Method for monitoring epitaxial filling degree of deep-groove super-junction MOSFET product

Abstract

The invention provides a method for monitoring the epitaxial filling degree of a deep-groove super-junction MOSFET product, and the method comprises the steps: obtaining the real-time temperature data of the surface of a substrate through a temperature detector during the epitaxial filling period, feeding back different temperature readings, obtaining regular temperature curve fluctuation, and judging the epitaxial filling degree according to the temperature curve fluctuation, thereby achieving the monitoring of the epitaxial filling degree of the deep-groove super-junction MOSFET product. And real-time and accurate monitoring of the epitaxial filling degree of the deep-groove super-junction MOSFET product is realized.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product. Background Art

[0002] Deep trench super junction MOSFET products are widely used in cloud servers, UPS uninterruptible power management, LED lighting, smart bicycles, mobile terminals and other fields due to their ultra-low on-resistance, ultra-fast switching speed, low internal resistance, low power consumption, high efficiency and small chip size. The application range covers various products from 200 to 1000V, and the product types are complex and diverse.

[0003] Deep trench epitaxial filling is a key step in the super junction project. In the process of forming alternating P-type semiconductor thin layers and N-type semiconductor thin layers, the P-type semiconductor thin layer is formed by a deep trench filling process, that is, a deep trench is first opened on the N-type epitaxial layer, and then the P-type epitaxial is filled in the deep trench through a silicon filling process. Deep trench epitaxial filling is a very critical process in the manufacturing process of such products. Since its epitaxial filling performance and epitaxial filling time are affected by factors such as the size of the deep trench (Deep Trench), the epitaxial filling time of products designed by different customers varies. The degree of epitaxial filling will affect the electrical parameters of the product. If the epitaxial filling time is too short, the deep trench of the product will be insufficiently filled, resulting in gaps in the deep trench. If the filling time is too long, the product will be filled too thickly, resulting in defects caused by stress problems, such as dislocations, which will lead to low leakage yield of the product. At the same time, too long filling time will also affect production capacity.

[0004] Since the epitaxial filling process of deep trench super junction SJNFET products is to grow single crystal silicon directly on the surface of single crystal silicon in the deep trench, it is impossible to directly measure the film thickness to monitor the degree of epitaxial filling. The previous method was to monitor the degree of epitaxial filling through optical microscope photos or CMP end point detection (EPD) technology. However, microscope photos can only make rough judgments. Although CMP EPD detection is more accurate, it has a delay and cannot provide timely feedback on the degree of epitaxial filling. Summary of the invention

[0005] The object of the present invention is to provide a method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product, so as to realize real-time and accurate monitoring of the epitaxial filling degree of the deep trench super junction.

[0006] To achieve the above object, the present invention provides a method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product, comprising:

[0007] Placing a substrate having a dielectric layer on its surface in a cavity having a temperature detector, and performing epitaxial filling on the substrate having a deep trench in the cavity, wherein the epitaxial filling includes growing an epitaxial layer in the deep trench of the substrate until the epitaxial layer is turned outward to cover part or all of the dielectric layer on the surface of the substrate;

[0008] During epitaxial filling, the temperature detector detects real-time temperature data of the substrate surface; and,

[0009] The epitaxial filling degree is monitored in real time based on the temperature data detected by the temperature detector.

[0010] Optionally, the dielectric layer includes a silicon nitride layer and / or a silicon oxide layer, and the epitaxial layer includes a single crystal silicon layer.

[0011] Optionally, the temperature detector is an infrared detector.

[0012] Optionally, the temperature detector is connected to a temperature monitoring system.

[0013] Optionally, the method for monitoring the degree of epitaxial filling also includes: a data module establishment program, the data module establishment program includes: collecting temperature data corresponding to different time periods in the epitaxial filling process of the same product, forming a corresponding relationship between the filling process time period and the temperature, and establishing a data module.

