unit 5. The signal sampling unit 1 uses two shared directional couplers as a sampling structure to sample energy signals as voltage signals using electromagnetic induction. The signal sampling unit 1 has a forward signal sampling terminal 3, a reverse signal sampling terminal 4, and two radio frequency connectors 2. The signal input terminal of the forward transfer coefficient monitoring unit 6 is connected to the forward signal sampling terminal 3, and the signal input terminal of the reverse transfer coefficient monitoring unit 7 is connected to the reverse signal sampling terminal 4. The signal output terminals of the forward transfer coefficient monitoring unit 6, the reverse transfer coefficient monitoring unit 7, and the temperature monitoring unit 5 are respectively connected to the signal analysis unit 8.

[0061] like Figure 2 As shown, the forward transfer coefficient monitoring unit 6 includes a forward sampling circuit 9, a forward transfer coefficient filtering circuit 10, a forward detection circuit 11, and a first analog-to-digital converter 12 connected in sequence. The signal input terminal of the forward sampling circuit 9 is connected to the forward signal sampling terminal 3, and the signal output terminal of the first analog-to-digital converter 12 is connected to the signal analysis unit 8. The forward sampling circuit 9 uses a conventional gap waveguide structure, the forward transfer coefficient filtering circuit 10 uses a conventional passive RLC filter circuit, the forward detection circuit 11 uses a conventional detector, and the first analog-to-digital converter 12 is a conventional analog-to-digital converter.

[0062] like Figure 3 As shown, the reverse transfer coefficient monitoring unit 7 includes a reverse sampling circuit 13, a reverse transfer coefficient filtering circuit 14, a reverse detection circuit 15, and a second analog-to-digital converter 16 connected in sequence. The signal input terminal of the reverse sampling circuit 13 is connected to the reverse signal sampling terminal 4, and the signal output terminal of the second analog-to-digital converter 16 is connected to the signal analysis unit 8. The reverse sampling circuit 13 can be a conventional gap waveguide structure, the reverse transfer coefficient filtering circuit 14 can be a conventional passive RLC filter circuit, the reverse detection circuit 15 can be a conventional detector, and the second analog-to-digital converter 16 is a conventional analog-to-digital converter.

[0063] like Figure 4 As shown, the temperature monitoring unit 5 includes a temperature sensor 17, a temperature filtering circuit 18, and a third analog-to-digital converter 19 connected in sequence. The signal output terminal of the third analog-to-digital converter 19 is connected to the signal analysis unit 8. The temperature sensor 17 is a conventional temperature sensor, the temperature filtering circuit 18 is a conventional passive RLC filter circuit, and the third analog-to-digital converter 19 is a conventional analog-to-digital converter.

[0064] Example 5

[0065] like Figure 1As shown, a semiconductor plasma process monitoring device includes a signal sampling unit 1, a signal analysis unit 8, a forward transfer coefficient monitoring unit 6, a reverse transfer coefficient monitoring unit 7, and a temperature monitoring unit 5. The signal sampling unit 1 is equipped with an inductive sampler as a sampling structure, which uses electromagnetic induction to sample energy signals as voltage signals. The signal sampling unit 1 has a forward signal sampling terminal 3, a reverse signal sampling terminal 4, and two radio frequency connectors 2. The signal input terminal of the forward transfer coefficient monitoring unit 6 is connected to the forward signal sampling terminal 3, and the signal input terminal of the reverse transfer coefficient monitoring unit 7 is connected to the reverse signal sampling terminal 4. The signal output terminals of the forward transfer coefficient monitoring unit 6, the reverse transfer coefficient monitoring unit 7, and the temperature monitoring unit 5 are respectively connected to the signal analysis unit 8.

[0066] like Figure 2 As shown, the forward transfer coefficient monitoring unit 6 includes a forward sampling circuit 9, a forward transfer coefficient filtering circuit 10, a forward detection circuit 11, and a first analog-to-digital converter 12 connected in sequence. The signal input terminal of the forward sampling circuit 9 is connected to the forward signal sampling terminal 3, and the signal output terminal of the first analog-to-digital converter 12 is connected to the signal analysis unit 8. The forward sampling circuit 9 uses a conventional circular waveguide structure, the forward transfer coefficient filtering circuit 10 uses a conventional passive RLC filter circuit, the forward detection circuit 11 uses a conventional detector, and the first analog-to-digital converter 12 is a conventional analog-to-digital converter.

[0067] like Figure 3 As shown, the reverse transfer coefficient monitoring unit 7 includes a reverse sampling circuit 13, a reverse transfer coefficient filtering circuit 14, a reverse detection circuit 15, and a second analog-to-digital converter 16 connected in sequence. The signal input terminal of the reverse sampling circuit 13 is connected to the reverse signal sampling terminal 4, and the signal output terminal of the second analog-to-digital converter 16 is connected to the signal analysis unit 8. The reverse sampling circuit 13 uses a conventional circular waveguide structure, the reverse transfer coefficient filtering circuit 14 uses a conventional passive RLC filter circuit, the reverse detection circuit 15 uses a conventional detector, and the second analog-to-digital converter 16 is a conventional analog-to-digital converter.