[0014] Optionally, monitoring the epitaxial filling degree of the substrate based on the temperature data detected by the temperature detector includes: a data processing program, wherein the data processing program includes:

[0015] The corresponding relationship between the process period and the temperature in the data module is retrieved, and the real-time process period corresponding to the real-time temperature is obtained according to the real-time temperature data detected by the temperature detector to determine the epitaxial filling degree.

[0016] Optionally, the method for monitoring the degree of epitaxial filling further includes: an epitaxial filling automatic termination procedure, wherein the epitaxial filling automatic termination procedure includes:

[0017] The relevant process of setting the automatic termination process conditions of the epitaxial process, when the temperature data detected by the temperature detector meets the conditions, the automatic termination of the epitaxial filling is triggered.

[0018] Optionally, the epitaxial filling automatic termination procedure also includes: performing signal amplification processing on the collected temperature data.

[0019] Optionally, the signal amplification process includes:

[0020] S1: Collect temperature data V at each time interval t, and process the collected temperature data V, including:

[0021] S11: Take 10 sets of temperature data and take the average value X:

[0022] X i-1 =(V i-10 +V i-9 +V i-8 +V i-7 +V i-6 +V i-5 +V i-4 +V i-3 +V i-2 +V i-1 ) / 10,

[0023] X i =(V i-9 +V i-8 +V i-7 +V i-6 +V i-5 +V i-4 +V i-3 +V i-2 +V i-1 +V i ) / 10,

[0024] Among them, i>10;

[0025] S12: Calculate the difference Δ, Δ j =X i -X i-1 , where j = i-10;

[0026] S13: Take n Δ in sequence and sum them up to S, Where k = j + n - 1, n > 10;

[0027] S2: Judge S. When m (m ≧ 5) consecutive Ss are all smaller than the set value T, start using X i Determine the peak position and record the process period corresponding to the peak position.

[0028] Optional, use X i Determining the peak position includes: when Max(X i-3 , X i-2 , X i-1 , X i , X i+1 , X i+2 , X i+3 )=X i , X i This is the peak position.

[0029] Optionally, in the signal amplification process, t=3s, n=20, m=5.

[0030] In summary, the present invention provides a method for monitoring the epitaxial filling degree of deep trench super junction MOSFET products. During the epitaxial filling, real-time temperature data of the substrate surface is obtained by a temperature detector, thereby feeding back regular temperature curve fluctuations obtained by different temperature readings, and then judging the epitaxial filling degree according to the temperature curve fluctuations, thereby realizing real-time and accurate monitoring of the epitaxial filling degree of deep trench super junction MOSFET products. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flow chart of a method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product provided by an embodiment of the present invention;

[0032] Figure 2 It is a schematic diagram of the structure corresponding to the formation of a deep trench in the method for monitoring the degree of epitaxial filling provided by an embodiment of the present invention;

[0033] Figure 3 It is a schematic diagram of the structure corresponding to epitaxial filling after the epitaxial filling is performed in the method for monitoring the degree of epitaxial filling provided by an embodiment of the present invention;

[0034] Figure 4 is a schematic diagram of a cavity corresponding to an epitaxial filling process;

[0035] Figure 5 It is the temperature profile of the substrate surface detected by the temperature probe during epitaxial filling;

[0036] Figure 6 yes Figure 5 The temperature curve of the part where the temperature detected by the temperature detector fluctuates;

[0037] 7A to 7E yes Figure 6 FA SEM images of MOSFET products corresponding to different time periods of the temperature curve;

[0038] Figure 8 The temperature curves corresponding to different manufacturing time periods after the temperature data is processed provided in the embodiment of the present invention;

[0039] Fig. 9 It is the temperature curve corresponding to the deep trench epitaxial filling etched by different etching machines using the same process.

[0040] The reference numerals are described as follows:

[0041] 100 - substrate; 110 - deep trench; 101 - dielectric layer; 102 - epitaxial layer. DETAILED DESCRIPTION

[0042] To make the content of the present invention more clear and understandable, the content of the present invention is further described below in conjunction with the accompanying drawings. Of course, the present invention is not limited to this specific embodiment, and general replacements known to those skilled in the art are also covered within the protection scope of the present invention.

[0043] Secondly, the present invention is described in detail using schematic diagrams. When describing the examples of the present invention in detail, for the sake of convenience, the schematic diagrams are not partially enlarged according to general proportions, and this should not be used as a limitation of the present invention.

[0044] For ease of description, some embodiments of the present invention may use spatially relative terms such as "above", "below", "top", "below", etc. to describe the relationship between one element or component and another (or other) elements or components as shown in the various figures of the embodiments. It should be understood that in addition to the orientations described in the drawings, the spatially relative terms are also intended to include different orientations of the device in use or operation. For example, if the device in the drawings is turned over, the elements or components described as being "below" or "beneath" other elements or components will subsequently be positioned as being "above" or "above" the other elements or components. The terms "first", "second", etc., hereinafter, are used to distinguish between similar elements and are not necessarily used to describe a specific order or time sequence.

[0045] Figure 1 A flow chart of a method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product provided by an embodiment of the present invention is shown as follows: Figure 1 As shown, the method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product provided in this embodiment includes the following steps:

[0046] Step S01: placing a substrate having a dielectric layer on its surface in a cavity having a temperature detector, and performing epitaxial filling on the substrate having a deep trench in the cavity, wherein the epitaxial filling includes growing an epitaxial layer in the deep trench of the substrate until the epitaxial layer is turned outward to cover part or all of the dielectric layer on the surface of the substrate;

[0047] Step S02: During the period of epitaxial filling of the substrate, the temperature detector detects real-time temperature data of the substrate surface; and,

[0048] Step S03: monitoring the epitaxial filling degree in real time based on the temperature data detected by the temperature detector.

[0049] The following combination Figures 1 to 6 Detailed description of the method to monitor the epitaxial fill level of deep trench super junction MOSFET products.

[0050] refer to Figure 4As shown, a substrate 100 to be epitaxially filled is loaded into a chamber with a temperature probe, and epitaxial filling is performed in the chamber. The epitaxial filling includes growing an epitaxial layer 102 in a deep trench 110 of the substrate 100 until the epitaxial layer 102 is turned outward and covers a portion of the substrate surface 100 .

[0051] Specifically, a substrate 100 is provided, a dielectric layer 101 is formed on the surface of the substrate 100, a photoresist is covered on the dielectric layer 101, an area corresponding to the deep trench 110 is exposed by exposure and development, and the deep trench 110 is formed by etching, such as Figure 2 As shown; an epitaxial layer 102 is grown in the deep trench 110. When the deep trench 110 is filled to a certain extent, the outward-turned epitaxial layer 102 will cover part of the substrate surface dielectric layer, such as Figure 3 As shown, or the medium layer covering the entire Cell position is merged (excluding the Scribe Line position).

[0052] The substrate 100 may be a semiconductor material such as single crystal silicon (Si), single crystal germanium (Ge), silicon germanium (GeSi) or silicon carbide (SiC), the dielectric layer 101 includes a silicon nitride (Si3N4) layer and / or a silicon oxide (SiO2) layer, the temperature detector is an infrared detector, the temperature detector is connected to a temperature monitoring system, such as an FDC system (Fault Detection and Classification), the temperature detector provides the detected data to the FDC system in real time, and the temperature detector may also directly detect the temperature detection module (Upper Temp Pyrometer) A in the FDC system. That is, an "EPI EPD" detection system is developed through the regular changes of the EPI Upper Temp of the FDC system, which can accurately and real-time monitor the degree of deep trench epitaxial filling.

[0053] In this embodiment, the substrate 100 is a silicon wafer, the dielectric layer 101 is a silicon oxide layer, and the epitaxial layer 102 is a single crystal silicon layer. During the epitaxial process, the substrate 100 rotates at a fixed speed, and the single crystal silicon grows simultaneously along the side walls and bottom of the deep trench 110 and continues to grow. When the slit (V-mouth) at the center of the deep trench 110 is closed, the epitaxial layer 102 turns outward to cover part of the dielectric layer on the surface of the substrate (covering the entire Cell area). When the temperature detector detects different positions, it will feedback different temperature readings.