[0068] like Figure 4 As shown, the temperature monitoring unit 5 includes a temperature sensor 17, a temperature filtering circuit 18, and a third analog-to-digital converter 19 connected in sequence. The signal output terminal of the third analog-to-digital converter 19 is connected to the signal analysis unit 8. The temperature sensor 17 is a conventional temperature sensor, the temperature filtering circuit 18 is a conventional passive RLC filter circuit, and the third analog-to-digital converter 19 is a conventional analog-to-digital converter.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A semiconductor plasma process monitoring device, characterized by, The signal sampling part, signal analysis part, forward transfer coefficient monitoring part, reverse transfer coefficient monitoring part and temperature monitoring part, the signal sampling part sets forward signal sampling end, reverse signal sampling end and two radio frequency connectors, the signal sampling part sets sampling structure which uses electromagnetic induction to sample energy signal into voltage signal, the signal input end of the forward transfer coefficient monitoring part is connected with the forward signal sampling end, the signal input end of the reverse transfer coefficient monitoring part is connected with the reverse signal sampling end, the signal output end of the forward transfer coefficient monitoring part, reverse transfer coefficient monitoring part and temperature monitoring part is connected with the signal analysis part respectively; The forward transfer coefficient monitoring part includes forward sampling circuit, forward transfer coefficient filter circuit, forward detection circuit and first analog-digital converter which are connected in sequence, the signal input end of the forward sampling circuit is connected with the forward signal sampling end, the signal output end of the first analog-digital converter is connected with the signal analysis part; The reverse transfer coefficient monitoring part includes reverse sampling circuit, reverse transfer coefficient filter circuit, reverse detection circuit and second analog-digital converter which are connected in sequence, the signal input end of the reverse sampling circuit is connected with the reverse signal sampling end, the signal output end of the second analog-digital converter is connected with the signal analysis part; The temperature monitoring part includes temperature sensor, temperature filter circuit and third analog-digital converter which are connected in sequence, the signal output end of the third analog-digital converter is connected with the signal analysis part.

2. The semiconductor plasma process monitoring device of claim 1, wherein, The sampling structure in the signal sampling part includes coupling circuit, double directional coupler, two directional couplers used in common or inductive inductor sampler.

3. The semiconductor plasma process monitoring device of claim 1, wherein, The structure of the forward sampling circuit includes microstrip branch structure, strip branch structure, gap waveguide structure or circular waveguide structure, the forward transfer coefficient filter circuit includes passive RLC filter circuit, the forward detection circuit sets detector or Schottky diode, the first analog-digital converter is analog-digital converter or MCU with analog-digital converter.

4. The semiconductor plasma process monitoring device of claim 1, wherein, The structure of the reverse sampling circuit includes microstrip branch structure, strip branch structure, gap waveguide structure or circular waveguide structure, the reverse transfer coefficient filter circuit includes passive RLC filter circuit, the reverse detection circuit sets detector or diode, the second analog-digital converter is analog-digital converter or MCU with analog-digital converter.

5. The semiconductor plasma process monitoring device of claim 1, wherein the at least one optical fiber is a single mode optical fiber. The temperature filter circuit includes passive RLC filter circuit, the third analog-digital converter is analog-digital converter or MCU with analog-digital converter.

6. A method of semiconductor plasma process monitoring, characterized by, The semiconductor plasma process monitoring device is used, including the following steps: S1, connect the two radio frequency connectors of the signal sampling part with the radio frequency energy transmission line, obtain the radio frequency energy data including transfer coefficient, and output the sampling signal as voltage signal; S2, the forward transfer coefficient monitoring part obtains the forward transmission signal in the sampling signal, and delivers the forward transfer coefficient to the signal analysis part after processing; S3, the reverse transfer coefficient monitoring part obtains the reverse transmission signal in the sampling signal, and delivers the reverse transfer coefficient to the signal analysis part after processing; S4, the temperature monitoring unit monitors the internal temperature of the semiconductor plasma process monitoring device, and processes the temperature signal into a temperature signal and sends it to the signal analysis unit; S5, the signal analysis unit corrects and analyzes the forward transfer coefficient and the reverse transfer coefficient combined with the temperature signal, and according to the numerical value of the transfer coefficient being too high or too low, issues an instruction to the plasma excitation source to increase or decrease the corresponding value until it is stable within the process requirement range.

7. The semiconductor plasma process monitoring method of claim 6, wherein, In step S5, the specific data obtained by calculation or the table is analyzed, and the numerical value includes frequency, power, temperature, standing wave ratio, altitude or humidity.

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