[0054] The FDC system is set to collect data at fixed time intervals, and the collected Upper Temp temperature will show regular fluctuations, such as Figure 5In the early stage of epitaxial filling, the epitaxial filling is mainly carried out in the deep trench 110, the dielectric layer in the cell has not yet been covered by the epitaxial layer turned outward, and the temperature detected by the temperature detector is kept in a certain temperature range, such as Figure 5 In the first region of the epitaxial filling, the dielectric layer between the deep trenches is covered by the epitaxial layer until the dielectric layer in the entire cell is completely covered. At this time, the temperature detected by the temperature detector fluctuates regularly, such as Figure 5 In the second region, the degree of epitaxial filling is determined based on the fluctuation of the temperature curve.

[0055] Figure 6 yes Figure 5 The temperature curve of the part where the temperature detected by the temperature detector fluctuates. 7A to 7E for Figure 6 FA SEM images corresponding to different time periods of the temperature curve. Specifically, in the early stage of epitaxial filling, the deep trench is filled to point A, the V-mouth in the center of the deep trench has not been filled, and the dielectric layer in the cell has not been turned outward. Fig. 7A As shown; epitaxial filling to point B, the central V-mouth is closed, and the dielectric layer in the cell has not yet turned outward, refer to Figure 7B As shown; epitaxial filling to point C, the central V-mouth has been filled, and the dielectric layer in the cell has not yet turned outward, refer to Figure 7C As shown; epitaxial filling to point D, the central V-mouth has been filled, and the dielectric layer in the cell is turned outward to cover the dielectric layer on the substrate surface, refer to Fig.7D As shown; epitaxial filling to point E, the central V-mouth has been overfilled, and the dielectric layer in the cell is turned outward to cover the dielectric layer on the substrate surface, refer to Fig. 7E shown.

[0056] The method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product provided in this embodiment also includes: a data module establishment program, wherein the data module establishment program includes: collecting temperature data corresponding to different time periods in the epitaxial filling process of the same product, forming a corresponding relationship between the filling process time period and the temperature, and establishing a data module. For example, by collecting FA SEM data of different time periods detected by the temperature detector, it is found that when the detected temperature begins to drop, the deep trench epitaxial filling has begun to close and enter the final closing stage.

[0057] The method for monitoring the epitaxial filling degree of deep trench super junction MOSFET products provided in this embodiment also includes: a data processing program, and the data processing program includes: retrieving the correspondence between the process period and the temperature in the data module, obtaining the real-time process period corresponding to the real-time temperature based on the real-time temperature data detected by the temperature detector, and determining the epitaxial filling degree.

[0058] The method for monitoring the epitaxial filling degree of deep trench super junction MOSFET products provided in the present embodiment also includes: an epitaxial filling automatic termination program, and the epitaxial filling automatic termination program includes: a related process for setting the automatic termination process conditions of the epitaxial process, and triggering the automatic termination of the epitaxial filling when the temperature data detected by the temperature detector meets the conditions. That is, the regular fluctuation of the temperature curve is used to prompt that the epitaxial filling has reached the process period, the degree of epitaxial filling is judged, and the epitaxial recipe is terminated in time to achieve maximum utilization of production capacity. Furthermore, to facilitate the judgment of the degree of epitaxial filling, after the temperature data is collected, the temperature data can be amplified. For example, the regular curve fluctuation can be amplified, and the epitaxial filling is completed when the first regular trough appears (reference Figure 6 , 7A to 7E ), by setting the relevant procedures for automatically terminating the process conditions through software, the process time of each wafer can be saved by 5%-20%, effectively improving the actual utilization rate and throughput of the machine. It should be noted that the prompt position of the corresponding temperature curve fluctuation after the epitaxial filling is completed is slightly different depending on the product structure.

[0059] Specifically, the epitaxial filling automatic termination procedure includes the following steps:

[0060] S1: Collect temperature data V at each time interval t, and process the collected temperature data V, including:

[0061] S11: Take 10 sets of temperature data and take the average value X:

[0062] X i-1 =(V i -10+V i-9 +V i-8 +V i-7 +V i-6 +V i-5 +V i-4 +V i-3 +V i-2 +V i-1 ) / 10,

[0063] Xi=(V i-9 +V i-8 +V i-7 +V i-6 +V i-5 +V i-4 +V i-3 +V i-2 +V i-1 +V i ) / 10,

[0064] Among them, i>10;

[0065] S12: Calculate the difference Δ, Δ j =X i -X i-1 , where j = i-10;

[0066] S13: Take n Δ in sequence and sum them up to S, that is Where, k=j+n-1, n>10, the purpose of summing n Δ is to amplify the judgment standard and facilitate setting the alarm point;

[0067] S2: Judge S. When m (m ≧ 5) consecutive S are less than the set value T, start using X i Determine the peak position and record the process time period (step time) corresponding to the peak position.

[0068] Figure 8 The temperature curves corresponding to different process periods after temperature data processing provided in one embodiment of the present invention (the temperature data V, average value X, and sum S in the horizontal axis have been sorted and unified into real-time process time points, i.e., data at the same time point). Figure 8 , the temperature data is amplified and processed. The specific operation is as follows: at the beginning of the epitaxial filling process, the temperature monitoring system (such as EAP / FDC) collects the real-time temperature data of the substrate surface, takes a data V every 3 (t=3) seconds, takes 10 sets of temperature data and takes the average value X in turn,

[0069] X i-1 =(V i-10 +V i-9 +V i-8 +V i-7 +V i-6 +V i-5 +V i-4 +V i-3 +V i-2 +V i-1 ) / 10,

[0070] X i =(V i-9 +V i-8 +V i-7 +V i-6 +V i-5 +V i-4 +V i-3 +V i-2 +V i-1 +V i ) / 10,

[0071] Among them, i>10;

[0072] Then, calculate the difference Δ, Δ j =X i -X i-1, where j = i-10;

[0073] Next, take 20 (n=20) Δ in turn and sum them up to S, Where, k = j + 19;

[0074] Next, for S k Make a judgment, when 5 (m=5) consecutive S k When it is less than the set value -20000 (T = -20000), S k+1 <-20000&S k+2 <-20000&S k+3 <-20000&S k+4 <T-20000&S k+5 <-20000, start using X i Determine the peak position. If Max(X i-3 , X i-2 , X i-1 , X i , X i+1 , X i+2 , X i+3 )=X i , that is, X i The maximum value is in the middle of 7 consecutive points (peak), record once during the process period, feedback this step time once, and so on, if there are N peaks, record N times, feedback N step times, and then calculate the temperature data X of each period of the epitaxial process. i The peak search is performed. The set value T can be adjusted according to the judgment requirements.

[0075] The temperature data curve after the above signal amplification processing is used to judge the epitaxial filling degree according to the curve fluctuation law, and the epitaxial filling process is terminated in time according to the filling degree.

[0076] Furthermore, the method for monitoring the epitaxial filling degree of deep trench super junction MOSFET products provided by the present invention can be applied to the epitaxial filling trial run (pi-run) confirmation of new products. After the new product is put into use, a pi-run is required to confirm the epitaxial filling. According to the temperature data obtained by the FDC system temperature detection module, the epitaxial filling degree can be quickly confirmed and the filling time guidance suggestions can be given.

[0077] Furthermore, the method for monitoring the epitaxial filling degree of deep trench super junction MOSFET products provided by the present invention can be applied to the detection of deep trench volume. The above-mentioned method for monitoring the epitaxial filling degree is used to obtain the temperature curve corresponding to the filling process period under the same process conditions, and the size of the corresponding cavity deep trench volume is judged according to the fluctuation of the temperature curve corresponding to the deep trench epitaxial process etched by different etching machines. Since the epitaxial filling amount required for deep trench epitaxial layers of different volumes is different, the chamber monitoring of the etching machine can be performed through the obtained temperature curve fluctuation.

[0078] Fig. 9 The temperature curves of deep trench epitaxial filling etched by different etching machines using the same recipe are shown in Table 1. Fig. 9 It can be seen that the performance of CHA and CHB in temperature curve fluctuation is different. The temperature curve of etching machine CHA fluctuates first, indicating that the deep trench volume of etching machine CHA is smaller than that of etching machine CHB.

[0079] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, a method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product is implemented.

[0080] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product.

[0081] The present invention provides a method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product. During the epitaxial filling, real-time temperature data of the substrate surface is obtained by a temperature detector, and regular temperature curve fluctuations obtained by different temperature readings are fed back, and then the epitaxial filling degree is judged according to the temperature curve fluctuations, thereby realizing real-time and accurate monitoring of the epitaxial filling degree of the deep trench super junction MOSFET product.

[0082] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product, characterized in that: include: Placing a substrate having a dielectric layer on its surface in a cavity having a temperature detector, and performing epitaxial filling on the substrate having a deep trench in the cavity, wherein the epitaxial filling includes growing an epitaxial layer in the deep trench of the substrate until the epitaxial layer is turned outward to cover part or all of the dielectric layer on the surface of the substrate; During epitaxial filling, the temperature detector detects real-time temperature data of the substrate surface; and, The epitaxial filling degree is monitored in real time based on the temperature data detected by the temperature detector.

2. The method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product according to claim 1, characterized in that: The dielectric layer includes but is not limited to a silicon nitride layer and / or a silicon oxide layer, and the epitaxial layer includes but is not limited to a single crystal silicon layer.

3. The method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product according to claim 2, characterized in that: The temperature detector is an infrared detector.

4. The method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product according to claim 1, characterized in that: The temperature detector is connected to a temperature monitoring system.

5. The method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product according to claim 1, characterized in that: Also includes: The data module establishment program includes: collecting temperature data corresponding to different time periods in the epitaxial filling process of the same product, forming a corresponding relationship between the filling process time period and the temperature, and establishing a data module.

6. The method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product according to claim 5, characterized in that: Monitoring the epitaxial filling degree of the substrate based on the temperature data detected by the temperature detector includes: a data processing program, the data processing program includes: The corresponding relationship between the process period and the temperature in the data module is retrieved, and the real-time process period corresponding to the real-time temperature is obtained according to the real-time temperature data detected by the temperature detector to determine the epitaxial filling degree.

7. The method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product according to claim 6, characterized in that: Also included: an epitaxial filling automatic termination program, the epitaxial filling automatic termination program comprising: The relevant process of setting the automatic termination process conditions of the epitaxial process, when the temperature data detected by the temperature detector meets the conditions, the automatic termination of the epitaxial filling is triggered.

8. The method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product according to claim 7, characterized in that: The epitaxial filling automatic termination procedure also includes: performing signal amplification processing on the collected temperature data.

9. The method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product according to claim 8, characterized in that: The signal amplification process comprises: S1: Collect temperature data V at each time interval t, and process the collected temperature data V, including: S11: Take 10 sets of temperature data and take the average value X: X i-1 =(V i-10 +V i-9 +V i-8 +V i-7 +V i-6 +V i-5 +V i-4 +V i-3 +V i-2 +V i-1 ) / 10, X i =(V i-9 +V i-8 +V i-7 +V i-6 +V i-5 +V i-4 +V i-3 +V i-2 +V i-1 +V i ) / 10, Among them, i>10; S12: Calculate the difference Δ, Δ j =X i -X i-1 , where j = i-10; S13: Take n Δ in sequence and sum them up to S, Where k = j + n - 1, n > 10; S2: Judge S. When m (m ≧ 5) consecutive Ss are all smaller than the set value T, start using X i Determine the peak position and record the process period corresponding to the peak position.

10. The method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product according to claim 9, characterized in that: Use X i Determining the peak position includes: when Max(X i-3 , X i-2 , X i-1 , X i , X i+1 , X i+2 , X i+3 )=X i , X i This is the peak position.

11. The method for monitoring the epitaxial filling degree of a deep trench super junction MOSFET product according to claim 9, characterized in that: t=3s, n=20, m=5.

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